Shoulder adhesive capsulitis in cancer patients undergoing positron emission tomography-computed tomography and the association with shoulder pain

BACKGROUND Adhesive capsulitis is a relatively common condition that can develop in cancer patients during treatment.Positron emission tomography-computed tomography(PET-CT)is routinely performed as a follow-up study in cancer patients after therapy.Being aware of PET-CT findings to suggest shoulder adhesive capsulitis may help to alert clinicians for the diagnosis of unsuspected shoulder capsulitis.AIM To assess the association of shoulder adhesive capsulitis with cancer/therapy type and symptoms in cancer patients undergoing PET-CT.METHODS Our prospective study received Institutional Review Board approval.Written informed consent was obtained from all patients,who answered a questionnaire regarding shoulder pain/stiffness at the time of PET-CT study,between March 2015 and April 2019.Patients with advanced glenohumeral arthrosis,metastatic disease or other mass in the shoulder,or shoulder arthroplasty were excluded.Patterns of shoulder capsule 18F-fluorodeoxyglucose(FDG)uptake were noted.Standard Uptake Value(SUV)max and SUVmean values were measured at rotator interval(RI)and deltoid muscle in bilateral shoulders.Normalized SUV(SUV of RI/SUV of deltoid muscle)was also calculated.We assessed if SUV values are different between symptomatic and asymptomatic patients in both shoulders.Covariates were age,gender,and therapy type(surgery,chemotherapy,radiation).Wilcoxon rank sum tests were used to compare unadjusted marginal differences for age,SUV measurements between symptomatic and asymptomatic patients.Multiple linear regression models were used to examine the relationship between right or left shoulder SUV measurements and symptom status,after adjusting for covariates.Statistical significance level was set at P<0.05.RESULTS Of 252 patients initially enrolled for the study(mean age 66 years,67 symptomatic),shoulder PET-CT data were obtained in 200 patients(52 were excluded due to exclusion criteria above).The most common cancer types were lymphoma(n=61),lung(n=54)and breast(n=53).No significant difference was noted between symptomatic and asymptomatic patients in terms of age,gender,proportion of patients who had surgical therapy and radiation therapy.A proportion of patients who received chemotherapy was higher in patients who were asymptomatic in the right shoulder compared to those symptomatic in the right shoulder(65%vs 48%,P=0.012).No such difference was seen for the left shoulder.In both shoulders,SUVmax and SUVmean were higher in symptomatic shoulders than asymptomatic shoulders(Left SUVmax 2.0 vs 1.6,SUVmean 1.6 vs 1.3,both P<0.002;Right SUVmax 2.2 vs 1.8,SUVmean 1.8 vs 1.5,both P<0.01).For lung cancer patients,bilateral RI SUVmax and SUVmean values were higher in symptomatic shoulders than asymptomatic shoulders.For other cancer patients,symptomatic patients had higher left RI SUVmax/mean than asymptomatic patients after adjustment.CONCLUSION In symptomatic patients metabolic activities in RI were higher than asymptomatic patients.Adhesive capsulitis should be considered in cancer patients with shoulder symptoms and positive FDG uptake in RI.

Proton therapy dosimetry using positron emission tomography

Protons deposit most of their kinetic energy at the end of their path with no energy deposition beyond the range, making proton therapy a valuable option for treating tumors while sparing surrounding tissues. It is imperative to know the location of the dose deposition to ensure the tumor, and not healthy tissue, is being irradiated. To be able to extract this information in a clinical situation, an accurate dosimetry measurement system is required. There are currently two in vivo methods that are being used for proton therapy dosimetry: (1) online or in-beam monitoring and (2) offline monitoring, both using positron emission tomography (PET) systems. The theory behind using PET is that protons experience inelastic collisions with atoms in tissues resulting in nuclear reactions creating positron emitters. By acquiring a PET image following treatment, the location of the positron emitters in the patient, and therefore the path of the proton beam, can be determined. Coupling the information from the PET image with the patient's anatomy, it is possible to monitor the location of the tumor and the location of the dose deposition. This review summarizes current research investigating both of these methods with promising results and reviews the limitations along with the advantages of each method.

