✓Choroid plexus papilloma is a benign central nervous system tumor that occasionally spreads along the subarachnoid space. The authors report the case of a 49-year-old man who presented with back pain 19 years after resection of a posterior fossa choroid plexus papilloma. Magnetic resonance imaging revealed multiple spinal lesions without any residual or recurrent intracranial tumor. All spinal lesions were resected and histologically diagnosed as atypical choroid plexus papilloma. The authors suggest that patients in whom choroid plexus papilloma is diagnosed should undergo total neuraxis imaging at the time of initial diagnosis as well as periodic follow-up examinations after resection to rule out drop metastases.
Hong Yu, Tom L. Yao, John Spooner, Jennifer R. Stumph, Ray Hester and Peter E. Konrad
Alireza M. Mohammadi, Jason L. Schroeder, Lilyana Angelov, Samuel T. Chao, Erin S. Murphy, Jennifer S. Yu, Gennady Neyman, Xuefei Jia, John H. Suh, Gene H. Barnett and Michael A. Vogelbaum
The impact of the stereotactic radiosurgery (SRS) prescription dose (PD) on local progression and radiation necrosis for small (≤ 2 cm) brain metastases was evaluated.
An institutional review board–approved retrospective review was performed on 896 patients with brain metastases ≤ 2 cm (3034 tumors) who were treated with 1229 SRS procedures between 2000 and 2012. Local progression and/or radiation necrosis were the primary end points. Each tumor was followed from the date of radiosurgery until one of the end points was reached or the last MRI follow-up. Various criteria were used to differentiate tumor progression and radiation necrosis, including the evaluation of serial MRIs, cerebral blood volume on perfusion MR, FDG-PET scans, and, in some cases, surgical pathology. The median radiographic follow-up per lesion was 6.2 months.
The median patient age was 56 years, and 56% of the patients were female. The most common primary pathology was non–small cell lung cancer (44%), followed by breast cancer (19%), renal cell carcinoma (14%), melanoma (11%), and small cell lung cancer (5%). The median tumor volume and median largest diameter were 0.16 cm3 and 0.8 cm, respectively. In total, 1018 lesions (34%) were larger than 1 cm in maximum diameter. The PD for 2410 tumors (80%) was 24 Gy, for 408 tumors (13%) it was 19 to 23 Gy, and for 216 tumors (7%) it was 15 to 18 Gy. In total, 87 patients (10%) had local progression of 104 tumors (3%), and 148 patients (17%) had at least radiographic evidence of radiation necrosis involving 199 tumors (7%; 4% were symptomatic). Univariate and multivariate analyses were performed for local progression and radiation necrosis. For local progression, tumors less than 1 cm (subhazard ratio [SHR] 2.32; p < 0.001), PD of 24 Gy (SHR 1.84; p = 0.01), and additional whole-brain radiation therapy (SHR 2.53; p = 0.001) were independently associated with better outcome. For the development of radiographic radiation necrosis, independent prognostic factors included size greater than 1 cm (SHR 2.13; p < 0.001), location in the corpus callosum (SHR 5.72; p < 0.001), and uncommon pathologies (SHR 1.65; p = 0.05). Size (SHR 4.78; p < 0.001) and location (SHR 7.62; p < 0.001)—but not uncommon pathologies—were independent prognostic factors for the subgroup with symptomatic radiation necrosis.
A PD of 24 Gy results in significantly better local control of metastases measuring < 2 cm than lower doses. In addition, tumor size is an independent prognostic factor for both local progression and radiation necrosis. Some tumor pathologies and locations may also contribute to an increased risk of radiation necrosis.
Rupesh Kotecha, Jacob A. Miller, Vyshak A. Venur, Alireza M. Mohammadi, Samuel T. Chao, John H. Suh, Gene H. Barnett, Erin S. Murphy, Pauline Funchain, Jennifer S. Yu, Michael A. Vogelbaum, Lilyana Angelov and Manmeet S. Ahluwalia
The goal of this study was to investigate the impact of stereotactic radiosurgery (SRS), BRAF status, and targeted and immune-based therapies on the recurrence patterns and factors associated with overall survival (OS) among patients with melanoma brain metastasis (MBM).
