Boron Neutron Capture Therapy as a Novel Approach for Chondrosarcoma: Case Study of Tumor Reduction and Long-term Control.

Purpose: Mesenchymal chondrosarcoma (MCS), a rare malignant tumor arising from cartilage-forming tissues, is known for its resistance to conventional therapies. This case report presents the first documented use of boron neutron capture therapy (BNCT) for treating a patient with chondrosarcoma. Methods and Materials: The treatment was carried out using the NeuPex AB-BNCT system in combination with the boron compound NBB-001 (boronophenylalanine) and the NeuMANTA treatment planning system. Over the course of 2 BNCT sessions, the patient experienced significant tumor reduction and a favorable clinical response, with no severe adverse effects reported. The therapy was guided by Results: The targeted nature of BNCT resulted in a 45.8% reduction in the tumor's maximum dimension, achieving a partial response according to Response Evaluation Criteria in Solid Tumors version 1.1. Most adverse events were mild (grades 1-2) and manageable, with only grade 3 mucositis observed, which was transient and resolved with supportive care. Conclusions: This case study underscored the potential of BNCT as a promising treatment modality for MCS, particularly for tumors that are resistant to conventional radiation therapy. Further research is warranted to refine treatment protocols and explore the broader applicability of BNCT in managing MCS and other challenging malignancies.