Multimodality imaging using proton magnetic resonance spectroscopic imaging and ^(18)F-fluorodeoxyglucose-positron emission tomography in local prostate cancer

AIM To assess the relationship using multimodality imaging between intermediary citrate/choline metabolism as seen on proton magnetic resonance spectroscopic imaging(1H-MRSI) and glycolysis as observed on ^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(^(18)F-FDG-PET/CT) in prostate cancer(PCa) patients. METHODS The study included 22 patients with local PCa who were referred for endorectal magnetic resonance imaging/1HMRSI(April 2002 to July 2007) and ^(18)F-FDG-PET/CT and then underwent prostatectomy as primary or salvage treatment. Whole-mount step-section pathology was used as the standard of reference. We assessed the relationships between PET parameters [standardized uptake value(SUVmax and SUVmean)] and MRSI parameters [choline + creatine/citrate(CC/Cmax and CC/Cmean) and total number of suspicious voxels] using spearman's rank correlation, and the relationships of PET and 1H-MRSI index lesion parameters to surgical Gleason score.RESULTS Abnormal intermediary metabolism on 1H-MRSI was present in 21/22 patients, while abnormal glycolysis on ^(18)F-FDG-PET/CT was detected in only 3/22 patients. Specifically, index tumor localization rates were 0.95(95%CI: 0.77-1.00) for 1H-MRSI and 0.14(95%CI: 0.03-0.35) for ^(18)F-FDG-PET/CT. Spearman rank correlations indicated little relationship(ρ =-0.36-0.28) between 1H-MRSI parameters and ^(18)F-FDG-PET/CT parameters. Both the total number of suspicious voxels(ρ = 0.55, P = 0.0099) and the SUVmax(ρ = 0.46, P = 0.0366) correlated weakly with the Gleason score. No significant relationship was found between the CC/Cmax, CC/Cmean or SUVmean and the Gleason score(P = 0.15-0.79). CONCLUSION The concentration of intermediary metabolites detected by 1H MRSI and glycolytic flux measured ^(18)F-FDG PET show little correlation. Furthermore, only few tumors were FDG avid on PET, possibly because increased glycolysis represents a late and rather ominous event in the progression of PCa.

Positron emission tomography/computer tomography:Challenge to conventional imaging modalities in evaluating primary and metastatic liver malignancies

Computer tomography (CT) and magnetic resonance imaging (MRI),as conventional imaging modalities,are the preferred methodology for tumor,nodal and systemic metastasis (TNM) staging. However,all the noninvasive techniques in current use are not sufficiently able to identify primary tumors and even unable to define the extent of metastatic spread. In addition,relying exclusively on macromorphological characteristics to make a conclusion runs the risk of misdiagnosis due mainly to the intrinsic limitations of the imaging modalities themselves. Solely based on the macromorphological characteristics of cancer,one cannot give an appropriate assessment of the biological characteristics of tumors. Currently,positron emission tomography/computer tomography (PET/CT) are more and more widely available and their application with 18F-fluorodeoxyglucose (18F-FDG) in oncology has become one of the standard imaging modalities in diagnosing and staging of tumors,and monitoring the therapeutic efficacy in hepatic malignancies. Recently,investigators have measured glucose utilization in liver tumors using 18F-FDG,PET and PET/CT in order to establish diagnosis of tumors,assess their biologic characteristics and predict therapeutic effects on hepatic malignancies. PET/ CT with 18F-FDG as a radiotracer may further enhance the hepatic malignancy diagnostic algorithm by accurate diagnosis,staging,restaging and evaluating its biological characteristics,which can benefit the patients suffering from hepatic metastases,hepatocellular carcinoma and cholangiocarcinoma.

Endocrine radionuclide scintigraphy with fusion single photon emission computed tomography/computed tomography

