Immune checkpoint inhibitors and radiosurgery for newly diagnosed melanoma brain metastases.

INTRODUCTION: Brain metastases are common in metastatic melanoma and radiosurgery is often utilized for local control. Immune checkpoint inhibitors (CPIs) play a central role in contemporary melanoma management; however, there is limited data exploring outcomes and potential toxicities for patients treated with CPIs and radiosurgery. METHODS: We retrospectively identified all consecutive cases of newly diagnosed melanoma brain metastases (MBM) treated with Gamma Knife radiosurgery at a single institution between 2012 and 2017, and included only patients that initiated CPIs within 8 weeks before or after radiosurgery. RESULTS: Thirty-eight patients were included with a median follow-up of 31.6 months. Two-year local control was 92%. Median time to out-of-field CNS and extra-CNS progression were 8.4 and 7.9 months, respectively. Median progression-free survival (PFS) was 3.4 months and median overall survival (OS) was not reached (NR). Twenty-five patients (66%) received anti-CTLA4 and 13 patients (34%) received anti-PD-1+/-anti-CTLA4. Compared with anti-CTLA4, patients that received anti-PD-1+/-anti-CTLA4 had significant improvements in time to out-of-field CNS progression (p = 0.049), extra-CNS progression (p = 0.015), and PFS (p = 0.043), with median time to out-of-field CNS progression of NR vs. 3.1 months, median time to extra-CNS progression of NR vs. 4.4 months, and median PFS of 20.3 vs. 2.4 months. Six patients (16%) developed grade ≥ 2 CNS toxicities (grade 2: 3, grade 3: 3, grade 4/5: 0). CONCLUSIONS: Excellent outcomes were observed in patients that initiated CPIs within 8 weeks of undergoing radiosurgery for newly diagnosed MBM. There appears to be an advantage to anti-PD-1 or combination therapy compared to anti-CTLA4.

Survival benefit of postoperative radiation in papillary meningioma: Analysis of the National Cancer Data Base.

AIM/BACKGROUND: Papillary meningioma represents a rare subset of World Health Organization (WHO) Grade III meningioma that portends an overall poor prognosis. There is relatively limited data regarding the benefit of postoperative radiation therapy (PORT). We used the National Cancer Data Base (NCDB) to compare overall survival (OS) outcomes of surgically resected papillary meningioma cases undergoing PORT compared to post-operative observation. MATERIALS AND METHODS: The NCDB was queried for patients with papillary meningioma, diagnosed between 2004 and 2013, who underwent upfront surgery with or without PORT. Overall survival (OS) was determined using the Kaplan-Meier method. Univariate (UVA) and multivariate (MVA) analyses were performed. RESULTS: In total, 190 patients were identified; 89 patients underwent PORT, 101 patients were observed. Eleven patients received chemotherapy (6 with PORT, 5 without). 2-Year OS was significantly improved with PORT vs. no PORT (93.0% vs. 74.4%), as was 5-year OS (78.5% vs. 62.5%) (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.27-0.85; p = 0.01). On MVA, patients receiving PORT had improved OS compared to observation (HR, 0.41; 95% CI, 0.22-0.76; p = 0.005). On subset analysis by age group, the benefit of PORT vs. no PORT was significant in patients ≤18 years (n = 13), with 2-year OS of 85.7% vs. 50.0% (HR, 0.08; 95% CI, 0.01-0.80; p = 0.032) and for patients >18 years (n = 184), with 2-year OS of 94.7% vs. 76.1% (HR, 0.55; 95% CI, 0.31-1.00; p = 0.049), respectively. CONCLUSIONS: In this large contemporary analysis, PORT was associated with improved survival for both adult and pediatric patients with papillary meningioma. PORT should be considered in those who present with this rare, aggressive tumor.

Local consolidative therapy versus maintenance therapy or observation for patients with oligometastatic non-small-cell lung cancer without progression after first-line systemic therapy: a multicentre, randomised, controlled, phase 2 study.

