Pediatric extremity rhabdomyosarcoma treated with re-brachytherapy in recurrent setting

Abstract
Rhabdomyosarcomas (RMS) are pediatric soft-tissue sarcomas arising from immature mesenchymal cells that are intended to form striated skeletal muscles. Brachytherapy delivers high-dose of precised radiation to the target tissue with high conformity, sparing the nearby normal tissues, hence allowing dose escalation and reducing the likelihood of normal tissue toxicity. There is a scarcity of reports on the use of brachytherapy for extremity RMS. We report the case of pediatric extremity RMS treated with re-brachytherapy in recurrent setting. A 4-year-old boy diagnosed with RMS of right upper arm underwent local excision of the lesion. Postoperative magnetic resonance imaging showed suspicious residual lesion. Revision surgery followed by brachytherapy with 30 Gy in 10 fractions twice a day over 5 days was delivered. The child developed local recurrence after 12 months. Reexcision and re-irradiation with brachytherapy were done delivering 27 Gy in 9 fractions twice a day over 5 days. The child is disease-free 18 months posttreatment with no significant disparity in limb length suggestive of successful preservation of growth epiphysis. Re-irradiation with interstitial brachytherapy can be considered as an option for the treatment of recurrent pediatric extremity rhabdomyosarcoma, in conjunction with surgery and chemotherapy, despite treated previously with brachytherapy.