Timmerman, Beate

ABSTRACT The local treatment of bladder and prostate rhabdomyosarcoma is a multidisciplinary decision, incorporating elements of patient age, tumor size and location, nodal involvement, and access to local expertise and technology. The relative absence of long‐term bladder and bowel function outcome data complicates discussions, particularly given improved survival rates and development of new surgical and radiotherapy techniques. These INSTRuCT guidelines, a collaboration of the Children's Oncology Group, Soft Tissue Sarcoma Committee, European Pediatric Soft Tissue Sarcoma Study Group, and the Cooperative Weichteilsarkom Studiengruppe, reflect international expert consensus and are intended to inform practice, generate discussion, and highlight areas of future inquiry.

AbstractPurposeRadiotherapy (RT) is associated with improved survival in atypical teratoid/rhabdoid tumor (ATRT); however, optimal RT delivery is unknown. A meta‐analysis was conducted for disseminated (M+) ATRT receiving focal or craniospinal radiation (CSI).MethodsAfter abstract screening, 25 studies (1995–2020) contained necessary patient, disease, and radiation treatment information (N = 96). All abstract, full text, and data capture were independently double‐reviewed. The corresponding author was contacted for cases of insufficient information. Response to pre‐radiation chemotherapy (N = 57) was categorized as complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). Univariate and multivariate statistics were performed to investigate survival correlation. Patients with M4 disease were excluded.ResultsThe 2‐ and 4‐year overall survival (OS) was 63.8% and 45.7%, respectively, with a median follow‐up of 2 years (range 0.3–13.5). The median age was 2 years (range 0.2–19.5), and 96% received chemotherapy. On univariate analysis, gross total resection (GTR, p = .0007), pre‐radiation chemotherapy response (p < .001), and high‐dose chemotherapy with stem cell recuse (HDSCT, p = .002) correlated with survival. On multivariate analysis, pre‐radiation chemotherapy response (p = .02) and GTR (p = .012) retained survival significance as compared to a trend for HDSCT (p = .072). Comparisons of focal RT (vs. CSI) and greater than or equal to 5400 cGy primary dose were nonsignificant. Following CR or PR, a statistical trend favored focal radiation (p = .089) over CSI.ConclusionChemotherapy response prior to RT and GTR correlated with improved survival on multivariate analysis for ATRT M+ receiving RT. No benefit was observed for CSI compared to focal RT among all patients and following favorable chemotherapy response, inviting further study of focal RT for ATRT M+.