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Smoking during breast radiotherapy (RT) may be associated with radiation-induced skin injury (RISI). We aimed to determine if a urinary biomarker of tobacco smoke exposure is associated with increased rates of RISI during and after breast RT.Women with Stage 0-IIIA breast cancer treated with breast-conserving surgery or mastectomy followed by RT to the breast or chest wall with or without regional nodal irradiation were prospectively enrolled on a multicenter study assessing acute/late RISI. 980 patients with urinary cotinine (UCot) measurements (baseline and end-RT) were categorized into three groups. Acute and late RISI was assessed using the ONS Acute Skin Reaction scale and the LENT-SOMA Criteria.Late Grade 2+ and Grade 3+ RISI occurred in 18.2% and 1.9% of patients, respectively-primarily fibrosis, pain, edema, and hyperpigmentation. Grade 2+ late RISI was associated with UCot group (P= 006). Multivariable analysis identified UCot-based light smoker/secondhand smoke exposure (HR 1.79, P= .10) and smoking (HR 1.60, p = .06) as non-significantly associated with an increased risk of late RISI. Hypofractionated breast RT was associated with decreased risk of late RISI (HR 0.51, P=.03). UCot was not associated with acute RISI, multivariable analysis identified race, obesity, RT site/fractionation, and bra size to be associated with acute RISI.Tobacco exposure during breast RT may be associated with an increased risk of late RISI without an effect on acute toxicity. Smoking cessation should be encouraged prior to radiotherapy to minimize these and other ill effects of smoking.

Radiation therapy plays an important role in the multidisciplinary management of breast cancer. Recent years have seen improvements in breast cancer survival and a greater appreciation of potential long-term morbidity associated with the dose and volume of irradiated organs. Proton therapy reduces the dose to nontarget structures while optimizing target coverage. However, there remain additional financial costs associated with proton therapy, despite reductions over time, and studies have yet to demonstrate that protons improve upon the treatment outcomes achieved with photon radiation therapy. There remains considerable heterogeneity in proton patient selection and techniques, and the rapid technological advances in the field have the potential to affect evidence evaluation, given the long latency period for breast cancer radiation therapy recurrence and late effects. In this consensus statement, we assess the data available to the radiation oncology community of proton therapy for breast cancer, provide expert consensus recommendations on indications and technique, and highlight ongoing trials' cost-effectiveness analyses and key areas for future research. (c) 2021 Elsevier Inc. All rights reserved.

Background A recent phase III trial (NCT01372774) comparing use of stereotactic radiosurgery [SRS] versus whole-brain radiation therapy [WBRT] after surgical resection of a single brain metastasis revealed that declines in cognitive function were more common with WBRT than with SRS. A secondary endpoint in that trial, and the primary objective in this secondary analysis, was to identify baseline biomarkers associated with cognitive impairment after either form of radiotherapy for brain metastasis. Here we report our findings on APOE genotype and serum levels of associated proteins and their association with radiation-induced neurocognitive decline. Methods In this retrospective analysis of prospectively collected samples from a completed randomized clinical trial, patients provided blood samples every 3 months that were tested by genotyping and enzyme-linked immunosorbent assay, and results were analyzed in association with cognitive impairment. Results The APOE genotype was not associated with neurocognitive impairment at 3 months. However, low serum levels of ApoJ, ApoE, or ApoA protein (all P < .01) and higher amyloid beta (Aβ 1–42) levels (P = .048) at baseline indicated a greater likelihood of neurocognitive decline at 3 months after SRS, whereas lower ApoJ levels were associated with decline after WBRT (P = .014). Conclusions Patients with these pretreatment serum markers should be counseled about radiation-related neurocognitive decline.

Purpose Stereotactic body radiation therapy (SBRT) and stereotactic ablative body radiation therapy is being increasingly used for pancreatic cancer (PCa), particularly in patients with locally advanced and borderline resectable disease. A wide variety of dose fractionation schemes have been reported in the literature. This HyTEC review uses tumor control probability models to evaluate the comparative effectiveness of the various SBRT treatment regimens used in the treatment of patients with localized PCa. Methods and Materials A PubMed search was performed to review the published literature on the use of hypofractionated SBRT (usually in 1-5 fractions) for PCa in various clinical scenarios (eg, preoperative [neoadjuvant], borderline resectable, and locally advanced PCa). The linear quadratic model with α/β= 10 Gy was used to address differences in fractionation. Logistic tumor control probability models were generated using maximum likelihood parameter fitting. Results After converting to 3-fraction equivalent doses, the pooled reported data and associated models suggests that 1-year local control (LC) without surgery is ≈79% to 86% after the equivalent of 30 to 36 Gy in 3 fractions, showing a dose response in the range of 25 to 36 Gy, and decreasing to less than 70% 1-year LC at doses below 24 Gy in 3 fractions. The 33 Gy in 5 fraction regimen (Alliance A021501) corresponds to 28.2 Gy in 3 fractions, for which the HyTEC pooled model had 77% 1-year LC without surgery. Above an equivalent dose of 28 Gy in 3 fractions, with margin-negative resection the 1-year LC exceeded 90%. Conclusions Pooled analyses of reported tumor control probabilities for commonly used SBRT dose-fractionation schedules for PCa suggests a dose response. These findings should be viewed with caution given the challenges and limitations of this review. Additional data are needed to better understand the dose or fractionation-response of SBRT for PCa.

Background: Adjuvant radiotherapy (RT) following surgery significantly improves breast cancer survival. However, some patients, particularly minorities, develop early adverse skin reactions (EASRs) or skin toxicities that negatively impact the quality of life (QOL). We assess RT-related EASRs and QOL using clinician-reported outcomes (CROs) and patient-reported outcomes (PROs) in a large multi-racial/ethnic breast cancer population. Methods: This prospective study recruited 1,000 breast cancer patients undergoing RT through the Wake Forest NCI Community Oncology Research Program (NCORP) Research Base between 2011 and 2013. We used the Oncology Nursing Society (ONS) Skin Toxicity Criteria for CROs and Skindex-16 (SD-16) for PROs. Results: This study included 405 non-Hispanic whites (NHW), 277 black/African Americans (AA), 241 HW, 62 Asian/Pacific Islanders (ASPI), and 15 others. About 42% and 15% of patients developed RT-induced ONS grade 3+ and 4+ skin toxicities, respectively. RT-induced EASRs differed significantly by race/ethnicity at mid-RT, 1-month, and 2-month post-RT, but not at the end of RT. Total SD-16 scores differ by race/ethnicity at pre-RT, 1-month, and 6-month post-RT, but not at the end of RT. Overall, PROs have a moderate but significant correlation with CROs at the end of RT. Conclusion: RT-induced EASRs differed significantly by race/ethnicity. There was a moderate but significant correlation between PROs and CROs. However, PROs delineated a broader spectrum in capturing the impact of RT on patients’ QOL, which highlights the importance of integrating PROs in accessing RT-induced EASRs, particularly in minorities with worse RT-induced EASRs. Trial Registration: NCT01407770 (09/02/2011) Citation Format: James J. Urbanic, Edward G. Shaw, Cristiane Takita, Jean L. Wright, Edward H. Ip, Lingyi Lu, Luis Baez-Diaz, Doris R. Brown, Jon Strasser, Kathy Baglan, Mark Palmer, Anu Thakrar, Amarinthia E. Curtis, Glenn Lesser, Jennifer J. Hu. Radiotherapy-induced early adverse skin reactions: Comparative analysis of clinician- and patient-reported outcomes in a multi-racial/ethnic breast cancer population (WF-97609) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1900.

