Adaptive Radiation Therapy in Lymphomas: Indications, Early Experiences, and Future Directions

Area of Science:

• Radiation Oncology
• Medical Physics
• Hematology Oncology

Background:

• Lymphomas are radiosensitive and can present in difficult-to-target locations.
• Adaptive radiation therapy (ART) offers potential benefits by allowing for smaller treatment volumes and adaptation to tumor shrinkage.

Purpose of the Study:

• To hypothesize that ART may be beneficial in various lymphoma cases.
• To describe early experiences and outline indications for ART in lymphomas.

Main Methods:

• A prospective registry of lymphoma patients treated with online adaptive RT (oART) using cone-beam CT was reviewed.
• Patients were categorized by lymphoma type, and reasons for adaptation were analyzed.

Main Results:

• Seventy-two treatment courses from 67 patients (26 low-grade, 46 high-grade lymphomas) were analyzed.
• Primary indications for oART included better targeting in mobile locations (69%), changing gross disease (69%), and hypofractionation (38%).
• oART improved planning target volume (PTV) coverage from 72.2% to 95.2% and reduced PTV size by 24.6% in cases with gross disease.

Conclusions:

• Online adaptive RT can be successfully implemented in diverse lymphoma cases.
• oART reduces treatment volume while maintaining PTV coverage, enabling safer and shorter radiation courses.
• Further studies are needed to confirm the clinical benefits of oART in lymphomas.