AIM: To review the benefits of single photon emission computed tomography(SPECT)/computed tomography(CT) hybrid imaging for diagnosis of various endocrine disorders.METHODS: We performed MEDLINE and Pub Med searches using the terms: "SPECT/CT"; "functional anatomic mapping"; "transmission emission tomography"; "parathyroid adenoma"; "thyroid cancer"; "neuroendocrine tumor"; "adrenal"; "pheochromocytoma"; "paraganglioma"; in order to identify relevant articles published in English during the years 2003 to 2015. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts(case reports, reviews, meta-analyses and abstracts) concerning the application of SPECT/CT to endocrine imaging were analyzed to provide a descriptive synthesis of the utility of this technology.RESULTS: The emergence of hybrid SPECT/CT camera technology now allows simultaneous acquisition of combined multi-modality imaging, with seamless fusion of three-dimensional volume datasets. The usefulness of combining functional information to depict the biodistribution of radiotracers that map cellular processes of the endocrine system and tumors of endocrine origin, with anatomy derived from CT, has improved the diagnostic capability of scintigraphy for a range of disorders of endocrine gland function. The literature describes benefits of SPECT/CT for ^(99m)Tc-sestamibi parathyroid scintigraphy and ^(99m)Tc-pertechnetate thyroid scintigraphy, ^(123)I- or ^(131)I-radioiodine for staging of differentiated thyroid carcinoma, ^(111)In- and ^(99m)Tclabeled somatostatin receptor analogues for detection of neuroendocrine tumors, ^(131)I-norcholesterol(NP-59) scans for assessment of adrenal cortical hyperfunction, and ^(123)I- or ^(131)I-metaiodobenzylguanidine imaging for evaluation of pheochromocytoma and paraganglioma.CONCLUSION: SPECT/CT exploits the synergism between the functional information from radiopharmaceutical imaging and anatomy from CT, translating to improved diagnostic accuracy and meaningful impact on patient care.

Mediastinal node staging by positron emission tomographycomputed tomography and selective endoscopic ultrasound with fine needle aspiration for patients with upper gastrointestinal cancer:Results from a regional centre

AIM To investigate the impact of endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA) and positron emission tomography-computed tomography(PET-CT) in the nodal staging of upper gastrointestinal(GI) cancer in a tertiary referral centre.METHODS We performed a retrospective review of prospectively recorded data held on all patients with a diagnosis of upper GI cancer made between January 2009 and December 2015. Only those patients who had both a PET-CT and EUS with FNA sampling of a mediastinal node distant from the primary tumour were included. Using a positive EUS-FNA result as the gold standard for lymph node involvement, the sensitivity, specificity, positive and negative predictive values(PPV and NPV) and accuracy of PET-CT in the staging of mediastinal lymph nodes were calculated. The impact on therapeutic strategy of adding EUS-FNA to PET-CT was assessed.RESULTS One hundred and twenty one patients were included. Sixty nine patients had a diagnosis of oesophageal adenocarcinoma(Thirty one of whom were junctional), forty eight had oesophageal squamous cell carcinoma and four had gastric adenocarcinoma. The FNA results were inadequate in eleven cases and the PET-CT findings were indeterminate in two cases, therefore thirteen patients(10.7%) were excluded from further analysis. There was concordance between PET-CT and EUS-FNA findings in seventy one of the remaining one hundred and eight patients(65.7%). The sensitivity, specificity, PPV and NPV values of PET-CT were 92.5%, 50%, 52.1% and 91.9% respectively. There was discordance between PET-CT and EUS-FNA findings in thirty seven out of one hundred and eight patients(34.3%). MDT discussion led to a radical treatment pathway in twenty seven of these cases, after the final tumour stage was altered as a direct consequence of the EUS-FNA findings. Of these patients, fourteen(51.9%) experienced clinical remission of a median of nine months(range three to forty two months). CONCLUSION EUS-FNA leads to altered staging of upper GI cancer, resulting in more patients receiving radical treatment that would have been the case using PET-CT staging alone.

Polyarteritis nodosa presenting as leg pain with resolution of positron emission tomography-images:A case report

BACKGROUND Although fluorodeoxyglucose-positron emission tomography/computed tomography(FDG-PET/CT)is widely used for diagnosis and follow-up of large sized vessel vasculitis,it is still not widely used for small to medium sized vessel vasculitis.CASE SUMMARY This is the case of a 68-year-old male who presented at the emergency department complaining of fever,myalgia,and bilateral leg pain of over two weeks duration,with elevated levels of C-reactive protein.He was subsequently admitted and despite the absence of clinically significant findings,the patient continued to exhibit recurrent fever.A fever of unknown origin workup,which included imaging studies using FDG-PET/CT,revealed vasculitis involving small to medium-sized vessels of both lower extremities,demonstrated by linear hypermetabolism throughout the leg muscles.The patient was treated with methylprednisolone and methotrexate after diagnosis leading to the gradual resolution of the patient’s symptoms.Three weeks later,a follow-up FDGPET/CT was performed.Previously hypermetabolic vessels were markedly improved.CONCLUSION Our case report demonstrated that FDG-PET/CT has tremendous potential to detect medium-sized vessel inflammation;it can also play a crucial role in prognosticating outcomes and monitoring therapeutic efficacy.

