Objective Radiation mucositis,especially pharyngeal mucositis,severely affects the oral intake of patients of head and neck cancer(HNC)during radiotherapy.Whether the nutritional status affects the severity of pharyng...Objective Radiation mucositis,especially pharyngeal mucositis,severely affects the oral intake of patients of head and neck cancer(HNC)during radiotherapy.Whether the nutritional status affects the severity of pharyngeal mucositis is currently unknown.This study investigated the incidence of malnutrition and radiation pharyngeal mucositis in patients with HNC during radiotherapy and analyzed the impact of the nutritional status on radiation pharyngeal mucositis.Methods Consecutive patients with HNC receiving radiotherapy were recruited for this longitudinal observational study.Data were collected at baseline(T_(1)),midtreatment(T_(2)),and at the end of treatment(T3).The Common Terminology Criteria for Adverse Events version 4.0 and the Global Leadership Initiative on Malnutrition criteria were used to assess pharyngeal mucositis and the nutritional status,respectively.Results There were 348 HNC patients who completed all assessments.The pharyngeal mucositis of patients with HNC was aggravated during radiotherapy(χ^(2)=553.521,P<0.001).At T3,56.0%of patients had moderate or severe pharyngeal mucositis.The proportion of patients with malnutrition increased significantly during treatment(21.3%at T_(1)vs 46.8%at T_(2)vs 76.1%at T3,χ^(2)=209.768,P<0.001).Both a multivariable analysis of generalized estimating equations and a logistic regression analysis showed that pharyngeal mucositis was associated with malnutrition.Conclusions Malnutrition was common in patients with HNC during radiotherapy,and it was closely related to pharyngeal mucositis.Joint interventions targeting nutrition and symptom management should be considered for patients with HNC.展开更多
18-fluorodeoxygluocose positron emission tomography/computed tomography(18FDG-PET/CT) provides significant information in multiple settings in the management of head and neck cancers(HNC). This article seeks to define...18-fluorodeoxygluocose positron emission tomography/computed tomography(18FDG-PET/CT) provides significant information in multiple settings in the management of head and neck cancers(HNC). This article seeks to define the additional benefit of PET/CT as related to radiation treatment planning for squamous cell carcinomas(SCCs) of the head and neck through a review of relevant literature. By helping further define both primary and nodal volumes, radiation treatment planning can be improved using PET/CT. Special attention is paid to the independent benefit of PET/CT in targeting mucosal primaries as well as in detecting nodal metastases. The utility of PET/CT is also explored for treatment planning in the setting of SCC of unknown primary as PET/CT may help define a mucosal target volume by guiding biopsies for examination under anesthesia thus changing the treatment paradigm and limiting the extent of therapy. Implications of the use of PET/CT for proper target delineation in patients with artifact from dental procedures are discussed and the impact of dental artifact on CT-based PET attenuation correction is assessed. Finally, comment is made upon the role of PET/CT in the high-risk post-operative setting, particularly in the context of radiation dose escalation. Real case examples are used in these settings to elucidate the practical benefits of PET/CT as related to radiation treatment planning in HNCs.展开更多
BACKGROUND:Few contemporary studies have assessed physicians’knowledge of radiation exposure associated with common imaging studies,especially in trauma care.The purpose of this study was to assess the knowledge of p...BACKGROUND:Few contemporary studies have assessed physicians’knowledge of radiation exposure associated with common imaging studies,especially in trauma care.The purpose of this study was to assess the knowledge of physicians involved in caring for trauma patients regarding the effective radiation doses of musculoskeletal(MSK)imaging studies routinely utilized in the trauma setting.METHODS:An electronic survey was distributed to United States orthopaedic surgery,general surgery,and emergency medicine(EM)residency programs.Participants were asked to estimate the radiation dose for common imaging modalities of the pelvis,lumbar spine,and lower extremity,in terms of chest X-ray(CXR)equivalents.Physician estimates were compared to the true effective radiation doses.Additionally,participants were asked to report the frequency of discussing radiation risk with patients.RESULTS:A total of 218 physicians completed the survey;102(46.8%)were EM physicians,88(40.4%)wereorthopaedicsurgeons,and28(12.8%)weregeneralsurgeons.Physicians underestimated the effective radiation doses of nearly all imaging modalities,most notably for pelvic computed tomaography(CT)(median 50 CXR estimation vs.162 CXR actual)and lumbar CT(median 50 CXR estimation vs.638 CXR actual).There was no difference between physician specialties regarding estimation accuracy(P=0.133).Physicians who regularly discussed radiation risks with patients more accurately estimated radiation exposure(P=0.007).CONCLUSION:The knowledge among orthopaedic and general surgeons and EM physicians regarding the radiation exposure associated with common MSK trauma imaging is lacking.Further investigation with larger scale studies is warranted,and additional education in this area may improve care.展开更多
AIM: To determine swallowing outcomes and hyolaryngeal mechanics associated with post radiation therapy head and neck cancer(rt HNC) patients using videofluoroscopic swallow studies. METHODS: In this retrospective coh...AIM: To determine swallowing outcomes and hyolaryngeal mechanics associated with post radiation therapy head and neck cancer(rt HNC) patients using videofluoroscopic swallow studies. METHODS: In this retrospective cohort study, video-fluoroscopic images of rt HNC patients(n = 21) were compared with age and gender matched controls(n = 21). Penetration-aspiration of the bolus and bolus residue were measured as swallowing outcome variables. Timing and displacement measurements of the anterior and posterior muscular slings elevating the hyolaryngeal complex were acquired. Coordinate data of anatomical landmarks mapping the action of the anterior muscles(suprahyoid muscles) and posterior muscles(long pharyngeal muscles) were used to calculate the distance measurements, and slice numbers were used to calculate time intervals. Canonical variate analysis with post-hoc discriminant function analysis was performed on coordinate data to determine multivariate mechanics of swallowing associated with treatment. Pharyngeal constriction ratio(PCR) was also measured to determine if weak pharyngeal constriction is associated with post radiation therapy.RESULTS: The rt HNC group was characterized by poor swallowing outcomes compared to the control group in regards to: Penetration-aspiration scale(P < 0.0001), normalized residue ratio scale(NRRS) for the valleculae(P = 0.002) and NRRS for the piriform sinuses(P = 0.003). Timing and distance measurements of the anterior muscular sling were not significantly different in the two groups, whereas for the PMS time of displacement was abbreviated(P = 0.002) and distance of excursion was reduced(P = 0.02) in the rt HNC group. A canonical variate analysis shows a significant reduction in pharyngeal mechanics in the rt HNC group(P < 0.0001). The PCR was significantly higher in the test group than the control group(P = 0.0001) indicating reduced efficiency in pharyngeal clearance. CONCLUSION: Using videofluoroscopy, this study shows rt HNC patients have worse swallowing outcomes associated with reduced hyolaryngeal mechanics and pharyngeal constriction compared with controls.展开更多
