Diagnostic CT-Enabled Planning (DART): Results of a Randomized Trial in Palliative Radiation Therapy.

PURPOSE: Using diagnostic computed tomography (dCT) scans instead of CT simulation (CTsim) scans can increase departmental efficiency and reduce patient burden. The goal of the DART trial was to assess the efficacy and acceptability of dCT-based planning workflows with a focus on patient experiences, plan deliverability and adequacy of target coverage, and workflows. METHODS AND MATERIALS: Patients undergoing same-day CTsim and treatment for palliative radiation therapy to thoracic, abdominopelvic, or proximal limb targets with a recent dCT (within 28 days) in a reproducible position were eligible. After stratifying by target type (bone or soft tissue vs. visceral), participants were randomized (1:2 ratio) between CTsim-based (CTsim arm) vs. dCT-based planning (dCT arm). The primary endpoint was time in center (TIC), defined as total time spent in the cancer center on first day of treatment, from first radiation department appointment to first fraction completion. Secondary endpoints included plan deliverability, adequacy of target coverage, and stakeholder acceptability. RESULTS: Thirty-three patients (42 treatment sites) were enrolled between June 2022 and April 2023. The median age was 72 (interquartile range [IQR]: 67-78), 73% were male, and the most common primary cancers were lung (33%), prostate (24%), and breast (12%). The most common dose and fractionations were 8 Gy in 1 and 20 Gy in 5 fractions (50% and 43% of plans, respectively). TIC was 4.7 ± 1.1 hours (mean ± SD) in the CTsim arm vs. 0.41 ± 0.14 hours in the dCT arm (P < .001). All dCT plans were deliverable. All plans in both arms were rated as "acceptable" (80% CTsim; 81% dCT) or "acceptable with minor deviation" (20% CTsim; 19% dCT). Patient perception of acceptability was similar in both arms with the exception of time burden, which was rated as "acceptable" by 50% in the CTsim arm vs. 90% in the dCT arm (P = .025). CONCLUSION: dCT-based radiation planning substantially reduced TIC without detriment in plan deliverability or quality and had a tangible impact on patient experience with reduced patient-reported time burden.

The Role of Post-Operative Radiotherapy for Non-Spine Bone Metastases (NSBMs).

Non-spine bone metastases (NSBMs) can cause significant morbidity and deterioration in the quality of life of cancer patients. This paper reviews the role of post-operative radiotherapy (PORT) in the management of NSBMs and provides suggestions for clinical practice based on the best available evidence. We identified six retrospective studies and several reviews that examined PORT for NSBMs. These studies suggest that PORT reduces local recurrence rates and provides effective pain relief. Based on the literature, PORT was typically delivered as 20 Gy in 5 fractions or 30 Gy in 10 fractions within 5 weeks of surgery. Complete coverage of the surgical hardware is an important consideration when designing an appropriate radiation plan and leads to improved local control. Furthermore, the integration of PORT in a multidisciplinary team with input from radiation oncologists and orthopedic surgeons is beneficial. A multimodal approach including PORT should be considered for an NSBM that requires surgery. However, phase III studies are needed to answer many remaining questions and optimize the management of NSBMs.

Predictors of pathologic fracture and local recurrence following stereotactic body radiation therapy to 505 non-spine bone metastases.

PURPOSE: Stereotactic Body Radiation Therapy (SBRT) is increasingly applied to treat non-spine bone metastases (NSBM) though data remains limited on this approach. In this retrospective study, we report outcomes and predictors of local failure (LF) and pathological fracture (PF) post-SBRT for NSBM using a mature single-institution database. METHODS: Patients with NSBM treated with SBRT between 2011 and 2021 were identified. The primary objective was to assess the rates of radiographic LF. Secondary objectives were to assess the rates of in-field PF, overall survival (OS), and late grade ≥ 3 toxicity. Competing risks analysis was used to assess rates of LF and PF. Univariable regression and multivariable regression (MVR) were performed to investigate predictors of LF and PF. RESULTS: A total of 373 patients with 505 NSBM were included in this study. Median follow-up was 26.5 months. The cumulative incidence of LF at 6, 12, and 24 months were 5.7%, 7.9%, and 12.6%, respectively. The cumulative incidence of PF at 6, 12, and 24 months were 3.8%, 6.1%, and 10.9%, respectively. Lytic NSBM (HR = 2.18; p < 0.01), a lower biologically effective dose (HR = 1.11 per 5 Gy10 decrease; p = 0.04), and a PTV ≥ 54 cc (HR = 4.32; p < 0.01) predicted for a higher risk of LF on MVR. Lytic NSBM (HR = 3.43; p < 0.01), mixed (lytic/sclerotic) lesions (HR = 2.70; p = 0.04), and rib metastases (HR = 2.68; p < 0.01) predicted for a higher risk of PF on MVR. CONCLUSION: SBRT is an effective modality to treat NSBM with high rates of radiographic local control with an acceptable rate of PF. We identify predictors of both LF and PF that can serve to inform practice and trial design.

