Dosimetric Comparative Analysis of Volumetric Modulated Arc Therapy and Intensity-Modulated Radiation Therapy in Cervical Cancer

Objective:To carry out dosimetric comparison between volumetric modulated arc therapy(VMAT)and intensity-modulated radiation therapy(IMRT)in cervical cancer.Methods:50 postoperative cervical cancer patients were included in this study.The patients were admitted for treatment from January 2021 to January 2022.VMAT and IMRT plans were designed for each patient to analyze the dose distribution in the target area of the two treatment techniques.Results:Comparing the monitor unit for single treatment(638.21±116.21 MU)and time of single treatment(143.21±23.14 s)in the observation group and the monitor unit for single treatment(932.14±74.11 MU)and time of single treatment(223.14±17.26 s)in the control group,there was significant difference(P<0.05);there was also significant difference(P<0.05)between the normal tissue(bladder and rectum)of the observation group and that(bladder and rectum)of the control group.Conclusion:VMAT is more effective in cervical cancer,and it has a certain protective effect on normal tissues in patients and can reduce the radiation dose.

Long-term outcomes of a phase Ⅱ randomized controlled trial comparing intensity-modulated radiotherapy with or without weekly cisplatin for the treatment of locally recurrent nasopharyngeal carcinoma

Background:Salvage treatment for locally recurrent nasopharyngeal carcinoma(NPC) is complicated and relatively limited.Radiotherapy,combined with effective concomitant chemotherapy,may improve clinical treatment outcomes.We conducted a phase Ⅱ randomized controlled trial to evaluate the efficacy of intensity-modulated radiotherapy with concomitant weekly cisplatin on locally recurrent NPC.Methods:Between April 2002 and January 2008,69 patients diagnosed with non-metastatic locally recurrent NPC were randomly assigned to either concomitant chemoradiotherapy group(n = 34) or radiotherapy alone group(n = 35).All patients received intensity-modulated radiotherapy.The radiotherapy dose for both groups was 60 Gy in 27 fractions for 37 days(range 23-53 days).The concomitant chemotherapy schedule was cisplatin 30 mg/m^2 by intravenous infusion weekly during radiotherapy.Results:The median follow-up period of all patients was 35 months(range 2-112 months).Between concomitant chemoradiotherapy and radiotherapy groups,there was only significant difference in the 3-year and 5-year overall survival(OS) rates(68.7%vs.42.2%,P = 0.016 and 41.8%vs.27.5%,P = 0.049,respectively).Subgroup analysis showed that concomitant chemoradiotherapy significantly improved the 5-year OS rate especially for patients in stage rT3-4(33.0%vs.13.2%,P = 0.009),stages Ⅲ-Ⅳ(34.3%vs.13.2%,P = 0.006),recurrence interval >30 months(49.0%vs.20.6%,P = 0.017),and tumor volume >26 cm^3(37.6%vs.0%,P = 0.006).Conclusion:Compared with radiotherapy alone,concomitant chemoradiotherapy can improve OS of the patients with locally recurrent NPC,especially those with advanced T category(rT3-4) and stage(lll-IV) diseases,recurrence intervals >30 months,and tumor volume >26 cm^3.

Prognostic factors and failure patterns in non-metastatic nasopharyngeal carcinoma after intensity-modulated radiotherapy

Background: The prognostic values of staging parameters require continual re?assessment amid changes in diag?nostic and therapeutic methods. This study aimed to identify the prognostic factors and failure patterns of non?meta?static nasopharyngeal carcinoma(NPC) in the intensity?modulated radiotherapy(IMRT) era.Methods: We reviewed the data from 749 patients with newly diagnosed, biopsy?proven, non?metastatic NPC in our cancer center(South China, an NPC endemic area) between January 2003 and December 2007. All patients under?went magnetic resonance imaging(MRI) before receiving IMRT. The actuarial survival rates were estimated using the Kaplan–Meier method, and survival curves were compared using the log?rank test. Multivariate analyses with the Cox proportional hazards model were used to test for the independent prognostic factors by backward eliminating insigniicant explanatory variables.Results: The 5?year occurrence rates of local failure, regional failure, locoregional failure, and distant failure were 5.4, 3.0, 7.4, and 17.4%, respectively. The 5?year survival rates were as follows: local relapse?free survival, 94.6%; nodal relapse?free survival, 97.0%; distant metastasis?free survival, 82.6%; disease?free survival, 75.1%; and overall survival, 82.0%. Multivariate Cox regression analysis revealed that orbit involvement was the only signiicant prognostic fac?tor for local failure(P = 0.011). Parapharyngeal tumor extension, retropharyngeal lymph node involvement, and the laterality, longest diameter, and Ho's location of the cervical lymph nodes were signiicant prognostic factors for both distant failure and disease failure(all P < 0.05). Intracranial extension had signiicant prognostic value for distant failure(P = 0.040).Conclusions: The key failure pattern for NPC was distant metastasis in the IMRT era. With changes in diagnostic and therapeutic technologies as well as treatment modalities, the signiicant prognostic parameters for local control have also been altered substantially.