BACKGROUND: Evidence from retrospective studies suggests that disease progression after first-line chemotherapy for metastatic non-small-cell lung cancer (NSCLC) occurs most often at sites of disease known to exist at baseline. However, the potential effect of aggressive local consolidative therapy for patients with oligometastatic NSCLC is unknown. We aimed to assess the effect of local consolidative therapy on progression-free survival. METHODS: In this multicentre, randomised, controlled, phase 2 study, eligible patients from three hospitals had histological confirmation of stage IV NSCLC, three or fewer metastatic disease lesions after first-line systemic therapy, an Eastern Cooperative Oncology Group performance status score of 2 or less, had received standard first-line systemic therapy, and had no disease progression before randomisation. First-line therapy was four or more cycles of platinum doublet therapy or 3 or more months of EGFR or ALK inhibitors for patients with EGFR mutations or ALK rearrangements, respectively. Patients were randomly assigned (1:1) to either local consolidative therapy ([chemo]radiotherapy or resection of all lesions) with or without subsequent maintenance treatment or to maintenance treatment alone, which could be observation only. Maintenance treatment was recommended based on a list of approved regimens, and observation was defined as close surveillance without cytotoxic treatment. Randomisation was not masked and was balanced dynamically on five factors: number of metastases, response to initial therapy, CNS metastases, intrathoracic nodal status, and EGFR and ALK status. The primary endpoint was progression-free survival analysed in all patients who were treated and had at least one post-baseline imaging assessment. The study is ongoing but not recruiting participants. This study is registered with ClinicalTrials.gov, number NCT01725165. FINDINGS: Between Nov 28, 2012, and Jan 19, 2016, 74 patients were enrolled either during or at the completion of first-line systemic therapy. The study was terminated early after randomisation of 49 patients (25 in the local consolidative therapy group and 24 in the maintenance treatment group) as part of the annual analyses done by the Data Safety Monitoring Committee of all randomised trials at MD Anderson Cancer Center, and before a planned interim analysis of 44 events. At a median follow-up time for all randomised patients of 12·39 months (IQR 5·52-20·30), the median progression-free survival in the local consolidative therapy group was 11·9 months (90% CI 5·7-20·9) versus 3·9 months (2·3-6·6) in the maintenance treatment group (hazard ratio 0·35 [90% CI 0·18-0·66], log-rank p=0·0054). Adverse events were similar between groups, with no grade 4 adverse events or deaths due to treatment. Grade 3 adverse events in the maintenance therapy group were fatigue (n=1) and anaemia (n=1) and in the local consolidative therapy group were oesophagitis (n=2), anaemia (n=1), pneumothorax (n=1), and abdominal pain (n=1, unlikely related). INTERPRETATION: Local consolidative therapy with or without maintenance therapy for patients with three or fewer metastases from NSCLC that did not progress after initial systemic therapy improved progression-free survival compared with maintenance therapy alone. These findings suggest that aggressive local therapy should be further explored in phase 3 trials as a standard treatment option in this clinical scenario. FUNDING: MD Anderson Lung Cancer Priority Fund, MD Anderson Cancer Center Moon Shot Initiative, and Cancer Center Support (Core), National Cancer Institute, National Institutes of Health.

Survival Outcomes of Dose-Escalated External Beam Radiotherapy versus Combined Brachytherapy for Intermediate and High Risk Prostate Cancer Using the National Cancer Data Base.

PURPOSE: We evaluated survival outcomes between dose-escalated EBRT (external beam radiotherapy) vs EBRT plus brachytherapy for intermediate and high risk prostate cancer using NCDB (National Cancer Data Base). MATERIALS AND METHODS: Patients with cN0M0 prostate cancer treated from 2004 to 2006 were divided into radiotherapy comparison groups, including EBRT alone (75.6 to 81 Gy) and EBRT (40 to 50.4 Gy) plus brachytherapy with EBRT delivered at 1.8 to 2.0 Gy per fraction. Brachytherapy data were limited to yes/no with no information on modality, dose or schedule. Eligible patients were known to have received androgen deprivation therapy. Overall survival was evaluated using multivariate Cox regression and propensity score matched analyses. RESULTS: Of the 20,279 study patients with prostate cancer, including 12,617 at intermediate risk and 7,662 at high risk, 71.3% received EBRT alone and 28.7% received EBRT plus brachytherapy. Median followup was 82 months (range 3 to 120) and median age was 70 years (range 36 to 90). On multivariate analysis compared to EBRT alone (75.6 to 81 Gy) EBRT plus brachytherapy was associated with improved survival (HR 0.75, p <0.001). This significance remained consistent for intermediate and high risk when analyzed separately (HR 0.73 and 0.76, respectively, each p <0.001). However on subset analysis compared to very high dose EBRT alone (79.2 to 81 Gy) in all patients combined EBRT plus brachytherapy was not associated with improved survival (HR 0.91, p = 0.083). CONCLUSION: Compared to EBRT (75.6 to 81 Gy) we observed an association of EBRT plus brachytherapy with a decreased risk of death in men with intermediate and high risk prostate cancer. However this association was no longer significant when EBRT doses of 79.2 to 81 Gy were used.

Hypofractionated-intensity modulated radiotherapy (hypo-IMRT) and temozolomide (TMZ) with or without bevacizumab (BEV) for newly diagnosed glioblastoma multiforme (GBM): a comparison of two prospective phase II trials.

