Boron neutron capture therapy (BNCT) is based on selective accumulation of B-10 carriers in
tumor followed by neutron irradiation. We demonstrated, in 2001, the
therapeutic effect of BNCT mediated by BPA (boronophenylalanine) in the hamster cheek pouch model of
oral cancer, at the RA-6
nuclear reactor. Between 2007 and 2011, the RA-6 was upgraded, leading to an improvement in the performance of the BNCT beam (B2 configuration). Our aim was to evaluate BPA-BNCT radiotoxicity and
tumor control in the hamster cheek pouch model of
oral cancer at the new "B2" configuration. We also evaluated, for the first time in the
oral cancer model, the radioprotective effect of
histamine against
mucositis in precancerous tissue as the dose-limiting tissue. Cancerized pouches were exposed to: BPA-BNCT; BPA-BNCT + histamine; BO: Beam only; BO + histamine; CONTROL: cancerized, no-treatment. BNCT induced severe
mucositis, with an incidence that was slightly higher than in "B1" experiments (86 vs 67%, respectively). BO induced low/moderate
mucositis.
Histamine slightly reduced the incidence of severe
mucositis induced by BPA-BNCT (75 vs 86%) and prevented
mucositis altogether in BO animals.
Tumor overall response was significantly higher in BNCT (94-96%) than in control (16%) and BO groups (9-38%), and did not differ significantly from the "B1" results (91%).
Histamine did not compromise BNCT therapeutic efficacy. BNCT radiotoxicity and
therapeutic effect at the B1 and B2 configurations of RA-6 were consistent.
Histamine slightly reduced
mucositis in precancerous tissue even in this overly aggressive
oral cancer model, without compromising
tumor control.