Residency training for diagnostic imaging physicists should be expanded to include nuclear medicine physics.

The American Board of Radiology offers certification in three specialties of medical physics: Therapeutic Medical Physics, Diagnostic Medical Physics, and Nuclear Medical Physics. Of these specialties, medical nuclear physics has the fewest active diplomates, only a few hundred. The diagnostic medical physics specialty certification incudes a variety of modalities (ultrasound, radiography, computed tomography, and magnetic resonance imaging) yet does not address nuclear medicine imaging or therapy. This separation dates to the beginning of the ABR certification process for medical physicists in 1947; originally there were three certificates available: X-ray and Radium Physics, Medical Nuclear Physics and, as combination of these two, Radiological Physics. Over the span of 75 years since the Medical Nuclear Physics certification was created, much has changed in the scope and proliferation of the nuclear medicine endeavor and the question arises as to the need for change in the preparation process for medical physicists in the field. I offer thanks to our contributors and note that they are writing in the classic style of a debate, the opinions that they argue may or may not reflect their personal views.

A Framework for Patient-Centered Pathways of Care for Radiopharmaceutical Therapy: An ASTRO Consensus Document.

Radiopharmaceutical therapy (RPT) is an area of projected growth and importance with several agents in clinical use, new agents in late-phase clinical trials, and many others under testing and development. This article proposes a framework for developing pathways of care that can be broadly applied to all RPTs, representing the current status of RPT. It suggests foundational elements for many pathways of care for patients with cancer and concludes with areas in active development and the future horizon for RPT treatment centers. Developing a framework for patient-centered pathways of care is a critical step in establishing RPT as standard therapy for patients with a diverse spectrum of cancers. This expected increase in RPT treatment options will affect a much larger population of patients with complex cancer. It will also require enhanced coordination and collaboration among appropriately qualified personnel with diverse expertise in image acquisition, image interpretation, quantitative imaging, dosimetry calculation, radiation quality assurance and safety as well as oncology care and RPT-induced sequelae and response assessment. The essential role of this evolving RPT care team within multidisciplinary oncology care is a cornerstone of this framework for a patient-centered pathway of care for RPT. Given the status of current RPT practice and the horizon for future applications, this patient-centered pathway of care guidance is timely and should help inform future clinical RPT practice paradigms. A task force was recruited from the Theranostic Working Group of the American Society for Radiation Oncology (ASTRO) in May 2019 with equal representation from the nuclear medicine community. The task force expanded on a framework that was originally conceived by the Working Group for patient-centered care. This framework was developed to incorporate the strengths of both radiation oncologists and nuclear medicine physicians. The manuscript was then developed by the task force and posted on the ASTRO website for a 6-week public comment period ending in July 2020. Comments were adjudicated, and the draft was sent to external organizations for potential endorsement. This document was sent to the ASTRO Board of Directors in October 2020 for approval.

AAPM Medical Physics Practice Guideline 8.a.: Linear accelerator performance tests.

PURPOSE: The purpose of this guideline is to provide a list of critical performance tests in order to assist the Qualified Medical Physicist (QMP) in establishing and maintaining a safe and effective quality assurance (QA) program. The performance tests on a linear accelerator (linac) should be selected to fit the clinical patterns of use of the accelerator and care should be given to perform tests which are relevant to detecting errors related to the specific use of the accelerator. METHODS: A risk assessment was performed on tests from current task group reports on linac QA to highlight those tests that are most effective at maintaining safety and quality for the patient. Recommendations are made on the acquisition of reference or baseline data, the establishment of machine isocenter on a routine basis, basing performance tests on clinical use of the linac, working with vendors to establish QA tests and performing tests after maintenance. RESULTS: The recommended tests proposed in this guideline were chosen based on the results from the risk analysis and the consensus of the guideline's committee. The tests are grouped together by class of test (e.g., dosimetry, mechanical, etc.) and clinical parameter tested. Implementation notes are included for each test so that the QMP can understand the overall goal of each test. CONCLUSION: This guideline will assist the QMP in developing a comprehensive QA program for linacs in the external beam radiation therapy setting. The committee sought to prioritize tests by their implication on quality and patient safety. The QMP is ultimately responsible for implementing appropriate tests. In the spirit of the report from American Association of Physicists in Medicine Task Group 100, individual institutions are encouraged to analyze the risks involved in their own clinical practice and determine which performance tests are relevant in their own radiotherapy clinics.

Prevention of needle displacement in multifraction high-dose-rate prostate brachytherapy: A prospective volumetric analysis and technical considerations.

PURPOSE: We conducted a prospective study to evaluate needle displacements between prostate high-dose-rate (HDR) brachytherapy fractions and offer technical recommendations to help prevent displacements from the outset. METHODS AND MATERIALS: Planning computed tomography and verification computed tomography scans were obtained at 1-mm slice thickness and prospectively assessed for interfraction needle movement for each fraction of a 2-fraction HDR prostate boost. For both the planning and verification CTs, distances from each needle tip to the centroid of 3 implanted prostate gold seeds were measured. We determined the mean and range of the displacement distances. RESULTS: Thirty-three consecutive patients (66 fractions, 540 needle-pair positions for a total of 1080 needles) were evaluated for changes in the length between the needle tip and centroid displacement. Overall, only 0.2% of the needles had any change greater than 3.5 mm between the needle tip and centroid. The mean amount of displacement was 0.97 mm, with a standard deviation of 0.76 mm. Among the patients, no fraction had more than 1 needle with a variation greater than 3.0 mm. CONCLUSIONS: Needle displacements in HDR prostate brachytherapy have been reported by numerous institutions using various techniques. We report the first study to demonstrate needle displacement of less than 1 mm on average, and we describe our process of care surrounding the implantation.