The reproducibility of patient setup is an important issue for head and neck cancers treated with intensity-modulated radiation therapy (IMRT). In this study, an image-guided radiation therapy (IGRT) system has been u...The reproducibility of patient setup is an important issue for head and neck cancers treated with intensity-modulated radiation therapy (IMRT). In this study, an image-guided radiation therapy (IGRT) system has been used to minimize the uncertainty of patient setup while standard thermoplastic masks were used to provide adequate immobilization for the head and neck. However, they do not provide sufficient immobilization of the shoulders, which is an important requirement in comprehensive nodal irradiation. Therefore, we investigated the setup and rotational shifts in head and neck cancer patients undergoing IMRT for which this immobilization device had been used together with an IGRT system. The setup and rotational shifts of patients were analyzed using the ExacTrac X-ray 6D IGRT system. The patients were classified as having head and neck tumors in the upper or lower regions. The upper neck nodes included lymph nodal level II while the lower neck nodes included lymph nodal levels III and IV. Clinical data from 227 treatment sessions of 12 head and neck cancer patients were analyzed. The random translational error in inter-and intra-fraction errors of the anterio-posterior (AP) direction might influence the rotational errors of pitch and roll in the upper region. At the same time, the random translational error in the inter-and intra-fraction errors of the AP direction might influence the rotational error of roll in the lower region. We believe that these random translational errors should be considered during treatment. We found variability in random translational errors for different regions in the anatomy of head and neck cancer patients due to rotational shifts. Depending on the location of the primary lesion or the selected nodal treatment targets, these relative positional variations should be considered when setup and rotational shifts are corrected with IGRT systems before treatment.展开更多
Oral cancer is usually treated combining surgery, radiation therapy and chemotherapy, following effective therapeutic protocols. Severe maxillary and mandibular bone atrophy resulting after therapies are usually treat...Oral cancer is usually treated combining surgery, radiation therapy and chemotherapy, following effective therapeutic protocols. Severe maxillary and mandibular bone atrophy resulting after therapies are usually treated with autologous bone grafting procedures even though these techniques often present a significant risk of postoperative complications and disadvantages. We describe the case of a 59-year-old woman presenting severe bone defect after being treated with surgery and radiotherapy for recurrent oral verrucous squamous cell carcinoma. We performed bone regeneration using Platelet-Derived Growth Factors (PDGF) in combination with autologous bone chips. Our procedure of bone regeneration allowed the placement of dental implants and the achievement of a good aesthetic and functional result. Regenerative surgery may enable the regeneration of substantial bone defects. Moreover, PDGF application decreases the risk of implant failure in irradiated patients.展开更多
BACKGROUND Carotid blowout syndrome(CBS)is a rupture of the carotid artery and is mainly caused by radiation and resection of head and neck cancers or direct tumor invasion of the carotid artery wall.It is a life-thre...BACKGROUND Carotid blowout syndrome(CBS)is a rupture of the carotid artery and is mainly caused by radiation and resection of head and neck cancers or direct tumor invasion of the carotid artery wall.It is a life-threatening clinical situation.There is no established and effective mode of management of CBS.Furthermore,there is no established preceding sign or symptom;therefore,preventive efforts are not clinically meaningful.CASE SUMMARY We described two cases of CBS that occurred in patients with head and neck cancer after definitive chemoradiotherapy(CRT)using three-dimensional conformal intensity-modulated radiation therapy.Two men aged 61 and 56 years with locally advanced head and neck cancer were treated with definitive CRT.After completing CRT,both of them achieved complete remission.Subsequently,they had persistent severe pain in the oropharyngeal mucosal region and the irradiated neck despite the use of opioid analgesics and rehabilitation for relief of contracted skin.However,continuous follow-up imaging studies showed no evidence of cancer recurrence.Eleven to twelve months after completing CRT,the patients visited the emergency room complaining about massive oronasal bleeding.Angiograms showed rupture of carotid artery pseudoaneurysms on the irradiated side.Despite attempting to secure hemostasis with carotid arterial stent insertion and coil embolization,both patients died because of repeated bleeding from the pseudoaneurysms.CONCLUSION In patients with persistent pain in irradiated sites,clinicians should be suspicious of progressing or impending CBS,even in the three-dimensional conformal intensity-modulated radiation therapy era.展开更多