Significant value of 18F-FDG-PET/CT in diagnosing small cervical lymph node metastases in patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy

Background: Little is known about the nature of metaistasis to small cervical lymph nodes(SCLNS) in the patients with nasopharyngeal carcinoma(NPC)examined by using 18-fluoro-2-deoxy-glucose(^(18)F-FDG) positron emission tomography/computed tomography(PET/CT).The present study aimed to evaluate the diagnostic values of PET/CT in identifying metastasis in SCLNs in NPC patients.Methods: Magnetic resonance images(MRI) and PET/CT scans for 470 patients with newly diagnosed, non-distant metastatic NPC were analyzed. Metastatic rates of SCLNs were defined by the positive number of SCLNs on PET/CT scans and total number of SCLNs on MRI scans. Receiver operating characteristic curve was applied to compare PET/CT-determined stage with MRI-determined stage.Results: In total, 2082 SCLNs were identified, with 808(38.8%) ≥ 5 and < 6 mm in diameter(group A), 526(25.3%)≥ 6 and < 7 mm in diameter(group B),374(18.0%)≥ 7 and < 8 mm in diameter(group C), 237(11.4%) ≥8 and<9 mm in diameter(group D),and 137(6.5%) ≥ 9 and <10 mm in diameter(group E).The overall metastatic rates examined by using PET/CT for groups A, B,C,D, and E were 3.5%, 8.0%, 31.3%, 60.0%, and 83.9%, respectively(P< 0.001). In level IV/Vb, the metastatic rate for nodes ≥ 8 mm was 84.6%. PET/CT examination resulted in modification of N category and overall stage for 135(28.7%) and 46(9.8%) patients, respectively. The areas under curve of MRIdetermined and PET/CT-determined overall stage were 0.659 and 0.704 for predicting overall survival, 0.661 and 0.711 for predicting distant metastasis-free survival, and 0.636 and 0.663 for predicting disease-free survival.Conclusions: PET/CT was more effective than MRI in identifying metastatic SCLNs, and the radiologic diagnostic criteria for metastatic lymph nodes in level IV/Vb should be re-defined.

Prognostic value and predictive threshold of tumor volume for patients with locally advanced nasopharyngeal carcinoma receiving intensity-modulated radiotherapy

Background: Gross target volume of primary tumor(GTV?P) is very important for the prognosis prediction of patients with nasopharyngeal carcinoma(NPC), but it is unknown whether the same is true for locally advanced NPC patients treated with intensity?modulated radiotherapy(IMRT). This study aimed to clarify the prognostic value of tumor volume for patient with locally advanced NPC receiving IMRT and to ind a suitable cut?of value of GTV?P for prognosis prediction.Methods: Clinical data of 358 patients with locally advanced NPC who received IMRT were reviewed. Receiver oper?ating characteristic(ROC) curves were used to identify the cut?of values of GTV?P for the prediction of diferent end?points [overall survival(OS), local relapse?free survival(LRFS), distant metastasis?free survival(DMFS), and disease?free survival(DFS)] and to test the prognostic value of GTV?P when compared with that of the American Joint Committee on Cancer T staging system.Results: The 358 patients with locally advanced NPC were divided into two groups by the cut?of value of GTV?P as determined using ROC curves: 219(61.2%) patients with GTV?P ≤46.4 mL and 139(38.8%) with GTV?P >46.4 mL. The 3?year OS, LRFS, DMFS, and DFS rates were all higher in patients with GTV?P ≤46.4 mL than in those with GTV?P > 46.4 mL(all P < 0.05). Multivariate analysis indicated that GTV?P >46.4 mL was an independent unfavorable prognostic factor for patient survival. The ROC curve veriied that the predictive ability of GTV?P was superior to that of T category(P < 0.001). The cut?of values of GTV?P for the prediction of OS, LRFS, DMFS, and DFS were 46.4, 57.9, 75.4 and 46.4 mL, respectively.Conclusion: In patients with locally advanced NPC, GTV?P >46.4 mL is an independent unfavorable prognostic indi?cator for survival after IMRT, with a prognostic value superior to that of T category.