Planning for the Effect of the SC.24 Trial on Spine Stereotactic Body Radiation Therapy Utilization at a Tertiary Cancer Center.

Purpose: The goal of this study was to assess the potential real-world effect of the recently reported SC.24 trial on spine stereotactic body radiation therapy (SBRT) utilization. We estimated the proportion of patients treated with conventional radiation therapy (CRT) who would have been eligible for spine SBRT per trial inclusion criteria and analyzed the potential estimated increased costs to our institution. Methods and Materials: This was a retrospective review of patients who received spine CRT at our institution between August and October 2020. Data abstracted included demographics, SC.24 eligibility criteria, provider-reported pain response, and survival. A cost analysis and time survey was performed using institutional and provincial data. Results: Of 73 patients reviewed, 24 patients (33%) were eligible. The most common exclusion factors included irradiation of ≥3 consecutive spinal segments (n = 32, 44%), Eastern Cooperative Oncology Group performance status >2 (n = 17, 23%), and symptomatic spinal cord compression (n = 13, 18%). Of eligible patients, the mean age was 68.92 years, median spinal instability in neoplasia score was 8 (interquartile range, 7-9), and median Eastern Cooperative Oncology Group performance status was 2 (interquartile range, 1-2). The most common primary cancer types among eligible patients were lung (n = 10) and breast (n = 4). The median survival of eligible patients was 10 months (95% confidence interval, 4 months to not reached) with 58% surviving longer than 3 months. Of patients who had subjective pain documented after CRT, 54% had at least some response. The cost of spine SBRT was estimated at CA$4764.80 compared with $3589.10 for CRT, and tasks for spine SBRT took roughly 3 times as long as those for CRT. Conclusions: One-third of patients who received palliative spine CRT met eligibility criteria for SC.24. This possible expanded indication for spine SBRT can have a substantial effect on resource utilization. These data may be useful in guiding resource planning at institutions looking to commence a spine SBRT program.

Exploring the Inner Lens: Examining Oncology Consultants' Use of Competency and Assessment Frameworks in Clinical Teaching Settings.

Medical education in oncology has adopted a competency-based medical education (CBME) approach in Canada. Oncologist competencies are arranged within assessment frameworks, but it is unknown whether oncologists routinely use assessment frameworks when determining what to teach oncology trainees. Understanding oncologists' actual approaches to assessment and teaching as a form of enacted CBME could inform and focus faculty development efforts. Using a participatory action research approach, oncology faculty were interviewed regarding their teaching practices and use of assessment frameworks. Faculty suggestions regarding challenges in setting teaching goals and completing assessment within the CBME paradigm were solicited. Furthermore, teaching objectives developed by faculty in-house were assessed regarding the domains of competence targeted. Thirty-one of the 40 faculty members in the Department of Oncology, Western University, agreed to participate. Trainee factors (training level, areas of interest), faculty personal values and experience, the teaching setting, and some components of frameworks (medical expert, communicator, advocate, and professional) were articulated as determinants of teaching goals. Of the 1117 in-house objectives reviewed, 76% focused on the medical role. Faculty held widely disparate views on assessment framework features which would enable teaching and assessment. Oncology faculty members used a multifaceted approach to determine what to teach trainees. This approach contains elements both of the conventional apprenticeship models under which many faculty members themselves were trained and of the CBME paradigm. Future research should focus on exploring ways to resolve the tension between established individual teaching approaches and nationally standardized competency frameworks which are being implemented.

DART: diagnostic-CT-enabled planning: a randomized trial in palliative radiation therapy (study protocol).