Objective: To evaluate the incidence of cervical angiopathy caused by radiation therapy for head and neck cancer. Methods: Segments of 57 cervical arteries were obtained during surgery for head and neck malignant tumo...Objective: To evaluate the incidence of cervical angiopathy caused by radiation therapy for head and neck cancer. Methods: Segments of 57 cervical arteries were obtained during surgery for head and neck malignant tumors and divided into two groups (irradiated group and non-irradiated group) based on the treatment prior to vascular resection. In order to evaluate vascular injury after radiation therapy, we examined the degree of medial atrophy, medial fibrosis, smooth muscle cell (SMC) differentiation in the media and intima, intimal hyperplasia and endothelial cell (EC) injury. Sections of arterial segments were stained with hematoxylin-eosin, Elastica van Gieson and Masson’s trichrome, and immunohistochemistry for α-smooth muscle actin (α-SMA), smoothelin, S100A4 and CD31 in the resected vessels was conducted. Results: The median interval between the completion of radiation therapy and vascular resection was nine months. No significant differences were observed between the two groups in terms of medial atrophy, medial fibrosis and intimal hyperplasia. The ratio of the smoothelin-positive area per α-SMA-positive area in the media and the S100A4-positive proportion in the intima, indicating the degree of differentiation of the medial SMC and dedifferentiation of the intimal SMC, respectively, showed no significant differences, despite the tendency toward a lower smoothelin-positive area per α-SMA-positive area in the media of the irradiated arteries. The EC coverage revealed on CD31 immunohistochemistry was significantly decreased, with mural thrombus adhesion, in the irradiated group. Conclusions: The ECs of small arteries are damaged by irradiation. Although we did not confirm the statistical significance of medial SMC dedifferentiation, a decreased expression of smoothelin tended to be observed in the media of the irradiated arteries. Our findings provide histopathological evidence of irradiation angiopathy in head and neck cancer and may help to improve the surgical safety of microvascular anastomosis and determine the treatment strategy for head and neck tumors.展开更多
Background: Radiation-induced gliomas of the spinal cord are rare late complications of spinal cord irradiation that typically occur in patients treated at younger ages. Aim: Raise awareness of radiation induced high ...Background: Radiation-induced gliomas of the spinal cord are rare late complications of spinal cord irradiation that typically occur in patients treated at younger ages. Aim: Raise awareness of radiation induced high grade gliomas with a case presentation and a review of the literature. Case Presentation: A 50-year-old male with Stage IVA squamous cell carcinoma of the oropharynx was treated with external beam radiotherapy with a complete response. Seven years later, he presented with a cervical spinal cord mass on MRI. An open biopsy was performed. Pathology revealed an intramedullary WHO grade IV astrocytoma, (i.e., glioblastoma multiforme) of the cervical spine that fulfilled the criteria for a radiation-induced malignancy. Conclusions : Review of the literature suggests that radiation-induced gliomas tend to be high grade and may occur at the periphery of an irradiated field. Radiation-induced gliomas of the spinal cord are a serious complication of radiotherapy that may occur in older patients with head and neck cancers, but are so rare that it should not affect treatment decisions.展开更多
Losses in channel flows are usually determined using a frictional head loss parameter. Fluid friction is however not the only source of loss in channel flows with heat transfer. For such flow problems, thermal energy ...Losses in channel flows are usually determined using a frictional head loss parameter. Fluid friction is however not the only source of loss in channel flows with heat transfer. For such flow problems, thermal energy degradation, in addition to mechanical energy degradation, add to the total loss in thermodynamic head. To assess the total loss in a channel with combined convection and radiation heat transfer, the conventional frictional head loss parameter is extended in this study. The analysis is applied to a 3D turbulent channel flow and identifies the critical locations in the flow domain where the losses are concentrated. The influence of Boltzmann number is discussed, and the best channel geometry for flows with combined heat transfer modes is also determined.展开更多
Xerostomia, or dry mouth, is a significant problem affecting quality of life in patients treated with radiation therapy for head and neck cancer. Strategies for reduction of xerostomia burden vary widely, with options...Xerostomia, or dry mouth, is a significant problem affecting quality of life in patients treated with radiation therapy for head and neck cancer. Strategies for reduction of xerostomia burden vary widely, with options including: sialagogue medications, saliva substitutes, acupuncture, vitamins, hyperbaric oxygen,submandibular gland transfer, and acupuncture or associated treatments. In this review, we sought to evaluate long-term outcomes of patients treated with various interventions for radiation-induced xerostomia. A literature search was performed using the terms "xerostomia" and "radiation" or "radiotherapy"; all prospective clinical trials were evaluated, and only studies that reported 1 year follow up were included. The search results yielded 2193 studies, 1977 of which were in English. Of those, 304 were clinical trials or clinical studies. After abstract review, 23 trials were included in the review evaluating the following treatment modalities: pilocarpine(three); cevimeline(one); amifostine(eleven);submandibular gland transfer(five); acupuncture like transcutaneous electrical nerve stimulation(ALTENS)(one); hyperbaric oxygen(one); and acupuncture(one). Pilocarpine, cevimeline, and amifostine have been shown in some studies to improve xerostomia outcomes, at the cost of toxicity. ALTENS has similar efficacy with fewer side effects. Submandibular gland transfer is effective but requires an elective surgery, and thus may not always be appropriate or practical.The use of intensity-modulated radiation therapy, in addition to dose deescalation in select patients, may result in fewer patients with late xerostomia,reducing the need for additional interventions.展开更多
INTRODUCTIONCrypt epithelial cells in normal small intestineproliferate at a high speed. But they are verydifficult to culture in vitro and passage stably. A lotof studies have been done[1-16]. Some domestic labsisola...INTRODUCTIONCrypt epithelial cells in normal small intestineproliferate at a high speed. But they are verydifficult to culture in vitro and passage stably. A lotof studies have been done[1-16]. Some domestic labsisolated and cultured crypt cells from embryonalintestines and aseptic animal intestine, but failed.We introduced normal rat epithelial cell line-IEC-6from the USA and its living condition for stablepassage was successfully established after trials. Thecell line was testified to be the small intestinalepithelial cell by electron microscopy,immunihistochemistry and enzymatic histoch-emistry. It has been applied to some relatedresearch work[17-21]. It was found that manyfactors were involved in the culture system. Ourpresent study focuses on the culture method and theinfluencing factors on IEC-6.展开更多