Clinical treatment considerationsin the intensity-modulated radiotherapy era for patients with NO-category nasopharyngeal carcinoma and enlarged neck lymph nodes

Background:Nasopharyngeal carcinoma(NPC) shows a high proportion of lymph node metastasis,and treatment guidelines have been developed for positive nodes.However,no irradiation guidelines have been proposed for patients with enlarged neck lymph nodes(ENLNs) that do not meet the radiological criteria of 10 mm in diameter for positive lymph nodes.This study aimed to determine the prognostic value and radiation dose for ENLNs in NO-category NPC patients treated with intensity-modulated radiotherapy(IMRT).Methods:We reviewed the medical data of 251 patients with non-metastatic,NO-category NPC treated with IMRT.Receiver operating characteristic curves were used to calculate the cut-off value of the ENLN diameter for the prediction of disease failure.The biological equivalent dose(BED) for ENLNs was calculated.Patient survival was compared between the small and large ENLN groups.Independent prognostic factors were identified using the Cox proportional hazards model.Results:The estimated 4-year regional relapse-free survival rate was higher in patients with ENLNs ≥5.5 mm than in those with ENLNs <5.5 mm(100%vs.98.8%,P=0.049),whereas disease-free,overall,and distant metastasis-free survival rates were similar between the two groups.After adjusting for various factors,ENLN diameter was not identified as an independent prognostic factor(P > 0.05 for all survival rates).In the subgroup analysis,patients receiving BED ≥72 Gy had a similar prognosis as patients receiving BED <72 Gy in both the small and large ENLN groups.The multivariate analysis also confirmed that BED≥72 Gy was not associated with significantly improved prognosis in patients with NO-category NPC.Conclusions:A BED of 72 Gy to ENLNs is considerably sufficient to provide a clinical benefit to patients with NO-category NPC.Prospective studies are warranted to validate the findings in the present study.

A model to predict the risk of lethal nasopharyngeal necrosis after re-irradiation with intensity-modulated radiotherapy in nasopharyngeal carcinoma patients

Background:For patients with nasopharyngeal carcinoma(NPC) who undergo re-irradiation with intensity-modulated radiotherapy(IMRT),lethal nasopharyngeal necrosis(LNN) is a severe late adverse event.The purpose of this study was to identify risk factors for LNN and develop a model to predict LNN after radical re-irradiation with IMRT in patients with recurrent NPC.Methods:Patients who underwent radical re-irradiation with IMRT for locally recurrent NPC between March 2001 and December 2011 and who had no evidence of distant metastasis were included in this study.Clinical characteristics,including recurrent carcinoma conditions and dosimetric features,were evaluated as candidate risk factors for LNN.Logistic regression analysis was used to identify independent risk factors and construct the predictive scoring model.Results:Among 228 patients enrolled in this study,204 were at risk of developing LNN based on risk analysis.Of the 204 patients treated,31(15.2%) developed LNN.Logistic regression analysis showed that female sex(P = 0.008),necrosis before re-irradiation(P = 0.008),accumulated total prescription dose to the gross tumor volume(GTV) ≥ 145.5 Gy(P = 0.043),and recurrent tumor volume >25.38 cm3(P = 0.009) were independent risk factors for LNN.A model to predict LNN was then constructed that included these four independent risk factors.Conclusions:A model that includes sex,necrosis before re-irradiation,accumulated total prescription dose to GTV,and recurrent tumor volume can effectively predict the risk of developing LNN in NPC patients who undergo radical re-irradiation with IMRT.

