Absence of thoracic radiation myelitis after hyperfractionated radiation therapy with and without concurrent chemotherapy for Stage III nonsmall-cell lung cancer.

Abstract

To investigate whether thoracic spinal cord dose of 50.4 Gy given via 1.2 Gy b.i.d. fractionation carries a risk of developing radiation myelitis during studies using hyperfractionated radiation therapy (HFX RT) with and without concurrent chemotherapy (CHT). Of 300 patients with Stage III nonsmall-cell lung cancer (NSCLC) who were treated on two consecutive Phase III studies, 158 patients received 50.4 Gy to a portion of their spinal cord and survived > 1 year after the beginning of the therapy. None of these 158 patients developed thoracic radiation myelitis. Therefore, influence of potentially contributing factors on the occurrence of radiation myelitis, such as interfraction interval, or those unproven yet, such as cord length or administration of concurrent CHT, was not possible to investigate. Given the continuing interest in HFX RT and encouraging results obtained in studies in lung cancer, further investigation is needed to get more informations about risks of developing thoracic radiation myelitis with this cord dose.