To compare progression-free (PFS) and overall survival (OS) in patients treated in two consecutive phase II trials of hypofractionated-intensity modulated radiotherapy (hypo-IMRT) and temozolomide (TMZ) with or without bevacizumab (BEV). Patients with newly diagnosed glioblastoma multiforme (GBM) after biopsy or resection were enrolled on a clinical trial with hypo-IMRT and TMZ (hypo-IMRT/TMZ alone) from 2008 to 2010, or in the second protocol with the same hypo-IMRT and TMZ plus BEV (hypo-IMRT/TMZ/BEV) from 2010 to 2013. All patients received postoperative hypo-IMRT to the surgical cavity and residual tumor plus margin to a total dose of 60 Gy and to the T2 abnormality with margin to 30 Gy, both in ten fractions. Concurrent TMZ (75 mg/m(2)/day) was given to all patients for 28 consecutive days followed by adjuvant TMZ (150-200 mg/m(2)/day). Patients enrolled on the hypo-IMRT/TMZ/BEV trial received concurrent and adjuvant BEV (10 mg/kg) on days 1 and 15 of each 28-day cycle. Hazard ratios of PFS and OS were compared between trials in a Cox proportional hazards model. Twenty-six patients were enrolled on the hypo-IMRT/TMZ alone trial and 30 patients on the hypo-IMRT/TMZ/BEV trial. Median follow-up was 13.9 and 14.7 months, respectively. Median PFS was 3.4 months longer with hypo-IMRT/TMZ/BEV but the difference was not statistically significant (12.8 vs. 9.4 months, p = 0.58). Median (OS) was 16.3 months for both trials. The addition of BEV to TMZ and hypo-IMRT did not improve OS for patients with GBM in two phase II trials with small patient numbers; PFS was longer with BEV, but the difference was not statistically significant.

Phase II trial of hypofractionated intensity-modulated radiation therapy combined with temozolomide and bevacizumab for patients with newly diagnosed glioblastoma.

Bevacizumab blocks the effects of VEGF and may allow for more aggressive radiotherapy schedules. We evaluated the efficacy and toxicity of hypofractionated intensity-modulated radiation therapy with concurrent and adjuvant temozolomide and bevacizumab in patients with newly diagnosed glioblastoma. Patients with newly diagnosed glioblastoma were treated with hypofractionated intensity modulated radiation therapy to the surgical cavity and residual tumor with a 1 cm margin (PTV1) to 60 Gy and to the T2 abnormality with a 1 cm margin (PTV2) to 30 Gy in 10 daily fractions over 2 weeks. Concurrent temozolomide (75 mg/m(2) daily) and bevacizumab (10 mg/kg) was administered followed by adjuvant temozolomide (200 mg/m(2)) on a standard 5/28 day cycle and bevacizumab (10 mg/kg) every 2 weeks for 6 months. Thirty newly diagnosed patients were treated on study. Median PTV1 volume was 131.1 cm(3) and the median PTV2 volume was 342.6 cm(3). Six-month progression-free survival (PFS) was 90 %, with median follow-up of 15.9 months. The median PFS was 14.3 months, with a median overall survival (OS) of 16.3 months. Grade 4 hematologic toxicity included neutropenia (10 %) and thrombocytopenia (17 %). Grades 3/4 non-hematologic toxicity included fatigue (13 %), wound dehiscence (7 %) and stroke, pulmonary embolism and nausea each in 1 patient. Presumed radiation necrosis with clinical decline was seen in 50 % of patients, two with autopsy documentation. The study was closed early to accrual due to this finding. This study demonstrated 90 % 6-month PFS and OS comparable to historic data in patients receiving standard treatment. Bevacizumab did not prevent radiation necrosis associated with this hypofractionated radiation regimen and large PTV volumes may have contributed to high rates of presumed radiation necrosis.

The Role of Local Therapy for Oligo-Progressive Disease in Oncogene-Addicted Non-Small-Cell Lung Cancer.

Purpose: We first described the role of local radiation therapy (LT) for oligoprogressive disease (OPD) on targeted therapy in 2012. Here, we present an updated and larger data set and extend the analysis beyond EGFR and ALK. Methods: A retrospective review of patients with metastatic NSCLC harboring EGFR/BRAF V600E mutations, or ALK/ROS1/RET rearrangements, who had OPD on respective tyrosine-kinase inhibitor (TKI) and treated with LT was performed. OPD was defined as disease progression on therapy in ≤5 sites. PFS1 (progression-free survival 1) was defined as time from initiation of TKI-containing regimen to the first course of LT for OPD. Subsequent PFS times (eg, PFS2, PFS3) were defined as time from prior LT to subsequent LT, switch of systemic therapy, death, or loss to follow-up, whichever occurred first. Extended-PFS was defined as time from the first day of the first LT course to the day of change in systemic therapy, death, or loss to follow-up, whichever came first. Results: Eighty-nine patients were identified. In 75.4% of the LT courses, a single lesion was treated. Median PFS1 was 10.2 months (95% CI, 8.7-13.1) and median Extended-PFS was 6.7 months (95% CI, 4.9-8.3). Extended-PFS was similar across different oncogenic drivers; 51.4% of patients who underwent LT to a single site had only 1 site on next disease progression. Conclusions: LT is effective in prolonging treatment duration on TKI in oncogene-addicted NSCLC across multiple oncogenes.

