Radiation pneumonitis in pediatric Hodgkin lymphoma patients receiving radiation therapy to the chest

Purpose: The purpose of this study is to determine the incidence of radiation pneumonitis (RP) in children receiving radiation therapy (RT) for Hodgkin lymphoma (HL). Methods and patients: A retrospective chart review was conducted of pediatric HL patients who received multiagent chemotherapy followed by RT to any part of the chest. The National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.03, was used to determine the RP grade. Parameters analyzed included sex; age; bleomycin dose; and RT dosimetric variables such as mean lung dose (MLD), mean individual (i; right vs left) lung dose or iMLD, V5 to V25, and individual lung V5 to V25. Results: From 2008 through 2016, 54 children with HL received RT to the chest and had follow-up and dosimetry information. All patients received induction chemotherapy; the most common regimen was Adriamycin, bleomycin, vincristine, etoposide, prednisone, and cyclophosphamide–based chemotherapy (n = 48). All received a prescribed dose of 21 Gy in 14 fractions. Median follow-up from completion of RT was 39.5 months. Three of 54 patients (5.6%) or 3 of 108 (2.8%) lungs developed RP; 2 lungs had grade 1, whereas 1 had grade 2 RP. RP was seen only in patients with MLD >12.4 Gy (P =.009), V5 >66% (P =.033), V10 >55% (P =.015), V15 >45% (P =.005), and V20 >32% (P =.007). Likewise, RP was only seen in lungs with iMLD >13.8 Gy, iV5 >75% (P =.02), iV10 >64% (P =.02), iV15 >47% (P <.005), and iV20 >34% (P =.003). Conclusions: RP in pediatric HL patients is an uncommon complication. MLD, iMLD, V5-V20, and iV5-iV20 correlated with RP.