Rest Thallium-201/Stress Technetium-99m Sestamibi Dual-Isotope Myocardial Perfusion Single-Photon Emission Computed Tomography in Detecting of Chronic Coronary Artery Disease

To investigate diagnostic accuracy of 2-hour protocol of rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion SPECT in chronic coronary artery disease. Sixty-seven patients with suspected CAD were enrolled in the prospective study. All patients underwent myocardial perfusion scintigraphy in SPECT with dual isotopes of T1-201 and dipyridamole stress Tc-99m sestamibi. Rest and stress imaging protocol were performed in 2 hours by dose of 3 mCi TI-201 and 25 mCi Tc-99m sestamibi. The acquisition parameters includes LEHR collimator, energy peak of 72 and 167 keV for T1-201 and 140 keV for Tc-99m, 180-degree rotation from RAO to LPO, matrix size 64x64, and 25second/frame/64 frames. The 20-segment model of left ventricle was used in automatic quantitation software. Coronary angiography was used as gold standard. CAD was defined as 50% of lumen stenosis on coronary angiography. Rest TI-201/stress tc-99m sestamibi dual-isotope SPECT demonstrated a sensitivity of 94.59% and specificity of 70%, positive predictive value of 79.54% and negative predictive value of 91.3% in detection of coronary artery disease. Sensitivity and specificity for detecting multi-vessel coronary artery disease were 82.75% and 81.57% for the left anterior descending, 77.77% and 91.83% for left circumflex and 94.11% and 82% for right coronary artery. 2-hour protocol of rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion SPECT has high sensitivity, specificity, positive predictive value and negative predictive value in detecting chronic coronary artery disease with greater than 50% stenosis assessed by coronary angiography Moreover, this imaging protocol gives high imaging quality, time-saving and convenience.

Rapid progress of an iris metastasis from esophageal cancer:a case report and review of literature

This case report details a rare instance of rapid iris metastasis from esophageal cancer in a 59-year-old man.A literature review was conducted to explore recent advances in detecting,diagnosing,and treating intraocular metastatic malignancies.Positron emission tomographycomputed tomography played a crucial role in identifying primary sites and systemic metastases.Local treatment combined with systemic therapy effectively reduced tumor size,preserved useful vision,and improved the patient’s survival rate.A comparison was made of the characteristics of iris metastases from esophageal cancer and lung cancer,including age,gender,tumor characteristics,and treatment.The challenges associated with diagnosis and treatment are discussed,highlighting the implications for clinical practice.

Multimodal imaging in the diagnosis of bone giant cell tumors:A retrospective study

BACKGROUND Giant cell tumor of bone is a locally aggressive and rarely metastasizing tumor,and also a potential malignant tumor that may develop into a primary malignant giant cell tumor.AIM To evaluate the role of multimodal imaging in the diagnosis of giant cell tumors of bone.METHODS The data of 32 patients with giant cell tumor of bone confirmed by core-needle biopsy or surgical pathology at our hospital between March 2018 and March 2023 were retrospectively selected.All the patients with giant cell tumors of the bone were examined by X-ray,computed tomography(CT)and magnetic resonance imaging(MRI),and 7 of them were examined by positron emission tomography(PET)-CT.RESULTS X-ray imaging can provide overall information on giant cell tumor lesions.CT and MRI can reveal the characteristics of the internal structure of the tumor as well as the adjacent relationships of the tumor,and these methods have unique advantages for diagnosing tumors and determining the scope of surgery.PET-CT can detect small lesions and is highly valuable for identifying benign and malignant tumors to aid in the early diagnosis of metastasis.CONCLUSION Multimodal imaging plays an important role in the diagnosis of giant cell tumor of bone and can provide a reference for the treatment of giant cell tumors.