Sex Differences in Odds of Brain Metastasis and Outcomes by Brain Metastasis Status after Advanced Melanoma Diagnosis.

Sex differences in cancer are well-established. However, less is known about sex differences in diagnosis of brain metastasis and outcomes among patients with advanced melanoma. Using a United States nationwide electronic health record-derived de-identified database, we evaluated patients diagnosed with advanced melanoma from 1 January 2011-30 July 2022 who received an oncologist-defined rule-based first line of therapy (n = 7969, 33% female according to EHR, 35% w/documentation of brain metastases). The odds of documented brain metastasis diagnosis were calculated using multivariable logistic regression adjusted for age, practice type, diagnosis period (pre/post-2017), ECOG performance status, anatomic site of melanoma, group stage, documentation of non-brain metastases prior to first-line of treatment, and BRAF positive status. Real-world overall survival (rwOS) and progression-free survival (rwPFS) starting from first-line initiation were assessed by sex, accounting for brain metastasis diagnosis as a time-varying covariate using the Cox proportional hazards model, with the same adjustments as the logistic model, excluding group stage, while also adjusting for race, socioeconomic status, and insurance status. Adjusted analysis revealed males with advanced melanoma were 22% more likely to receive a brain metastasis diagnosis compared to females (adjusted odds ratio [aOR]: 1.22, 95% confidence interval [CI]: 1.09, 1.36). Males with brain metastases had worse rwOS (aHR: 1.15, 95% CI: 1.04, 1.28) but not worse rwPFS (adjusted hazard ratio [aHR]: 1.04, 95% CI: 0.95, 1.14) following first-line treatment initiation. Among patients with advanced melanoma who were not diagnosed with brain metastases, survival was not different by sex (rwOS aHR: 1.06 [95% CI: 0.97, 1.16], rwPFS aHR: 1.02 [95% CI: 0.94, 1.1]). This study showed that males had greater odds of brain metastasis and, among those with brain metastasis, poorer rwOS compared to females, while there were no sex differences in clinical outcomes for those with advanced melanoma without brain metastasis.

Prospective evaluation of health-related quality of life in patients with glioblastoma multiforme treated on a phase II trial of hypofractionated IMRT with temozolomide.

To report health-related quality of life (HRQOL) in glioblastoma (GBM) patients treated on a phase II trial of hypofractionated intensity-modulated radiotherapy (hypo-IMRT) with temozolomide (TMZ). GBM patients received postoperative hypo-IMRT to 60 Gy in 10 fractions with TMZ. HRQOL was assessed using the EORTC quality of life questionnaire core-30 and the EORTC brain cancer module, performed at baseline, RT completion, 1 mo post-RT, and every 3 mos thereafter. Changes from baseline were calculated for each specific HRQOL scale. A ≥ 10 point change in any HRQOL scale from the mean baseline score was significant. 24 patients were treated. Compliance with HRQOL assessments at baseline, RT completion, and 1, 3, 6, 9, and 12 mos post-RT was 100, 96, 92, 79, 70, 68 and 53 %, respectively. Up to 12 mos post-RT, no significant changes were seen in global health status, physical functioning, role functioning, emotional functioning, fatigue, nausea, vision, headache or seizure. Significant improvement was seen in insomnia, future uncertainty, motor dysfunction and drowsiness. Significant worsening was observed in cognitive functioning, social functioning, appetite loss and communication deficit. 60 Gy hypo-IMRT in 6-Gy fractions with TMZ does not appear to negatively impact overall HRQOL.

CNS Downstaging: An Emerging Treatment Paradigm for Extensive Brain Metastases in Oncogene-Addicted Lung Cancer.

