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Purpose Our previous work demonstrated that 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine (18F-DOPA) positron emission tomography (PET) is sensitive and specific for identifying regions of high density and biologically aggressive glioblastoma. The purpose of this prospective phase 2 study was to determine the safety and efficacy of biologic-guided, dose-escalated radiation therapy (DERT) using 18F-DOPA PET in patients with glioblastoma. Methods and Materials Patients with newly diagnosed, histologically confirmed glioblastoma aged ≥18 years without contraindications to 18F-DOPA were eligible. Target volumes included 51, 60, and 76 Gy in 30 fractions with a simultaneous integrated boost, and concurrent and adjuvant temozolomide for 6 months. 18F-DOPA PET imaging was used to guide DERT. The study was designed to detect a true progression-free survival (PFS) at 6 months (PFS6) rate ≥72.5% in O6‐methylguanine methyltransferase (MGMT) unmethylated patients (DE-Un), with an overall significance level (alpha) of 0.20 and a power of 80%. Kaplan-Meier analysis was performed for PFS and overall survival (OS). Historical controls (HCs) included 139 patients (82 unmethylated) treated on prospective clinical trials or with standard RT at our institution. Toxicities were evaluated with Common Terminology Criteria for Adverse Events v4.0. Results Between January 2014 and December 2018, 75 evaluable patients were enrolled (39 DE-Un, 24 methylated [DE-Mth], and 12 indeterminate). PFS6 for DE-Un was 79.5% (95% confidence interval, 63.1%-90.1%). Median PFS was longer for DE-Un patients compared with historical controls (8.7 months vs 6.6 months; P = .017). OS was similarly longer, but the difference was not significant (16.0 vs 13.5 months; P = .13). OS was significantly improved for DE-Mth patients compared with HC-Mth (35.5 vs 23.3 months; P = .049) despite nonsignificant improvement in PFS (10.7 vs 9.0 months; P = .26). Grade 3 central nervous system necrosis occurred in 13% of patients, but treatment with bevacizumab improved symptoms in all cases. Conclusions 18F-DOPA PET–guided DERT appears to be safe, and it significantly improves PFS in MGMT unmethylated glioblastoma. OS is significantly improved in MGMT methylated patients. Further investigation of 18F-DOPA PET biologic guided DERT for glioblastoma is warranted.

To determine whether whole-brain radiation therapy (WBRT) is associated with improved overall survival among non-small cell lung cancer (NSCLC) patients with favorable prognoses at diagnosis.In the N0574 trial, patients with 1 to 3 brain metastases were randomized to receive stereotactic radiosurgery (SRS) or SRS plus WBRT (SRS + WBRT), with a primary endpoint of cognitive deterioration. We calculated diagnosis-specific graded prognostic assessment (DS-GPA) scores for NSCLC patients and evaluated overall survival according to receipt of WBRT and DS-GPA score using 2 separate cut-points (≥2.0 vs2.0 and ≥2.5 vs2.5).A total of 126 NSCLC patients were included for analysis, with median follow-up of 14.2 months. Data for DS-GPA calculation were available for 86.3% of all enrolled NSCLC patients. Overall, 50.0% of patients had DS-GPA score ≥2.0, and 23.0% of patients had DS-GPA scores ≥2.5. The SRS and SRS + WBRT groups were well balanced with regard to prognostic factors. The median survival according to receipt of WBRT was 11.3 months (+WBRT) and 17.9 months (-WBRT) for patients with DS-GPA ≥2.0 (favorable prognoses, P=.63; hazard ratio 0.86; 95% confidence interval 0.47-1.59). Median survival was 3.7 months (+WBRT) and 6.6 months (-WBRT) for patients with DS-GPA2.0 patients (unfavorable prognoses, P=.85; hazard ratio 0.95; 95% confidence interval 0.56-1.62). Outcomes according to the receipt of WBRT and DS-GPA remained similar utilizing DS-GPA ≥2.5 as a cutoff for favorable prognoses. There was no interaction between the continuum of the DS-GPA groups and WBRT on overall survival (P=.53).We observed no significant differences in survival according to receipt of WBRT in favorable-prognosis NSCLC patients. This study further supports the approach of SRS alone in the majority of patients with limited brain metastases.