Incidence of exclusive extrapelvic skeletal metastasis in prostate carcinoma on bone scintigraphy

BACKGROUND Bone is one of the common sites of metastasis from prostate carcinoma.Bone scintigraphy(BS)is one of the most sensitive imaging modalities currently used for bone metastatic work-up.Skeletal metastasis in prostate carcinoma commonly involves pelvic bones but rarely involves extrapelvic-extraspinal sites.AIM To retrospectively analyze the BS data to determine the pattern of skeletal metastases in the prostate carcinoma.METHODS This retrospective observational study involves patients with biopsy-proven prostate carcinoma referred for BS for staging assessment.Patients with abnormal BS were evaluated for the pattern of skeletal involvement and data were pre-sented in descriptive format in the form of percentages.RESULTS A total of 150 patients with biopsy-proven prostate cancer who were referred for staging were included in the study.Thirteen of 150 patients(8.67%)had no abnormal uptake on planar images,ruling out metastatic disease.Twenty-four patients(16%)had heterogeneous uptake in the spine with distribution charac-teristic of degenerative disease and no scan pattern of metastatic disease.Thirty patients(20%)had multifocal uptake involving both pelvic and extra pelvic bones on planar images typical for skeletal metastasis and were considered metastatic.Eighty-three out of 150 patients(55.3%)had increased tracer uptake,which was indeterminate,thus,single photon emission computed tomography-computed tomography(SPECT-CT)was acquired,which showed 51 with metastatic disease,31 benign lesions,and one indeterminate finding.Seven of 150 patients had exclusive pelvic bone uptake,which was found to be metastatic in 4/7 patients in SPECT-CT.Fifty six out of 150 patients showed exclusive extrapelvic tracer uptake,of which only 3 had vertebral metastatic disease.None of the patients with increased uptake exclusively in the extrapelvic-extraspinal location was metastatic.CONCLUSION The incidence of exclusive extrapelvic skeletal metastatic disease in prostate carcinoma is 2%(excluding one patient with indeterminate findings).Further,none of the patients in the current study had exclusive extrapelvic-extraspinal metastasis.Thus,exclusive extrapelvic-extraspinal focal abnormality on planar BS carries a very low probability of metastatic disease and hence,further imaging or SPECT-CT can be safely avoided in such cases.

Role of molecular imaging in prognosis,diagnosis,and treatment of gastrointestinal cancers:An update on new therapeutic methods

One of the leading causes of cancer-related death is gastrointestinal cancer,which has a significant morbidity and mortality rate.Although preoperative risk assessment is essential for directing patient care,its biological behavior cannot be accurately predicted by conventional imaging investigations.Potential pathophysiological information in anatomical imaging that cannot be visually identified can now be converted into high-dimensional quantitative image features thanks to the developing discipline of molecular imaging.In order to enable molecular tissue profile in vivo,molecular imaging has most recently been utilized to phenotype the expression of single receptors and targets of biological therapy.It is expected that molecular imaging will become increasingly important in the near future,driven by the expanding range of biological therapies for cancer.With this live molecular fingerprinting,molecular imaging can be utilized to drive expression-tailored customized therapy.The technical aspects of molecular imaging are first briefly discussed in this review,followed by an examination of the most recent research on the diagnosis,prognosis,and potential future clinical methods of molecular imaging for GI tract malignancies.

^(99m)Tc-MIBI SPECT/CT显像诊断原发性甲状旁腺功能亢进症的价值

目的·评价^(99m)锝-甲氧基异丁基异腈(^(99m)Tc-MIBI)单光子发射型计算机断层显像/计算机断层扫描(SPECT/CT)对原发性甲状旁腺功能亢进症(PHPT)的诊断价值和优势。方法·系统回顾为诊断PHPT而行^(99m)Tc-MIBI SPECT/CT显像的249例患者的临床资料,以术后病理诊断及临床随访为最终结果,与同期颈部超声、血液指标检查(根据WHO制订的诊断标准需同时满足高甲状旁腺激素、高血钙)及双时相平面显像(静脉注射^(99m)Tc-MIBI 740 MBq后行颈胸部30 min及120 min的早期和延迟双时相静态平面采集)结果对比。结果·249例患者中,^(99m)Tc-MIBI SPECT/CT显像诊断PHPT的灵敏度、特异度、阳性预测值、阴性预测值及准确率分别为89.9%、88.1%、90.4%、85.0%、88.0%;颈部超声分别为82.7%、57.8%、74.3%、69.3%、72.6%;血液指标分别为91.4%、82.6%、87.1%、80.4%、87.6%;平面显像分别为77.9%、89.0%、90.1%、75.8%、82.7%。结论·^(99m)Tc-MIBI SPECT/CT显像诊断PHPT有较大的价值,综合临床价值高于颈部超声及^(99m)Tc-MIBI双时相平面,且能准确定位病灶位置,对手术具有很好的指导意义。

