Single-Fraction Versus Fractionated Preoperative Radiosurgery for Resected Brain Metastases: A PROPS-BM International Multicenter Cohort Study.

PURPOSE: Preoperative stereotactic radiosurgery (SRS) is a feasible alternative to postoperative SRS for resected brain metastases (BM). Most reported studies of preoperative SRS used single-fraction SRS (SF-SRS). The goal of this study was to compare outcomes and toxicity of preoperative SF-SRS with multifraction (3-5 fractions) SRS (MF-SRS) in a large international multicenter cohort (Preoperative Radiosurgery for Brain Metastases-PROPS-BM). METHODS AND MATERIALS: Patients with BM from solid cancers, of which at least 1 lesion was treated with preoperative SRS followed by planned resection, were included from 8 institutions. SRS to synchronous intact BM was allowed. Exclusion criteria included prior or planned whole brain radiation therapy. Intracranial outcomes were estimated using cumulative incidence with competing risk of death. Propensity score matched (PSM) analyses were performed. RESULTS: The study cohort included 404 patients with 416 resected index lesions, of which SF-SRS and MF-SRS were used for 317 (78.5%) and 87 patients (21.5%), respectively. Median dose was 15 Gy in 1 fraction for SF-SRS and 24 Gy in 3 fractions for MF-SRS. Univariable analysis demonstrated that SF-SRS was associated with higher cavity local recurrence (LR) compared with MF-SRS (2-year: 16.3% vs 2.9%; P = .004), which was also demonstrated in multivariable analysis. PSM yielded 81 matched pairs (n = 162). PSM analysis also demonstrated significantly higher rate of cavity LR with SF-SRS (2-year: 19.8% vs 3.3%; P = .003). There was no difference in adverse radiation effect, meningeal disease, or overall survival between cohorts in either analysis. CONCLUSIONS: Preoperative MF-SRS was associated with significantly reduced risk of cavity LR in both the unmatched and PSM analyses. There was no difference in adverse radiation effect, meningeal disease, or overall survival based on fractionation. MF-SRS may be a preferred option for neoadjuvant radiation therapy of resected BMs. Additional confirmatory studies are needed. A phase 3 randomized trial of single-fraction preoperative versus postoperative SRS (NRG-BN012) is ongoing (NCT05438212).

Full Dose SBRT in Combination With Mediastinal Chemoradiation for Locally Advanced, Non-Small Cell Lung Cancer: A Practical Guide for Planning, Dosimetric Results From a Phase 2 Study, and a Treatment Planning Guide for the Phase 3 NRG Oncology LU-008 Trial.

PURPOSE: Stereotactic body radiation therapy (SBRT) has been used with high effectiveness in early-stage non-small cell lung cancer (NSCLC) but has not been studied extensively in locally advanced NSCLC. We conducted a phase 2 study delivering SBRT to the primary tumor followed by conventionally fractionated chemoradiation to the involved lymph nodes for patients with node-positive locally advanced NSCLC. This manuscript serves as both a guide to planning techniques used on this trial and the subsequent phase 3 study, NRG Oncology LU-008, and to report patient dosimetry and toxicity results. METHODS AND MATERIALS: We initiated a phase 2 multicenter single arm study evaluating SBRT to the primary tumor (50-54 Gy in 3-5 fractions) followed by conventionally fractionated chemoradiation to 60 Gy in 2 Gy fractions with doublet chemotherapy to the involved lymph nodes for patients with stage III or unresectable stage II NSCLC. Patients eligible for adjuvant immunotherapy received up to 12 months of durvalumab. We report a detailed guide for the entire treatment process from computed tomography simulation through treatment planning and delivery. The dosimetric outcomes from the 60 patients who completed therapy on study are reported both for target coverage and normal structure doses. We also report correlation between radiation-related toxicities and dosimetric parameters. RESULTS: Sixty patients were enrolled between 2017 and 2022. Planning techniques used were primarily volumetric modulated arc therapy for SBRT to the primary tumor and conventionally fractionated radiation to the involved nodes, with a minority of cases using dynamic conformal arc technique or static dynamic multileaf collimator intensity modulated radiation therapy. Grade 2 or higher pneumonitis was associated with lung dose V5 Gy > 70% and grade 2 or higher pulmonary toxicity was associated with lung dose V10 Gy > 50%. Only 3 patients (5%) experienced grade 3 or higher pneumonitis. Grade 2 or higher esophagitis was associated with esophageal doses, including mean dose > 20 Gy, V60 Gy > 7%, and D1cc > 55 Gy. Only 1 patient (1.7%) experienced grade 3 esophagitis. CONCLUSIONS: SBRT to the primary tumor followed by conventionally fractionated chemoradiation to the involved lymph nodes is feasible with planning techniques as described. Radiation-related toxicity on this phase 2 study was low. This manuscript serves as a guideline for the recently activated NRG Oncology LU-008 phase 3 trial evaluating this experimental regimen.