ImportanceLong-term outcomes of radiotherapy are important in understanding the risks and benefits of therapies for patients with brain metastases.ObjectiveTo determine how the use of postoperative whole-brain radiotherapy (WBRT) or stereotactic radiosurgery (SRS) is associated with quality of life (QOL), cognitive function, and intracranial tumor control in long-term survivors with 1 to 4 brain metastases.Design, Setting, and ParticipantsThis secondary analysis of a randomized phase 3 clinical trial included 48 institutions in the US and Canada. Adult patients with 1 resected brain metastases but limited to those with 1 to 4 brain metastasis were eligible. Unresected metastases were treated with SRS. Long-term survivors were defined as evaluable patients who lived longer than 1 year from randomization. Patients were recruited between July 2011 and December 2015, and data were first analyzed in February 2017. For the present study, intracranial tumor control, cognitive deterioration, QOL, and cognitive outcomes were measured in evaluable patients who were alive at 12 months from randomization and reanalyzed in June 2017.InterventionsStereotactic radiosurgery or WBRT.Main Outcomes and MeasuresIntracranial tumor control, toxic effects, cognitive deterioration, and QOL.ResultsFifty-four patients (27 SRS arm, 27 WBRT arm; female to male ratio, 65% vs 35%) were included for analysis with a median follow-up of 23.8 months. Cognitive deterioration was less frequent with SRS (37%-60%) compared with WBRT (75%-91%) at all time points. More patients declined by 2 or more standard deviations (SDs) in 1 or more cognitive tests for WBRT compared with SRS at 3, 6, and 9 months (70% vs 22%, 46% vs 19%, and 50% vs 20%, respectively). A 2 SD decline in at least 2 cognitive tests was associated with worse 12-month QOL in emotional well-being, functional well-being, general, additional concerns, and total scores. Overall QOL and functional independence favored SRS alone for categorical change at all time points. Total intracranial control for SRS alone vs WBRT at 12 months was 40.7% vs 81.5% (difference, −40.7; 95% CI, −68.1% to −13.4%), respectively. Data were first analyzed in February 2017.Conclusions and RelevanceThe use of SRS alone compared with WBRT resulted in less cognitive deterioration among long-term survivors. The association of late cognitive deterioration with WBRT was clinically meaningful. A significant decline in cognition (2 SD) was associated with overall QOL. However, intracranial tumor control was improved with WBRT. This study provides detailed insight into cognitive function over time in this patient population.Trial RegistrationClinicalTrials.gov Identifier: NCT01372774; ALLIANCE/CCTG: N107C/CEC.3 (Alliance for Clinical Trials in Oncology/Canadian Cancer Trials Group)

Purpose Some recent studies have suggested a relationship between cardiac dose and mortality in non-small cell lung cancer (NSCLC), but others have reported conflicting data. The goal of this study was to conduct a systematic review and meta-analysis to provide an evidence-based estimate of the relationship between cardiac dose and mortality in these patients. Methods and Materials A systematic review of MEDLINE (PubMed) and Embase databases (inception to January 2018) was performed according to PRISMA guidelines. Studies that evaluated cardiac dosimetric factors in patients with NSCLC and included outcomes of cardiac events, cardiac mortality, and/or overall survival were identified. Results From 5614 patients across 22 studies, a total of 214 cardiac dosimetric parameters (94 unique) were assessed as possible predictors of cardiac toxicity or death. Assessed predictors included general (eg, mean heart dose [MHD]), threshold-based (eg, heart V5), and anatomic-based (eg, atria, ventricles) dosimetric factors. The most commonly analyzed parameters were MHD, heart V5, and V30. Most studies did not make corrections for multiplicity of testing. For overall survival, V5 was found to be significant on multivariable analysis (MVA) in 1 of 11 studies and V30 in 2 of 12 studies; MHD was not significant in any of 8 studies. For cardiac events, V5 was found to be significant on multivariable analysis in 1 of 2 studies, V30 in 1 of 3 studies, and MHD in 2 of 4 studies. A meta-analysis of the data could not be performed because most negative studies did not report effect estimates. Conclusions Consistent heart dose-volume parameters associated with overall survival of patients with NSCLC were not identified. Multiplicity of testing is a major issue and likely inflates the overall risk of type I errors in the literature. Future studies should specify predictors a priori, correct for multiplicity of testing, and report effect estimates for nonsignificant variables.

Introduction The 5 year survival rate for patients with locally advanced non-small-cell lung cancer (NSCLC) not amenable for definitive resection with historical standard-of-care concurrent chemoradiotherapy (cCRT) ranges from 15% to 32%. cCRT primes anti-tumor immunity and also upregulates programmed death ligand-1 (PD-L1), providing a rationale for combining an immune checkpoint inhibitor with cCRT to improve outcomes. In the PACIFIC trial, consolidation therapy with the PD-L1 inhibitor durvalumab improved progression-free survival (PFS) and overall survival (OS) vs. placebo in patients with stage III NSCLC who did not have disease progression after cCRT. CheckMate73L (NCT04026412), a randomized phase 3 study, evaluates the efficacy of nivolumab plus cCRT followed by nivolumab with or without ipilimumab vs. cCRT followed by durvalumab for untreated, stage III NSCLC. Patients and Methods Patients with untreated, stage III NSCLC will be randomized 1:1:1 to nivolumab plus cCRT followed by nivolumab in combination with ipilimumab (Arm A) or nivolumab alone (Arm B); or cCRT followed by durvalumab (Arm C). Primary endpoints are PFS and OS (Arm A vs. Arm C). Secondary endpoints include additional analyses of PFS and OS (Arm A vs. Arm B; Arm B vs. Arm C), as well as objective response rate, complete response rate, time to response, duration of response, time to death or distant metastases, and safety and tolerability. Recruitment began on August 20, 2019, and the estimated primary completion date is October 17, 2022.

Purpose Long-term outcomes after external beam radiation therapy (EBRT) and radiofrequency ablation (RFA) for medically inoperable early-stage non-small cell lung cancer (NSCLC) are not well known. Methods and Materials Patients with medically inoperable early-stage NSCLC were enrolled in a prospective single-arm, phase 2 study between June 2007 and October 2008 and were treated with RFA followed by EBRT. Radiation was delivered using hypofractionated radiation therapy (HFRT; 70.2 Gy in 26 fractions) or stereotactic body radiation therapy (54 Gy in 3 fractions). Results Twelve patients were evaluable; 10 patients were treated with HFRT. The cumulative incidence of local progression at 5 years was 16.7% (95% confidence interval [CI], 0-37.8). Median progression-free survival was 37.8 months (95% CI, 11.1 to not reached) and median overall survival was 53.6 months (95% CI, 21.0 to not reached). There were no mortalities within 30 days after RFA and no grade ≥4 toxicity. Conclusions The combination of RFA with EBRT appears feasible with favorable long-term local control. However, because SBRT alone has similar or better rates of control, we do not recommend routine combined RFA and EBRT.

