Evolution and Evaluation of a Structured Applied Physics Course for Radiation Oncology and Radiation Physics Trainees.

We sought to supplement medical physics textbook knowledge and clinical learning with case-based discussions. To our knowledge, this is the first report on a structured combined applied physics curriculum for radiation oncology (RO) and medical physics (MP) trainees. We reviewed our yearly applied physics course given from the years 2016-2021 inclusive. The number of applied physics trainees ranged from 7 to 14 per year (2-9 RO and 3-6 MP residents per year). Each session was taught by a pair of (RO and MP) faculty members. Twenty-nine case-based sessions were given yearly (2016 to 2019). Because of the COVID-19 pandemic restrictions, the course was shortened to 8 case-based sessions in 2020 and 2021. For the years 2016-2021, the mean and median teaching evaluation scores were 4.65 and 5, respectively (range 2-5), where 1 represents worse teaching quality and 5, the best teaching quality. For the year 2021, 2 questions relating to the video virtual format (implemented due to the covid-19 pandemic), revealed consistent high scores with the mean and median responses of 4.14 and 5, respectively (range 1-5). The results from the teaching evaluation scores indicate that the trainees highly valued the teaching sessions and teachers. Our experience indicates that a case-based applied physics course was delivered successfully with continued high teaching evaluation scores. A video virtual platform for an applied physics course could be useful, especially for small programs without a structured applied physics curriculum.

Observer variation in contouring gross tumor volume in patients with poorly defined non-small-cell lung tumors on CT: the impact of 18FDG-hybrid PET fusion.

PURPOSE: To quantify interobserver variation in gross tumor volume (GTV) localization using CT images for patients with non-small-cell lung carcinoma and poorly defined tumors on CT and to determine whether variability would be reduced if coregistered 2-[18F]fluoro-2-deoxy-d-glucose (FDG)-hybrid positron emission tomography (PET) with CT images were used. METHODS AND MATERIALS: Prospectively, 30 patients with non-small-cell lung carcinoma had CT and FDG-hybrid PET examinations in radiation treatment position on the same day. Images were coregistered using eight fiducial markers. Guidelines were established for contouring GTVs. Three radiation oncologists performed localization independently. The coefficient of variation was used to assess interobserver variability. RESULTS: The size of the GTV defined showed great variation among observers. The mean ratios of largest to smallest GTV were 2.31 and 1.56 for CT only and for CT/FDG coregistered data, respectively. The addition of PET reduced this ratio in 23 of 30 cases and increased it in 7. The mean coefficient of variation for GTV based on the combined modalities was significantly smaller (p < 0.01) than that for CT data only. CONCLUSIONS: High observer variability in CT-based definition of the GTV can occur. A more consistent definition of the GTV can often be obtained if coregistered FDG-hybrid PET images are used.

Comparing treatment outcomes of radiotherapy and surgery in locally advanced carcinoma of the larynx: a comparison limited to patients eligible for surgery.

PURPOSE: The use of radical radiotherapy and surgery for salvage (RRSS) in locally advanced squamous cell carcinoma (SCC) of the larynx is controversial. In the absence of randomized studies, it is unclear if RRSS can match the rates of locoregional control and survival reported for primary surgery in this setting. The aim of this study was to compare treatment outcomes of radiotherapy and surgery in comparable patients with CS III-IV SCC of the larynx. METHODS AND MATERIALS: Eighty-two patients with untreated T2N+M0 or T3T4NM0 SCC of the larynx were treated with a policy RRSS at the Toronto-Sunnybrook Regional Cancer Centre between June 1980 and December 1990. The medical records at presentation were reviewed independently by a panel of three surgical oncologists blinded as to treatment outcome to determine patient suitability for laryngectomy and neck dissection using eligibility criteria adopted by recent clinical trials. Treatment outcomes for surgery-eligible patients were compared to results of comparably staged patients in the surgical literature since 1980. RESULTS: Sixty-three patients (77%) were eligible for study. With a median follow-up of 3 years, radiotherapy controlled the primary in 8/20 evaluable glottic primaries and 21/41 evaluable supraglottic primaries. Forty-five percent of patients surviving 5 years retained a functional larynx. Sixteen of 29 relapsing patients were salvaged with surgery. Disease above the clavicles was controlled in 65% of T3T4N0N+ glottic primaries (compared to a published range of 53% to 79%) and 82% of T3N0 glottic primaries (compared to a published range of 69% to 84%). The 5-year overall survival of patients with T3T4 glottic cancer was 54% compared to a published range of 50% to 63%. The cause-specific survival (CSS) of patients with T3N0 glottic primaries (86% at 1 year and 73% at 2 years) was identical to the only published report of CSS in the surgical literature. CONCLUSION: A policy of RRSS offers a good chance of laryngeal conservation without compromising ultimate locoregional control or survival when compared to primary laryngectomy and neck dissection in patients with locally advanced carcinoma of the larynx meeting the surgical eligibility of clinical trials.