BACKGROUND: Palliative radiotherapy (PRT) is an effective treatment for managing symptoms of advanced cancer. At least half of all radiation treatments are delivered with palliative intent, aimed at relieving symptoms, such as pain or shortness of breath. Symptomatic patients must receive PRT quickly, therefore expeditious treatment planning is essential. Standard radiation planning requires a dedicated CT scan acquired at the cancer centre, called a 'CT simulation', which facilitates treatment planning (i.e. tumor delineation, placement of radiation beams and dose calculation). However, the CT simulation process creates a bottleneck and often leads to delays in starting treatment. Other researchers have indicated that CT simulation can be replaced by the use of standard diagnostic CT scans for target delineation and planning, which are normally acquired through the radiology department as part of standard patient workup. The goals of this feasibility study are to assess the efficacy, acceptability and scalability of diagnostic-CT-enabled planning, compared to conventional CT simulation planning, for patients receiving PRT to bone, soft tissue and lung disease. METHODS: This is a randomized, phase II study, with 33 PRT patients to be randomized in a 1:2 ratio between conventional CT simulation (Arm 1), and the diagnostic CT enabled planning workflow (Arm 2). Patients will be stratified by treatment target volume (bone and soft tissue metastasis vs. primary or metastatic intrathoracic disease targets). The primary endpoint is the amount of time the patient spends at the cancer centre. Secondary endpoints include efficacy (rate of plan deliverability and rate of plan acceptability on blinded dose distribution review), stakeholder acceptability (based on patient and clinician perception of acceptability questionnaires) and scalability. DISCUSSION: This study will investigate the efficacy, acceptability and scalability of a "sim-free" PRT pathway compared to conventional CT simulation. The workflow may provide opportunity for resource optimization by using pre-existing diagnostic imaging and requires minimal investment due to its similarity to current PRT models. It also offers potential benefit to patients by eliminating an imaging procedure, reducing the amount of time spent at the cancer centre, and expediting time to treatment. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT05233904. Date of registration: February 10, 2022; current version: 1.4 on April 29, 2022.

Stereotactic Body Radiation Therapy for Metastases in Long Bones.

PURPOSE: To evaluate the cumulative incidence of fracture and local failure and associated risk factors after stereotactic body radiation therapy (SBRT) for long bone metastases. METHODS AND MATERIALS: Data from 111 patients with 114 metastases in the femur, humerus, and tibia treated with SBRT in 7 international centers between October 2011 and February 2021 were retrospectively reviewed and analyzed using a competing risk regression model. RESULTS: The median follow-up was 21 months (range, 6-91 months). All but 1 patient had a Karnofsky performance status ≥70. There were 84 femur (73.7%), 26 humerus (22.8%), and 4 tibia (3.5%) metastases from prostate (45 [39.5%]), breast (22 [19.3%]), lung (15 [13.2%]), kidney (13 [11.4%]), and other (19 [16.6%]) malignancies. Oligometastases accounted for 74.8% of metastases and 28.1% were osteolytic. The most common total doses were 30 to 50 Gy in 5 daily fractions (50.9%). Eight fractures (5 in the femur, 2 in the tibia, and 1 in the humerus) were observed with a median time to fracture of 12 months (range, 0.8-33 months). In 6 out of 8 patients, fracture was not associated with local failure. The cumulative incidence of fracture was 3.5%, 6.1%, and 9.8% at 1, 2, and 3 years, respectively. The cumulative incidence of local failure (9/110 metastases with imaging follow-up) was 5.7%, 7.2%, and 13.5% at 1, 2, and 3 years, respectively. On multivariate analysis, extraosseous disease extension was significantly associated with fracture (P = .001; subhazard ratio, 10.8; 95% confidence interval, 2.8-41.9) and local failure (P = .02; subhazard ratio, 7.9; 95% confidence interval, 1.4-44.7). CONCLUSIONS: SBRT for metastases in long bones achieved high rates of durable local metastasis control without an increased risk of fracture. Similar to spine SBRT, patients with extraosseous disease extension are at higher risk of local failure and fracture.

International Multi-institutional Patterns of Contouring Practice and Clinical Target Volume Recommendations for Stereotactic Body Radiation Therapy for Non-Spine Bone Metastases.