Risk Factors for Progression and Toxic Effects After Preoperative Stereotactic Radiosurgery for Patients With Resected Brain Metastases.

Importance: Preoperative stereotactic radiosurgery (SRS) has been demonstrated as a feasible alternative to postoperative SRS for resectable brain metastases (BMs) with potential benefits in adverse radiation effects (AREs) and meningeal disease (MD). However, mature large-cohort multicenter data are lacking. Objective: To evaluate preoperative SRS outcomes and prognostic factors from a large international multicenter cohort (Preoperative Radiosurgery for Brain Metastases-PROPS-BM). Design, Setting, and Participants: This multicenter cohort study included patients with BMs from solid cancers, of which at least 1 lesion received preoperative SRS and a planned resection, from 8 institutions. Radiosurgery to synchronous intact BMs was allowed. Exclusion criteria included prior or planned whole-brain radiotherapy and no cranial imaging follow-up. Patients were treated between 2005 and 2021, with most treated between 2017 and 2021. Exposures: Preoperative SRS to a median dose to 15 Gy in 1 fraction or 24 Gy in 3 fractions delivered at a median (IQR) of 2 (1-4) days before resection. Main Outcomes and Measures: The primary end points were cavity local recurrence (LR), MD, ARE, overall survival (OS), and multivariable analysis of prognostic factors associated with these outcomes. Results: The study cohort included 404 patients (214 women [53%]; median [IQR] age, 60.6 [54.0-69.6] years) with 416 resected index lesions. The 2-year cavity LR rate was 13.7%. Systemic disease status, extent of resection, SRS fractionation, type of surgery (piecemeal vs en bloc), and primary tumor type were associated with cavity LR risk. The 2-year MD rate was 5.8%, with extent of resection, primary tumor type, and posterior fossa location being associated with MD risk. The 2-year any-grade ARE rate was 7.4%, with target margin expansion greater than 1 mm and melanoma primary being associated with ARE risk. Median OS was 17.2 months (95% CI, 14.1-21.3 months), with systemic disease status, extent of resection, and primary tumor type being the strongest prognostic factors associated with OS. Conclusions and Relevance: In this cohort study, the rates of cavity LR, ARE, and MD after preoperative SRS were found to be notably low. Several tumor and treatment factors were identified that are associated with risk of cavity LR, ARE, MD, and OS after treatment with preoperative SRS. A phase 3 randomized clinical trial of preoperative vs postoperative SRS (NRG BN012) has began enrolling (NCT05438212).

Immune niches in brain metastases contain TCF1+ stem-like T cells, are associated with disease control and are modulated by preoperative SRS.

The CD8+ T-cell response is prognostic for survival outcomes in several tumor types. However, whether this extends to tumors in the brain, an organ with barriers to T cell entry, remains unclear. Here, we analyzed immune infiltration in 67 brain metastasis (BrM) and found high frequencies of PD1+ TCF1+ stem-like CD8+ T-cells and TCF1- effector-like cells. Importantly, the stem-like cells aggregate with antigen presenting cells in immune niches, and niches were prognostic for local disease control. Standard of care for BrM is resection followed by stereotactic radiosurgery (SRS), so to determine SRS's impact on the BrM immune response, we examined 76 BrM treated with pre-operative SRS (pSRS). pSRS acutely reduced CD8+ T cells at 3 days. However, CD8+ T cells rebounded by day 6, driven by increased frequency of effector-like cells. This suggests that the immune response in BrM can be regenerated rapidly, likely by the local TCF1+ stem-like population.

