Reduced incidence of the somnolence syndrome in leukemic children with steroid coverage during prophylactic cranial radiation therapy. Results of a pilot study
Chemotherapeutic regimens for childhood acute lymphoblastic leukemia (ALL) include a remission induction period with high, daily doses of prednisone among other agents. A period of central nervous system (CNS) prophylaxis follows, during which steroids are often tapered entirely before cranial radiation (CRT) is completed or even initiated. The somnolence syndrome (SS) has been described 4 to 6 weeks after completion of CRT in up to 60% of the children with doses as low as 1800 cGy. A pilot study of continuous steroid coverage during CRT in childhood ALL was conducted. From July 1984 to July 1986, 38 children entered on Children's Cancer Study Group ALL protocols received CRT of 1800 cGy (180 cGy x 10). All patients received oral prednisone throughout the entire course of CRT at daily doses varying from 3.0 to 60.0 mg/m2. The overall incidence of the SS was 13% (five patients). The development of the syndrome was steroid dose-dependent: greater than or equal to 15 mg/m2/d (one of 32 patients), 3% incidence; less than 15 mg/m2 (four of six patients), 67% incidence. The presence of headache during CRT was also steroid dose-related: greater than or equal to 15 mg/m2, one of 32 patients; less than 15 mg/m2, six of six patients. Of the seven patients with headache during CRT, five developed the SS. The two patients (both of the less than 15 mg/m2 group) who did not develop the SS were the only cases treated with increased steroid doses at the onset of headache symptoms. Steroid coverage at a dose of greater than or equal to 15 mg/m2 during CRT appears to significantly reduce the incidence of acute radiation reactions and the SS. A prospective randomized study is planned to confirm these initial findings.