PURPOSE: Despite the increasing use of stereotactic body radiation therapy for non-spine bone metastases (NSBM), there is no established standard for target delineation. The objective of this study was to provide consensus recommendations on clinical target volume (CTV) delineation based on international expert contours. METHODS AND MATERIALS: Eleven cases of NSBM were contoured by 9 international radiation oncologists. For each case, the gross tumor volume was provided on the simulation computed tomography scans with accompanying magnetic resonance imaging. Participants contoured the CTV and completed a clinical survey. Agreement between CTV contours were analyzed with simultaneous truth and performance level estimation using the kappa coefficient and the Dice similarity coefficient (DSC) and summarized to establish contouring recommendations. A direction-dependent analysis was applied to the consensus contours to quantify margins. RESULTS: All CTV contours were completed. Six participants used a single-dose level, whereas 3 used a 2-dose level simultaneous integrated boost (SIB) technique. For the SIB cases, the largest volume receiving a stereotactic body radiation therapy (SBRT) dose was used for contour analysis. There was substantial agreement between contours across cases with a mean kappa of 0.72 (mean sensitivity 0.85, mean specificity 0.97). The mean DSC value was 0.77 (range, 0.67-0.87). Consensus CTV contouring recommendations were (1) an intraosseous CTV margin of 5 to 10 mm should be strongly considered within contiguous bone; (2) an extraosseous margin of 5 to 10 mm should be strongly considered where there is soft tissue disease or cortical bone disruption; (3) CTVs should be manually cropped to respect anatomic barriers to spread (eg, peritoneal cavity, pleura, uninvolved joint space and cortical bone). CONCLUSIONS: CTV contouring recommendations for NSBM-SBRT were established based on analysis of international expert consensus contours with a high level of agreement. These principles may provide guidance to treating physicians and inform future study until prospective clinical data can provide further refinement.

Remote Contouring and Virtual Review during the COVID-19 Pandemic (RECOVR-COVID19): Results of a Quality Improvement Initiative for Virtual Resident Training in Radiation Oncology.

The need to minimize in-person interactions during the COVID-19 pandemic has led to fewer clinical learning opportunities for trainees. With ongoing utilization of virtual platforms for resident education, efforts to maximize their value are essential. Herein we describe a resident-led quality improvement initiative to optimize remote contouring and virtual contour review. From April to June 2020, radiation oncology (RO) residents at our institution were assigned modified duties. We implemented a program to source and assign cases to residents for remote contouring and to promote and optimize virtual contour review. Resident-perceived educational value was prospectively collected and analyzed. All nine RO residents at our institution (PGY1-5) participated, and 97 cases were contoured during the evaluation period. Introduction of the Remote Contouring and Virtual Review (RECOVR) program coincided with a significant increase in mean cases contoured per week, from 5.5 to 17.3 (p = 0.015), and an increased proportion of cases receiving virtual review, from 14.8% to 58.6% (p < 0.001). Residents reported that the value of immediate feedback during virtual review was similar to that of in-person review (4.6 ± 0.1 vs. 4.5 ± 0.2, p = 0.803) and significantly higher than feedback received post hoc (e.g., email; 3.6 ± 0.2, p < 0.001). The implementation of a remote process for contour review led to significant increases in contouring, and virtual contour review was rated as highly as in-person interactions. Our findings provide a data-driven rationale and framework for integrating remote contouring and virtual review into competency-based medical education.

A Framework for Assuring the Safety, Training, Evaluation, and Wellness of Radiation Oncology Residents During the COVID-19 Pandemic (ASTEROiD-COVID19).

As the coronavirus disease 2019 (COVID-19) pandemic continues to disrupt nearly all facets of daily life, residency programs must ensure the safety and wellness of their residents while maintaining a commitment to their training and advancement. In addition to standard clinical training, radiation oncology residency programs integrate highly specialized elements specific to the delivery of radiation therapy. Few publications have addressed the significant effects of the pandemic on medical training and even fewer have addressed concerns specific to radiation oncology. We report our experience developing a resident-led adaptation of our training program in response to the COVID-19 pandemic with the aim of assisting other programs to meet this challenge.

Method of computing direction-dependent margins for the development of consensus contouring guidelines.