Intensified intensity-modulated radiotherapy in anal cancer with prevalent HPV p16 positivity

AIM: To investigate the toxicity and response of intensity-modulated radiotherapy schedule intensified with a simultaneous integrated boost in anal canal cancer.METHODS: From March 2009 to March 2014, we retrospectively analyzed 41 consecutive patients treated with intensity-modulated radiotherapy(IMRT) and concurrent chemotherapy for anal canal squamous cell carcinoma at our center. Radiotherapy was delivered via simultaneous integrated boost(SIB) technique by helical tomotherapy, and doses were adapted to two clinical target volumes according to the tumor-nodemetastasis(TNM) stage: 50.6 Gy and 41.4 Gy in 23 fractions in T1N0, 52.8 Gy and 43.2 Gy in 24 fractionsin T2N0, and 55 Gy and 45 Gy in 25 fractions in all patients with N positive and/or ≥ T3, respectively, to planning target volumes 1 and 2. The most common chemotherapy regimen was 5-fluorouracil and mitomycin-based. Human papilloma virus(HPV) p16 expression was performed by immunohistochemistry and evaluated in the majority of patients. Acute and late toxicity was scored according to CTCAe v 3.0 and RTOG scales.RESULTS: The median follow-up was 30 mo(range:12-71). Median age was 63 years(range 32-84). The stage of disease was: stage Ⅰ in 2 patients, stage Ⅱin 13 patients, stage ⅢA in 12 patients, and stage ⅢB in 14 patients, respectively. Two patients were known to be HIV positive(4.9%). HPV p16 expression status was positive in 29/34(85.3%) patients. The 4-year progression-free survival and overall survival in HPVpositive patients were 78% and 92%, respectively.Acute grade 3 skin and gastrointestinal toxicities were reported in 5% and 7.3% of patients, respectively;patients' compliance to the treatment was good due to a low occurrence of severe acute toxicity, although treatment interruptions due to toxicity were required in 7.3% of patients. At 6 mo from end of treatment,36/40(90%) patients obtained complete response;during follow-up, 5(13.8%) patients presented with disease progression(local or systemic).CONCLUSION: In our experience, intensified SIBIMRT with chemotherapy is very feasible in clinical practice, with excellent results in terms of overall survival and local control.

A prospective trial of volumetric intensity-modulated arc therapy vs conventional intensity modulated radiation therapy in advanced head and neck cancer

AIM: To prospectively compare volumetric intensitymodulated arc therapy(VMAT) and conventional intensity-modulated radiation therapy(IMRT) in coverage of planning target volumes and avoidance of multiple organs at risk(OARs) in patients undergoing definitive chemoradiotherapy for advanced(stage Ⅲ or Ⅳ)squamous cell cancer of the head and neck. METHODS: Computed tomography scans of 20 patients with advanced tumors of the larynx, naso-, oroand hypopharynx were prospectively planned using IMRT(7 field) and VMAT using two arcs. Calculated doses to planning target volume(PTV) and OAR were compared between IMRT and VMAT plans. Dose-volume histograms(DVH) were utilized to obtain calculated doses to PTV and OAR, including parotids, cochlea,spinal cord, brainstem, anterior tongue, pituitary and brachial plexus. DVH's for all structures were compared between IMRT and VMAT plans. In addition the planswere compared for dose conformity and homogeneity. The final treatment plan was chosen by the treating radiation oncologist. RESULTS: VMAT was chosen as the ultimate plan in 18 of 20 patients(90%) because the plans were thought to be otherwise clinically equivalent. The IMRT plan was chosen in 2 of 20 patients because the VMAT plan produced concentric irradiation of the cord which was not overcome even with an avoidance structure. For all patients, VMAT plans had a lower number of average monitor units on average(MU = 542.85) than IMRT plans(MU = 1612.58)(P < 0.001). Using the conformity index(CI), defined as the 95% isodose volume divided by the PTV, the IMRT plan was more conformal with a lower conformity index(CI = 1.61) than the VMAT plan(CI = 2.00)(P = 0.003). Dose homogeneity, as measured by average standard deviation of dose distribution over the PTV, was not different with VMAT(1.45 Gy) or IMRT(1.73 Gy)(P = 0.069). There were no differences in sparing organs at risk.CONCLUSION: In this prospective study, VMAT plans were chosen over IMRT 90% of the time. Compared to IMRT, VMAT plans used only one third of the MUs, had shorter treatment times, and similar sparing of OAR. Overall, VMAT provided similar dose homogeneity but less conformity in PTV irradiation compared to IMRT. This difference in conformity was not clinically significant.