Purpose Concurrent chemoradiation plays an integral role in the treatment of esophageal cancer. Proton beam radiation therapy has the potential to spare adjacent critical organs, improving toxicity profiles and potentially improving clinical outcomes. Methods and materials We evaluated the REG001-09 registry for patients undergoing proton radiation therapy for esophageal cancer. Demographic, clinicopathologic, toxicity, and dosimetry information were compiled. Results We identified 155 patients treated at 10 institutions between 2010 and 2019. One hundred twenty (77%) had adenocarcinoma and 34 (22%) had squamous cell carcinoma. One hundred thirty-seven (88%) received concurrent chemotherapy. The median delivered dose was 50.51 Gy-equivalent (GyE; range, 41.4-70.1). Grade ≥3 toxicities occurred in 22 (14%) of patients and were most commonly dysphagia (6%), esophagitis (4%), anorexia (4%), and nausea (2%). There were no episodes of grade ≥4 lymphopenia and no grade 5 toxicities. The average mean heart, lung, and liver doses and average maximum spinal cord dose were 10.0 GyE, 4.8 GyE, 3.8 GyE, and 34.2 GyE, respectively. For gastroesophageal junction tumors, 8% of patients developed acute grade ≥3 toxicity and the mean heart, liver, right kidney, and left kidney doses were 10.5 GyE, 3.9 GyE, 0.4 GyE, and 4.9 GyE, respectively. Gastroesophageal junction location was protective against development of grade ≥3 toxicity on univariate (P = .0009) and multivariate (P = .004) analysis. Conclusions Proton beam radiation therapy affords excellent dosimetric parameters and low toxicity in patients with esophageal cancer treated with curative intent. Prospective trials are underway investigating the comparative benefit of proton-based therapy.

Background Recent advances in radiotherapy techniques have allowed ablative doses to be safely delivered to inoperable liver tumors. In this setting, proton beam radiotherapy (PBT) provides the means to escalate radiation dose to the target volume while sparing the uninvolved liver. This study evaluated the safety and efficacy of hypofractionated PBT for liver tumors, predominantly hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). Methods We evaluated the prospective registry of the Proton Collaborative Group for patients undergoing definitive PBT for liver tumors. Demographic, clinicopathologic, toxicity, and dosimetry information were compiled. Results To date, 63 patients have been treated at 9 institutions between 2013 and 2019. Thirty (48%) had HCC and 25 (40%) had ICC. The median dose and biological equivalent dose (BED) delivered was 58.05 GyE (range 32.5–75) and 80.5 GyE (range 53.6–100), respectively. The median mean liver BED was 13.9 GyE. Three (4.8%) patients experienced at least one grade ≥ 3 toxicity. With median follow-up of 5.1 months (range 0.1–40.8), the local control (LC) rate at 1 year was 91.2% for HCC and 90.9% for ICC. The 1-year LC was significantly higher (95.7%) for patients receiving BED greater than 75.2 GyE than for patients receiving BED of 75.2 GyE or lower (84.6%, p = 0.029). The overall survival rate at 1 year was 65.6% for HCC and 81.8% for ICC. Conclusions Hypofractionated PBT results in excellent LC, sparing of the uninvolved liver, and low toxicity, even in the setting of dose-escalation. Higher dose correlates with improved LC, highlighting the importance of PBT especially in patients with recurrent or bulky disease.

Purpose A multi-field optimization (MFO) technique that uses beam-specific spot placement volumes (SPVs) and spot avoidance volumes (SAVs) is introduced for bilateral head and neck (H&N) cancers. These beam-specific volumes are used to guide the optimizer to consistently achieve optimal organ-at-risk (OAR) sparing with target coverage and plan robustness. Materials and Methods Implementation of this technique using a 4-beam, 5-beam, and variant 5-beam arrangement is discussed. The generation of beam-specific SPVs and SAVs derived from target and OARs are shown. The SPVs for select fields are further partitioned into optimization volumes for uniform dose distributions that resemble those of single-field optimization (SFO). A conventional MFO plan that does not use beam-specific spot placement guidance (MFOcon) and an MFO plan that uses only beam-specific SPV (MFOspv) are compared with current technique (MFOspv/sav), using both simulated scenarios and forward-calculated plans on weekly verification computed tomography (VFCT) scans. Results Dose distribution characteristics of the 4-beam, 5-beam, and variant 5-beam technique are demonstrated with discussion on OAR sparing. When comparing the MFOcon, MFOspv, and MFOspv/sav, the MFOspv/sav is shown to have superior OAR sparing in 9 of the 14 OARs examined. It also shows clinical plan robustness when evaluated by using both simulated uncertainty scenarios and forward-calculated weekly VFCTs throughout the 7-week treatment course. Conclusion The MFOspv/sav technique is a systematic approach using SPVs and SAVs to guide the optimizer to consistently reach desired OAR dose values and plan robustness.

Purpose Whole brain radiation therapy (WBRT) remains a commonly used cancer treatment, although controversy exists regarding the optimal dose/fractionation to optimize intracranial tumor control and minimize resultant cognitive deficits. Methods and Materials NCCTG N107C [Alliance]/CEC.3 randomized 194 patients with brain metastases to either stereotactic radiosurgery alone or WBRT after surgical resection. Among the 92 patients receiving WBRT, sites predetermined the dose/fractionation that would be used for all patients treated at that site (either 30 Gy in 10 fractions or 37.5 Gy in 15 fractions). Analyses were performed using Kaplan-Meier estimates, log rank tests, and Fisher’s exact tests. Results Among 92 patients treated with surgical resection and adjuvant WBRT, 49 were treated with 30 Gy in 10 fractions (53%), and 43 were treated with 37.5 Gy in 15 fractions (47%). Baseline characteristics, including cognitive testing, were well balanced between groups with the exception of primary tumor type (lung cancer histology was more frequent with protracted WBRT: 72% vs 45%, P = .01), and 93% of patients completed the full course of WBRT. A more protracted WBRT dose regimen (37.5 Gy in 15 fractions) did not significantly affect time to cognitive failure (hazard ratio [HR], 0.9; 95% confidence interval [CI], 0.6-1.39; P = .66), surgical bed control (HR, 0.52 [95% CI, 0.22-1.25], P = .14), intracranial tumor control (HR, 0.56 [95% CI, 0.28-1.12], P = .09), or overall survival (HR, 0.72 [95% CI, 0.45-1.16], P = .18). Although there was no reported radionecrosis, there is a statistically significant increase in the risk of at least 1 grade ≥3 adverse event with 37.5 Gy in 15 fractions versus 30 Gy in 10 fractions (54% vs 31%, respectively, P = .03). Conclusions This post hoc analysis does not demonstrate that protracted WBRT courses reduce the risk of cognitive deficit, improve tumor control in the hypoxic surgical cavity, or otherwise improve the therapeutic ratio. Adverse events were significantly higher with the lengthened course of WBRT. For patients with brain metastases where WBRT is recommended, shorter course hypofractionated regimens remain the current standard of care.

Purpose This study examined an inflammatory biomarker, high-sensitivity C-reactive protein (hsCRP), in radiotherapy (RT)-induced early adverse skin reactions or toxicities in breast cancer. Patients and Methods Between 2011 and 2013, 1,000 patients with breast cancer who underwent RT were evaluated prospectively for skin toxicities through the National Cancer Institute–funded Wake Forest University Community Clinical Oncology Program Research Base. Pre- and post-RT plasma hsCRP levels and Oncology Nursing Society skin toxicity criteria (0 to 6) were used to assess RT-induced skin toxicities. Multivariable logistic regression analyses were applied to ascertain the associations between hsCRP and RT-induced skin toxicities after adjusting for potential confounders. Results The study comprised 623 white, 280 African American, 64 Asian/Pacific Islander, and 33 other race patients; 24% of the patients were Hispanic, and 47% were obese. Approximately 42% and 15% of patients developed RT-induced grade 3+ and 4+ skin toxicities, respectively. The hsCRP levels differed significantly by race and body mass index but not by ethnicity. In multivariable analysis, grade 4+ skin toxicity was significantly associated with obesity (odds ratio [OR], 2.17; 95% CI, 1.41 to 3.34], post-RT hsCRP ≥ 4.11 mg/L (OR, 1.61; 95% CI, 1.07 to 2.44), and both factors combined (OR, 3.65; 95% CI, 2.18 to 6.14). Above-median post-RT hsCRP (OR, 1.93; 95% CI, 1.03 to 3.63), and change in hsCRP (OR, 2.80; 95% CI, 1.42 to 5.54) were significantly associated with grade 4+ skin toxicity in nonobese patients. Conclusion This large prospective study is the first to our knowledge of hsCRP as an inflammatory biomarker in RT-induced skin toxicities in breast cancer. We demonstrate that nonobese patients with elevated RT-related change in hsCRP levels have a significantly increased risk of grade 4+ skin toxicity. The outcomes may help to predict RT responses and guide decision making.

