The impact of radiotherapy on clinical outcomes in parameningeal rhabdomyosarcoma.
OBJECTIVE
Radiotherapy (RT) is considered a mainstay of treatment in parameningeal rhabdomyosarcoma (PM-RMS). We aim to determine the treatment outcomes and prognostic factors for PM-RMS patients who treated with RT. In addition, we tried to evaluate the adequate dose and timing of RT.


METHODS
Twenty-two patients with PM-RMS from 1995 to 2013 were evaluated. Seven patients had intracranial extension (ICE) and 17 patients had skull base bony erosion (SBBE). Five patients showed distant metastases at the time of diagnosis. All patients underwent chemotherapy and RT. The median radiation dose was 50.4 Gy (range, 40.0 to 56.0 Gy).


RESULTS
The median follow-up was 28.7 months. Twelve patients (54.5%) experienced failure after treatment; 4 local, 2 regional, and 6 distant failures. The 5-year local control (LC) and overall survival (OS) were 77.7% and 38.5%, respectively. The 5-year OS rate was 50.8% for patients without distant metastases and 0% for patients with metastases (p < 0.001). Radiation dose (<50 Gy vs. ≥50 Gy) did not compromise the LC (p = 0.645). However, LC was affected by ICE (p = 0.031). Delayed administration (>22 weeks) of RT was related to a higher rate of local failure (40.0%).


CONCLUSIONS
RT resulted in a higher rate of local control in PM-RMS. However, it was not extended to survival outcome. A more effective treatment for PM-RMS is warranted.
Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Department of Radiation Oncology, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Korea.
Yunseon
Y
Choi
Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Do Hoon
DH
Lim
Local control; Meninges; Radiotherapy; Rhabdomyosarcoma