The BNCT Project at the National Atomic Energy Commission (CNEA)

The BNCT project began at CNEA in the year 1996 to develop the technology, the facilities and the scientific and medical expertise leading to clinical research for that therapy in patients in Argentina.

Participants include staff from all three Atomic Centres and a medical team of specialists from the Roffo Institute of Oncology. Forty professionals (equivalent to 20 full-time) constitute the multidisciplinary team.
 

Figure 1. RA-6 Reactor, Bariloche Atomic Center.

The irradiation facility, the clinical beam and the corresponding dosimetry were developed at the RA-6 Reactor at the Bariloche Atomic Centre (CAB) (Figure 1) for cutaneous melanoma patients. Computational dosimetry, treatment planning, boron measurements in biological matrices, basic studies in radiobiology, microdosimetry, dynamic infrared thermography and autoradiography are carried out at the Constituyentes Atomic Centre (CAC). The development, characterization and instrumentation of a thermal beam at the RA-3 Reactor to irradiate small animals, cell cultures and future BNCT application in liver metastases patients are performed at the Ezeiza Atomic Centre (CAE). The clinical aspects of the therapy have been addressed by the Roffo Institute of Oncology within the context of an agreement with CNEA for this purpose. Figure 2 shows the organization of the team.

The basic radiobiological research allow for the study of new clinical applications of  BNCT and the optimization of its efficacy by testing the potential therapeutic gain for new boron compounds. Two experimental models for BNCT studies were developed: the model of oral cancer in the hamster cheek pouch and the model of undifferentiated thyroid cancer. Both models were evaluated employing BNCT mediated by BPA and other boron compounds.

The first pathology under study was melanoma of extremities. The Fase I/II protocol was approved by the National Administration of Drugs, Food and Clinical Technology (ANMAT) and licensed by the Nuclear Regulatory Authority (ARN). The patients receive an infusion of about 14g/m² of L-p boronophenylalanine (¹⁰BPA)-fructose followed by the exposition of the area to the hyperthermal neutron beam (mixed field of thermal and epithermal neutrons) at the RA-6 reactor. The boron measurements are performed by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES).

The first clinical trial was performed on October 9, 2003. Up to date (August 2008), eight BNCT irradiations covering ten anatomical areas were accomplished.
New BNCT applications are under development: colorectal liver metastases, undifferentiated thyroid cancer, lung and cancer in the oral cavity.