PurposeTo investigate the safety of accelerated hypofractionated radiation therapy (AHRT) with concurrent chemotherapy (CT) for inoperable stage III non-small cell lung cancer (NSCLC).Patients and methodsThe primary objectives were to define the maximally tolerable course of accelerated radiation therapy and to describe toxicities of therapy. Total radiation therapy remained at 60Gy. The number of once-daily fractions in each successive cohort was reduced as follows: cohort 1, 60Gy in 27 fractions; cohort 2, 60Gy in 24 fractions; cohort 3, 60Gy in 22 fractions; and cohort 4, 60Gy in 20 fractions. Concurrent treatment consisted of weekly carboplatin area under the curve (AUC) 2 and paclitaxel 45mg/m2. Consolidation treatment consisted of carboplatin AUC 6 and paclitaxel 200mg/m2 every weeks×2 cycles. Maximum tolerated dose: Of 6 patients/cohort, ≤2 patients experienced grade ≥3 toxicity, and ≤1 patient experienced grade ≥4 toxicity.Results22 patients were accrued; of those, 21 patients were evaluable between July 2012 and May 2014. Grade 5 toxicity occurred in 3 patients: 1 patient in cohort 2 (hemoptysis), 2 patients in cohort 3 (hemoptysis, pneumonitis). The maximum tolerated dose (MTD) was defined by cohort 2 (60Gy in 2.5Gy/fraction). Time to grade 5 toxicity was 9months, 6months, and 9months after the start of treatment. The median follow-up time was 23.0months (range, 7.6-30.6months) in living patients, the median overall survival was 19.3months (95% confidence interval [CI] 9.3-34.0months), and the median progression-free survival was 12.2months (95% CI 6.1-22.5months).ConclusionsOnly modest hypofractionation was achievable as a result of long-term toxicities. Nevertheless, the MTD of 60Gy given at 2.5Gy/fraction allows completion of RT in 20% fewer treatments than conventional therapy. Further investigation of AHRT may help to better define the therapeutic index.

Background Stereotactic body radiation therapy (SBRT) has been proposed as a potential alternative to surgery for early lung cancer, although we lack well-powered prospective randomized data comparing these treatments, and existing studies suffer from incomplete information on confounders that can bias results. Here, we evaluated the comparative effectiveness of surgery and SBRT in lung cancer treatment using a large extensively detailed database from the Veteran's Affairs system. Methods We identified veterans with biopsy-proven clinical stage I non-small cell lung cancer diagnosed between 2006 and 2015 from within the Veteran's Affairs Informatics and Computing Infrastructure. We compared cancer-specific survival among patients receiving lobectomy, sublobar resection, or SBRT using univariable and multivariable competing risk analyses. Multivariable analyses adjusted for confounders including preoperative pulmonary function, smoking status, comorbidity, and staging workup procedures. Results In all, 4,069 patients were included (449 SBRT, 2,986 lobectomy, 634 sublobar resection). Unadjusted analysis found higher immediate postprocedural mortality in the surgery groups compared with the SBRT group. The multivariable analysis considering long-term survival found higher cancer-specific mortality for SBRT compared with lobectomy (subdistribution hazard ratio 1.45, 95% confidence interval: 1.09 to 1.94, p = 0.01), although no survival difference between SBRT and sublobar resection (subdistribution hazard ratio 1.25, 95% confidence interval: 0.93 to 1.68, p = 0.15). Conclusions Among a large cohort of early stage lung cancer patients, we found that lobectomy had improved survival compared with SBRT, although we found no survival difference between sublobar resection and SBRT. Despite these findings, the potential for unmeasured confounding remains and prospective randomized trials are needed to better compare these treatment modalities.

PURPOSE Patients with centrally located early-stage non–small-cell lung cancer (NSCLC) are at a higher risk of toxicity from high-dose ablative radiotherapy. NRG Oncology/RTOG 0813 was a phase I/II study designed to determine the maximum tolerated dose (MTD), efficacy, and toxicity of stereotactic body radiotherapy (SBRT) for centrally located NSCLC. MATERIALS AND METHODS Medically inoperable patients with biopsy-proven, positron emission tomography–staged T1 to 2 (≤ 5 cm) N0M0 centrally located NSCLC were accrued into a dose-escalating, five-fraction SBRT schedule that ranged from 10 to 12 Gy/fraction (fx) delivered over 1.5 to 2 weeks. Dose-limiting toxicity (DLT) was defined as any treatment-related grade 3 or worse predefined toxicity that occurred within the first year. MTD was defined as the SBRT dose at which the probability of DLT was closest to 20% without exceeding it. RESULTS One hundred twenty patients were accrued between February 2009 and September 2013. Patients were elderly, there were slightly more females, and the majority had a performance status of 0 to 1. Most cancers were T1 (65%) and squamous cell (45%). Organs closest to planning target volume/most at risk were the main bronchus and large vessels. Median follow-up was 37.9 months. Five patients experienced DLTs; MTD was 12.0 Gy/fx, which had a probability of a DLT of 7.2% (95% CI, 2.8% to 14.5%). Two-year rates for the 71 evaluable patients in the 11.5 and 12.0 Gy/fx cohorts were local control, 89.4% (90% CI, 81.6% to 97.4%) and 87.9% (90% CI, 78.8% to 97.0%); overall survival, 67.9% (95% CI, 50.4% to 80.3%) and 72.7% (95% CI, 54.1% to 84.8%); and progression-free survival, 52.2% (95% CI, 35.3% to 66.6%) and 54.5% (95% CI, 36.3% to 69.6%), respectively. CONCLUSION The MTD for this study was 12.0 Gy/fx; it was associated with 7.2% DLTs and high rates of tumor control. Outcomes in this medically inoperable group of mostly elderly patients with comorbidities were comparable with that of patients with peripheral early-stage tumors.