Comparing pre-operative versus post-operative single and multi-fraction stereotactic radiotherapy for patients with resectable brain metastases.

Background: The standard treatment for patients with large brain metastases and limited intracranial disease is surgical resection and post-operative stereotactic radiosurgery (SRS). However, post-operative SRS still has elevated rates of local failure (LF) and is complicated by radiation necrosis (RN), and meningeal disease (MD). Pre-operative SRS may reduce the risk of RN and MD, while fractionated therapy may improve local control through delivering a higher biological effective dose. We hypothesize that pre-operative fractionated stereotactic radiation therapy (FSRT) will have less toxicity compared to patients who receive post-operative SRS or FSRT. Methods: A multi-institutional analysis was conducted and included patients who had surgical resection and stereotactic radiation therapy to treat at least one brain metastasis. Pertinent demographic, clinical, radiation, surgical, and follow up data were collected for each patient. The primary outcome was a composite endpoint defined as patients with one of the following adverse events: 1) LF, 2) MD, and/or 3) Grade 2 or higher (symptomatic) RN. Results: 279 patients were eligible for analysis. The median follow-up time was 9 months. 87 % of patients received fractionated treatment. 29 % of patients received pre-operative treatment. The composite endpoint incidences for post-operative SRS (n = 10), post-operative FSRT (n = 189), pre-operative SRS (n = 27), and pre-operative FSRT (n = 53) were 0 %, 17 %, 15 %, and 7.5 %, respectively. Conclusions: In our study, the composite endpoint of 7.5% for pre-operative FSRT compares favorably to our post-operative FSRT rate of 17%. Pre-operative FSRT was observed to have low rates of LF, MD, and RN. Prospective validation is needed.

Fractionated pre-operative stereotactic radiotherapy for patients with brain metastases: a multi-institutional analysis.

BACKGROUND: The current standard of care for patients with a large brain metastasis and limited intracranial disease burden is surgical resection and post-operative single fraction stereotactic radiosurgery (SRS). However, post-operative SRS can still lead to substantial rates of local failure (LF), radiation necrosis (RN), and meningeal disease (MD). Pre-operative SRS may reduce the risk of RN and MD, while fractionated treatments may improve local control by allowing delivery of higher biological effective dose. We hypothesize that pre-operative fractionated stereotactic radiation therapy (FSRT) can minimize rates of LF, RN, and MD. METHODS: A retrospective, multi-institutional analysis was conducted and included patients who had pre-operative FSRT for a large or symptomatic brain metastasis. Pertinent demographic, clinical, radiation, surgical, and follow up data were collected for each patient. A primary measurement was the rate of a composite endpoint of (1) LF, (2) MD, and/or (3) Grade 2 or higher (symptomatic) RN. RESULTS: 53 patients with 55 lesions were eligible for analysis. FSRT was prescribed to a dose of 24-25 Gy in 3-5 fractions. There were 0 LFs, 3 Grade 2-3 RN events, and 1 MD occurrence, which corresponded to an 8% per-patient composite endpoint event rate. CONCLUSIONS: In this study, the composite endpoint of 8% for pre-operative FSRT was improved compared to previously reported rates with post-operative SRS of 49-60% (N107C, Mahajan etal. JCOG0504) and pre-operative SRS endpoints of 20.6% (PROPS-BM). Pre-operative FSRT appears to be safe, effective, and may decrease the incidence of adverse outcomes. Prospective validation is needed.

Extremity Soft Tissue Sarcoma: A Multi-Institutional Validation of Prognostic Nomograms.

