Final height in pediatric patients after hyperfractionated total body irradiation and stem cell transplantation

Impaired linear growth has been shown to occur in individuals treated during childhood with single-dose and fractionated total body irradiation (TBI) before stem cell transplantation. Our objective was to describe the final heights attained and patient/treatment factors correlating with final height in a cohort of childhood cancer survivors treated with hyperfractionated TBI (total dose 1375 or 1500 cGy). Thirty individuals (18 men) were included in the study. The mean final height standard deviation score (s.d.s.) was -1.9 +/- 0.2, significantly lower than height s.d.s. at TBI (-0.2 +/- 0.2, P < 0.001). Final height s.d.s. was significantly correlated with age at diagnosis, age at TBI and target height (P = 0.04, P < 0.001, P < 0.001, respectively). Treatment with growth hormone (GH) (n = 7) maintained mean height s.d.s. at -2.0 from the onset of GH therapy until attainment of final height. The mean final sitting height s.d.s. was -2.2 +/- 0.2 (n = 16), significantly shorter than mean final standing height s.d.s. (P < 0.01). In conclusion, treatment with hyperfractionated TBI is associated with a reduction in standing height and an even greater reduction in sitting height. Final height after hyperfractionated TBI was similar to that reported after fractionated TBI.