BACKGROUND: Clinical target volume (CTV) contouring guidelines are frequently developed through studies in which experts contour the CTV for a representative set of cases for a given treatment site and the consensus CTVs are analyzed to generate margin recommendations. Measures of interobserver variability are used to quantify agreement between experts. In cases where an isotropic margin is not appropriate, however, there is no standard method to compute margins in specified directions that represent possible routes of tumor spread. Moreover, interobserver variability metrics are often measures of volume overlap that do not account for the dependence of disagreement on direction. To aid in the development of consensus contouring guidelines, this study demonstrates a novel method of quantifying CTV margins and interobserver variability in clinician-specified directions. METHODS: The proposed algorithm was applied to 11 cases of non-spine bone metastases to compute the consensus CTV margin in each direction of intraosseous and extraosseous disease. The median over all cases for each route of spread yielded the recommended margins. The disagreement between experts on the CTV margin was quantified by computing the median of the coefficients of variation for intraosseous and extraosseous margins. RESULTS: The recommended intraosseous and extraosseous margins were 7.0 mm and 8.0 mm, respectively. The median coefficient of variation quantifying the margin disagreement between experts was 0.59 and 0.48 for intraosseous and extraosseous disease. CONCLUSIONS: The proposed algorithm permits the generation of margin recommendations in relation to adjacent anatomy and quantifies interobserver variability in specified directions. This method can be applied to future consensus CTV contouring studies.

Ablative radiation therapy to restrain everything safely treatable (ARREST): study protocol for a phase I trial treating polymetastatic cancer with stereotactic radiotherapy.

BACKGROUND: Patients with polymetastatic cancer are most often treated with systemic therapy to improve overall survival and/or delay progression, with palliative radiotherapy reserved for sites of symptomatic disease. Stereotactic ablative radiotherapy (SABR) has shown promise in the treatment of oligometastatic disease, but the utility of SABR in treating all sites of polymetastatic disease has yet to be evaluated. This study aims to evaluate the maximally tolerated dose (MTD) of SABR in patients with polymetastatic disease. METHODS: Up to 48 patients with polymetastatic cancer (> 10 sites) will be enrolled on this phase I, modified 3 + 3 design trial. Eligible patients will have exhausted (or refused) standard systemic therapy options. SABR will be delivered as an escalating number of weekly fractions of 6 Gy, starting at 6 Gy × 2 weekly fractions (dose level 1). The highest dose level (dose level 4) will be 6 Gy × 5 weekly fractions. Feasibility and safety of SABR will be evaluated 6 weeks following treatment using a composite endpoint of successfully completing treatment as well as toxicity outcomes. DISCUSSION: This study will be the first to explore delivering SABR in patients with polymetastatic disease. SABR will be planned using the guiding principles of: strict adherence to dose constraints, minimization of treatment burden, and minimization of toxicity. As this represents a novel use of radiotherapy, our phase I study will allow for careful selection of the MTD for exploration in future studies. TRIAL REGISTRATION: This trial was prospectively registered in ClinicalTrials.gov as NCT04530513 on August 28, 2020.

Red Blood Cell Transfusion Practices for Patients With Cervical Cancer Undergoing Radiotherapy.

Importance: Packed red blood cell (PRBC) transfusions are used to treat anemia in patients with cervical cancer undergoing radiotherapy (RT) owing to concerns of hypoxia-induced radioresistance. In the absence of high-quality evidence informing transfusion practices for patients receiving external beam RT (EBRT) and brachytherapy, various arbitrary hemoglobin target levels are used worldwide. Objective: To develop consensus statements to guide PRBC transfusion practices in patients with cervical cancer receiving curative-intent RT with EBRT and brachytherapy. Design, Setting, and Participants: This international Delphi consensus study was completed between November 1, 2019, and July 31, 2020. A total of 63 international clinical experts in gynecologic radiation oncology were invited; 39 (62%) accepted and consented to participate. Consensus building was achieved using a 3-round anonymous Delphi consensus method. Participants rated their agreement or disagreement with statements using a 5-point Likert scale. An a priori threshold of 75% or more was required for consensus. Main Outcomes and Measures: The preplanned primary outcome of this study was to assess hemoglobin transfusion thresholds and targets for both EBRT and brachytherapy by expert consensus. Results: Response rates of 100% (39 of 39), 92% (36 of 39), and 97% (35 of 36) were achieved for the first, second, and third rounds of surveys, respectively. Twenty-three experts (59%) practiced in Canada, 11 (28%) in the United States, 3 (8%) in South America, 1 (3%) in Europe, and 1 (3%) in Asia. Consensus was reached for 44 of 103 statements (43%), which were combined to form the final 27-statement consensus guideline. No specific hemoglobin transfusion threshold was agreed on by consensus for EBRT or brachytherapy. By consensus (89% [31 of 35]), a hemoglobin transfusion target for patients who receive a PRBC transfusion should be 9 g/dL or more and less than 12 g/dL. Conclusions and Relevance: This study presents the first international expert consensus guideline informing PRBC transfusion practices for patients with cervical cancer undergoing EBRT and brachytherapy. A minimum hemoglobin transfusion target of 9 g/dL was endorsed to balance tumor radiosensitivity with appropriate use of a scarce resource. Randomized clinical trials are required to evaluate the optimal transfusion threshold and target that maximize clinical benefit in this patient population.