CyberKnife radiosurgery for trigeminal neuralgia: unanticipated iatrogenic effect following successful treatment.

This case report of 74-year-old man with trigeminal neuralgia is presented to underscore the importance of evaluating the entire treatment plan, especially when delivering large doses where even a low percentage of the prescription dose can contribute a substantial dose to an unintended target. The patient was treated using the CyberKnife stereotactic radiosurgery system utilizing a nonisocentric beam treatment plan with a 5-mm fixed collimator generating 111 beams to deliver 6000 cGy to the 79% isodose line with a maximum dose of 7594 cGy to the target. Two weeks after treatment the patient's trigeminal neuralgia symptoms resolved; however, the patient developed oral mucositis due to the treatment. This case report reviews the cause of mucositis and makes recommendations on how to prevent unintended targets from receiving treatment.

Accelerated fractionation head and neck intensity-modulated radiation therapy and concurrent chemotherapy in the community setting: safety and efficacy considerations.

BACKGROUND: This article reviews our community cancer center's experience treating head and neck cancer primarily with accelerated fractionation intensity-modulated radiation therapy (IMRT), with or without concurrent chemotherapy, focusing on acute toxicity and efficacy. METHODS: Fifty-two patients treated with IMRT at the Penrose Cancer Center between 2002 and 2007 constitute the cohort. The majority (75%) received an accelerated, altered fractionation regimen, typically concomitant boost to 7200 cGy. Concurrent chemotherapy was delivered to 32 (62%). The median follow-up was 24 months. RESULTS: The 2-year actuarial rates of local control, regional control, and distant metastasis-free survival were 100%, 91%, and 94%, respectively. Relapse-free survival and overall survival at 2 years were 89% and 91%, respectively. Overall, 32 of 52 patients (62%) experienced at least 1 type of grade 3 or 4 acute toxicity. CONCLUSION: Accelerated fractionation IMRT, with or without chemotherapy, can be given safely and effectively in a community cancer center setting.

Factors associated with radiation-induced nausea and vomiting in head and neck cancer patients treated with intensity modulated radiation therapy.

BACKGROUND AND PURPOSE: To investigate factors associated with radiation-induced nausea and vomiting (RINV) in the setting of head and neck intensity modulated radiation therapy (IMRT). MATERIALS AND METHODS: Forty-three patients treated with IMRT for head and neck cancer between 2002 and 2007 comprise the cohort. The majority (79%) were treated with an accelerated altered fractionation scheme, and concurrent chemotherapy was delivered to 23. A retrospective review of factors associated with nausea was performed. RESULTS: Eighteen patients (42%) reported grade 1 acute nausea, and seven patients (16%) reported grade 2 nausea. Factors significant for grade 1-2 nausea on univariate analysis included dose to the dorsal vagal complex of the mid-medulla, younger age, use of a low neck field, and Amifostine use. Only young age retained significance on multivariate analysis. High-grade nausea was associated with use of Amifostine (p=0.003) and concurrent chemotherapy (p=0.015). CONCLUSIONS: In addition to previously recognized emetic factors, young age and radiation dose to the dorsal vagal complex of the brainstem may play a role in development of nausea during head and neck IMRT.

Low morbidity following high dose rate brachytherapy in the setting of prior transurethral prostate resection.

PURPOSE: We reviewed our single institution experience with high dose rate brachytherapy in patients who underwent prior transurethral prostate resection. MATERIALS AND METHODS: A total of 28 patients treated with high dose rate brachytherapy for prostate cancer at our institution between 2001 and 2006 were identified as having undergone prior transurethral prostate resection. All patients received high dose rate brachytherapy as a boost before or after conformal external beam radiation therapy to 4,500 cGy. Boost brachytherapy doses ranged from 1,600 to 1,900 cGy, given in 2 or 3 fractions. Changes in American Urological Association symptom scores were assessed. RESULTS: Dosimetric goals were adequately achieved in all patients with a median minimal dose to 90% of the prostate of 109% of the prescription dose (range 100% to 117%). The median volume receiving 100% of the prescribed dose was 95% (range 87.9% to 100%) Three patients (11%) required temporary urinary catheter placement for acute obstructive symptoms after brachytherapy. At a median followup of 2.5 years there was 1 case each of grade 1 rectal proctitis, grade 1 hemorrhage and grade 2 cystitis. Two patients had worsening of existing grade 1 urge incontinence to grade 2. No patient had a bulbourethral stricture requiring dilation or new onset incontinence. Patients with a higher baseline American Urological Association score demonstrated significantly improved scores over those with lower baseline scores (less than 15) at least 1 year after treatment. CONCLUSIONS: High dose rate brachytherapy with careful attention to dosimetry is a reasonable treatment option for patients who have undergone prior transurethral prostate resection with the expectation of low morbidity.