8513 Background: A minority of the approximately 40,000 US patients diagnosed annually with stage III NSCLC can be cured by concurrent CRT. Standard adjuvant immune checkpoint inhibitors (ICI) improve outcome for those patients who complete CRT with good performance status (PS) and without disease progression, but most patients diagnosed with unresectable stage III NSCLC will not meet the criteria for adjuvant ICI. AFT-16 investigated safety and efficacy of neoadjuvant and adjuvant atezolizumab as a strategy that may allow more patients to benefit from ICI. Methods: Eligible patients received 4 cycles (cy) of atezolizumab 1200 mg IV q 21 days followed by CRT with 60 Gy + weekly carboplatin and paclitaxel (CP), CP consolidation and adjuvant atezolizumab to complete 1 year of therapy (17 cy). The primary endpoint of disease control rate at 12 weeks (wks) has been reported. Secondary endpoints reported here include overall response rate, safety, and progression-free and overall survival (PFS, OS) measured from the start of induction therapy. Correlative science data and quality of life endpoints will be reported elsewhere. Results: 64 patients with unresectable stage III NSCLC, PS 0-1 and no active autoimmune disease or significant organ dysfunction were enrolled at 13 Alliance for Clinical Trials in Oncology sites from 11/2017 to 7/2019. 62 patients who received at least one dose of atezolizumab are included in this analysis. Median age was 63.9 years (range 38.1-86.5). Patients were 51.6% female, 77.4% white, 88.7% current & former smokers and 56.5% PS 0. All patients are off study treatment. Mean cycles of treatment received was 9 (1-17). 46 patients were alive at median follow up 24.1 mo (range 3 – 34.1 mo). PFS at 12 and 18 mo from start of induction atezolizumab was 66% (95%CI 55-79) and 57% (95%CI 45-71) respectively. Median PFS was 23.7 mo (95%CI 13.2-NE). OS at 18 mo was 84% (95%CI 75-94). Median OS is not yet estimable. Atezolizumab was well tolerated. One grade (gr) 4 Guillain-Barre syndrome and 1 each gr 3 pneumonia, pneumonitis and colitis were attributable to neoadjuvant atezolizumab. The remaining 9 severe adverse events were unrelated to ICI. Conclusions: Atezolizumab prior to and following CRT for stage III unresectable NSCLC was well tolerated with encouraging PFS and OS without unexpected safety signals. Analysis of correlative endpoints and quality of life are ongoing. Further study of induction atezolizumab is warranted in patients with unresectable stage III NSCLC. Support: https://acknowledgments.alliancefound.org ; Clinical trial information: NCT03102242.

Purpose Image guided radiation therapy (IGRT) is designed to ensure accurate and precise targeting, but whether improved clinical outcomes result is unknown. Methods and materials A retrospective comparison of locally advanced lung cancer patients treated with and without IGRT from 2001 to 2012 was conducted. Median local failure-free survival (LFFS), regional, locoregional failure-free survival (LRFFS), distant failure-free survival, progression-free survival, and overall survival (OS) were estimated. Univariate and multivariate models assessed the association between patient- and treatment-related covariates and local failure. Results A total of 169 patients were treated with definitive radiation therapy and concurrent chemotherapy with a median follow-up of 48 months in the IGRT cohort and 96 months in the non-IGRT cohort. IGRT was used in 36% (62 patients) of patients. OS was similar between cohorts (2-year OS, 47% vs 49%, P = .63). The IGRT cohort had improved 2-year LFFS (80% vs 64%, P = .013) and LRFFS (75% and 62%, P = .04). Univariate analysis revealed IGRT and treatment year improved LFFS, whereas group stage, dose, and positron emission tomography/computed tomography planning had no impact. IGRT remained significant in the multivariate model with an adjusted hazard ratio of 0.40 ( P = .01). Distant failure-free survival (58% vs 59%, P = .67) did not differ significantly. Conclusion IGRT with daily cone beam computed tomography confers an improvement in the therapeutic ratio relative to patients treated without this technology.

9045 Background: A minority of the > 40,000 patients (pts) diagnosed with stage III NSCLC annually in the US are cured by CRT, more recently followed by adjuvant immune checkpoint inhibitors (ICI). PD-L1 blockade with CRT may attenuate tumor-related immunosuppression via depletion of regulatory T cells and clonal expansion of effector T cells. Further, CRT may expose otherwise hidden antigens that present additional targets to the reconstituting immune system. Adjuvant ICI has improved survival. Whether ICI before CRT will further improve outcomes is unknown. Methods: This Alliance Foundation Trials (AFT) study evaluated safety and efficacy of atezolizumab before and after CRT. 4 cycles of atezolizumab 1200 mg IV q 21 days with restaging after cycles 2 and 4 were followed by carboplatin and paclitaxel (C/P) weekly with 60 Gy radiation and C/P consolidation followed by atezolizumab for 1 year of therapy. Primary endpoint is disease control rate (DCR) (complete response + partial response (PR) + stable disease (SD)) at 12 weeks (wks). Secondary endpoints include overall response rate, progression-free survival, overall survival, safety and quality of life assessed by EORTC QLQ-30. Correlatives include PD-L1 and tumor mutation burden as predictive biomarkers. Tumor tissue was obtained at study entry; plasma and immune cells were isolated at multiple timepoints. Results: 64 pts with stage III NSCLC, performance status (PS) 0-1, no active autoimmune disease or significant organ dysfunction enrolled at 13 Alliance sites from 11/2017 to 7/2019. 62 pts received ≥ 1 dose of atezolizumab and are included in the primary analysis; median age 63.9 years (38.1-86.5), 51.6% female, 77.4% white, 61.3% former smokers, 56.5% PS 0. DCR at 12 wks was 77.4% (80% confidence interval 69.2-84.3%) (30.7% PR, 46.8% SD). 54 pts reported adverse events (AEs) during induction, mostly grade (gr) 1. There were 13 serious AEs, most unrelated to study treatment; 1 gr 3 anaphylactic reaction, 1 gr 3 colitis, and 1 gr 4 Guillain-Barre syndrome were attributable to atezolizumab. Baseline PD-L1 status was available for 49 pts. DCR was 82.4% for pts with PD-L1 negative and 90.9% for pts with PD-L1 positive tumors. Conclusions: Atezolizumab prior to and following CRT for stage III unresectable NSCLC was well tolerated with an encouraging 12-wk DCR. Analysis of secondary endpoints is ongoing. Further study of induction ICI therapy is warranted in patients with unresectable stage III NSCLC. Support: AFT, Genentech; Clinical trial information: NCT03102242.

Pulmonary blastoma is a rare lung cancer classified into three subtypes: classic biphasic pulmonary blastoma (CBPB), well-differentiated fetal adenocarcinoma (WDFA), and pleuropulmonary blastoma (PPB) of childhood. Compared to the other subtypes, CPPB is an aggressive tumor with an overall five-year survival of 16% across all stages. We present two cases of biopsy-proven metastatic CBPB, who have been disease-free for over 10 years since treatment completion. Both patients were treated with surgery to the primary tumor followed by an adjuvant cisplatin-based chemotherapy for four cycles and thoracic radiation. One patient relapsed shortly after the completion of thoracic radiation with brain metastases and underwent craniotomy, gamma knife radiosurgery (GKRS), and whole brain radiation therapy. The other patient presented with synchronous pelvic metastases and underwent metastasectomy after the completion of chemotherapy but before the initiation of thoracic radiation. We review the literature regarding surgical, chemotherapeutic, and radiation treatment for patients with metastatic pulmonary blastoma. Based on our experience and review of the existing case reports, aggressive tri-modality treatment including surgery, chemotherapy with a cisplatin backbone, and a definitive treatment of oligometastatic lesions amenable to local therapy including resection or radiosurgery is reasonable to consider for medically fit patients with CBPB.

PurposeTo present long-term results of RTOG 0915/NCCTG N0927, a randomized lung stereotactic body radiation therapy trial of 34Gy in 1 fraction versus 48Gy in 4 fractions.Methods and materialsThis was a phase 2 multicenter study of patients with medically inoperable non-small cell lung cancer with biopsy-proven peripheral T1 or T2 N0M0 tumors, with 1-year toxicity rates as the primary endpoint and selected failure and survival outcomes as secondary endpoints. The study opened in September 2009 and closed in March 2011. Final data were analyzed through May 17,2018.ResultsEighty-four of 94 patients accrued were eligible for analysis: 39 in arm 1 and 45 in arm 2. Median follow-up time was 4.0years for all patients and 6.0years for those alive at analysis. Rates of grade 3 and higher toxicity were 2.6% in arm 1 and 11.1% in arm 2. Median survival times (in years) for 34Gy and 48Gy were 4.1 versus 4.6, respectively. Five-year outcomes (95% confidence interval) for 34Gy and 48Gy were a primary tumor failure rate of 10.6% (3.3%-23.1%) versus 6.8% (1.7%-16.9%); overall survival of 29.6% (16.2%-44.4%) versus 41.1% (26.6%-55.1%); and progression-free survival of 19.1% (8.5%-33.0%) versus 33.3% (20.2%-47.0%). Distant failure as the sole failure or a component of first failure occurred in 6 patients (37.5%) in the 34Gy arm and in 7 (41.2%) in the 48Gy arm.ConclusionsNo excess in late-appearing toxicity was seen in either arm. Primary tumor control rates at 5years were similar by arm. A median survival time of 4years for each arm suggests similar efficacy, pending any larger studies appropriately powered to detect survival differences.

