Effects of two different radiotherapies for craniopharyngiomas using stereotactic radiosurgery/ stereotactic radiotherapy or fractionated stereotactic radiotherapy.

Background:Numerous studies have reported about good tumor control with both stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) for residual and recurrent craniopharyngiomas, but no studies have reported on the appropriate use of different types of radiation modalities. This study aimed to report the outcomes of SRS/stereotactic radiotherapy (SRT) or FSRT and compare tumor control in a single center. Methods:From 2014 when TrueBeamTM STx with Novalis was introduced in our hospital to 2021, 21 patients underwent SRS/SRT or FSRT with gamma knife surgery (GKS) and Novalis. We have selected the radiation modalities considering mainly the distance of the optic nerve and chiasm. Imaging and clinical follow-up data were sent and reviewed. Results:The mean age was 52 years and there were 11 men. Of the 21 total patients, three experienced SRS (GKS, 50% isodose 12-15 Gy), five underwent SRT (GKS or Novalis, 19.5-24 Gy 3 fractions), and 13 patients underwent FSRT (Novalis, 54 Gy 30 fractions). The median follow-up was 32.6 (range 17-44) months after SRS/SRT and 34.0 (range 4-61) months after FSRT. In the SRS/SRT group, the mean tumor volume decreased from 1.103 to 0.131 cm3 (P < 0.01), and in the FSRT group, from 3.015 to 1.012 cm3 (P < 0.01). No radiation-induced optic neuropathy and other acute toxicity occurred. Conclusion:Craniopharyngioma can be expected to have very good tumor control by selecting SRS/SRT or FSRT depending on the distance between the optic nerve and the tumor.