食管癌放射治疗技术的进展

同步放化疗和手术是食管癌的主要治疗模式。不断发展的现代放疗手段的目标是通过改进GTV、CTV勾画(基于PET的计划设计),减少分次间(影像引导放疗手段,如Varian的Trilogy、Elekta的Synergy、Siemens的Artiste、Tomotherapy)和分次内(4DCT成像和呼吸门控)的器官运动,实现最佳的剂量分布(调强放疗和质子治疗),在最大可能提高治疗增益比的前提下,使疗后并发症的发生率降至最低。尽管食管癌靶区剂量递增的概念一直存在争议,但通过现代放疗技术可降低放疗相关毒性反应,从而为提高食管癌放疗的临床结果打下坚实的基础。本文围绕PET/CT在食管癌放疗计划设计中的作用、调强适形放射治疗,断层放疗(Tomotherapy),图像引导放疗(IGRT)、四维CT和呼吸门控技术和质子放疗对近年来食管癌放疗技术的发展进行了概述。指出,尽管PET/CT在放疗计划制定中的应用越来越多,由于目前仍缺乏足够的支撑数据,在放疗计划制定过程中应用PET或PET/CT应持谨慎态度。在今后临床实践中可通过进一步应用和研究新技术和新方法以尽可能提高食管癌和胃食管结合部肿瘤的放疗效果。

核素心肌灌注显像在心肌桥中的应用价值

目的:探讨运动-静息心肌灌注显像在心肌桥-壁冠状动脉患者中的临床应用价值。方法:回顾性分析36例经冠状动脉CTA发现心肌桥-壁冠状动脉患者的心肌灌注图像,分析心肌灌注图像结果与临床症状、壁冠状动脉长度、心肌桥厚度及壁冠状动脉近远端形态之间的关系。利用χ2检验比较不同壁冠状动脉长度、不同心肌桥厚度及不同壁冠状动脉近远端形态所引起的心肌缺血情况是否有差异。结果:(1)36例患者中有临床症状者22例,出现心肌灌注缺血26例。(2)壁冠状动脉<10mm者7例,出现心肌灌注缺血2例(2/7,28.57%);10~20mm者17例,出现心肌灌注缺血13例(13/17,76.47%);>20mm者12例,出现心肌灌注缺血11例(11/12,91.66%)。(3)心肌桥厚度<1mm者5例,未出现心肌灌注缺血;1~2mm者14例,出现心肌灌注缺血10例(10/14,71.42%);>2mm者17例,出现心肌灌注缺血16例(16/17,94.11%)。(4)血管平滑者12例,出现心肌灌注缺血5例(5/12,41.66%);一侧成角组15例,出现心肌灌注缺血13例(13/15,86.66%);两侧成角组9例,出现心肌灌注缺血8例(8/9,88.88%)。结论:(1)仅依靠是否有临床症状对心肌桥-壁冠状动脉者是否进行进一步检查和治疗是不全面的,会遗漏一部分无症状的患者。(2)壁冠状动脉的长度、心肌桥的厚度及壁冠状动脉近远端血管形态均会对血流灌注造成影响,灌注结果与壁冠状动脉的长度、心肌桥的厚度及壁冠状动脉近远端血管形态呈正相关。

质子和重离子治疗在线监测成像技术的研究进展

不同于传统的高能电子线和光子线治疗,质子/重离子治疗利用重带电粒子与物质作用的布拉格曲线特性,将主要能量沉积在癌变组织上,从而最大限度地保护正常组织和器官。由于质子/重离子在治疗过程中的射程和剂量存在不确定性,因而对其射程和剂量的监测和验证尤为重要。治疗过程中质子/重离子与组织相互作用能够释放出正电子和瞬发γ光子。对这些粒子进行探测成像可实时反映质子/重离子的能量沉积情况。目前在线监测成像技术尚处在研究和初步临床试验阶段,其中主要的3种技术包括:in-beam PET、准直单光子成像和康普顿散射成像。本文介绍这3种技术的原理、优缺点和研究进展,并对质子/重离子治疗在线监测成像技术的发展方向进行展望。