Oral mucositis is a common morbidity induced by radiation therapy and chemo-radiotherapy for head and neck malignancies. This often results in treatment delays, premature treatment cessation and increased cost. New tr...Oral mucositis is a common morbidity induced by radiation therapy and chemo-radiotherapy for head and neck malignancies. This often results in treatment delays, premature treatment cessation and increased cost. New treatments of oral mucositis are emerging but effective remedies remain limited. Between February 2007 and May 2008, 21 patients with head and neck malignancies were treated with a supersaturated calcium phosphate oral rinse (Caphosol) that was performed for 4-10 times daily, each consisting of two one-minute rinses. There were 21 matched patients who received supportive care without the oral rinse. All patients in the two groups were treated with intensity modulated radiation therapy (IMRT) for average prescription doses of 66 Gy in 33 fractions. The effects of this rinse vs. supportive care on mucositis, PEG tube requirements, hospitalization, xerostomia, analgesic requirements and weight was respectively evaluated. We have observed statistically significant decreases in the incidence of radiation induced oral mucositis (p=0.0002) with WHO grade 3 (38% vs. 52%) and 4 mucositis (0% vs. 19%), need for PEG tube placement (33% vs. 57%) and hospitalization (0% vs 19%). There was also a favorable impact on the incidence of grade 3 (29% vs. 43%) xerostomia in the treated patients but it was statistically insignificant (p=0.58). Incremental costs related to treatment of oral mucositis were reduced considerably. Our data suggest that use of a supersaturated calcium phosphate oral rinse is an effective treatment for mucositis in patients undergoing IMRT. It may also be helpful in the reduction of hospitalization and PEG tube requirements.展开更多
Objective:To comprehensively and accurately analyze the out-performance of low-dose chest CT(LDCT)vs.standard-dose CT(SDCT).Methods:The image quality,size measurements and radiation exposure for LDCT and SDCT protocol...Objective:To comprehensively and accurately analyze the out-performance of low-dose chest CT(LDCT)vs.standard-dose CT(SDCT).Methods:The image quality,size measurements and radiation exposure for LDCT and SDCT protocols were evaluated.A total of 117 patients with extra-thoracic malignancies were prospectively enrolled for non-enhanced CT scanning using LDCT and SDCT protocols.Three experienced radiologists evaluated subjective image quality independently using a 5-point score system.Nodule detection efficiency was compared between LDCT and SDCT based on nodule characteristics(size and volume).Radiation metrics and organ doses were analyzed using Radimetrics.Results:The images acquired with the LDCT protocol yielded comparable quality to those acquired with the SDCT protocol.The sensitivity of LDCT for the detection of pulmonary nodules(n=650)was lower than that of SDCT(n=660).There was no significant difference in the diameter and volume of pulmonary nodules between LDCT and SDCT(for BMI<22 kg/m^(2),4.37 vs.4.46 mm,and 43.66 vs.46.36 mm^(3);for BMI>22 kg/m^(2),4.3 vs.4.41 mm,and 41.66 vs.44.86 mm^(3))(P>0.05).The individualized volume CT dose index(CTDI_(vol)),the size specific dose estimate and effective dose were significantly reduced in the LDCT group compared with the SDCT group(all P<0.0001).This was especially true for dose-sensitive organs such as the lung(for BMI<22 kg/m^(2),2.62 vs.12.54 mSV,and for BMI>22 kg/m^(2),1.62 vs.9.79 mSV)and the breast(for BMI<22 kg/m^(2),2.52 vs.10.93 mSV,and for BMI>22 kg/m^(2),1.53 vs.9.01 mSV)(P<0.0001).Conclusion:These results suggest that with the increases in image noise,LDCT and SDCT exhibited a comparable image quality and sensitivity.The LDCT protocol for chest scans may reduce radiation exposure by about 80% compared to the SDCT protocol.展开更多
Purpose: Post-operative radiotherapy (PORT) for resected cutaneous squamous cell carcinoma (CSCC) with perineural invasion (PNI) is controversial. Therefore, we conducted a survey to review treatment recommendations a...Purpose: Post-operative radiotherapy (PORT) for resected cutaneous squamous cell carcinoma (CSCC) with perineural invasion (PNI) is controversial. Therefore, we conducted a survey to review treatment recommendations among Radiation Oncologists (ROs) in the management of CSCC with PNI. Materials & Methods: In March 2011, we contacted all ROs and trainees in the US through email addresses listed in the 2009 ASTRO directory. Our web-based survey presented clinical vignettes involving Mohs micrographically resected CSCC with microscopic PNI (mPNI) or clinical PNI (cPNI). For each vignette, ROs were asked to indicate if PORT was appropriate and to further specify the dose and volume to treat. Results: Three hundred fifty two responses were completed and analyzed. The majority of ROs (72%) had over 10 years of post residency experience. 64% of the sampled ROs had a special interest in treating head and neck cancers, and 64% treated 4 or more cases per year. Approximately 95% recommended PORT for cPNI whereas 59% recommended PORT for mPNI. Post residency experience (10+ yrs vs. <10 yrs) was associated with a greater propensity to recommend PORT for mPNI (48% vs. 30%, p = 0.005) and for mPNI of deep subcutaneous non-named nerve involvement (80% vs. 60%, p = 0.001). ROs treating 8 or more cases per year (vs. <7) were more likely to recommend PORT for mPNI in immunocompromised patients (74% vs. 57%, p = 0.01). Conclusions: Our study demonstrates significant variability among ROs in the management of CSCC with mPNI. For cases of cPNI, an overwhelming majority recommended PORT. In cases of mPNI, there was no consensus for recommending PORT, although experienced practitioners had a lower threshold for offering treatment. These results indicate the need for prospective clinical studies to clarify the role of PORT in CSCC patients with mPNI.展开更多
Measurements of radiation dose to patients in spiral computed tomography (CT) were completed for various collimations,table speeds and pitch. A standard CT head dosimetry phantom and thermoluminescent dosime- ters (TL...Measurements of radiation dose to patients in spiral computed tomography (CT) were completed for various collimations,table speeds and pitch. A standard CT head dosimetry phantom and thermoluminescent dosime- ters (TLD) were used for the measurement. The effect of collimation and pitch on radiation dose was studied. The results indicated that the radiation dose at the given tube current,voltage and rotation speed was inversely propor- tional to pitch. And the increasing times of dose were as decreasing times of pitch. This regular pattern was tenable for radiation dose at both central holes and peripheral holes of the phantom at pitch = 1,>1 and <1. The collimation had no impact on the radiation dose. The results also indicated that radiation dose at central holes was nearly equal to that at peripheral holes. There was no significant difference between them statistically. The study demonstrates that the pitch in spiral CT scans is the primary parameter and has significant impact on radiation dose.展开更多
基金This research was supported by the National Key Research and Development Project of China(No.2017YFC1309204)the Medical Nutrition Clinical Research Project of China International Medical Foundation(No.Z-2017-24-2110).