BACKGROUND: Prognostic nomograms for patients with resected extremity soft tissue sarcoma (STS) include the Sarculator and Memorial Sloan Kettering (MSKCC) nomograms. We sought to validate these two nomograms within a large, modern, multi-institutional cohort of resected primary extremity STS patients. METHODS: Resected primary extremity STS patients from 2000 to 2017 were identified across nine high-volume U.S. institutions. Predicted 5- and 10-year overall survival (OS) and distant metastases cumulative incidence (DMCI), and 4-, 8-, and 12-year disease-specific survival (DSS) were calculated with Sarculator and MSKCC nomograms, respectively. Predicted survival probabilities stratified in quintiles were compared in calibration plots to observed survival assessed by Kaplan-Meier estimates. Cumulative incidence was estimated for DMCI. Harrell's concordance index (C-index) assessed discriminative ability of nomograms. RESULTS: A total of 1326 patients underwent resection of primary extremity STS. Common histologies included: undifferentiated pleomorphic sarcoma (35%), fibrosarcoma (13%), and leiomyosarcoma (9%). Median tumor size was 8.0 cm (IQR 4.5-13.0). Tumor grade distribution was: Grade 1 (13%), Grade 2 (9%), Grade 3 (78%). Median OS was 172 months, with estimated 5- and 10-year OS of 70% and 58%. C-indices for 5- and 10-year OS (Sarculator) were 0.72 (95% CI 0.70-0.75) and 0.73 (95% CI 0.70-0.75), and 0.72 (95% CI 0.69-0.75) for 5- and 10-year DMCI. C-indices for 4-, 8-, and 12-year DSS (MSKCC) were 0.71 (95% CI 0.68-0.75). Calibration plots showed good prognostication across all outcomes. CONCLUSIONS: Sarculator and MSKCC nomograms demonstrated good prognostic ability for survival and recurrence outcomes in a modern, multi-institutional validation cohort of resected primary extremity STS patients. External validation of these nomograms supports their ongoing incorporation into clinical practice.

Volumetric Modulated Arc Therapy (VMAT) Craniospinal Irradiation (CSI) for Children and Adults: A Practical Guide for Implementation.

PURPOSE: Volumetric modulated arc therapy (VMAT) craniospinal irradiation (CSI) has been shown to have significant dosimetric advantages compared to 3-dimensional conformal therapy but is a technically complex process. We sought to develop a guide for all aspects of the VMAT CSI process and report patient dosimetry results. METHODS AND MATERIALS: We initiated VMAT CSI in 2017 and have regularly revised our standard operating procedure for this process since then. Herein, we report a detailed template for the entire VMAT CSI process from initial patient setup and immobilization at time of computed tomography (CT) simulation to contouring and treatment planning, quality assurance, and therapy delivery. The records of 12 patients who were treated with VMAT CSI were also retrospectively reviewed. RESULTS: Patient age ranged from 2 to 59 years with 5 pediatric patients (age <18 years), 5 young adults (age 18-35 years), and 2 older adults (age >35 years). The majority of patients (67%) had medulloblastoma. CSI dose ranged from 21.6 to 36 Gy, with a median of 36 Gy. The median CSI planning target volume was 2383 cc with a median V95% of 99.8% and median 0.03 cc hotspot of 112.5%. The average V107% was 7.4% and the average conformality index was 1.01. CONCLUSIONS: VMAT CSI has potentially significant dosimetric and acute toxicity advantages compared to 3-dimensional conformal. However, proper procedures need to be in place throughout the process in order to be able to realize these potential advantages. We herein describe our detailed standard operating procedure for VMAT CSI. Recognizing the scarcity of proton beam centers in many areas, VMAT CSI represents a feasible treatment with more widespread availability.

PET Imaging and Rate of Pathologic Complete Response in Esophageal Squamous Cell Carcinoma.

