Patterns of Failure in Pediatric Rhabdomyosarcoma After Proton Therapy.

摘要: Purpose To report on the patterns of failure in children with rhabdomyosarcoma treated proton therapy. Patients and Methods Between February 2007 November 2013, 66 a median age 4.1 years (range, 0.6-15.3 years) diagnosed nonmetastatic were Clinical target volume 1 was defined as prechemotherapy tumor plus 1-cm anatomically constrained margin. 2 postchemotherapy (or bed) 0.5-cm margin, further expanded to encompass potential pathways spread, including soft tissue infiltrated at diagnosis. Results Of children, 11 developed locally progressive disease 16 months 14-32 months), for an actuarial 2-year local control rate 88%. Among who progressed, size diagnosis 6.7 years 0.6-16 years) 6 cm 2-8 cm), respectively. recurrences, 64% 36% embryonal alveolar, Disease progression observed 7 (64%) parameningeal, (18%) head neck (other), bladder/prostate subsites. At diagnosis, 8 patients recurrence Intergroup Rhabdomyosarcoma Study stage 3, all group III. relapses, 100% (11 11) confirmed in-field within composite 95% isodose line. One (9%) new simultaneous regional nodal outside previously radiation field. Conclusion Early data suggest that sharp dosimetric gradient associated therapy is not increased risk marginal failure. Routine use 0.5- clinical 1/2 margin highly conformal does compromise unfavorable features.