Quantifying lateral penumbra advantages of collimated spot-scanning beam for intensity-modulated proton therapy

Intensity-modulated proton therapy(IMPT)is becoming essential for proton therapy and is under rapid development.However,for IMPT,the lateral penumbra of the spot-scanning proton beam is still an urgent issue to be solved.Patient-specific block collimators(PSBCs),which can block unnecessary doses,play a crucial role in passive scattering delivery technology but are rarely used in spot scanning.One objective of this study is to investigate the lateral penumbra variations of intensity-modulated spot scanning with and without a PSBC.For fields with varying degrees of sharpness and at varying depths in a water phantom,the lateral penumbral widths were calculated using a Monte Carlo-based dose engine from RayStation 6.The results suggest that the lateral penumbral widths can be reduced by more than 30%for uniform target volumes,regardless of whether a range-shifter is used,and that the maximum dose beyond the field edges can be reduced significantly.The results of patient cases show that the doses in organs-at-risk near the edge of the target volume decrease if a PSBC is implemented.This study demonstrates that intensity-modulated spot scanning with a PSBC can effectively reduce the lateral penumbra and block unnecessary doses and is therefore promising for clinical applications in spot-scanning proton therapy.

Comparison of efficacy and safety between late-course and simultaneous integrated dose-increasing intensity-modulated radiation therapy for cervical cancer complicated with pelvic lymph node metastasis

Objective This study aimed to compare and analyze the clinical efficacy and safety of late-course and simultaneous integrated dose-increasing intensity-modulated radiation therapy(IMRT) for cervical cancer complicated with pelvic lymph node metastasis. Methods Sixty patients with cervical cancer complicated with pelvic lymph node metastasis who were admitted to our hospital from January 2013 to January 2015 were enrolled. The patients were randomly divided into the late-course dose-increasing IMRT group and the simultaneous integrated dose-increasing IMRT group, with 30 cases included in each group, respectively. All patients were concurrently treated with cisplatin. After treatment, the clinical outcomes of the two groups were compared. Results The remission rate of symptoms in the simultaneous integrated dose-increasing IMRT group was significantly higher than that in the late-course dose-increasing IMRT group(P < 0.05). The follow-up results showed that the overall survival time, progression-free survival time, and distant metastasis time of patients in the simultaneous integrated dose-increasing IMRT group were significantly longer than those in the late-course dose-increasing IMRT group(P < 0.05). The recurrent rate of lymph nodes in the radiation field in the simultaneous integrated dose-increasing IMRT group was significantly lower(P < 0.05) than in the late-course dose-increasing IMRT group. There was no significant difference in the incidence of cervical and vaginal recurrence and distant metastasis between the two groups(P > 0.05). The radiation doses of Dmax in the small intestine, D1 cc(the minimum dose to the 1 cc receiving the highest dose) in the bladder, and Dmax in the rectum in the simultaneous integrated dose-increasing IMRT group were significantly lower(P < 0.05) than in the late-course dose-increasing IMRT group. There was no significant difference in intestinal D2 cc(the minimum dose to the 2 cc receiving the highest dose) between the two groups(P > 0.05). The incidence of bone marrow suppression in the simultaneous integrated dose-increasing IMRT group was significantly lower(P < 0.05) than in the late-course dose-increasing IMRT group.Conclusion The application of simultaneous integrated dose-increasing IMRT in the treatment of cervical cancer patients complicated with pelvic lymph node metastasis can significantly control tumor progression, improve the long-term survival time, and postpone distant metastasis time with high safety.

Selective partial salivary glands sparing during intensity-modulated radiation therapy for nasopharyngeal carcinoma

Objective This study evaluated the dosimetric consequences of selective partial salivary gland sparing during intensity-modulated radiotherapy(IMRT) for patients with nasopharyngeal carcinoma(NPC).Methods Ten patients with NPC were enrolled in the study.Two IMRT plans were produced for each patient:conventional(control) and partial salivary glands-sparing(treatment),with dose constraints to the entire parotid glands or partial salivary glands(including the parotid and submandibular glands,delineated with the adjacent distance of at least 0.5 cm between the glands and PTV,the planning target volume) in planning,respectively.Dosimetric parameters were compared between the two plans,including the V_(110%),V_(100%),V_(95%)(the volume covered by more than 110%,100%,or 95% of the prescribed dose),Dmin(the minimum dose) of PTV,homogeneity index(HI),conformity index(CI),and the mean dose and percentage of the volume receiving 30 Gy or more(V_(30)) for the parotid glands and submandibular glands.Results Treatment plans had significantly lower mean doses and V_(30) to both the entire parotid glands and partial parotid glands than those in control plans.The mean doses to the partial submandibular glands were also significantly lower in treatment plans than in control plans.The PTV coverage was comparable between the two plans,as indicated by V_(100%),V_(95%),Dmin,CI,and HI.The doses to critical structures,including brainstem and spinal cord,were slightly but not significantly higher in treatment plans than in control plans.Conclusion A selective partial salivary gland-sparing approach reduces the doses to parotid and submandibular glands during IMRT,which may decrease the risk of post-radiation xerostomia while not compromising target dose coverage in patients with NPC.

