Published in Pediatric Blood & Cancer, this study by the Jacksonville group evaluated the secondary tumor risk based on the data of 1713 children that underwent treatment with proton therapy. 11 patients developed secondary tumors.

Excluding patients with tumor predisposition syndromes, the 5- and 10-year rates were 0.6% and 1.7%. The authors conclude that secondary tumors are rare within the decade following proton therapy, particularly among children irradiated at >5 years old and those without tumor predisposition syndrome.