用于医学诊断和治疗的质子回旋加速器

在许多医院都安装了生产短寿命放射性同位素的回旋加速器 ,但用于质子治疗的回旋加速器还处于起步阶段。质子治疗可以达到精确的幅照剂量分布 ,质子能量决定了穿透深度 ,因而产生的能量释放点可以精确控制 ,技术先进。由于质子束传播的线形度好 ,引起的横向二次散射小 ,肿瘤前端的健康组织接受的剂量很小 ,在其周围和之后的组织几乎就没有照射剂量 ,因此质子束治疗是一种非常有效的方法。束流传输到治疗房间的效率 ,束流的能量控制、强度及位置的稳定性 ,快速而精确的改变束流参数来满足临床需要等 ,都是关键。开发安装于医院的并可满足病人实际需要的质子治疗回旋加速器 ,包括束流输运系统和一系列的控制系统都相当复杂 ,文章提出了用于该目的的概念框图和建议。

辅助检查对28例癫痫患者病灶定位探讨

目的:分析癫痫患者视频脑电图(VEEG)、磁共振成像(MRI)及单光子发射计算机断层成像/X线计算机断层成像复合系统(SPECT/CT)结果,探讨辅助检查工作定位的应用价值。方法:入组患者均行VEEG、MRI及SPECT/CT检查,比较三者对致痫灶的术前定位准确性。结果:SPECT/CT和VEEG的阳性率均高于MRI(P<0.05),SPECT/CT、MRI病灶准确定位率明显高于VEEG(P<0.05)。结论:SPECT/CT对癫痫患者早期发现致痫灶具有独特优势。

三维酰胺质子转移成像鉴别前列腺癌伴骨转移与不伴骨转移的可行性研究

目的探讨三维酰胺质子转移(3D amide proton transfer,3D-APT)成像鉴别前列腺癌(prostate cancer,PCa)伴骨转移与不伴骨转移的价值。材料与方法回顾性分析2019年4月至2022年8月于我院经病理证实的62例PCa病例,根据同位素发射计算机辅助断层显像(emission computed tomography,ECT)结果分为两组:PCa伴骨转移组(21例)和PCa不伴骨转移组(41例)。所有患者在3.0 T MR扫描仪上进行图像扫描,扫描序列包括T2加权成像(T2 weighted imaging,T2WI)、扩散加权成像(diffusion weighted imaging,DWI)及3D-APT。由两名观察者采用双盲法进行数据测量,根据T2WI和DWI图像确定病灶,在3D-APT和DWI融合图像上病灶显示最大层面手动勾画圆形感兴趣区(region of interest,ROI)进行APT值测量。采用组内相关系数(intra-class correlation coefficient,ICC)检验两名观察者之间APT值的测量一致性。采用两独立样本t检验比较两组病例APT值的差异。采用受试者工作特征(receiver operating characteristic,ROC)曲线及其曲线下面积(area under the curve,AUC)来评估APT值对PCa是否伴骨转移的鉴别诊断效能。结果两名观察者APT测量结果一致性良好(ICC>0.75)。PCa伴骨转移组的APT值(2.76%±0.44%)高于PCa不伴骨转移组(2.26%±0.64%),差异有统计学意义(P<0.05)。APT值诊断PCa伴有骨转移的AUC为0.766。当APT值>2.50%时,其诊断PCa伴有骨转移的敏感度和特异度分别为71.43%和70.73%。结论本研究首次采用3D-APT成像技术来鉴别PCa伴骨转移与不伴骨转移,伴有骨转移的PCa患者病变组织的APT值要显著高于无骨转移的PCa患者,且APT值诊断PCa伴有骨转移具有较高的敏感度和特异度;因此,APT成像可作为一种潜在的、无创可靠的影像方法来预测PCa的侵袭性。

Technological advances in radiotherapy for esophageal cancer

Radiotherapy with concurrent chemotherapy and surgery represent the main treatment modalities in esophageal cancer.The goal of modern radiotherapy approaches,based on recent technological advances,is to minimize post-treatment complications by improving the gross tumor volume definition (positron emission tomography-based planning),reducing interfraction motion (image-guided radiotherapy) and intrafraction motion (respiratory-gated radiotherapy),and by better dose delivery to the precisely defined planning target volume (intensity-modulated radiotherapy and proton therapy).Reduction of radiotherapy-related toxicity is fundamental to the improvement of clinical results in esophageal cancer,although the dose escalation concept is controversial.