Applications of Intraoperative Betatherapy in Veterinary Oncology

Abstract

Betatherapy is a radiotherapy modality that uses beta radiation applicators used in the treatment of superficial injuries. With the advancement of therapeutic techniques, new clinical protocols of veterinary medicine will be established and betatherapy emerges as an important option for performing radiotherapy procedures, and further studies for the definition of oncological clinical protocols become necessary. This study reports some procedures in animals involving intraoperative betatherapy with a strontium-90 applicator (90Sr). Five procedures were performed, including 1 lioness (Panthera leo), 2 rats (Rattus norvegicus), 1 equine female (Equidae) and 1 rabbit (Oryctolagus cuniculus), all with a confirmed diagnosis of neoplasm. The TDF (TimeDose-Fraction) radiographic model was used to determine the radiological equivalent of the clinical cases. It was observed that the neoplasms in each case (1 to 5) partially differed from those found in the literature on intraoperative betatherapy in veterinary medicine. We observed that the radiologic effectiveness of the treatment was directly related to the value of TDF. Cases 1, 3 and 4 presented TDF values greater than 175, which implies a greater probability of injury control. As observed in the follow-up of the patients, case 5 (lower TDF) presented tumor recurrence only one month after the betatherapy procedure. Betatherapy with Sr90 applicators has proven to be feasible and easy to handle for the clinical cases analyzed in this study, especially during intraoperative procedures.