BACKGROUND: For locally advanced esophageal squamous cell carcinoma (ESCC), chemoradiation (ChemoRT) followed by surgery offers the best chance of cure, with a 35-50% pathologic complete response (pCR) rate. Given the morbidity of esophagectomy and the possibility of pCR with ChemoRT, a 'watch and wait' strategy has been proposed, particularly for squamous cell carcinoma. The ability to accurately predict which patients will have pCR from ChemoRT is critical in treatment decision making. This study assessed positron emission tomography (PET) in predicting pCR after neoadjuvant ChemoRT for ESCC. METHODS: ESCC patients treated with ChemoRT followed by surgery were identified. Maximum standard uptake value (SUV), metabolic tumor volume, total lesion glycolysis, and first-order textual features of standard deviation, kurtosis and skewness were measured from PET. Univariable and multivariable generalized linear method analyses were performed. A metabolic complete response (mCR) was defined as a post-therapy PET scan with maximum SUV < 4.0. RESULTS: Twenty-seven patients underwent ChemoRT followed by surgery, with overall pCR seen in 11 (41%) patients and radiographic mCR seen in 12 (44%) patients. Final pathology for these 12 patients revealed pCR (ypT0N0M0) in 5 (42%) patients and persistent disease in 7 (58%) patients. Univariate analysis did not reveal PET parameters predictive of pCR. CONCLUSION: Treatment of ESCC with ChemoRT often results in a robust clinical response. Among patients with an mCR after ChemoRT, disease persistence was found in 58%. The inability of PET to predict pCR is important in the context of a 'watch and wait' strategy for ESCC treated with ChemoRT.

A multi-institutional validation study of prognostic nomograms for retroperitoneal sarcoma.

BACKGROUND AND OBJECTIVES: Prognostic nomograms for patients undergoing resection of retroperitoneal sarcoma (RPS) include the Sarculator and Memorial Sloan Kettering (MSK) sarcoma nomograms. We sought to validate the Sarculator and MSK nomograms within a large, modern multi-institutional cohort of patients with primary RPS undergoing resection. METHODS: Patients who underwent resection of primary RPS between 2000 and 2017 across nine high-volume US institutions were identified. Predicted 7-year disease-free (DFS) and overall survival (OS) and 4-, 8-, and 12-year disease-specific survival (DSS) were calculated from the Sarculator and MSK nomograms, respectively. Nomogram-predicted survival probabilities were stratified in quintiles and compared in calibration plots to observed survival outcomes assessed by Kaplan-Meier estimates. Discriminative ability of nomograms was quantified by Harrell's concordance index (C-index). RESULTS: Five hundred and two patients underwent resection of primary RPS. Histologies included leiomyosarcoma (30%), dedifferentiated liposarcoma (23%), and well-differentiated liposarcoma (15%). Median tumor size was 14.0 cm (interquartile range [IQR], 8.5-21.0 cm). Tumor grade distribution was: Grade 1 (27%), Grade 2 (17%), and Grade 3 (56%). Median DFS was 31.5 months; 7-year DFS was 29%. Median OS was 93.8 months; 7-year OS was 51%. C-indices for 7-year DFS, and OS by the Sarculator nomogram were 0.65 (95% confidence interval [CI]: 0.62-0.69) and 0.69 (95%CI: 0.65-0.73); plots demonstrated good calibration for predicting 7-year outcomes. The C-index for 4-, 8-, and 12-year DSS by the MSK nomogram was 0.71 (95%CI: 0.67-0.75); plots demonstrated similarly good calibration ability. CONCLUSIONS: In a diverse, modern validation cohort of patients with resected primary RPS, both Sarculator and MSK nomograms demonstrated good prognostic ability, supporting their ongoing adoption into clinical practice.

Preoperative Radiosurgery for Resected Brain Metastases: The PROPS-BM Multicenter Cohort Study.

