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Updated: Jul 9, 2026

Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Novel technique of craniospinal axis proton therapy with the spot-scanning system: avoidance of patching multiple
Beate Timmermann1, Antony Jonathan Lomax, Luisa Nobile
1Center for Proton Radiation Therapy, Paul Scherrer Institute, Villigen, Switzerland. beate.timmermann@psi.ch
Background And Purpose:
Conventional craniospinal irradiation (CSI) is a complex procedure carrying a high risk of adverse side effects. Still, it is indispensable for cure in a number of pediatric brain tumors. In this study, the feasibility and the potential advantage of spot-scanning proton therapy for CSI are investigated.
Material And Methods:
A boy (5.5 years of age) with a recurrent medulloblastoma received CSI with a single posterior field using the spot-scanning system at Paul Scherrer Institute. Dose distribution to the targets and the organs at risk, treatment time, reproducibility of patient positioning, toxicity (according to EORTC/RTOG score), and treatment outcome were evaluated.
Results:
The plan achieved a homogeneous coverage of the target volume, even using a single field. The doses to the organs ventral to the target were minimized. During treatment, grade 1 skin reaction and grade 2 central nervous system toxicity were observed. After 2 months, the boy presented with a transitory fatigue. After 24 months, he is alive and free of disease. Growth hormones and thyroid hormones are reduced.
Conclusion:
These results, based on a single patient, suggest that spot-scanning proton therapy for craniospinal treatment is feasible and safe. By applying a single dorsal field, difficulties of multiple-field patching can be avoided and the ventral dose spread can be minimized.

