Preclinical Studies to Optimize the Application of Boron Neutron Capture Therapy (BNCT) for Treatment the Superficial Cancer

NIEVAS S; BOGGIO E; CABRINI R; JUVENAL G; PISAREV M; BROLLO F; LONGHINO J; DAGROSA MA

MISSOURI, COLUMBIA

Congreso; 117 th International congress of boron nêutron capture therapy (BNCT).; 2016

Society of Neutron Capture Therapy

BNCT is a cancerous, cells selective, non-conventional radiotherapy ) Li-7. The Argentinemodality to treat malignant tumors. It is based on a nuclear reaction B-10(n, clinical facility located at the RA-6 Research Reactor (Bariloche Atomic Center) developed a neutron beam for BNCT on superficial tumors called ?Hyperthermal?. Because of the characteristics of this neutron beam, the maximum thermal flux is 1cm deep, the total absorbed dose in superficial tumors such as melanoma is lower in the first millimeters than in the center of the tumor. Some materials (eg. Silver, Rhodium and Indium) have the ability to capture neutrons and emit high energy beta radiation. Thin foils of these materials, named Enhancers Beta (BE) could be used to compensate the irradiation over the tumor and even increase the local total dose during a conventional BNCT treatment. Our goal was to evaluate the toxicity and effectiveness of BE devices as a complementary tool for BNCT. Materials and Methods: NIH nude mice 6-8 weeks of age were implanted subcutaneously into the right rear flank with 106 cells of a human colon cancer cell line (ARO) developed from 15 days post injection, tumors between 50 and 100 mm3 . Thirty animals were divided into 5 groups: a) Control; b) NCT: neutron irradiation (without BPA); c) Rhodium BE + NCT (without BPA); d) BNCT: BPA 350 mg / Kg; e) BNCT + Rhodium BE. To adapt the neutron beam for BNCT patients small animals reflector / neutron scattering was placed. The animals were irradiated in a specific position for 37 minutes with a flow in tumor 4.96x108 n/cm2 .seg. Mice were anesthetized with a combination of diazepam (40mg / kg) and ketamine (200mg / kg) administered both subcutaneously with a period of 20 min each. Post irradiation animal weight, tumor volume growth and further histological studies of tumor and surrounding normal tissues evaluated were performed. Results: The post irradiation monitoring of animals did not report any sign of radiotoxicity in the treatment volume and the surrounding normal tissues. The tumor growth curves versus time showed significant differences between the groups c, d and e (NCT + BE; BNCT; BNCT + BE) compared to groups 1 and 2 (Control; NCT) (p