RARE-02.RE-IRRADIATION FOR RECURRENT CRANIOPHARYNGIOMA

Abstract PURPOSE Patients with recurrent craniopharyngioma after radiotherapy (RT) have few treatment options. At our institution, re-irradiation has been offered to selected individuals with recurrent craniopharyngioma not suitable for further surgery, intracystic therapy or targeted agents. METHODS A retrospective study was performed of patients with craniopharyngioma treated with two courses of fractionated RT. First RT (RT1) prescriptions ranged from 50–54 Gy in 25–30 fractions; re-irradiation (RT2) prescriptions were 54 Gy in 30 fractions with full, in-field overlap of dose. The maximum dose to organs-at-risk (brainstem, optic structures) were maintained at or below the prescription dose. There was no cumulative dose limit to any structure. RESULTS We identified four patients. Median RT1-to-RT2 interval was 5.8 years (range, 4.7–20.4). Cumulative maximum doses to optic chiasma and nerves were >100 Gy in all four patients. With a median follow-up of 33 months after RT2, three patients had disease control and are alive at 9, 23 and 42 months from RT2; one patient developed progressive disease and died 33 months after RT2. In three evaluable patients, vision remained stable or improved after RT2; the remaining one patient had no light perception prior to re-irradiation. Two patients had neuropsychological testing before and after RT2; neurocognitive domains were generally stable in one patient but working memory declined in the second patient. CONCLUSIONS Despite exceeding usual tolerances for optic chiasm and nerves, visual outcomes were stable in all living patients. Re-irradiation should be discussed as a treatment option for patients with recurrent craniopharyngioma but without other therapeutic options.