文摘Objective Radiation mucositis,especially pharyngeal mucositis,severely affects the oral intake of patients of head and neck cancer(HNC)during radiotherapy.Whether the nutritional status affects the severity of pharyngeal mucositis is currently unknown.This study investigated the incidence of malnutrition and radiation pharyngeal mucositis in patients with HNC during radiotherapy and analyzed the impact of the nutritional status on radiation pharyngeal mucositis.Methods Consecutive patients with HNC receiving radiotherapy were recruited for this longitudinal observational study.Data were collected at baseline(T_(1)),midtreatment(T_(2)),and at the end of treatment(T3).The Common Terminology Criteria for Adverse Events version 4.0 and the Global Leadership Initiative on Malnutrition criteria were used to assess pharyngeal mucositis and the nutritional status,respectively.Results There were 348 HNC patients who completed all assessments.The pharyngeal mucositis of patients with HNC was aggravated during radiotherapy(χ^(2)=553.521,P<0.001).At T3,56.0%of patients had moderate or severe pharyngeal mucositis.The proportion of patients with malnutrition increased significantly during treatment(21.3%at T_(1)vs 46.8%at T_(2)vs 76.1%at T3,χ^(2)=209.768,P<0.001).Both a multivariable analysis of generalized estimating equations and a logistic regression analysis showed that pharyngeal mucositis was associated with malnutrition.Conclusions Malnutrition was common in patients with HNC during radiotherapy,and it was closely related to pharyngeal mucositis.Joint interventions targeting nutrition and symptom management should be considered for patients with HNC.
文摘18-fluorodeoxygluocose positron emission tomography/computed tomography(18FDG-PET/CT) provides significant information in multiple settings in the management of head and neck cancers(HNC). This article seeks to define the additional benefit of PET/CT as related to radiation treatment planning for squamous cell carcinomas(SCCs) of the head and neck through a review of relevant literature. By helping further define both primary and nodal volumes, radiation treatment planning can be improved using PET/CT. Special attention is paid to the independent benefit of PET/CT in targeting mucosal primaries as well as in detecting nodal metastases. The utility of PET/CT is also explored for treatment planning in the setting of SCC of unknown primary as PET/CT may help define a mucosal target volume by guiding biopsies for examination under anesthesia thus changing the treatment paradigm and limiting the extent of therapy. Implications of the use of PET/CT for proper target delineation in patients with artifact from dental procedures are discussed and the impact of dental artifact on CT-based PET attenuation correction is assessed. Finally, comment is made upon the role of PET/CT in the high-risk post-operative setting, particularly in the context of radiation dose escalation. Real case examples are used in these settings to elucidate the practical benefits of PET/CT as related to radiation treatment planning in HNCs.
文摘BACKGROUND:Few contemporary studies have assessed physicians’knowledge of radiation exposure associated with common imaging studies,especially in trauma care.The purpose of this study was to assess the knowledge of physicians involved in caring for trauma patients regarding the effective radiation doses of musculoskeletal(MSK)imaging studies routinely utilized in the trauma setting.METHODS:An electronic survey was distributed to United States orthopaedic surgery,general surgery,and emergency medicine(EM)residency programs.Participants were asked to estimate the radiation dose for common imaging modalities of the pelvis,lumbar spine,and lower extremity,in terms of chest X-ray(CXR)equivalents.Physician estimates were compared to the true effective radiation doses.Additionally,participants were asked to report the frequency of discussing radiation risk with patients.RESULTS:A total of 218 physicians completed the survey;102(46.8%)were EM physicians,88(40.4%)wereorthopaedicsurgeons,and28(12.8%)weregeneralsurgeons.Physicians underestimated the effective radiation doses of nearly all imaging modalities,most notably for pelvic computed tomaography(CT)(median 50 CXR estimation vs.162 CXR actual)and lumbar CT(median 50 CXR estimation vs.638 CXR actual).There was no difference between physician specialties regarding estimation accuracy(P=0.133).Physicians who regularly discussed radiation risks with patients more accurately estimated radiation exposure(P=0.007).CONCLUSION:The knowledge among orthopaedic and general surgeons and EM physicians regarding the radiation exposure associated with common MSK trauma imaging is lacking.Further investigation with larger scale studies is warranted,and additional education in this area may improve care.