A Scoping Review of Radiation Oncology Educational and Career-Planning Interventions in Undergraduate Medical Education.

Radiation oncology (RO) teaching in undergraduate medical education (UME) is lacking worldwide with potentially detrimental effects on medical student career choices and patient care. The objective of this scoping review is to examine the extent of published literature describing RO educational and career-planning interventions in UME. Online databases were searched from respective dates of inception to June 2020 for articles that reported outcomes from RO educational and career-planning interventions in UME. Two independent reviewers screened entries for inclusion. Following full-text reviews, 25 articles were analyzed. Most interventions were a single session, involved clinical medical students, and were based in North America. Didactic teaching was most commonly used, though a majority included interactive learning in addition to or in place of didactic teaching. As expected, there was a heterogeneity of outcomes reported, and most studies collected data using surveys alone. Recurring topics included the multidisciplinary nature of oncology and psychosocial oncology. There was a paucity of studies reporting on formal mentorship programs and research programs. The data collated in this study can help develop new initiatives based on what has succeeded in the past. Areas that may benefit from future studies include mentorship programs, research programs, and interventions from outside North America.

An overview of leptomeningeal disease.

Leptomeningeal disease (LMD) is a poor prognosis pattern of disease progression in patients with metastatic malignancy with limited treatment options. Patients may be asymptomatic or present with non-specific neurologic deficits, therefore gadolinium-enhanced magnetic resonance imaging of the brain and spine is critical for establishing a diagnosis. Although the treatment intent is palliative in the context of LMD, a multidisciplinary approach is still important to ensure patients receive a timely diagnosis and appropriate treatment to maximize symptom control and preserve quality of life. Radiotherapy is typically delivered to the whole brain or focal spinal regions for the purposes of treating bulky disease, stabilizing symptoms, or relieving cerebrospinal fluid obstruction. Whole craniospinal irradiation (CSI) is generally avoided given its toxicity profile and should only be considered in carefully selected patients where the potential benefit may outweigh the adverse effects. CSI with proton radiotherapy (oppose to conventional photon radiotherapy) has shown promise with improved toxicity for patients with primary CNS tumors. This may be a preferred option for patients being considered for CSI at centres with the proton therapy capabilities. Focal hypofractionated stereotactic radiotherapy (SRT) to intracranial targets is an emerging approach to LMD that may be useful in select patients with limited disease particularly in the setting of reirradiation. Chemotherapies may be delivered intrathecally, although the evidence supporting its efficacy is limited and heterogeneous in regards to the tumor sites examined. Finally, targeted therapy and novel applications of immune checkpoint inhibitors are promising; however, further research is required to guide the use of these agents.

Mature Imaging-Based Outcomes Supporting Local Control for Complex Reirradiation Salvage Spine Stereotactic Body Radiotherapy.