Advances in radiotherapy in the gynecologic malignancies.

We review, for their wider applicability, four advances in the radiotherapeutic management of the gynecologic malignancies. Attempts at improving upon results obtained with radiotherapy by the addition of chemotherapy have usually followed one of two temporal strategies: Sequential chemotherapy-radiotherapy (so-called neo-adjuvant chemotherapy), or chemotherapy given concurrently with radiotherapy. The pros and cons of both models are discussed. Recent work suggests that there is a differential response between the acutely reacting normal tissues, as well as tumor, and the late-reacting normal tissues, which is dependent upon the radiation fraction size. The rationale and some important clinical applications are reviewed. Advances in brachytherapy include the high dose rate treatment and the use of rigid templates to guide the accurate placement of the interstitial implant. The controversies surrounding these approaches require further study before the precise place of these techniques is known. Finally, in vulvar cancer, the addition of radiotherapy to surgery is being studied to permit less radical operations in early disease, and greater local tumor control in advanced disease.

Orbital nonchromaffin paraganglioma. A case report and review of the literature.

Nonchromaffin paraganglioma (NCP), also called glomus body tumor or chemodectoma, is rarely found in the orbit. The behavior of orbital nonchromaffin paraganglioma may potentially be more aggressive than in other head and neck locations. Diagnosis depends on electron microscopic demonstration of membrane-bound neurosecretory granules. Results of histopathologic study show a well-circumscribed lesion without a true capsule with alveolar or organoid arrangements of epithelioid cells within a reticulin framework with thin-walled blood vessels. Cells are polygonal with round or oval nuclei containing rare mitotic figures and pale-staining cytoplasm. Differential diagnosis includes alveolar soft-part sarcoma, alveolar rhabdomyosarcoma, neuroblastoma, carcinoid, and granular cell tumor. Of 29 previously reported cases of orbital NCP, 16 have been reclassified as alveolar soft-part sarcoma. The authors report a patient with an electron microscopically established orbital NCP, with the history of a contralateral glomus jugulare tumor irradiated 14 years previously.

Osteoradionecrosis of the mandible: a review.

Osteoradionecrosis (ORN) is a complex metabolic and tissue homeostatic deficiency created by radiation-induced tissue injury. Although infection was initially felt to play an important role in its pathogenesis, the role of microorganisms has been relegated to that of a contaminant. Trauma in some cases may provide a possible initiating factor for the process, or in the case of spontaneous ORN, the use of radioactive implants and the higher doses of radiation therapy as practised in the megavoltage era, may have an influence. The role of prevention cannot be over-emphasized. Dental evaluation is an important part of the initial patient assessment. Preservation of good or average teeth is recommended with subsequent regular follow-up and dental care. Post-treatment dental extraction should be minimized and delayed if possible until at least nine-12 months after completion of radiation therapy. Management of ORN requires assessment of the extent, both clinically and radiologically. Conservative management is recommended unless the disease is advanced or progressive. Radiologic evidence of fracture requires surgery. Modern surgical techniques offer satisfactory reconstruction. The role of hyperbaric oxygen remains controversial and limited to centers where hyperbaric techniques exist. The treatment is complex and time-consuming and results are confounded by the concurrent use of local antiseptic/antibiotic measures and surgery.