文摘AIM: To determine swallowing outcomes and hyolaryngeal mechanics associated with post radiation therapy head and neck cancer(rt HNC) patients using videofluoroscopic swallow studies. METHODS: In this retrospective cohort study, video-fluoroscopic images of rt HNC patients(n = 21) were compared with age and gender matched controls(n = 21). Penetration-aspiration of the bolus and bolus residue were measured as swallowing outcome variables. Timing and displacement measurements of the anterior and posterior muscular slings elevating the hyolaryngeal complex were acquired. Coordinate data of anatomical landmarks mapping the action of the anterior muscles(suprahyoid muscles) and posterior muscles(long pharyngeal muscles) were used to calculate the distance measurements, and slice numbers were used to calculate time intervals. Canonical variate analysis with post-hoc discriminant function analysis was performed on coordinate data to determine multivariate mechanics of swallowing associated with treatment. Pharyngeal constriction ratio(PCR) was also measured to determine if weak pharyngeal constriction is associated with post radiation therapy.RESULTS: The rt HNC group was characterized by poor swallowing outcomes compared to the control group in regards to: Penetration-aspiration scale(P < 0.0001), normalized residue ratio scale(NRRS) for the valleculae(P = 0.002) and NRRS for the piriform sinuses(P = 0.003). Timing and distance measurements of the anterior muscular sling were not significantly different in the two groups, whereas for the PMS time of displacement was abbreviated(P = 0.002) and distance of excursion was reduced(P = 0.02) in the rt HNC group. A canonical variate analysis shows a significant reduction in pharyngeal mechanics in the rt HNC group(P < 0.0001). The PCR was significantly higher in the test group than the control group(P = 0.0001) indicating reduced efficiency in pharyngeal clearance. CONCLUSION: Using videofluoroscopy, this study shows rt HNC patients have worse swallowing outcomes associated with reduced hyolaryngeal mechanics and pharyngeal constriction compared with controls.
文摘The reproducibility of patient setup is an important issue for head and neck cancers treated with intensity-modulated radiation therapy (IMRT). In this study, an image-guided radiation therapy (IGRT) system has been used to minimize the uncertainty of patient setup while standard thermoplastic masks were used to provide adequate immobilization for the head and neck. However, they do not provide sufficient immobilization of the shoulders, which is an important requirement in comprehensive nodal irradiation. Therefore, we investigated the setup and rotational shifts in head and neck cancer patients undergoing IMRT for which this immobilization device had been used together with an IGRT system. The setup and rotational shifts of patients were analyzed using the ExacTrac X-ray 6D IGRT system. The patients were classified as having head and neck tumors in the upper or lower regions. The upper neck nodes included lymph nodal level II while the lower neck nodes included lymph nodal levels III and IV. Clinical data from 227 treatment sessions of 12 head and neck cancer patients were analyzed. The random translational error in inter-and intra-fraction errors of the anterio-posterior (AP) direction might influence the rotational errors of pitch and roll in the upper region. At the same time, the random translational error in the inter-and intra-fraction errors of the AP direction might influence the rotational error of roll in the lower region. We believe that these random translational errors should be considered during treatment. We found variability in random translational errors for different regions in the anatomy of head and neck cancer patients due to rotational shifts. Depending on the location of the primary lesion or the selected nodal treatment targets, these relative positional variations should be considered when setup and rotational shifts are corrected with IGRT systems before treatment.
文摘Oral cancer is usually treated combining surgery, radiation therapy and chemotherapy, following effective therapeutic protocols. Severe maxillary and mandibular bone atrophy resulting after therapies are usually treated with autologous bone grafting procedures even though these techniques often present a significant risk of postoperative complications and disadvantages. We describe the case of a 59-year-old woman presenting severe bone defect after being treated with surgery and radiotherapy for recurrent oral verrucous squamous cell carcinoma. We performed bone regeneration using Platelet-Derived Growth Factors (PDGF) in combination with autologous bone chips. Our procedure of bone regeneration allowed the placement of dental implants and the achievement of a good aesthetic and functional result. Regenerative surgery may enable the regeneration of substantial bone defects. Moreover, PDGF application decreases the risk of implant failure in irradiated patients.
文摘BACKGROUND Carotid blowout syndrome(CBS)is a rupture of the carotid artery and is mainly caused by radiation and resection of head and neck cancers or direct tumor invasion of the carotid artery wall.It is a life-threatening clinical situation.There is no established and effective mode of management of CBS.Furthermore,there is no established preceding sign or symptom;therefore,preventive efforts are not clinically meaningful.CASE SUMMARY We described two cases of CBS that occurred in patients with head and neck cancer after definitive chemoradiotherapy(CRT)using three-dimensional conformal intensity-modulated radiation therapy.Two men aged 61 and 56 years with locally advanced head and neck cancer were treated with definitive CRT.After completing CRT,both of them achieved complete remission.Subsequently,they had persistent severe pain in the oropharyngeal mucosal region and the irradiated neck despite the use of opioid analgesics and rehabilitation for relief of contracted skin.However,continuous follow-up imaging studies showed no evidence of cancer recurrence.Eleven to twelve months after completing CRT,the patients visited the emergency room complaining about massive oronasal bleeding.Angiograms showed rupture of carotid artery pseudoaneurysms on the irradiated side.Despite attempting to secure hemostasis with carotid arterial stent insertion and coil embolization,both patients died because of repeated bleeding from the pseudoaneurysms.CONCLUSION In patients with persistent pain in irradiated sites,clinicians should be suspicious of progressing or impending CBS,even in the three-dimensional conformal intensity-modulated radiation therapy era.