Author(s): Hong, Julian C; Ayala-Peacock, Diandra N; Lee, Jason; Blackstock, A William; Okunieff, Paul; Sung, Max W; Weichselbaum, Ralph R; Kao, Johnny; Urbanic, James J; Milano, Michael T; Chmura, Steven J; Salama, Joseph K | Abstract: BackgroundRadiotherapy is increasingly used to treat oligometastatic patients. We sought to identify prognostic criteria in oligometastatic patients undergoing definitive hypofractionated image-guided radiotherapy (HIGRT).MethodsExclusively extracranial oligometastatic patients treated with HIGRT were pooled. Characteristics including age, sex, primary tumor type, interval to metastatic diagnosis, number of treated metastases and organs, metastatic site, prior systemic therapy for primary tumor treatment, prior definitive metastasis-directed therapy, and systemic therapy for metastasis associated with overall survival (OS), progression-free survival (PFS), and treated metastasis control (TMC) were assessed by the Cox proportional hazards method. Recursive partitioning analysis (RPA) identified prognostic risk strata for OS and PFS based on pretreatment factors.Results361 patients were included. Primary tumors included non-small cell lung (17%), colorectal (19%), and breast cancer (16%). Three-year OS was 56%, PFS was 24%, and TMC was 72%. On multivariate analysis, primary tumor, interval to metastases, treated metastases number, and mediastinal/hilar lymph node, liver, or adrenal metastases were associated with OS. Primary tumor site, involved organ number, liver metastasis, and prior primary disease chemotherapy were associated with PFS. OS RPA identified five classes: class 1: all breast, kidney, or prostate cancer patients (BKP) (3-year OS 75%, 95% CI 66-85%); class 2: patients without BKP with disease-free interval of 75+ months (3-year OS 85%, 95% CI 67-100%); class 3: patients without BKP, shorter disease-free interval, ≤ two metastases, and age l 62 (3-year OS 55%, 95% CI 48-64%); class 4: patients without BKP, shorter disease-free interval, ≥ three metastases, and age l 62 (3-year OS 38%, 95% CI 24-60%); class 5: all others (3-year OS 13%, 95% CI 5-35%). Higher biologically effective dose (BED) (p l 0.01) was associated with OS.ConclusionsWe identified clinical factors defining oligometastatic patients with favorable outcomes, who we hypothesize are most likely to benefit from metastasis-directed therapy.

PURPOSE: Recent data indicate consolidative radiation therapy improves progression-free survival (PFS) for patients with oligometastatic non-small cell lung cancer (NSCLC). Data on long-term outcomes are limited. METHODS AND MATERIALS: This prospective, multicenter, single-arm, phase 2 trial was initiated in 2010 and enrolled patients with oligometastatic NSCLC. Oligometastatic disease was defined as a maximum of 5 metastatic lesions for all disease sites, including no more than 3 active extracranial metastatic lesions. Limited mediastinal lymph node involvement was allowed. Patients achieving a partial response or stable disease after 3 to 6 cycles of platinum-based chemotherapy were treated with CRT to the primary and metastatic sites of disease, followed by observation alone. The primary endpoint was PFS, with secondary endpoints of local control, overall survival (OS), and safety. RESULTS: Twenty-nine patients were enrolled between October 2010 and October 2015, and 27 were eligible for consolidative radiation therapy. The study was closed early because of slow accrual but met its primary endpoint for success, which was PFS >6 months (P < .0001). The median PFS (95% confidence interval) was 11.2 months (7.6–15.9 months), and the median OS was 28.4 months (14.5–45.8 months). Survival outcomes were not significantly different for patients with brain metastases (P = .87 for PFS; P = .12 for OS) or lymph node involvement (P = .74 for PFS; P = .86 for OS). CONCLUSIONS: For patients with oligometastatic NSCLC, chemotherapy followed by consolidative radiation therapy without maintenance chemotherapy was associated with encouraging long-term outcomes.

Purpose To compare 2 stereotactic body radiation therapy (SBRT) schedules for medically inoperable early-stage lung cancer to determine which produces the lowest rate of grade ≥3 protocol-specified adverse events (psAEs) at 1 year. Methods and Materials Patients with biopsy-proven peripheral (≥2 cm from the central bronchial tree) T1 or T2, N0 (clinically node negative by positron emission tomography), M0 tumors were eligible. Patients were randomized to receive either 34 Gy in 1 fraction (arm 1) or 48 Gy in 4 consecutive daily fractions (arm 2). Rigorous central accreditation and quality assurance confirmed treatment per protocol guidelines. This study was designed to detect a psAEs rate >17% at a 10% significance level (1-sided) and 90% power. Secondary endpoints included rates of primary tumor control (PC), overall survival (OS), and disease-free survival (DFS) at 1 year. Designating the better of the 2 regimens was based on prespecified rules of psAEs and PC for each arm. Results Ninety-four patients were accrued between September 2009 and March 2011. The median follow-up time was 30.2 months. Of 84 analyzable patients, 39 were in arm 1 and 45 in arm 2. Patient and tumor characteristics were balanced between arms. Four (10.3%) patients on arm 1 (95% confidence interval [CI] 2.9%-24.2%) and 6 (13.3%) patients on arm 2 (95% CI 5.1%-26.8%) experienced psAEs. The 2-year OS rate was 61.3% (95% CI 44.2%-74.6%) for arm 1 patients and 77.7% (95% CI 62.5%-87.3%) for arm 2. The 2-year DFS was 56.4% (95% CI 39.6%-70.2%) for arm 1 and 71.1% (95% CI 55.5%-82.1%) for arm 2. The 1-year PC rate was 97.0% (95% CI 84.2%-99.9%) for arm 1 and 92.7% (95% CI 80.1%-98.5%) for arm 2. Conclusions 34 Gy in 1 fraction met the prespecified criteria and, of the 2 schedules, warrants further clinical research.

