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Purpose: Optimal timing of SRS after surgical resection of brain metastases (BMs) remains debated but is generally advocated to occur within 4 weeks of surgery to account for cavity remodeling. Our study assesses this recommendation by examining cavity dynamics and any downstream effects on outcome. Methods: Post-operative MRIs were used to compare target lesion volumes to target volume at time of SRS. Spearman's analysis identified a relationship between the time to SRS (ttSRS) and target remodeling. The Mann-Whitney-U test compared median remodeling between groups receiving standard (=4 weeks) and late (>4 weeks) adjuvant SRS. Kaplan Meier functions estimated probabilities of local recurrence (LR) and survival (OS). A Cox proportional hazards model (CPH) identified predictors of OS, LR, and leptomeningeal disease (LMD). Results: Median ttSRS was 32 days (3-72). A positive correlation exists when comparing ttSRS to reduction in cavity volume (0-10 weeks; p = 0.01) with no difference in median cavity remodeling between standard and late SRS groups. OS and LR rates were respectively 53.3% and 70.2% at 12 months with no difference in OS (p = 0.16) or LR (p = 0.54) between standard and late SRS groups. Subtotal resection predicted LMD (HR: 6.37; p = 0.03). No grade 3 or higher toxicity was seen in follow-up. Conclusions: Resection cavities may continue to shrink well after resection. There is no significant difference in OS or LR based on ttSRS, however, treatment factors such as the extent of resection may account for outcomes such as LMD. [ABSTRACT FROM AUTHOR]

Purpose: Meningiomas are tumors originating from arachnoid cap cells on the surface of the brain or spinal cord. Treatment differs by grade but can consist of observation, surgery, radiation therapy or both. We utilized the National Cancer Database (NCDB) to compare trends in the use stereotactic radiosurgery (SRS) and external beam radiation therapy (EBRT) in the management of meningioma. Materials and Methods: We queried the NCDB from 2004-2015 for meningioma patients (grade 1-3) treated with radiation therapy, either SRS or EBRT. Multivariable logistic regression was used to identify predictors of each treatment and to generate a propensity score. Propensity adjusted Kaplan-Meier survival curve analysis and multivariable Cox hazards ratios were used to identify predictors of survival. Results: We identified 5,406 patients with meningioma meeting above criteria with 45%, 44%, and 11% having World Health Organization (WHO) grade 1, 2, and 3 disease, respectively. Median follow up was 43 months. Predictors for SRS were grade 1 disease, distance from treatment facility, and histology. The only predictor of EBRT was grade 3 disease. Treatment year, histology, race and female sex were associated with improved survival. Five- and 10-year survival rates were 89.2% versus 72.6% (p < 0.0001) and 80.3% versus 61.4% (p = 0.29) for SRS and EBRT respectively. After propensity matching 226 pairs were generated. For SRS, 5-year survival was not significantly improved at 88.2% compared with EBRT (p = 0.056). Conclusion: In the present analysis, predictors of SRS utilization in management of meningioma include WHO grade 1 disease, distance from treatment facility and histology whereas conventional EBRT utilization was associated with grade 2 and 3 disease. Future studies need to be performed in order to optimize management of atypical and malignant meningioma. [ABSTRACT FROM AUTHOR]

Purpose: Glioblastoma (GBM) carries a high propensity for in-field failure despite trimodality management. Past studies have failed to show outcome improvements with dose-escalation. Herein, we examined trends and outcomes associated with dose-escalation for GBM. Materials and Methods: The National Cancer Database was queried for GBM patients who underwent surgical resection and external-beam radiation with chemotherapy. Patients were excluded if doses were less than 59.4 Gy; dose-escalation referred to doses =66 Gy. Odds ratios identified predictors of dose-escalation. Univariable and multivariable Cox regressions determined potential predictors of overall survival (OS). Propensity-adjusted multivariable analysis better accounted for indication biases. Results: Of 33,991 patients, 1,223 patients received dose-escalation. Median dose in the escalation group was 70 Gy (range, 66 to 89.4 Gy). The use of dose-escalation decreased from 8% in 2004 to 2% in 2014. Predictors of escalated dose were African American race, lower comorbidity score, treatment at community centers, decreased income, and more remote treatment year. Median OS was 16.2 months and 15.8 months for the standard and dose-escalated cohorts, respectively (p = 0.35). On multivariable analysis, age >60 years, higher comorbidity score, treatment at community centers, decreased education, lower income, government insurance, Caucasian race, male gender, and more remote year of treatment predicted for worse OS. On propensity-adjusted multivariable analysis, age >60 years, distance from center >12 miles, decreased education, government insurance, and male gender predicted for worse outcome. Conclusion: Dose-escalated radiotherapy for GBM has decreased over time across the United States, in concordance with guidelines and the available evidence. Similarly, this large study did not discern survival improvements with dose-escalation. [ABSTRACT FROM AUTHOR]

PURPOSE: Preoperative chemoradiotherapy followed by radical surgical resection has been the preferred treatment for patients presenting with locally advanced distal rectal carcinoma at our institutions. We postulated that chemoradiotherapy-induced pathologic response of the primary tumor would identify which patients would be candidates for local excision as definitive surgical therapy. METHODS: A retrospective analysis of 60 patients with palpable, locally advanced, distal rectal adenocarcinomas treated from 1995 to 2000 was performed. All patients received preoperative chemoradiotherapy consisting of 5-fluorouracil (325 mg/ m²) and leucovorin (20 mg/m²) by bolus infusion on Days 1 through 5 and 29 through 33 delivered concurrently with at least 45.0 to 50.4 Gy of pelvic radiation, followed six to eight weeks later by radical surgery and then adjuvant chemotherapy. RESULTS: Among 60 patients (20 females) there was a mean age of 58.7 (28-84) years. Clinical staging was as follows: Stage II, 14 patients (23 percent); Stage III, 35 patients (58 percent): and Stage IV, 11 patients (18 percent). Pathologic examination revealed that negative margins were obtained in 58 patients (97 percent). Down-staging to T0-2N0 was achieved in 17 patients (28 percent), with five (8 percent) achieving a pathologically complete response. Lymph nodes were positive in 24 patients (40 percent) despite chemoradiotherapy. Pathologic node positivity was found in 0 of 5 pT0 patients, 9 (41 percent) of 22 pT1 or pT2, and 15 (45 percent) of 33 pT3. Clinical stage, tumor size, pathologic stage, and adverse histologic features could not reliably predict pN0 status, except pT0 (5 patients only). CONCLUSIONS: Preoperative chemoradiotherapy often downsizes and downstages locally advanced rectal carcinoma. Neither pretreatment clinical characteristics, response to preoperative chemoradiotherapy, or pathologic features reliably predict pN0 status. Therefore, local excision is not recommended as an alternative to radical surgery for locally advanced adenocarcinoma of the distal rectum regardless of the response of the primary tumor to preoperative chemoradiotherapy. [ABSTRACT FROM AUTHOR]