Induction of severe cataract and late renal dysfunction following total body irradiation: dose-effect relationships.

BACKGROUND: Severe cataract and renal dysfunction are late effects following myeloablative total body irradiation (TBI) and hematopoietic stem cell transplantation in patients with hematological malignancies. The aim of the study was to determine radiation dose-response relationships for these late effects.
MATERIALS AND METHODS: A retrospective review of articles reporting incidences for cataract induction and late renal dysfunction was performed, using PubMed. The radiation regimens identified were normalized using the linear-quadratic model; biologically effective doses (BEDs) were calculated.
RESULTS: For cataract induction, 17 articles were identified allowing a dose-effect relationship to be derived. A threshold BED of approximately 40 Gy was indicated below which severe cataract seldom occurs. For late renal toxicity, 14 articles were found. The resulting dose-effect relationship indicates a threshold BED of approximately 16 Gy.
CONCLUSION: To prevent severe cataract, fractionated TBI should be applied to keep the BED <40 Gy. Only when single-dose TBI cannot be avoided should eye shielding be applied. To prevent late renal toxicity, fractionated TBI is recommended, but kidney shielding remains necessary for almost all myeloablative TBI regimens.