Determination of Relative Biological Effectiveness Factors for Human Melanoma Cell Lines for the Improvement of Boron Neutron Capture Therapy (BNCT)

ROSSINI, AE; DAGROSA, MA; CARPANO, M; POZZI, E; THOP, S; CASAL, M; JUVENAL, G; PISAREV , M

Buenos Aires

Congreso; 14th International Congress of Neutron Capture Therapy; 2010

CNEA, UNSAM, ROFFO

Despite the fact that many tumors appear similar histologically, their radiosensitivity may be different. Therefore it is important to know the radiobiological characteristics of each tumor in order to improve the therapeutic effectiveness, either for conventional radiotherapy or alternative radiation modalities like Boron Neutron Capture Therapy (BNCT). Since the approval of a protocol to evaluate the efficacy of BNCT for skin melanomas in extremities in Argentina, the task of determining the relative biological effectiveness (RBE) of the neutron source and the compound biological effectiveness (CBE) for BPA have been of particular importance. CBE vaIues for p-borophenylalanine (BPA) and RBE values of the neutron beam has been determined for three human melanoma cell lines. Either the RBE of the beam and the CBE for BPA were determined for two different levels of endpoints based on the survival fraction. Two cell lines of melanoma had similar RBE and CBE values. The third had slightly higher RBE values and a markedly higher CBE value. These in vitro results support previous clinical studies and showed that BNCT can be an effective alternative therapy for melanoma. These are the first measured data of RBE and CBE for human melanoma cell lines and should be useful for the optimization of the dosimetric analysis prior to the treatment of cutaneous melanomas with BNCT in Argentina.