Long-term Therapeutic Outcome and Prognostic Factors of Patients with Nasopharyngeal Carcinoma Receiving Intensity-modulated Radiotherapy: An Analysis of 608 Patients from Low-endemic Regions of China

Objective To evaluate the long-term outcome and prognostic factors of patients with nasopharyngeal carcinoma(NPC)from low-endemic regions of China who received definitive intensity-modulated radiation therapy(IMRT).Methods The clinical data from 608 patients with newly-diagnosed non-metastatic NPC who have received initial treatment at our cancer center from January,2008 to December,2013 were retrospectively reviewed.All patients received definitive IMRT,and 87.7%received platinum-based chemotherapy.Results The median follow-up duration was 51 months(follow-up rate,98.5%;range,10–106 months)for the entire cohort.The 5-year overall survival rate was 79.7%.The 5-year local relapse-free survival rate,regional relapse-free survival rate,distant metastasis-free survival rate and progression-free survival rate were 92.4%,93.3%,79.2%and 74.3%,respectively.A total of 153 patients had experienced treatment failure,with distant metastasis as the primary cause in 77.1%(118/153).Patients with T4 or N3 diseases had a significantly poorer prognosis than other subcategories.Stage T4 and N3 were closely associated with distant metastasis,with the metastatic rate of 29.3%and 45.5%,respectively.Conclusion IMRT provides patients with non-metastatic NPC with satisfactory long-term survival.Both T stage and N stage are important prognostic factors for NPC patients.Patients with T4 or N3 diseases have significantly increased distant metastatic rates and poor survival time.

Dose Comparison between Eclipse Dose Calculation and Fast Dose Calculator in Single- and Multi-Field Optimization Intensity-Modulated Proton Therapy Plans with Various Multi-Beams for Brain Cancer

The purpose of this study was to grasp current potential problems of dose error in intensity-modulated proton therapy (IMPT) plans. We were interested in dose differences of the Varian Eclipse treatment planning system (TPS) and the fast dose calculation method (FDC) for single-field optimization (SFO) and multi-field optimization (MFO) IMPT plans. In addition, because some authors have reported dosimetric benefit of a proton arc therapy with ultimate multi-fields in recent years, we wanted to evaluate how the number of fields and beam angles affect the differences for IMPT plans. Therefore, for one brain cancer patient with a large heterogeneity, SFO and MFO IMPT plans with various multi-angle beams were planned by the TPS. Dose distributions for each IMPT plan were calculated by both the TPS’s conventional pencil beam algorithm and the FDC. The dosimetric parameters were compared between the two algorithms. The TPS overestimated 400 - 500 cGy (RBE) for minimum dose to the CTV relative to the dose calculated by the FDC. These differences indicate clinically relevant effect on clinical results. In addition, we observed that the maximum difference in dose calculated between the TPS and the FDC was about 900 cGy (RBE) for the right optic nerve, and this quantity also has a possibility to have a clinical effect. The major difference was not seen in calculations for SFO IMPT planning and those for MFO IMPT planning. Differences between the TPS and the FDC in SFO and MFO IMPT plans depend strongly on beam arrangement and the presence of a heterogeneous body. We advocate use of a Monte Carlo method in proton treatment planning to deliver the most precise proton dose in IMPT.

Local definitive intensity-modulated radiation therapy recommended for patients initially diagnosed with nasopharyngeal carcinoma with distant metastasis after an effective systemic chemotherapy

Objective The aim of the study was to propose a hypothesis that local definitive intensity-modulated radiation therapy(IMRT) should be recommended for initially diagnosed metastatic nasopharyngeal carcinoma(NPC) and demonstrate its feasibility.Methods Recently published papers on local definitive radiotherapy for initially diagnosed metastatic NPC were reviewed to propose a hypothesis.Results Several studies revealed the survival benefits of adding local definitive radiotherapy to the systemic chemotherapy in patients initially diagnosed with metastatic NPC.Conclusion We suggested that local definitive IMRT should be recommended in patients initially diagnosed with NPC with distant metastasis after an effective systemic chemotherapy, which may possibly prolong their survival time and potentially treat the disease.