Background The purpose of this study was to examine outcomes, toxicity, and dosimetric characteristics of patients treated with reirradiation for head and neck cancers. Methods Fifty patients underwent ≥2 courses of radiation therapy (RT) postoperatively or definitively with or without chemotherapy. Composite dose volume histograms (DVHs) for selected anatomic structures were correlated with grade ≥3 late toxicity. Results Median initial and retreatment radiation dose was 64 and 60 Gy, respectively. Median overall survival (OS), progression-free survival (PFS), and 1-year PFS rates were 18 months, 11 months, and 45%, respectively, with 13 months median follow-up. Thirty-four percent of patients experienced grade ≥3 late toxicity with 1 death from carotid blowout. The DVH corresponding to the carotid blowout fell above the third quartile compared with other patients. Conclusion Our analysis is the first to systematically evaluate the dose to the carotid artery using composite dosimetry in head and neck reirradiation patients, and demonstrates a promising technique for evaluating the dose to other normal tissue structures. © 2015 Wiley Periodicals, Inc. Head Neck, 2015

Objectives To examine the efficacy of prophylactic cranial irradiation (PCI) in elderly patients with small cell lung cancer (SCLC) (≥70years of age) from a pooled analysis of four prospective trials. Materials & Methods One hundred fifty-five patients with SCLC (limited stage, LSCLC, and extensive stage, ESCLC) participated in four phase II or III trials. Ninety-one patients received PCI (30Gy/15 or 25Gy/10) and 64 patients did not receive PCI. Survival was compared in a landmark analysis that included only patients who had stable disease or better in response to primary therapy. Results Patients who received PCI had better survival than patients who did not receive PCI (median survival 12.0months vs. 7.6months, 3-year overall survival 13.2% vs. 3.1%, HR=0.53 [95% CI 0.36–0.78], p =0.001). On multivariate analysis of the entire cohort, the only factor that remained significant for survival was stage (ESCLC vs. LSCLC, p =0.0072). In contrast, the multivariate analysis of patients who had ESCLC revealed that PCI was the sole factor associated with a survival advantage (HR=0.47 [95% CI 0.24–0.93], p =0.03). Grade 3 or higher adverse events (AEs) were significantly greater in patients who received PCI (71.4% vs. 47.5%, p =0.0031), with non-neuro and non-heme being the specific AE categories most strongly correlated with PCI delivery. Conclusions PCI was associated with a significant improvement in survival for our entire elderly SCLC patient cohort on univariate analysis. Multivariate analysis suggested that the survival advantage remained significant in patients with ESCLC. PCI was also associated with a modest increase in grade 3 or higher AEs.

Introduction NRG Oncology RTOG 0937 is a randomized phase II trial evaluating 1-year overall survival (OS) with prophylactic cranial irradiation (PCI) or PCI plus consolidative radiation therapy (PCI+cRT) to intrathoracic disease and extracranial metastases for extensive-disease SCLC. Methods Patients with one to four extracranial metastases were eligible after a complete response or partial response to chemotherapy. Randomization was to PCI or PCI+cRT to the thorax and metastases. Original stratification included partial response versus complete response after chemotherapy and one versus two to four metastases; age younger than 65 years versus 65 years or older was added after an observed imbalance. PCI consisted of 25 Gy in 10 fractions. cRT consisted of 45 Gy in 15 fractions. To detect an improvement in OS from 30% to 45% with a 34% hazard reduction (hazard ratio = 0.66) under a 0.1 type 1 error (one sided) and 80% power, 154 patients were required. Results A total of 97 patients were randomized between March 2010 and February 2015. Eleven patients were ineligible (nine in the PCI group and two in the PCI+cRT group), leaving 42 randomized to receive PCI and 44 to receive PCI+cRT. At planned interim analysis, the study crossed the futility boundary for OS and was closed before meeting the accrual target. Median follow-up was 9 months. The 1-year OS was not different between the groups: 60.1% (95% confidence interval [CI]: 41.2–74.7) for PCI and 50.8% (95% CI: 34.0–65.3) for PCI+cRT ( p = 0.21). The 3- and 12-month rates of progression were 53.3% and 79.6% for PCI and 14.5% and 75% for PCI+cRT, respectively. Time to progression favored PCI+cRT (hazard ratio = 0.53, 95% CI: 0.32–0.87, p = 0.01). One patient in each arm had grade 4 therapy-related toxicity and one had grade 5 therapy-related pneumonitis with PCI+cRT. Conclusions OS exceeded predictions for both arms. cRT delayed progression but did not improve 1-year OS.

Management for in-field failures after thoracic radiation is poorly defined. We evaluated SBRT as an initial or second course of treatment re-irradiating in a prior high dose region.Thirty-three patients were treated with re-irradiation defined by the prior 30 Gy isodose line. Kaplan-Meier estimates were performed for local (LC), regional (RC), distant control (DC), and overall survival (OS). The plans when available were summed to evaluate doses to critical structures. Patient and treatment variables were analyzed on UVA for the impact on control and survival measures.Median follow-up was 17 months. Treatment for sequential courses was as follows: (course1:course2) EBRT:SBRT (24 patients), SBRT:SBRT (7 patients), and SBRT:EBRT (3 patients). Median re-irradiation dose and fractionation was 50 Gy and 10 fractions (fx), with a median of 18 months (6-61) between treatments. Median OS was 21 months and 2 year LC 67%, yet LC for1 fraction was 88% (p=0.006 for single vs. multiple). 10 patients suffered chronic grade 2-3 toxicity (6 chest wall pain, 3 dyspnea, 1 esophagitis) and 1 grade 5 toxicity with aorta-esophageal fistula after 54 Gy in 3 fx for a central tumor with an estimated EQD2 to the aorta of 200 Gy.Tumor control can be established with re-irradiation using SBRT techniques for in-field thoracic failures at the cost of manageable toxicity.

Gamma Knife Radiosurgery (GKRS) has been reported in the treatment of brainstem metastases while dose volume toxicity thresholds remain mostly undefined. A retrospective review of 52 brainstem metastases in 44 patients treated with GKRS was completed. A median dose of 18 Gy (range 10–22 Gy) was prescribed to the tumor margin (median 50 % isodose). 25 patients had undergone previous whole brain radiation therapy. Toxicity was graded by the LENT-SOMA scale. Mean and median follow-up was 10 and 6 months. Only 3 of the 44 patients are living. Multiple brain metastases were treated in 75 % of patients. Median size of lesions was 0.134 cc, (range 0.013–6.600 cc). Overall survival rate at 1 year was 32 % (95 % CI 51.0–20.1 %) with a median survival time of 6 months (95 % CI 5.0–16.5). Local control rate at 6 months and 1 year was 88 % (95 % CI 70–95 %) and 74 % (95 % CI 52–87 %). Cause of death was neurologic in 17 patients, non-neurologic in 20 patients, and unknown in four. Four patients experienced treatment related toxicities. Univariate analysis of tumor volume revealed that volume greater than 1.0 cc predicted for toxicity. A strategy of using lower marginal doses with GKRS to brain stem metastases appears to lead to a lower local control rate than seen with lesions treated within the standard dose range in other locations. Tumor size greater than 1.0 cc predicted for treatment-related toxicity.

e20614 Background: The central nervous system (CNS) remains a common site of metastatic disease for NSCLC, especially in EGFR-driven disease. Surgery and RT are upfront treatment options but have potential early and late onset complications. Osimertinib (Osi) is now approved for use in the front-line setting for EGFR-mutated NSCLC and is highly CNS penetrant. A prior retrospective study showed that the use of early generation EGFR TKIs had an inferior overall survival (OS) compared to upfront RT in newly diagnosed brain metastases, but the applicability of this data in the Osi-era is unknown. Methods: This was a single institution retrospective analysis of patients with EGFR mutated NSCLC and brain metastases who were referred to Radiation Oncology from 1/1/2012 to 12/31/2018. We separated EGFR TKIs between Osi and non-Osi. The primary objectives were to evaluate OS, intracranial progression free survival (icPFS), and intracranial response (icORR) among upfront or delayed RT, and type of EGFR TKI. Results: 67 patients with a median age of 64 years old (33-89) were divided into one of four groups: non-Osi TKI with (N = 38) or without RT (N = 12), and Osi with (N = 14) or without RT (N = 3). Fourteen patients who did not get upfront Osi, received Osi with (N = 7) or without RT (N = 7) after intracranial progressive disease (icPD). Patients were predominantly female, never-smokers, and with an ECOG PS 0-1. Brain metastases were mostly asymptomatic and < 10 mm. The OS for the entire population was 26.7 months (95% CI, 23.9-29.5); there was no difference between groups, and use or type of RT versus TKI. The icPFS was 14.3 months (95% CI, 9.1-19.5), icORR was 64.2%, and icDCR was 82.7%, without any difference between groups. Among those patients who did not receive upfront Osi, use in the post-progression setting resulted in a significantly longer OS (54.8 vs. 23.0 months, p = 0.001). Conclusions: We found no statistical difference in OS, icPFS, or icORR in patients treated with upfront RT or EGFR TKI. Results should be confirmed with a prospective study.