INTRODUCTION: For extensive brain metastases (BrM) presentations arising from oncogene-addicted lung cancer, tyrosine kinase inhibitors (TKIs) with high response rates in the central nervous system (CNS) could potentially downstage the CNS disease burden, allowing for the avoidance of upfront whole-brain radiotherapy (WBRT) and the conversion of some patients into candidates for focal stereotactic radiosurgery (SRS). METHODS: We describe the outcomes of patients with ALK, EGFR, and ROS1-driven NSCLC with extensive BrM presentations (defined as > 10 BrMs or leptomeningeal disease) treated with upfront newer generation CNS-active TKIs alone, including osimertinib, alectinib, brigatinib, lorlatinib, and entrectinib, from 2012 to 2021 at our institution. All BrMs were contoured at study entry, best CNS response (nadir), and first CNS progression. RESULTS: Twelve patients met criteria including 6 with ALK, 3 with EGFR, and 3 with ROS1-driven NSCLC. The median number and volume of BrMs at presentation were 49 and 19.6 cm3, respectively. Eleven patients (91.7 %) achieved a CNS response by modified-RECIST criteria to upfront TKI (10 partial responses, 1 complete response, 1 stable disease) with nadir observed at a median of 5.1 months. At nadir, the median number and volume of BrMs were 5 (median 91.7 % reduction per-patient) and 0.3 cm3(median 96.5 % reduction per-patient), respectively. Eleven patients (91.6 %) developed subsequent CNS progression (7 local failures, 3 local + distant, 1 distant) at a median of 17.9 months. At CNS progression, the median number and volume of BrMs were 7 and 0.7 cm3, respectively. Seven patients (58.3 %) received salvage SRS and no patients received salvage WBRT. The median overall survival from initiation of TKI for the extensive BrM presentation was 43.2 months. CONCLUSION: In this initial case series, we describe CNS downstaging as a promising multidisciplinary treatment paradigm involving the upfront administration CNS-active systemic therapy and close MRI surveillance for extensive BrMs as a strategy to avoid upfront WBRT and to convert some patients into SRS candidates.

Development of a United States Radiation Oncology Curricular Framework: A Stakeholder Delphi Consensus.

PURPOSE: A United States (US) radiation oncology curriculum, developed using best practices for curriculum inquiry, is needed to guide residency education and qualifying examinations. Competency-based training, including entrustable professional activities (EPAs), provides an outcomes-based approach to modern graduate medical education. This study aimed to define US radiation oncology EPAs and curricular content domains using a deliberative process with input from multiple stakeholder groups. METHODS AND MATERIALS: The Radiation Oncology Education Collaborative Study Group Core Curriculum Project Leadership Committee developed initial content domains and EPAs. Following recruitment of stakeholders, a Delphi process was used to achieve consensus. In the first round, content domains and EPAs were reviewed for inclusion and exclusion, clarity, time allocation (content domains), and level of training (EPAs). Participants submitted additional content domains and EPAs for consideration. Any content domains or EPAs 1 standard deviation below the median for inclusion and exclusion underwent Leadership Committee review. All participants completing the first Delphi round were invited to the second round. Percent curriculum time allocated for content domains and a single subdomain were finalized. New EPAs or EPAs undergoing major revisions were reviewed. RESULTS: A total of 186 participants representing diverse stakeholder groups participated. One hundred fourteen completed the first Delphi round (61.3%). Of 114 invited, 77 participants completed the second round of the Delphi process (67.5%). Overall, 6 of 9 content domains met consensus, 1 content domain was removed, and 2 content domains were combined. Four subdomains of a single content domain were reviewed and met consensus. Consensus on percent time allocated per content domain and subdomain was reached. Of 55 initial EPAs, 52 final EPAs met consensus. CONCLUSIONS: Deliberative curriculum inquiry was successfully used to develop a consensus on US radiation oncology content domains and EPAs. These data can guide the allocation of educational time in training programs, help inform weighting for qualifying examinations, and help guide clinical training and resident assessment.

Comparison of first-line radiosurgery for small-cell and non-small cell lung cancer brain metastases (CROSS-FIRE).

INTRODUCTION: Historical reservations regarding stereotactic radiosurgery (SRS) for small-cell lung cancer (SCLC) brain metastases include concerns for short-interval and diffuse central nervous system (CNS) progression, poor prognoses, and increased neurological mortality specific to SCLC histology. We compared SRS outcomes for SCLC and non-small cell lung cancer (NSCLC) where SRS is well established. METHODS: Multicenter first-line SRS outcomes for SCLC and NSCLC from 2000 to 2022 were retrospectively collected (n = 892 SCLC, n = 4785 NSCLC). Data from the prospective Japanese Leksell Gamma Knife Society (JLGK0901) clinical trial of first-line SRS were analyzed as a comparison cohort (n = 98 SCLC, n = 814 NSCLC). Overall survival (OS) and CNS progression were analyzed using Cox proportional hazard and Fine-Gray models, respectively, with multivariable adjustment for cofactors including age, sex, performance status, year, extracranial disease status, and brain metastasis number and volume. Mutation-stratified analyses were performed in propensity score-matched retrospective cohorts of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) positive NSCLC, mutation-negative NSCLC, and SCLC. RESULTS: OS was superior for patients with NSCLC compared to SCLC in the retrospective dataset (median OS = 10.5 vs 8.6 months; P < .001) and in the JLGK0901 dataset. Hazard estimates for first CNS progression favoring NSCLC were similar in both datasets but reached statistical significance in the retrospective dataset only (multivariable hazard ratio = 0.82, 95% confidence interval = 0.73 to 0.92, P = .001). In the propensity score-matched cohorts, there were continued OS advantages for NSCLC patients (median OS = 23.7 [EGFR and ALK positive NSCLC] vs 13.6 [mutation-negative NSCLC] vs 10.4 months [SCLC], pairwise P values < 0.001), but no statistically significant differences in CNS progression were observed in the matched cohorts. Neurological mortality and number of lesions at CNS progression were similar for NSCLC and SCLC patients. Leptomeningeal progression was increased in patients with NSCLC compared to SCLC in the retrospective dataset only (multivariable hazard ratio = 1.61, 95% confidence interval = 1.14 to 2.26, P = .007). CONCLUSIONS: After SRS, SCLC histology was associated with shorter OS compared to NSCLC. CNS progression occurred earlier in SCLC patients overall but was similar in patients matched on baseline factors. SCLC was not associated with increased neurological mortality, number of lesions at CNS progression, or leptomeningeal progression compared to NSCLC. These findings may better inform clinical expectations and individualized decision making regarding SRS for SCLC patients.