Effect of intensity-modulated radiotherapy combined with local hyperthermia on Mortalin expression in advanced liver cancer lesions and its relationship with cell proliferation and EMT

Objective:To investigate the effect of intensity-modulated radiotherapy combined with local hyperthermia on Mortalin expression in advanced liver cancer lesions and its relationship with cell proliferation and EMT.Methods: A total of 82 patients with advanced liver cancer who were treated in this hospital between February 2016 and September 2017 were chosen as the research subjects, and the therapeutic regimens were reviewed and used to divide these patients into the control group (n=43) who received intensity-modulated radiotherapy and the combined treatment group (n=39) who received intensity-modulated radiotherapy combined with local hyperthermia. Abdominal puncture was done after treatment to obtain liver cancer tissue samples, and the differences in Mortalin gene, cell proliferation gene and EMT gene expression in tissues were compared.Results: After treatment, Mortalin mRNA expression in liver cancer tissues of combined treatment group was lower than that of control group;Fbxw7 mRNA expression in liver cancer tissues was higher than that of control group whereas NCX1, PRMT5 and XBP1S mRNA expression were lower than those of control group;Twist, ZEB-1, ZEB-2, Snail and HOXB7 mRNA expression in liver cancer tissues were lower than those of control group. Pearson test showed that the Mortalin gene expression in liver cancer tissues was directly correlated with cell proliferation genes and EMT genes.Conclusion:Intensity-modulated radiotherapy combined with local hyperthermia can effectively reduce Mortalin gene expression, and further optimize patients'condition by inhibiting hepatic cell proliferation, EMT activity and other pathways.

The Impact of Variation in Bladder Volume on the Doses of Target and Organ-at-Risk in Intensity-Modulated Radiation Therapy for Localized Prostate Cancer

Intensity-modulated radiation therapy (IMRT) has become the mainstay of treatment for localized prostate cancer. In IMRT, minimizing differences between the conditions used during planning CT and daily treatment is important to prevent adverse events in normal tissues. In the present study, we evaluated the impact of variation in bladder volume on the doses to various organs. A total of 35 patients underwent definitive radiotherapy at Saitama Medical Center. A Light Speed RT16 (GE Healthcare) was used for planning and to obtain examination CT images. Such images were acquired after 4 - 6 days of planning CT image acquisition. The IMRT plans were optimized using the planning CT data to satisfy the dose constraints set by our in-house protocols for the PTV and the OARs. The dose distributions were then re-calculated using the same IMRT beams, and checked on examination CT images. It was clear that bladder volume affected the doses to certain organs. We focused on the prostate, bladder, rectum, small bowel, and large bowel. Regression coefficients were calculated for variables that correlated strongly with bladder volume (p < 0.05). We found that variation in bladder volume [cm3] predicted deviations in the bladder V70Gy, V50Gy, and V30Gy [%];the maximum dose to the small bowel [cGy];and the maximum dose to the large bowel [cGy]. The regression coefficients were -0.065, -0.125, -0.180, -10.22, and -9.831, respectively. We evaluated the impacts of such variation on organ doses. These may be helpful when checking a patient’s bladder volume before daily IMRT for localized prostate cancer.

Effect of Tegafur Gimeracil Oteracil Potassium Capsule + Kangai injection + intensity-modulated radiation therapy on the cellular malignant biological processes in advanced cervical cancer lesion

Objective:To study the effect of Tegafur Gimeracil Oteracil Potassium Capsule + Kangai injection + intensity-modulated radiation therapy on the cellular malignant biological processes in advanced cervical cancer lesion.Methods: Patients who were diagnosed with advanced cervical cancer in the Second People Hospital of Banan District Chongqing between April 2015 and March 2017 were selected and divided into two groups, group A received Tegafur Gimeracil Oteracil Potassium Capsule + Kangai injection + intensity-modulated radiation therapy, and group B received cisplatin + intensity-modulated radiation therapy. Serum contents of tumor markers, tumor invasion molecules and tumor proliferation molecules of two groups of patients were detected before treatment as well as 2 weeks and 4 weeks after treatment.Results: Serum E-cad, STMN1, Fas and p53 levels of both groups of patients 2 weeks and 4 weeks after treatment were significantly higher than those before treatment while TSGF, TK1, SCC-Ag, CA125, OPN, MMP9, NGAL, CyclinE, CyclinD1 and PCNA levels were significantly lower than those before treatment, and serum E-cad, STMN1, Fas and p53 levels of group A 2 weeks and 4 weeks after treatment were significantly higher than those of group B while TSGF, TK1, SCC-Ag, CA125, OPN, MMP9, NGAL, CyclinE, CyclinD1 and PCNA levels were significantly lower than those of group B.Conclusion: Tegafur Gimeracil Oteracil Potassium Capsule + Kangai injection + intensity-modulated radiation therapy for advanced cervical cancer can induce cancer cell apoptosis and inhibit cancer cell proliferation and invasion.