A total of 366 patients were treated for 1336 MBMs; a lesion-based analysis was performed on 793 SRS lesions. The BRAF status was available for 78 patients: 35 had BRAF mut and 43 had BRAF wild-type (BRAF-WT) lesions. The Kaplan-Meier method evaluated unadjusted OS; cumulative incidence analysis determined the incidences of local failure (LF), distant failure, and radiation necrosis (RN), with death as a competing risk.
The 12-month OS was 24% (95% CI 20%–29%). On multivariate analysis, younger age, lack of extracranial metastases, better Karnofsky Performance Status score, and fewer MBMs, as well as treatment with BRAF inhibitors (BRAFi), anti–PD-1/CTLA-4 therapy, or cytokine therapy were significantly associated with OS. For patients who underwent SRS, the 12-month LF rate was lower among those with BRAF mut lesions (6%, 95% CI 2%–11%) compared with those with BRAF-WT lesions (22%, 95% CI 13%–32%; p < 0.01). The 12-month LF rates among lesions treated with BRAFi and PD-1/CTLA-4 agents were 1% (95% CI 1%–4%) and 7% (95% CI 1%–13%), respectively. On multivariate analysis, BRAF inhibition within 30 days of SRS was protective against LF (HR 0.08, 95% CI 0.01–0.55; p = 0.01). The 12-month rates of RN were low among lesions treated with BRAFi (0%, 95% CI 0%–0%), PD-1/CTLA-4 inhibitors (2%, 95% CI 1%–5%), and cytokine therapies (6%, 95% CI 1%–13%).
Prognostic schema should incorporate BRAFi or immunotherapy status and use of targeted therapies. Treatment with a BRAF inhibitor within 4 weeks of SRS improves local control without an increased risk of RN.
Aditya Juloori, Jacob A. Miller, Shireen Parsai, Rupesh Kotecha, Manmeet S. Ahluwalia, Alireza M. Mohammadi, Erin S. Murphy, John H. Suh, Gene H. Barnett, Jennifer S. Yu, Michael A. Vogelbaum, Brian Rini, Jorge Garcia, Glen H. Stevens, Lilyana Angelov and Samuel T. Chao
The object of this retrospective study was to investigate the impact of targeted therapies on overall survival (OS), distant intracranial failure, local failure, and radiation necrosis among patients treated with radiation therapy for renal cell carcinoma (RCC) metastases to the brain.
All patients diagnosed with RCC brain metastasis (BM) between 1998 and 2015 at a single institution were included in this study. The primary outcome was OS, and secondary outcomes included local failure, distant intracranial failure, and radiation necrosis. The timing of targeted therapies was recorded. Multivariate Cox proportional-hazards regression was used to model OS, while multivariate competing-risks regression was used to model local failure, distant intracranial failure, and radiation necrosis, with death as a competing risk.
Three hundred seventy-six patients presented with 912 RCC BMs. Median OS was 9.7 months. Consistent with the previously validated diagnosis-specific graded prognostic assessment (DS-GPA) for RCC BM, Karnofsky Performance Status (KPS) and number of BMs were the only factors prognostic for OS. One hundred forty-seven patients (39%) received vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs). Median OS was significantly greater among patients receiving TKIs (16.8 vs 7.3 months, p < 0.001). Following multivariate analysis, KPS, number of metastases, and TKI use remained significantly associated with OS.
The crude incidence of local failure was 14.9%, with a 12-month cumulative incidence of 13.4%. TKIs did not significantly decrease the 12-month cumulative incidence of local failure (11.4% vs 14.5%, p = 0.11). Following multivariate analysis, age, number of BMs, and lesion size remained associated with local failure. The 12-month cumulative incidence of radiation necrosis was 8.0%. Use of TKIs within 30 days of SRS was associated with a significantly increased 12-month cumulative incidence of radiation necrosis (10.9% vs 6.4%, p = 0.04).
Use of targeted therapies in patients with RCC BM treated with intracranial SRS was associated with improved OS. However, the use of TKIs within 30 days of SRS increases the rate of radiation necrosis without improving local control or reducing distant intracranial failure. Prospective studies are warranted to determine the optimal timing to reduce the rate of necrosis without detracting from survival.