Search

Objectives Searching for more effective and selective therapies for head and neck cancer, we demonstrated the therapeutic effect of boron neutron capture therapy ( BNCT) to treat oral cancer and inhibit long-term tumor development from field-cancerized tissue in the hamster cheek pouch model. However, BNCT-induced mucositis in field-cancerized tissue was dose limiting. In a clinical scenario, oral mucositis affects patients' treatment and quality of life. Our aim was to evaluate different radioprotectors, seeking to reduce the incidence of BNCT-induced severe mucositis in field-cancerized tissue. Materials and Methods Cancerized pouches treated with BNCT mediated by boronophenylalanine at 5 Gy were treated as follows: control: saline solution; Hishigh: histamine 5 mg kg−1; Hislow: histamine 1 mg kg−1; and JNJ7777120: 10 mg kg−1. Results Hislow reduced the incidence of severe mucositis in field-cancerized tissue to 17% vs CONTROL: 55%; Hishigh: 67%; JNJ7777120: 57%. Hislow was non-toxic and did not compromise the long-term therapeutic effect of BNCT or alter gross boron concentration. Conclusion: Histamine reduces BNCT-induced mucositis in experimental oral precancer without jeopardizing therapeutic efficacy. The fact that both histamine and boronophenylalanine are approved for use in humans bridges the gap between experimental work and potential clinical application to reduce BNCT-induced radiotoxicity in patients with head and neck cancer. [ABSTRACT FROM AUTHOR]

Objectives Field-cancerized tissue can give rise to second primary tumours, causing therapeutic failure. Boron neutron capture therapy ( BNCT) is based on biological targeting and would serve to treat undetectable foci of malignant transformation. The aim of this study was to optimize BNCT for the integral treatment for oral cancer, with particular emphasis on the inhibitory effect on tumour development originating in precancerous conditions, and radiotoxicity of different BNCT protocols in a hamster cheek pouch oral precancer model. Materials and Methods Groups of cancerized hamsters were locally exposed to single or double (2 or 4 weeks apart) applications of BNCT at different dose levels, mediated by the boron compounds boronophenylalanine ( BPA) or BPA and decahydrodecaborate ( GB-10) administered jointly. Cancerized, sham-irradiated hamsters served as controls. Clinical status, tumour development from field-cancerized tissue and mucositis were followed for 8 months. Results A double application (4 weeks apart) of BNCT mediated by GB-10+ BPA at a total dose of 10 Gy in two 5-Gy doses rendered the best therapeutic advantage (63-100% inhibition of tumour development from field-cancerized tissue), minimizing dose-limiting mucositis. Conclusion BNCT can be optimized for the integral treatment for head and neck cancer, considering the implications for field-cancerized tissue. [ABSTRACT FROM AUTHOR]