Overall survival of patients with brain metastases has improved in the past decade.1,2 Such improvement can often be offset by the late toxicities of whole-brain radiotherapy (WBRT), for which the likelihood and severity of cognitive decline continues to worsen with time.3 Multiple randomized trials have now shown that using radiosurgery as an upfront single modality and without WBRT does not affect overall survival in select patients.4,5 However, there are patients who will experience early or multiple distant brain failures, and these patients will likely need WBRT earlier in the course of their disease. As a result, an increasing emphasis is being placed on prognostic factors that may distinguish populations that benefit more from upfront radiosurgery from those that may benefit from upfront WBRT. Recent data from the scientific literature have suggested that the natural history of brain metastases can depend on the histological subtype of the primary cancer. Some histologies such as renal cell carcinoma have proved more radioresistant.6 Even for tumors of the same primary histology, such as invasive ductal carcinoma of the breast, there can be variability in the natural history of brain metastases depending on the Her2 receptor status of the individual patient’s cancer.7 It has been suggested that patients with melanoma and triple-negative breast cancers may have higher rates of distant brain failure after radiosurgery.8,9 Within lung cancer, there are several known differences between the various histological subtypes with regard to the natural history of the disease. Small cell lung cancer (SCLC) has a high rate of metastatic brain disease, and prophylactic cranial irradiation has in fact resulted in survival benefits both in limited- and extensive-stage disease.10,11 Adenocarcinoma appears to have a survival advantage over squamous cell carcinoma (SCC) within the non-small cell subtypes in the setting of locally advanced disease.12 It has been previously unknown, however, whether biological differences in various subtypes of lung cancer affect the biological behavior of brain metastases. Objectives To this end, we present a single-institution retrospective review of patients with lung cancer and first diagnosis of brain metastases treated with Gamma Knife radiosurgery (GKRS) and without previous therapeutic WBRT. Our analysis focuses on variations of clinical outcomes caused by histological differences of the primary cancer. Furthermore, we evaluate factors that may predict survival, distant brain failure, and neurological death.

Radiation Therapy Oncology Group (RTOG) 3505 is a randomized phase 3 study of concurrent chemoradiation followed by immune checkpoint inhibitor therapy or placebo in patients with locally advanced non-small-cell lung cancer (NSCLC). Patients with surgically unresectable stage 3 NSCLC will receive thoracic radiotherapy to 60 Gy with concurrent cisplatin 50 mg/m2 intravenously (I.V.) on days 1, 8, 29, and 36, and etoposide 50 mg/m2 I.V. on days 1 to 5 and days 29 to 33. Between 4 and 12 weeks after completion of concurrent chemoradiation, eligible patients will be randomized to the anti-programmed death 1 (PD-1) monoclonal antibody nivolumab 240 mg I.V. or placebo every 2 weeks for up to 1 year. The primary end points are overall survival (OS) and progression-free survival (PFS), as determined by central independent radiology review. Secondary objectives include toxicity assessment, patient-reported outcomes and quality of life, and OS and PFS in programmed death ligand 1 (PD-L1) expressors (≥ 1%) and PD-L1 nonexpressors (< 1%). Assuming a rate of 16.7% due to ineligibility and dropout before randomization, a total of 660 patients will be enrolled to ensure 550 patients will be randomized after completion of chemoradiation. This sample size will provide≥ 90% power to detect a hazard ratio of 0.7 for OS with 2-sided type I error of 0.04, and to detect a hazard ratio of 0.667 for PFS 2-sided type I error of 0.01. (NCT02768558).

Objective: We hypothesized that omission of clinical target volumes (CTV) in lung cancer radiotherapy would not compromise control by determining retrospectively if the addition of a CTV would encompass the site of failure. Methods: Stage II-III patients were treated from 2009-2012 with daily cone-beam imaging and a 5 mm planning target volume (PTV) without a CTV. PTVs were expanded 1 cm and termed CTVretro. Recurrences were scored as 1) within the PTV, 2) within CTVretro, or 3) outside the PTV. Locoregional control (LRC), distant control (DC), progression-free survival (PFS), and overall survival (OS) were estimated. Result: Among 110 patients, Stage IIIA 57%, IIIB 32%, IIA 4%, and IIB 7%. Eighty-six percent of Stage III patients received chemotherapy. Median dose was 70 Gy (45-74 Gy) and fraction size ranged from 1.5-2.7 Gy. Median follow-up was 12 months, median OS was 22 months (95% CI 19-30 months), and LRC at two years was 69%. Fourteen local and eight regional events were scored with two CTVretro failures equating to a two-year CTV failure-free survival of 98%. Conclusion: Omission of a 1 cm CTV expansion appears feasible based on only two events among 110 patients and should be considered in radiation planning.

Introduction The goal of this study was to determine if clinically relevant endpoints were changed by improved MRI resolution during radiosurgical treatment planning. Methods and Materials Between 2003 and 2008, 200 consecutive patients with brain metastases treated with Gamma Knife radiosurgery (GKRS) using either 1.5 T or 3.0 T MRI for radiosurgical treatment planning were retrospectively analysed. The number of previously undetected metastases at time of radiosurgery, distant brain failures, time delay to whole brain radiotherapy (WBRT), overall survival and likelihood of neurological death were determined. Results Additional metastases were detected in 31.3% and 24.5% of patients at time of radiosurgery with 3.0 T and 1.5 T MRI, respectively (P = 0.27). Patients with multiple metastases at diagnostic scan were more likely to have additional metastases detected by 3.0 T MRI (P

Object Gamma Knife surgery (GKS) has been reported as an effective modality for treating brain metastases from renal cell carcinoma (RCC). The authors aimed to determine if targeted agents such as tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, and bevacizumab affect the patterns of failure of RCC after GKS. Methods Between 1999 and 2010, 61 patients with brain metastases from RCC were treated with GKS. A median dose of 20 Gy (range 13–24 Gy) was prescribed to the margin of each metastasis. Kaplan-Meier analysis was used to determine local control, distant failure, and overall survival rates. Cox proportional hazard regression was performed to determine the association between disease-related factors and survival. Results Overall survival at 1, 2, and 3 years was 38%, 17%, and 9%, respectively. Freedom from local failure at 1, 2, and 3 years was 74%, 61%, and 40%, respectively. The distant failure rate at 1, 2, and 3 years was 51%, 79%, and 89%, respectively. Twenty-seven percent of patients died of neurological disease. The median survival for patients receiving targeted agents (n = 24) was 16.6 months compared with 7.2 months (n = 37) for those not receiving targeted therapy (p = 0.04). Freedom from local failure at 1 year was 93% versus 60% for patients receiving and those not receiving targeted agents, respectively (p = 0.01). Multivariate analysis showed that the use of targeted agents (hazard ratio 3.02, p = 0.003) was the only factor that predicted for improved survival. Two patients experienced post-GKS hemorrhage within the treated volume. Conclusions Targeted agents appear to improve local control and overall survival in patients treated with GKS for metastastic RCC.