PURPOSE: Preoperative radiosurgery (SRS) is a feasible alternative to postoperative SRS, with potential benefits in adverse radiation effect (ARE) and leptomeningeal disease (LMD) relapse. However, previous studies are limited by small patient numbers and single-institution designs. Our aim was to evaluate preoperative SRS outcomes and prognostic factors from a large multicenter cohort (Preoperative Radiosurgery for Brain Metastases [PROPS-BM]). METHODS AND MATERIALS: Patients with brain metastases (BM) from solid cancers who had at least 1 lesion treated with preoperative SRS and underwent a planned resection were included from 5 institutions. SRS to synchronous intact BM was allowed. Radiographic meningeal disease (MD) was categorized as either nodular or classical "sugarcoating" (cLMD). RESULTS: The cohort included 242 patients with 253 index lesions. Most patients (62.4%) had a single BM, 93.7% underwent gross total resection, and 98.8% were treated with a single fraction to a median dose of 15 Gray to a median gross tumor volume of 9.9 cc. Cavity local recurrence (LR) rates at 1 and 2 years were 15% and 17.9%, respectively. Subtotal resection (STR) was a strong independent predictor of LR (hazard ratio, 9.1; P < .001). One and 2-year rates of MD were 6.1% and 7.6% and of any grade ARE were 4.7% and 6.8% , respectively. The median overall survival (OS) duration was 16.9 months and the 2-year OS rate was 38.4%. The majority of MD was cLMD (13 of 19 patients with MD; 68.4%). Of 242 patients, 10 (4.1%) experienced grade ≥3 postoperative surgical complications. CONCLUSIONS: To our knowledge, this multicenter study represents the largest cohort treated with preoperative SRS. The favorable outcomes previously demonstrated in single-institution studies, particularly the low rates of MD and ARE, are confirmed in this expanded multicenter analysis, without evidence of an excessive postoperative surgical complication risk. STR, though infrequent, is associated with significantly worse cavity LR. A randomized trial between preoperative and postoperative SRS is warranted and is currently being designed.

The Association Between Radiation Therapy Dose and Overall Survival in Patients With Intracranial Infiltrative Low-Grade Glioma Treated With Concurrent and/or Adjuvant Chemotherapy.

PURPOSE: Previous trials have shown no benefit for radiation therapy (RT) dose escalation when RT is given as adjuvant monotherapy for infiltrative low-grade glioma (LGG). However, the current standard of care for high-risk LGG is RT with concurrent and/or adjuvant chemotherapy. The effect of RT dose escalation on overall survival (OS) in the setting of concurrent and/or adjuvant chemotherapy is not well established. METHODS AND MATERIALS: We used the National Cancer Database to select records for adult patients with intracranial grade 2 LGG diagnosed between 2004 and 2015. Patients must have received adjuvant external beam RT with concurrent and/or adjuvant chemotherapy. RT dose level was categorized as standard (45-54 Gy) or high (>54-65 Gy). Multivariable and propensity score matched analyses were used. RESULTS: The study cohort consisted of 1043 patients, of whom 644 (62%) received standard dose (median, 54 Gy) and 399 (38%) received high-dose RT (median, 60 Gy). RT dose level was not associated with OS (hazard ratio, 1.2; P = .1) in multivariable analysis. Propensity score matching yielded 380 matched pairs (n = 760). There was no difference in OS for high-dose versus standard-dose RT in the matched cohort (5-year OS 64% vs 69%; P = .14) or in the 2 prespecified subgroups of astrocytoma histology and 1p/19q noncodeleted. CONCLUSIONS: Adjuvant RT dose escalation above 54 Gy in the setting of concurrent and/or adjuvant chemotherapy was not associated with improved OS for patients with infiltrative LGG in this National Cancer Database retrospective study. This was also true for the subgroups with less chemotherapy-sensitive disease, including astrocytoma histology and 1p/19q noncodeleted, although these analyses were limited by small size. Methods to improve OS other than RT dose escalation in the setting of concurrent and/or adjuvant chemotherapy should be considered for patients with poor-prognosis LGG.

Leptomeningeal disease and neurologic death after surgical resection and radiosurgery for brain metastases: A multi-institutional analysis.