文摘Objective: To evaluate the incidence of cervical angiopathy caused by radiation therapy for head and neck cancer. Methods: Segments of 57 cervical arteries were obtained during surgery for head and neck malignant tumors and divided into two groups (irradiated group and non-irradiated group) based on the treatment prior to vascular resection. In order to evaluate vascular injury after radiation therapy, we examined the degree of medial atrophy, medial fibrosis, smooth muscle cell (SMC) differentiation in the media and intima, intimal hyperplasia and endothelial cell (EC) injury. Sections of arterial segments were stained with hematoxylin-eosin, Elastica van Gieson and Masson’s trichrome, and immunohistochemistry for α-smooth muscle actin (α-SMA), smoothelin, S100A4 and CD31 in the resected vessels was conducted. Results: The median interval between the completion of radiation therapy and vascular resection was nine months. No significant differences were observed between the two groups in terms of medial atrophy, medial fibrosis and intimal hyperplasia. The ratio of the smoothelin-positive area per α-SMA-positive area in the media and the S100A4-positive proportion in the intima, indicating the degree of differentiation of the medial SMC and dedifferentiation of the intimal SMC, respectively, showed no significant differences, despite the tendency toward a lower smoothelin-positive area per α-SMA-positive area in the media of the irradiated arteries. The EC coverage revealed on CD31 immunohistochemistry was significantly decreased, with mural thrombus adhesion, in the irradiated group. Conclusions: The ECs of small arteries are damaged by irradiation. Although we did not confirm the statistical significance of medial SMC dedifferentiation, a decreased expression of smoothelin tended to be observed in the media of the irradiated arteries. Our findings provide histopathological evidence of irradiation angiopathy in head and neck cancer and may help to improve the surgical safety of microvascular anastomosis and determine the treatment strategy for head and neck tumors.
文摘Background: Radiation-induced gliomas of the spinal cord are rare late complications of spinal cord irradiation that typically occur in patients treated at younger ages. Aim: Raise awareness of radiation induced high grade gliomas with a case presentation and a review of the literature. Case Presentation: A 50-year-old male with Stage IVA squamous cell carcinoma of the oropharynx was treated with external beam radiotherapy with a complete response. Seven years later, he presented with a cervical spinal cord mass on MRI. An open biopsy was performed. Pathology revealed an intramedullary WHO grade IV astrocytoma, (i.e., glioblastoma multiforme) of the cervical spine that fulfilled the criteria for a radiation-induced malignancy. Conclusions : Review of the literature suggests that radiation-induced gliomas tend to be high grade and may occur at the periphery of an irradiated field. Radiation-induced gliomas of the spinal cord are a serious complication of radiotherapy that may occur in older patients with head and neck cancers, but are so rare that it should not affect treatment decisions.
文摘Losses in channel flows are usually determined using a frictional head loss parameter. Fluid friction is however not the only source of loss in channel flows with heat transfer. For such flow problems, thermal energy degradation, in addition to mechanical energy degradation, add to the total loss in thermodynamic head. To assess the total loss in a channel with combined convection and radiation heat transfer, the conventional frictional head loss parameter is extended in this study. The analysis is applied to a 3D turbulent channel flow and identifies the critical locations in the flow domain where the losses are concentrated. The influence of Boltzmann number is discussed, and the best channel geometry for flows with combined heat transfer modes is also determined.
文摘Xerostomia, or dry mouth, is a significant problem affecting quality of life in patients treated with radiation therapy for head and neck cancer. Strategies for reduction of xerostomia burden vary widely, with options including: sialagogue medications, saliva substitutes, acupuncture, vitamins, hyperbaric oxygen,submandibular gland transfer, and acupuncture or associated treatments. In this review, we sought to evaluate long-term outcomes of patients treated with various interventions for radiation-induced xerostomia. A literature search was performed using the terms "xerostomia" and "radiation" or "radiotherapy"; all prospective clinical trials were evaluated, and only studies that reported 1 year follow up were included. The search results yielded 2193 studies, 1977 of which were in English. Of those, 304 were clinical trials or clinical studies. After abstract review, 23 trials were included in the review evaluating the following treatment modalities: pilocarpine(three); cevimeline(one); amifostine(eleven);submandibular gland transfer(five); acupuncture like transcutaneous electrical nerve stimulation(ALTENS)(one); hyperbaric oxygen(one); and acupuncture(one). Pilocarpine, cevimeline, and amifostine have been shown in some studies to improve xerostomia outcomes, at the cost of toxicity. ALTENS has similar efficacy with fewer side effects. Submandibular gland transfer is effective but requires an elective surgery, and thus may not always be appropriate or practical.The use of intensity-modulated radiation therapy, in addition to dose deescalation in select patients, may result in fewer patients with late xerostomia,reducing the need for additional interventions.
基金Supported by the National Natural Science Foundation of China, No.39100119
文摘INTRODUCTIONCrypt epithelial cells in normal small intestineproliferate at a high speed. But they are verydifficult to culture in vitro and passage stably. A lotof studies have been done[1-16]. Some domestic labsisolated and cultured crypt cells from embryonalintestines and aseptic animal intestine, but failed.We introduced normal rat epithelial cell line-IEC-6from the USA and its living condition for stablepassage was successfully established after trials. Thecell line was testified to be the small intestinalepithelial cell by electron microscopy,immunihistochemistry and enzymatic histoch-emistry. It has been applied to some relatedresearch work[17-21]. It was found that manyfactors were involved in the culture system. Ourpresent study focuses on the culture method and theinfluencing factors on IEC-6.