BACKGROUND: Upon progression after upfront radiotherapy to spinal metastases, low-dose re-irradiation conventional external beam radiation (cEBRT) provides limited clinical benefit. Spine stereotactic body radiotherapy (SBRT) allows for dose escalation in the salvage setting with the potential for improved local control. OBJECTIVE: To report mature clinical and imaging-based outcomes for salvage SBRT. METHODS: A retrospective review was undertaken of consecutive patients with spinal metastases treated with re-irradiation spine SBRT having failed either cEBRT (n = 60 with 1 prior course and n = 17 with 2 or more prior cEBRT courses), or prior SBRT (n = 6) to the same spinal segment. The primary outcome was local failure (LF), and secondary outcomes included overall survival (OS) and the rate of vertebral compression fracture (VCF). RESULTS: A total of 43 patients with 83 spinal segments treated with salvage SBRT were reviewed. The crude risk of LF was 18%, and actuarial LF rates at 6, 12, and 24 mo were 7%, 14%, and 19%, respectively. The presence of extensive paraspinal disease (hazard ratio [HR] = 7.1, 95% CI 1.5-34) significantly predicted for LF. The median OS was 13.2 (95% CI 6.1-16.3) mo, and the presence of neurological deficits (HR = 4.7, 95% CI 1.8-12.1) and brain metastases (HR = 2.6, 95% CI 1.1-6.3) were significant prognostic factors. The crude risk of VCF was 4%, and radiation myelopathy was not observed. CONCLUSION: These data support the safety and efficacy of spinal re-irradiation with SBRT including patients with prior SBRT and multiple courses of prior cEBRT.

Stereotactic Body Radiation Therapy for Nonspine Bone Metastases: International Practice Patterns to Guide Treatment Planning.

PURPOSE: Stereotactic body radiation therapy (SBRT) is increasingly used for nonspine bone metastases (NSBM); however, there are limited data informing treatment planning. We surveyed international experts to better understand worldwide practice patterns in delivering NSBM-SBRT. METHODS AND MATERIALS: Nine international radiation oncologists were invited to participate based on demonstrated expertise with NSBM-SBRT. Experts were sent gross tumor volume contours and planning computed tomography and magnetic resonance images for 11 NSBM cases that covered a range of bony sites, including metastases to long bones (femur, humerus), pelvic bones (ilium, ischium, acetabulum, pubic symphysis), and thoracic bones (rib, sternum, scapula, clavicle). Experts were surveyed regarding treatment planning decisions and dose-fractionation selection. Descriptive analysis was conducted on the survey data. RESULTS: All experts participated and completed the survey. Most (56%) routinely fused magnetic resonance imaging with planning computed tomography imaging for target delineation. Dose fractionation schedules included single-fraction (18-24 Gy/1), 2 fractions (24 Gy/2), 3 fractions (28-30 Gy/3), 5 fractions (30-50 Gy/5), and 10 fractions (42-50 Gy/10). Although doses varied considerably, all had a biological equivalent dose of ≤100 Gy10. Five-fraction schedules were most common, specifically 35 Gy/5, with 56% opting for this dose-fractionation in at least 1 case. Other dose-fractionation schedules used by at least 3 experts were 20 Gy/1, 30 Gy/3, and 30 Gy/5. Three experts prescribed 2 dose volumes using a simultaneous integrated boost. The 2 dose volumes were either the gross tumor volume and clinical target volume (CTV) or a smaller CTV (CTV1) encompassed within a larger CTV (CTV2) (eg, 30 Gy/3 to gross tumor volume or CTV1 and 15-24 Gy/3 to CTV or CTV2). Dose de-escalation was recommended by all experts in the setting of previous SBRT and by most in the context of previous convevoltherapy or in weight-bearing bones, especially if moderate-to-severe cortical erosion was present. CONCLUSIONS: Significant heterogeneity exists worldwide in radiation technique and dose-fractionation for NSBM-SBRT, which supports the need for consensus guidelines to inform practice and trial design. Nonetheless, these data demonstrate expert agreement on selecting dose schedules with a biologically effective dose ≤100 Gy10, reasons for dose de-escalation, and in determining acceptable dose schedules based on bony site.

Research Productivity of Canadian Radiation Oncology Residents: A Time-Trend Analysis.

