Craniospinal Irradiation in Medulloblastoma using High Energy Medical Linear Accelerator: an Innovative Approach to...

Area of Science:

• Radiation Oncology
• Medical Physics
• Pediatric Oncology

Background:

• Craniospinal irradiation (CSI) for medulloblastoma presents significant technical challenges due to large treatment volumes.
• Conventional CSI techniques often require frequent junction shifts between treatment fields to manage dose heterogeneity.

Purpose of the Study:

• To evaluate a novel CSI planning technique that avoids repeated patient re-planning and re-setup.
• To assess the dosimetric and clinical feasibility of this innovative CSI approach.

Main Methods:

• Fifteen medulloblastoma patients (10 children, 5 adults) underwent CT simulation for treatment planning.
• A single plan for children and two plans for adults were designed using 6 MV and 15 MV energies.
• Treatment planning aimed for 36 Gray in 20 fractions, with dose distribution and acute toxicities meticulously recorded.

Main Results:

• The new CSI technique achieved over 95% coverage of the planning target volume with the prescribed dose in all patients.
• Dosimetric evaluation showed acceptable hot spots and a good homogeneity index.
• Common radiation-induced acute toxicities such as headache, vomiting, and weakness were observed.

Conclusions:

• The novel CSI planning technique demonstrates acceptable dosimetric and acute clinical profiles.
• This technique offers a viable alternative for craniospinal irradiation, potentially improving dose homogeneity.