文摘Oral mucositis is a common morbidity induced by radiation therapy and chemo-radiotherapy for head and neck malignancies. This often results in treatment delays, premature treatment cessation and increased cost. New treatments of oral mucositis are emerging but effective remedies remain limited. Between February 2007 and May 2008, 21 patients with head and neck malignancies were treated with a supersaturated calcium phosphate oral rinse (Caphosol) that was performed for 4-10 times daily, each consisting of two one-minute rinses. There were 21 matched patients who received supportive care without the oral rinse. All patients in the two groups were treated with intensity modulated radiation therapy (IMRT) for average prescription doses of 66 Gy in 33 fractions. The effects of this rinse vs. supportive care on mucositis, PEG tube requirements, hospitalization, xerostomia, analgesic requirements and weight was respectively evaluated. We have observed statistically significant decreases in the incidence of radiation induced oral mucositis (p=0.0002) with WHO grade 3 (38% vs. 52%) and 4 mucositis (0% vs. 19%), need for PEG tube placement (33% vs. 57%) and hospitalization (0% vs 19%). There was also a favorable impact on the incidence of grade 3 (29% vs. 43%) xerostomia in the treated patients but it was statistically insignificant (p=0.58). Incremental costs related to treatment of oral mucositis were reduced considerably. Our data suggest that use of a supersaturated calcium phosphate oral rinse is an effective treatment for mucositis in patients undergoing IMRT. It may also be helpful in the reduction of hospitalization and PEG tube requirements.
文摘Objective:To comprehensively and accurately analyze the out-performance of low-dose chest CT(LDCT)vs.standard-dose CT(SDCT).Methods:The image quality,size measurements and radiation exposure for LDCT and SDCT protocols were evaluated.A total of 117 patients with extra-thoracic malignancies were prospectively enrolled for non-enhanced CT scanning using LDCT and SDCT protocols.Three experienced radiologists evaluated subjective image quality independently using a 5-point score system.Nodule detection efficiency was compared between LDCT and SDCT based on nodule characteristics(size and volume).Radiation metrics and organ doses were analyzed using Radimetrics.Results:The images acquired with the LDCT protocol yielded comparable quality to those acquired with the SDCT protocol.The sensitivity of LDCT for the detection of pulmonary nodules(n=650)was lower than that of SDCT(n=660).There was no significant difference in the diameter and volume of pulmonary nodules between LDCT and SDCT(for BMI<22 kg/m^(2),4.37 vs.4.46 mm,and 43.66 vs.46.36 mm^(3);for BMI>22 kg/m^(2),4.3 vs.4.41 mm,and 41.66 vs.44.86 mm^(3))(P>0.05).The individualized volume CT dose index(CTDI_(vol)),the size specific dose estimate and effective dose were significantly reduced in the LDCT group compared with the SDCT group(all P<0.0001).This was especially true for dose-sensitive organs such as the lung(for BMI<22 kg/m^(2),2.62 vs.12.54 mSV,and for BMI>22 kg/m^(2),1.62 vs.9.79 mSV)and the breast(for BMI<22 kg/m^(2),2.52 vs.10.93 mSV,and for BMI>22 kg/m^(2),1.53 vs.9.01 mSV)(P<0.0001).Conclusion:These results suggest that with the increases in image noise,LDCT and SDCT exhibited a comparable image quality and sensitivity.The LDCT protocol for chest scans may reduce radiation exposure by about 80% compared to the SDCT protocol.
文摘Purpose: Post-operative radiotherapy (PORT) for resected cutaneous squamous cell carcinoma (CSCC) with perineural invasion (PNI) is controversial. Therefore, we conducted a survey to review treatment recommendations among Radiation Oncologists (ROs) in the management of CSCC with PNI. Materials & Methods: In March 2011, we contacted all ROs and trainees in the US through email addresses listed in the 2009 ASTRO directory. Our web-based survey presented clinical vignettes involving Mohs micrographically resected CSCC with microscopic PNI (mPNI) or clinical PNI (cPNI). For each vignette, ROs were asked to indicate if PORT was appropriate and to further specify the dose and volume to treat. Results: Three hundred fifty two responses were completed and analyzed. The majority of ROs (72%) had over 10 years of post residency experience. 64% of the sampled ROs had a special interest in treating head and neck cancers, and 64% treated 4 or more cases per year. Approximately 95% recommended PORT for cPNI whereas 59% recommended PORT for mPNI. Post residency experience (10+ yrs vs. <10 yrs) was associated with a greater propensity to recommend PORT for mPNI (48% vs. 30%, p = 0.005) and for mPNI of deep subcutaneous non-named nerve involvement (80% vs. 60%, p = 0.001). ROs treating 8 or more cases per year (vs. <7) were more likely to recommend PORT for mPNI in immunocompromised patients (74% vs. 57%, p = 0.01). Conclusions: Our study demonstrates significant variability among ROs in the management of CSCC with mPNI. For cases of cPNI, an overwhelming majority recommended PORT. In cases of mPNI, there was no consensus for recommending PORT, although experienced practitioners had a lower threshold for offering treatment. These results indicate the need for prospective clinical studies to clarify the role of PORT in CSCC patients with mPNI.
文摘Measurements of radiation dose to patients in spiral computed tomography (CT) were completed for various collimations,table speeds and pitch. A standard CT head dosimetry phantom and thermoluminescent dosime- ters (TLD) were used for the measurement. The effect of collimation and pitch on radiation dose was studied. The results indicated that the radiation dose at the given tube current,voltage and rotation speed was inversely propor- tional to pitch. And the increasing times of dose were as decreasing times of pitch. This regular pattern was tenable for radiation dose at both central holes and peripheral holes of the phantom at pitch = 1,>1 and <1. The collimation had no impact on the radiation dose. The results also indicated that radiation dose at central holes was nearly equal to that at peripheral holes. There was no significant difference between them statistically. The study demonstrates that the pitch in spiral CT scans is the primary parameter and has significant impact on radiation dose.