Parameningeal rhabdomyosarcoma: Results of an International Workshop

Adult rhabdomyosarcoma

“…36,37 Later IRSG reports indicated that meningeal recurrence is not a common event, but the prognosis for parameningeal RMS remains relatively poor with 5-year survival rates of approximately 70 -75% [5][6][7] and the parameningeal site is classified as unfavorable in the current IRS-V protocol. 3 The major recurrence pattern for children with RMS in this site is local, 38 as it was in our adult series. Another significant difference between childhood and adult RMS is the proportion of histopathologic subtypes.…”

“…For this presentation, it may also be advantageous to employ the IRSG strategy of utilizing radiation early in the treatment course with appropriate concomitant chemotherapy. 3,26 For sites other than parameningeal sites, the overall local control was satisfactory. Our data did not reveal any significant prognostic factors for local control other than the parameningeal site.…”

“…33 Our patients did not experience a significant rate of meningeal dissemination; the problem was one of local recurrence, as also noted in recent IRSG studies. 3,7,38 The retrospective nature of our analysis and small dataset precluded a clear definition of the reasons for, and solutions to, this problem. Tumors arising in these sites are rarely resectable with clear margins and local control depends on delivering adequate radiation doses to an appropriate tumor volume while respecting the radiation tolerance of numerous nearby critical normal structures.…”

Local control of parameningeal rhabdomyosarcoma: Outcomes in non‐complete responders to chemoradiation

“…Survival prior to the formation of the Intergroup Rhabdomyosarcoma Study (IRS) Group was less than 25% whereas the current estimated 5-year overall survival rate on the IRS is 73% [1]. Key to the improvement in outcome is the radiotherapeutic approach to these tumors; proper radiotherapy (RT) volume, dose, and timing are necessary to maximize local control [2,3]. Because of the close proximity of these tumors to the meninges and the possibility that surgery may cause cosmetic deformities, most patients with PM-RMS in North America are treated with chemotherapy and RT.…”

Parameningeal rhabdomyosarcomas—accomplishment of the IRS

“…For example, the French investigators did not use radiation therapy for young children who attained a complete response after chemotherapy if they were considered not to have a high risk of meningeal impingement. An international workshop was organized by the International Society of Pediatric Oncology (SIOP) in the mid 1990s to perform a retrospective analysis of children with nonmetastatic parameningeal rhabdomyosarcoma treated by one of the four major cooperative groups: IRS, SIOP, German Cooperative Group (CWS), or Italian Cooperative Group (ICS) (3). Although the radiation therapy doses were similar in the four studies, there were differences in the treatment volumes and the timing of radiation therapy, and some young children in the SIOP study did not receive radiation therapy.…”