Minimally invasive surgery alone compared with intensity-modulated radiotherapy for primary stage I nasopharyngeal carcinoma

Background:The National Comprehensive Cancer Network guidelines recommend intensity-modulated radiotherapy(IMRT)as the primary curative treatment for newly diagnosed nasopharyngeal carcinoma(NPC),but the radiation-related complications and relatively high medical costs remain a consequential burden for the patients.Endoscopic nasopharyngectomy(ENPG)was successfully applied in recurrent NPC with radiation free and relatively low medical costs.In this study,we examined whether ENPG could be an effective treatment for localized stage I NPC.Methods:Ten newly diagnosed localized stage I NPC patients voluntarily received ENPG alone from June 2007 to September 2017 in Sun Yat-sen University Cancer Center.Simultaneously,the data of 329 stage I NPC patients treated with IMRT were collected and used as a reference cohort.The survival outcomes,quality of life(QOL),and medical costs between two groups were compared.Results:After a median follow-up of 59.0 months(95%CI 53.4-64.6),no death,locoregional recurrence,or distant metastasis was observed in the 10 patients treated with ENPG.The 5-year overall survival,local relapse-free survival,regional relapse-free survival,and distant metastasis-free survival among the ENPG-treated patients was similar to that among the IMRT-treated patients(100%vs.99.1%,100%vs.97.7%,100%vs.99.0%,100%vs.97.4%,respectively,P>0.05).In addition,compared with IMRT,ENPG was associated with decreased total medical costs($4090.42±1502.65 vs.$12620.88±4242.65,P<0.001)and improved QOL scores including dry mouth(3.3±10.5 vs.34.4±25.8,P<0.001)and sticky saliva(3.3±10.5 vs.32.6±23.3,P<0.001).Conclusions:ENPG alone was associated with promising long-term survival outcomes,low medical costs,and satisfactory QOL and might therefore be an alternative strategy for treating newly diagnosed localized stage I NPC patients who refused radiotherapy.However,the application of ENPG should be prudent,and prospective clinical tri-als were needed to further verify the results.

Long-term outcome of a moderately hypofractionated, intensity-modulated radiotherapy approach using an endorectal balloon for patients with localized prostate cancer

Background:Technical advances in radiotherapy delivery have simultaneously enabled dose escalation and enhanced bladder and rectal sparing.However,the optimal radiation fractionation regimen for localized prostate cancer is unclear.Laboratory and clinical evidence suggest that hypofractionation may improve the therapeutic ratio of radiotherapy.We report our institutional outcomes using moderately hypofractionated,intensity-modulated radio-therapy(IMRT),and an endorectal balloon,with emphasis on long-term biochemical control and treatment-related adverse events in patients with localized prostate cancer.Methods:Between January 1997 and April 2004,596 patients with cT1-T3 prostate cancer underwent IMRT using a moderate hypofractionation regimen(76.70 Gy at 2.19 Gy/fraction)with an endorectal balloon.Using D’Amico clas-sification,226(37.9%),264(44.3%),and 106(17.8%)patients had low-,intermediate-,or high-risk disease,respectively.The majority of intermediate-and high-risk patients received androgen deprivation therapy.Biochemical relapse-free survival(bRFS)was evaluated using 2005 Phoenix criteria and estimated using the Kaplan-Meier method.Results:The median follow-up was 62 months.Overall 5-and 10-year bRFS rates were 92.7%and 87.7%.For low-,intermediate-,and high-risk patients,the 5-year bRFS rates were 96.9%,93.3%,and 82.0%,respectively;the 10-year bRFS rates were 91.4%,89.3%,and 76.2%,respectively.Prostate-specific antigen,Gleason score,and T stage were significant predictors of bRFS(all P<0.01).The 5-year rates of severe(≥Grade 3)adverse events were very low:1.2%for gastrointestinal events and 1.1%for genitourinary events.Conclusions:Long-term outcomes after moderately hypofractionated IMRT are encouraging.Moderate hypofrac-tionation represents a safe,efficacious,alternative regimen in the treatment of localized prostate cancer.