Pulmonary Function After Treatment for Embryonal Brain Tumors on SJMB03 That Included Craniospinal Irradiation.

ABSTRACT

PURPOSE: The treatment of children with embryonal brain tumors (EBT) includes craniospinal irradiation (CSI). There are limited data regarding the effect of CSI on pulmonary function. METHODS: Protocol SJMB03 enrolled patients 3 to 21 years of age with EBT. Pulmonary function tests (PFTs) (forced expiratory volume in 1 second [FEV1] and forced vital capacity [FVC] by spirometry, total lung capacity [TLC] by nitrogen washout or plethysmography, and diffusing capacity of the lung for carbon monoxide corrected for hemoglobin [DLCO(corr)]) were obtained. Differences between PFTs obtained immediately after the completion of CSI and 24 or 60 months after the completion of treatment (ACT) were compared using exact Wilcoxon signed-rank tests and repeated-measures models. RESULTS: Between June 24, 2003, and March 1, 2010, 303 eligible patients (spine dose ≤ 2345 cGy, 201; >2345 cGy, 102; proton beam, 20) were enrolled, 260 of whom had at least 1 PFT. The median age at diagnosis was 8.9 years (range, 3.1-20.4 years). The median thoracic spinal radiation dose was 23.4 Gy (interquartile range [IQR], 23.4-36.0 Gy). The median cyclophosphamide dose was 16.0 g/m(2) (IQR, 15.7-16.0 g/m(2)). At 24 and 60 months ACT, DLCO(corr) was <75% predicted in 23% (27/118) and 25% (21/84) of patients, FEV1 was <80% predicted in 20% (34/170) and 29% (32/109) of patients, FVC was <80% predicted in 27% (46/172) and 28% (30/108) of patients, and TLC was <75% predicted in 9% (13/138) and 11% (10/92) of patients. DLCO(corr) was significantly decreased 24 months ACT (median difference [MD] in % predicted, 3.00%; P = .028) and 60 months ACT (MD in % predicted, 6.00%; P = .033) compared with the end of radiation therapy. These significant decreases in DLCO(corr) were also observed in repeated-measures models (P = .011 and P = .032 at 24 and 60 months ACT, respectively). CONCLUSIONS: A significant minority of EBT survivors experience PFT deficits after CSI. Continued monitoring of this cohort is planned.