PURPOSE: Postoperative stereotactic radiosurgery (SRS) is associated with up to 30% risk of subsequent leptomeningeal disease (LMD). Radiographic patterns of LMD (classical sugarcoating [cLMD] vs. nodular [nLMD]) in this setting has been shown to be prognostic. However, the association of these findings with neurologic death (ND) is not well described. METHODS AND MATERIALS: The records for patients with brain metastases who underwent surgical resection and adjunctive SRS to 1 lesion (SRS to other intact lesions was allowed) and subsequently developed LMD were combined from 7 tertiary care centers. Salvage radiation therapy (RT) for LMD was categorized according to use of whole-brain versus focal cranial RT. RESULTS: The study cohort included 125 patients with known cause of death. The ND rate in these patients was 79%, and the rate in patients who underwent LMD salvage treatment (n = 107) was 76%. Univariate logistic regression demonstrated radiographic pattern of LMD (cLMD vs. nLMD, odds ratio: 2.9; P = .04) and second LMD failure after salvage treatment (odds ratio: 3.9; P = .02) as significantly associated with ND. The ND rate was 86% for cLMD versus 68% for nLMD. Whole-brain RT was used in 95% of patients with cLMD and 52% with nLMD. In the nLMD cohort (n = 58), there was no difference in ND rate based on type of salvage RT (whole-brain RT: 67% vs. focal cranial RT: 68%, P = .92). CONCLUSIONS: LMD after surgery and SRS for brain metastases is a clinically significant event with high rates of ND. Classical LMD pattern (vs. nodular) and second LMD failure after salvage treatment were significantly associated with a higher risk of ND. Patients with nLMD treated with salvage focal cranial RT did not have higher ND rates compared with WBRT. Methods to decrease LMD and the subsequent high risk of ND in this setting warrant further investigation.

Implementation, adherence, and results of systematic SARS-CoV-2 testing for asymptomatic patients treated at a tertiary care regional radiation oncology network.

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus is a current pandemic. We initiated a program of systematic SARS-CoV-2 polymerase chain reaction (PCR) testing in all asymptomatic patients receiving radiotherapy (RT) at a large radiation oncology network in the Charlotte, NC metropolitan region and report adherence and results of the testing program. METHODS: Patients undergoing simulation for RT between May 18, 2020 and July 10, 2020 within the Levine Cancer Institute radiation oncology network who were asymptomatic for COVID-19 associated symptoms, without previous positive SARS-CoV-2 testing, and without recent high-risk contacts were included. PCR testing was performed on nasal cavity or nasopharyngeal swab samples. Testing was performed within 2 weeks of RT start (pre-RT) and at least every 4 weeks during RT for patients with prolonged RT courses (intra-RT). An automated task based process using the oncology electronic medical record (EMR) was developed specifically for this purpose. RESULTS: A total of 604 unique patients were included in the cohort. Details on testing workflow and implementation are described herein. Pre-RT PCR testing was performed in 573 (94.9%) patients, of which 4 (0.7%) were positive. The adherence rate to intra-RT testing overall was 91.6%. Four additional patients (0.7%) tested positive during their RT course, of whom 3 were tested due to symptom development and 1 was asymptomatic and identified via systematic testing. A total of 8 (1.3%) patients tested positive overall. There were no known cases of SARS-CoV-2 transmission from infected patients to clinic staff and/or other patients. CONCLUSIONS: We detailed the workflows used to implement systematic SARS-CoV-2 for asymptomatic patients at a large radiation oncology network. Adherence rates for pre-RT and intra-RT testing were high using this process. This information allowed for appropriate delay in initiating RT, minimizing the occurrence of RT treatment interruptions, and no known cases of transmission from infected patients to clinic staff and/or other patients.

The effect of adjuvant radiotherapy on overall survival in adults with intracranial ependymoma.

BACKGROUND: Adult intracranial ependymoma is rare, and the role for adjuvant radiotherapy (RT) is not well defined. METHODS: We used the National Cancer Database (NCDB) to select adults (age ≥ 22 years) with grade 2 to 3 intracranial ependymoma status postresection between 2004 and 2015 and treated with adjuvant RT vs observation. Four cohorts were generated: (1) all patients, (2) grade 2 only, (3) grade 2 status post-subtotal resection only, (4) and grade 3 only. The association between adjuvant RT use and overall survival (OS) was assessed using multivariate Cox and propensity score matched analyses. RESULTS: A total of 1787 patients were included in cohort 1, of which 856 patients (48%) received adjuvant RT and 931 (52%) were observed. Approximately two-thirds of tumors were supratentorial and 80% were grade 2. Cohorts 2, 3, and 4 included 1471, 345, and 316 patients, respectively. There was no significant association between adjuvant RT use and OS in multivariate or propensity score matched analysis in any of the cohorts. Older age, male sex, urban location, higher comorbidity score, earlier year of diagnosis, and grade 3 were associated with increased risk of death. CONCLUSIONS: This large NCDB study did not demonstrate a significant association between adjuvant RT use and OS for adults with intracranial ependymoma, including for patients with grade 2 ependymoma status post-subtotal resection. The conflicting results regarding the efficacy of adjuvant RT in this patient population highlight the need for high-quality studies to guide therapy recommendations in adult ependymoma.