High-dose MVCT image guidance for stereotactic body radiation therapy.

PURPOSE: Stereotactic body radiation therapy (SBRT) is a potent treatment for early stage primary and limited metastatic disease. Accurate tumor localization is essential to administer SBRT safely and effectively. Tomotherapy combines helical IMRT with onboard megavoltage CT (MVCT) imaging and is well suited for SBRT; however, MVCT results in reduced soft tissue contrast and increased image noise compared with kilovoltage CT. The goal of this work was to investigate the use of increased imaging doses on a clinical tomotherapy machine to improve image quality for SBRT image guidance. METHODS: Two nonstandard, high-dose imaging modes were created on a tomotherapy machine by increasing the linear accelerator (LINAC) pulse rate from the nominal setting of 80 Hz, to 160 Hz and 300 Hz, respectively. Weighted CT dose indexes (wCTDIs) were measured for the standard, medium, and high-dose modes in a 30 cm solid water phantom using a calibrated A1SL ion chamber. Image quality was assessed from scans of a customized image quality phantom. Metrics evaluated include: contrast-to-noise ratios (CNRs), high-contrast spatial resolution, image uniformity, and percent image noise. In addition, two patients receiving SBRT were localized using high-dose MVCT scans. Raw detector data collected after each scan were used to reconstruct standard-dose images for comparison. RESULTS: MVCT scans acquired using a pitch of 1.0 resulted in wCTDI values of 2.2, 4.7, and 8.5 cGy for the standard, medium, and high-dose modes respectively. CNR values for both low and high-contrast materials were found to increase with the square root of dose. Axial high-contrast spatial resolution was comparable for all imaging modes at 0.5 lp∕mm. Image uniformity was improved and percent noise decreased as the imaging dose increased. Similar improvements in image quality were observed in patient images, with decreases in image noise being the most notable. CONCLUSIONS: High-dose imaging modes are made possible on a clinical tomotherapy machine by increasing the LINAC pulse rate. Increasing the imaging dose results in increased CNRs; making it easier to distinguish the boundaries of low contrast objects. The imaging dose levels observed in this work are considered acceptable at our institution for SBRT treatments delivered in 3-5 fractions.

Practical Implementation of Emergent After-Hours Radiation Treatment Process Using Remote Treatment Planning on Optimized Diagnostic CT Scans.

The purpose of this report is to present the implementation of a process for after-hours radiation treatment (RT) utilizing remote treatment planning based on optimized diagnostic computed tomography (CT) scans for the urgent palliative treatment of inpatients. A standardized operating procedure was developed by an interprofessional panel to improve the quality of after-hours RT and minimize the risk of treatment errors. A new diagnostic CT protocol was created that could be performed after-hours on hospital scanners and would ensure a reproducible patient position and adequate field of view. An on-call structure for dosimetry staff was created utilizing remote treatment planning. The optimized CT protocol was developed in collaboration with the radiology department, and a novel order set was created in the electronic health system. The clinical workflow begins with the radiation oncologist notifying the on-call team (therapist, dosimetrist, and physicist) and obtaining an optimized diagnostic CT scan on a hospital-based scanner. The dosimetrist remotely creates a plan; the physicist checks the plan; and the patient is treated. Plans are intentionally simple (parallel opposed fields, symmetric jaws) to expedite care and reduce the risk of error. Education on the new process was provided for all relevant staff. Our process was successfully implemented with the use of an optimized CT protocol and remote treatment planning. This approach has the potential to improve the quality and safety of emergent after-hours RT by better approximating the normal process of care.

Factors associated with progression and mortality among patients undergoing stereotactic radiosurgery for intracranial metastasis: results from a national real-world registry.

