A dosimetric comparison of proton and intensity modulated radiation therapy in pediatric rhabdorhyosarcoma patients enrolled on a prospective phase II proton study

作者：Ladra Matthew M; Edgington Samantha K; Mahajan Anita; Grosshans David; Szymonifka Jackie; Khan Fazal; Moteabbed Maryam; Friedmann Alison M; MacDonald Shannon M; Tarbell Nancy J; Yock Torunn I^*

来源：Radiotherapy and Oncology, 2014, 113(1): 77-83.

DOI：10.1016/j.radonc.2014.08.033

• Pediatrics
• Rhabdomyosarcoma
• Protons

Background: Pediatric rhabdomyosarcoma (RMS) is highly curable, however, cure may come with significant radiation related toxicity in developing tissues. Proton therapy (PT) can spare excess dose to normal structures, potentially reducing the incidence of adverse effects. %26lt;br%26gt;Methods: Between 2005 and 2012,54 patients were enrolled on a prospective multi-institutional phase II trial using PT in pediatric RMS. As part of the protocol, intensity modulated radiation therapy (IMRT) plans were generated for comparison with clinical PT plans. %26lt;br%26gt;Results: Target coverage was comparable between PT and IMRT plans with a mean CTV V-95 of 100% for both modalities (p = 0.82). However, mean integral dose was 1.8 times higher for IMRT (range 1.0-4.9). By site, mean integral dose for IMRT was 1.8 times higher for H%26N (p %26lt; 0.01) and GU (p = 0.02), 2.0 times higher for trunk/extremity (p %26lt; 0.01), and 3.5 times higher for orbit (p %26lt; 0.01) compared to PT. Significant sparing was seen with PT in 26 of 30 critical structures assessed for orbital, head and neck, pelvic, and trunk/extremity patients. %26lt;br%26gt;Conclusions: Proton radiation lowers integral dose and improves normal tissue sparing when compared to IMRT for pediatric RMS. Correlation with clinical outcomes is necessary once mature long-term toxicity data are available.

• 出版日期2014-10