Genomic copy number variation correlates with survival outcomes in WHO grade IV glioma.

Allele-specific copy number analysis of tumors (ASCAT) assesses copy number variations (CNV) while accounting for aberrant cell fraction and tumor ploidy. We evaluated if ASCAT-assessed CNV are associated with survival outcomes in 56 patients with WHO grade IV gliomas. Tumor data analyzed by Affymetrix OncoScan FFPE Assay yielded the log ratio (R) and B-allele frequency (BAF). Input into ASCAT quantified CNV using the segmentation function to measure copy number inflection points throughout the genome. Quantified CNV was reported as log R and BAF segment counts. Results were confirmed on The Cancer Genome Atlas (TCGA) glioblastoma dataset. 25 (44.6%) patients had MGMT hyper-methylated tumors, 6 (10.7%) were IDH1 mutated. Median follow-up was 36.4 months. Higher log R segment counts were associate with longer progression-free survival (PFS) [hazard ratio (HR) 0.32, p < 0.001], and overall survival (OS) [HR 0.45, p = 0.01], and was an independent predictor of PFS and OS on multivariable analysis. Higher BAF segment counts were linked to longer PFS (HR 0.49, p = 0.022) and OS (HR 0.49, p = 0.052). In the TCGA confirmation cohort, longer 12-month OS was seen in patients with higher BAF segment counts (62.3% vs. 51.9%, p = 0.0129) and higher log R (63.6% vs. 55.2%, p = 0.0696). Genomic CNV may be a novel prognostic biomarker for WHO grade IV glioma patient outcomes.

Use of surface-guided radiation therapy in combination with IGRT for setup and intrafraction motion monitoring during stereotactic body radiation therapy treatments of the lung and abdomen.

BACKGROUND AND PURPOSE: Multiple techniques can be used to assist with more accurate patient setup and monitoring during Stereotactic body radiation therapy (SBRT) treatment. This study analyzes the accuracy of 3D surface mapping with Surface-guided radiation therapy (SGRT) in detecting interfraction setup error and intrafraction motion during SBRT treatments of the lung and abdomen. MATERIALS AND METHODS: Seventy-one patients with 85 malignant thoracic or abdominal tumors treated with SBRT were analyzed. For initial patient setup, an alternating scheme of kV/kV imaging or SGRT was followed by cone beam computed tomography (CBCT) for more accurate tumor volumetric localization. The CBCT six degree shifts after initial setup with each method were recorded to assess interfraction setup error. Patients were then monitored continuously with SGRT during treatment. If an intrafractional shift in any direction >2 mm for longer than 2 sec was detected by SGRT, then CBCT was repeated and the recorded deltas were compared to those detected by SGRT. RESULTS: Interfractional shifts after SGRT setup and CBCT were small in all directions with mean values of <5 mm and < 0.5 degrees in all directions. Additionally, 25 patients had detected intrafraction motion by SGRT during a total of 34 fractions. This resulted in 25 (73.5%) additional shifts of at least 2 mm on subsequent CBCT. When comparing the average vector detected shift by SGRT to the resulting vector shift on subsequent CBCT, no significant difference was found between the two. CONCLUSIONS: Surface-guided radiation therapy provides initial setup within 5 mm for patients treated with SBRT and can be used in place of skin marks or planar kV imaging prior to CBCT. In addition, continuous monitoring with SGRT during treatment was valuable in detecting potentially clinically meaningful intrafraction motion and was comparable in magnitude to shifts from additional CBCT scans. PTV margin reduction may be feasible for SBRT in the lung and abdomen when using SGRT for continuous patient monitoring during treatment.