OBJECTIVE: Stereotactic radiosurgery (SRS) has been increasingly employed in recent years to treat intracranial metastatic lesions. However, there is still a need for optimization of treatment paradigms to provide better local control and prevent progressive intracranial disease. In the current study, the authors utilized a national collaborative registry to investigate the outcomes of patients with intracranial metastatic disease who underwent SRS and to determine factors associated with lesion treatment response, overall progression, and mortality. METHODS: The NeuroPoint Alliance SRS registry was queried for all patients with intracranial metastatic lesions undergoing single- or multifraction SRS at participating institutions between 2016 and 2020. The main outcomes of interest included lesion response (lesion-level analysis), progression using Response Assessment for Neuro-Oncology criteria, and mortality (patient-level analysis). Kaplan-Meier analysis was used to report time to progression and overall survival, and multivariable Cox proportional hazards analysis was used to investigate factors associated with lesion response, progression, and mortality. RESULTS: A total of 501 patients (1447 intracranial metastatic lesions) who underwent SRS and had available follow-up were included in the current analyses. The most common primary tumor was lung cancer (49.5%, n = 248), followed by breast (15.4%, n = 77) and melanoma (12.2%, n = 61). Most patients had a single lesion (44.9%, n = 225), 29.3% (n = 147) had 2 or 3 lesions, and 25.7% (n = 129) had > 3 lesions. The mean sum of baseline measurements of the lesions according to Response Evaluation Criteria in Solid Tumors (RECIST) was 35.54 mm (SD 25.94). At follow-up, 671 lesions (46.4%) had a complete response, 631 (43.6%) had a partial response (≥ 30% decrease in longest diameter) or were stable (< 30% decrease but < 20% increase), and 145 (10%) showed progression (> 20% increase in longest diameter). On multivariable Cox proportional hazards analysis, melanoma-associated lesions (HR 0.48, 95% CI 0.34-0.67; p < 0.001) and larger lesion size (HR 0.94, 95% CI 0.93-0.96; p < 0.001) showed lower odds of lesion regression, while a higher biologically effective dose was associated with higher odds (HR 1.001, 95% CI 1.0001-1.00023; p < 0.001). A total of 237 patients (47.3%) had overall progression (local failure or intracranial progressive disease), with a median time to progression of 10.03 months after the index SRS. Factors found to be associated with increased hazards of progression included male sex (HR 1.48, 95% CI 1.108-1.99; p = 0.008), while administration of immunotherapy (before or after SRS) was found to be associated with lower hazards of overall progression (HR 0.62, 95% CI 0.460-0.85; p = 0.003). A total of 121 patients (23.95%) died during the follow-up period, with a median survival of 19.4 months from the time of initial SRS. A higher recursive partitioning analysis score (HR 21.3485, 95% CI 1.53202-3.6285; p < 0.001) was found to be associated with higher hazards of mortality, while single-fraction treatment compared with hypofractionated treatment (HR 0.082, 95% CI 0.011-0.61; p = 0.015), administration of immunotherapy (HR 0.385, 95% CI 0.233-0.64; p < 0.001), and presence of single compared with > 3 lesions (HR 0.427, 95% CI 0.187-0.98; p = 0.044) were found to be associated with lower risk of mortality. CONCLUSIONS: The comparability of results between this study and those of previously published clinical trials affirms the value of multicenter databases with real-world data collected without predetermined research purpose.

Stereotactic body radiotherapy for colorectal liver metastases: a pooled analysis.

BACKGROUND: This study was undertaken to determine outcomes of stereotactic body radiotherapy for colorectal liver metastases in a pooled patient cohort. METHODS: Patients with colorectal liver metastases from 3 institutions were included if they had 1 to 4 lesions, received 1 to 6 fractions of stereotactic body radiotherapy, and had radiologic imaging ≥ 3 months post-treatment. Sixty-five patients with 102 lesions treated from August 2003 to May 2009 were retrospectively analyzed. A tumor control probability (TCP) model was used to estimate the 3-fraction dose required for > 90% local control after converting the schedule into biologically equivalent dose (BED), single-fraction equivalent dose, or linear quadratic model-based single-fraction dose. RESULTS: Forty-seven (72%) patients had ≥ 1 chemotherapy regimen before stereotactic body radiotherapy, and 27 (42%) patients had ≥ 2 regimens. The median follow-up was 1.2 years (range, 0.3-5.2 years). The median dose was 42 gray (Gy; range, 22-60 Gy). When evaluated separately by multivariate analysis, total dose (P = .0015), dose/fraction (P = .003), and BED (P = .004) all correlated with local control by lesion. On multivariate analysis, nonactive extrahepatic disease was associated with overall survival (OS; P = .046), and sustained local control was closely correlated (P = .06). By using single-fraction equivalent dose, BED, or linear quadratic model-based single-fraction dose in the TCP model, the estimated dose range needed for 1-year local control > 90% is 46 to 52 Gy in 3 fractions. CONCLUSIONS: Liver stereotactic body radiotherapy is well tolerated and effective for colorectal liver metastases. The strong correlation between local control and OS supports controlling hepatic disease even for heavily pretreated patients. For a 3-fraction regimen of stereotactic body radiotherapy, a prescription dose of ≥ 48 Gy should be considered, if normal tissue constraints allow.

