High-precision radiotherapy achieves excellent long-term control and preserves function in pediatric craniopharyngioma - Subset analysis of a randomized trial.

Abstract

Background: The evolving treatment paradigm in children and adolescents with craniopharyngioma (CP) aims at minimizing late functional sequelae. Advanced radiotherapeutic techniques offer theoretical advantages of preserving neurological functions, however, clinical evidence of such is limited. The current study constitutes a secondary analysis of CP patients in a Randomized Control Trial testing Conventional RT (ConvRT) versus Stereotactic Conformal Radiotherapy (SCRT)(NCT00517959).

Methods: Eighty-two patients of CP (SCRT: 39, ConvRT: 43, Dose: 54Gy in 30 fractions) were analysed, assessing the clinical impact of dosimetric sparing on neurocognitive function, endocrine function, overall survival (OS) and local control (LC). Patients were longitudinally assessed from baseline through five years post-treatment using the WISC/WAIS scales.

Results: The median age was 13 years (IQR= 9-17 years). The 10-year OS and LC rates were 86.4% and 92.7%, respectively, with no significant difference between the arms.SCRT patients showed significant improvement in mean full-scale IQ (difference in slope=3.3 points per year, p= 0.01) and performance quotient (difference in slope=3.6, p= 0.04) compared to those treated with ConvRT. Freedom from cognitive decline (a 5-point drop) at 5 years was higher with SCRT (66.6% vs. 38.2%; HR=0.41, p=0.03). Younger age (<15 years) was a significant negative predictor of neurocognitive outcomes (p=0.002). SCRT patients also experienced lower cumulative incidence of new neuroendocrine dysfunction (25.7% vs. 48.8%, p=0.029).

Conclusion: SCRT offers excellent tumour control and similar survival with superior long-term preservation of neurocognitive and endocrine functions in CP patients compared to conventional RT. High precision RT should constitute the standard of care in CP.