(1) Background: Research productivity is a mandatory component of Canadian radiation oncology (RO) resident training. To our knowledge, Canadian RO resident research publication productivity has not previously been analysed. (2) Methods: We compiled a 12-year database of RO residents in Canadian training programs who completed residency between June 2005 and June 2016. Resident names and dates of training were abstracted from provincial databases and department websites and were used to abstract data from PubMed, including training program, publication year, journal, type of research, topic and authorship position. Residents were divided into four time periods and the linear trend test evaluated publication rates over time. Univariable and multivariable logistic regression analyses were performed to identify authorship predictors. (3) Results: 227 RO residents representing 363 publications were identified. The majority were first-author publications (56%) and original research (77%). Overall, 82% of first-author, and 80% of any-author articles were published in resident year 4 or higher. Mean number of publications for first-author and any-author positions increased significantly over time (p = 0.016 and p = 0.039, respectively). After adjusting for gender and time period, large institutions (> 3 residents per year) trended toward associations with more first-author publications (odds ratio (OR): 2.44; p = 0.066) and more any-author publications (OR: 2.49; p = 0.052). No significant differences were observed by gender. (4) Conclusions: Canadian RO resident publication productivity nearly doubled over a 12-year period. The majority of publications are released in the last 2 years of residency, and larger residency programs may be associated with more publications. These findings serve as a baseline as programs transition to Competency Based Medical Education (CBME).

Predictors of leptomeningeal disease following hypofractionated stereotactic radiotherapy for intact and resected brain metastases.

BACKGROUND: The objective was to evaluate the risk and predictors of developing leptomeningeal disease (LMD) in patients with brain metastases treated with 5-fraction hypofractionated stereotactic radiotherapy (HSRT). METHODS: Patients treated with HSRT for intact brain metastases and/or surgical cavities were reviewed from a prospectively maintained database. Radiographic patterns of LMD were classified as focal classical, diffuse classical, focal nodular, and diffuse nodular. RESULTS: HSRT was delivered, most commonly 30 Gy in 5 fractions, to 320 intracranial lesions (57% intact and 43% surgical cavities) in 235 patients. The median follow-up was 13.4 months (range, 0.8 to 60 mo). LMD developed in 19% of patients with a 1-year LMD rate of 12%. From the diagnosis of LMD, the median overall survival (OS) was 3.8 months (range, 2-20.8 mo). The most common LMD pattern was diffuse nodular (44%). No difference in OS was observed between LMD patterns (P = 0.203). Multivariable analysis identified surgical cavities at significantly higher risk of LMD compared with intact lesions (odds ratio [OR] = 2.30, 95% CI: 1.24, 4.29, P = 0.008). For cavities, radiosensitive tumors (OR = 2.35, 95% CI: 1.04, 5.35, P = 0.041) predicted for LMD, while, for intact metastases, patients receiving treatment with targeted agents or immunotherapy (TA/I) were at lower risk (OR = 0.178, 95% CI: 0.04, 0.79, P = 0.023). CONCLUSIONS: Patients who had a brain metastasis resected were at an increased risk of LMD. OS was poor despite treatment of LMD, and no differences in OS based on the pattern of LMD was observed. Treatment with TA/I was observed to be protective against LMD and requires further study.

Hypofractionated stereotactic radiotherapy for intracranial meningioma: a systematic review.

BACKGROUND: The availability of image guidance and intensity modulation has led to the increasing use of hypofractionated stereotactic radiotherapy (hSRT) as an alternative to conventionally fractionated radiotherapy or radiosurgery for intracranial meningiomas (ICMs). As the safety and efficacy of this approach is not well characterized, we conducted a systematic review of the literature to assess the clinical outcomes of hSRT in the setting of ICMs. METHODS: A systematic review of Medline and EMBASE databases was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included studies were retrospective or prospective series that examined an ICM population of ≥10 patients, delivered >1 fraction of photon hSRT (≥2.5 Gy per fraction), and had a median follow-up of ≥2 years. Descriptive statistics were generated for included studies. RESULTS: Of 1480 initial studies, 14 met eligibility criteria for inclusion, reporting on 630 patients (age range, 18-90) treated for 638 tumors. Primary radiotherapy was delivered in 37% of patients, 36% had radiation following surgery, and surgical details were unavailable for 27%. In 474 tumors assessed for radiologic response, 78% remained stable, 18% decreased in size, and 4% increased in size. Crude local control was 90%-100% as reported in 10 studies. The median late toxicity rate was 10%. The most common significant late toxicities were decreased visual acuity and new cranial neuropathy. CONCLUSIONS: With limited follow-up, the available literature suggests hSRT for ICMs has local control and toxicity profiles comparable to other radiotherapy approaches. Confirmation in larger patient cohorts with a longer duration of follow-up is required.