The Economics of Using Locally Ablative Therapy in Oligometastatic Cancer.

Locally ablative therapy for oligometastatic cancers can improve clinical outcomes in some settings, but the interventional procedures used will also add expense to the overall cost of care for individual patients. The physician's responsibility to be a thoughtful steward of health care resources obliges evaluations of the cost-effectiveness of local therapy when used in an effort to prolong duration of survival or improve quality of life in patients with metastatic cancer. The challenge for investigators in this domain is to capture appropriate prospective data that can inform proper patient selection and identify the conditions in which locally ablative therapy for oligometastatic cancer provides high value care.

Prostate Cancer Central Nervous System Metastasis in a Contemporary Cohort.

INTRODUCTION: Central nervous system (CNS) metastasis from prostate cancer (PCA) is a rare event, but one with significant prognostic impact for those affected. There are limited data on its impact in contemporary cohorts treated with modern agents. PATIENTS AND METHODS: A retrospective institutional review was performed to characterize the occurrence/outcome of PCA CNS metastasis on all cases of PCA from 2011 to 2017. A manual chart review was performed to confirm PCA CNS metastases in all cases identified through a diagnostic code screening of the health data. RESULTS: A total of 6596 cases of PCA were identified, with 29 (20 dural and 9 intraparenchymal) confirmed cases of CNS metastases from PCA. The median survival from the time of diagnosis of CNS metastasis was 2.6 months (95% confidence interval, 2.04-10.78 months) and 5.41 months (95% confidence interval, 3.03 months to not reached) for dural and parenchymal metastases, respectively. Among those who developed CNS metastases, approximately 79% of patients had prior exposure to abiraterone and/or enzalutamide, of whom 50% had ≥ 6 months of exposure. Four (0.07%) of the 5841 patients developed CNS metastases prior to the initiation of therapy or on androgen deprivation therapy alone. In contrast, 24 (8.6%) of the 279 patients with 2 or more lines of medical therapy developed CNS metastases. CONCLUSIONS: Our analysis highlights the continued poor prognosis of parenchymal and dural CNS metastases from PCA. CNS metastases in PCA remain a rare event with a 0.4% incidence in this series, but this incidence is considerably increased in patients who receive medical therapy beyond first-line androgen deprivation therapy.

No Longer a Match: Trends in Radiation Oncology National Resident Matching Program (NRMP) Data from 2010-2020 and Comparison Across Specialties.

PURPOSE: To report trends in the number and types of applicants and matched trainees to radiation oncology in comparison to other specialties participating in the National Resident Matching Program (NRMP) between 2010 and 2020. METHODS AND MATERIALS: Data from the NRMP and Electronic Residency Application System (ERAS) were obtained for 18 medical specialties between 2010 and 2020. We assessed the numbers and types of applicants and matched trainees relative to available positions in the NRMP and Supplemental Offer and Acceptance Program (SOAP). RESULTS: In the 2020 NRMP, 122 US MD senior graduates preferentially ranked radiation oncology, a significant decrease from a median of 187 between 2010 to 2019 (interquartile range [IQR], 170-192; P < .001). Across all 18 specialties, radiation oncology experienced the greatest declines in the 2020 NRMP cycle relative to 2010 to 2019, in both the number of ERAS applicants from the United States and Canada (-31%) and the percentage of positions filled by US MD or DO senior graduates (-28%). Of 189 available positions, 81% (n = 154) filled in the NRMP prior to the SOAP, of which 65% (n = 122) were "matched" by US MD senior graduates who preferentially ranked radiation oncology as their top choice of specialty, representing a significant decrease from a median of 92% between 2010 to 2019 (IQR, 88%-94%; P = .002). The percentages of radiation oncology programs and positions unfilled in the NRMP prior to the SOAP were significantly increased in 2020 compared with 2010 to 2019 (programs: 29% vs 8% [IQR, 5%-8%; P < .001]; positions: 19% vs 4% [IQR, 2%-4%; P <.001]). Despite >99% (n = 127 of 128) of US MD or DO senior applicants preferring radiation oncology successfully matching to a radiation oncology position in the 2020 NRMP, 16 of 35 remaining unfilled positions were filled via the SOAP. Radiation oncology was the top user of the SOAP across all specialties participating in the 2020 NRMP, filling 15% of total positions versus a median of 0.9% (IQR, 0.3%-2.3%; P <.001). CONCLUSIONS: The supply of radiation oncology residency positions now far exceeds demand by graduating US medical students. Efforts to nullify a market correction revealed by medical student behavior via continued reliance on the SOAP to fill historical levels of training positions may not be in the best of interest of trainees, individual programs, or the specialty as a whole.