Análisis dosimétrico en braquiterapia ginecológica de alta tasa de dosis

Abstract

Objective: We analyze the gynecologycal high dose rate brachytherapy dosimetry using the Fletcher-Suit-Delclos device, comparing orthogonal films (anteroposterior and lateral) versus axial computarized tomography. Methods: 4 implants were analized with orthogonal films and axial computarized tomography in the Brachyhterapy Unit of the National Cancer Institute on February 2006. The dose/fraction was 8 Gy to the H point. The bladder, rectal and vaginal dose point were evaluated according to international specifications. Results: Axial computarized tomography reveals hot points higher than orthogonal films dosimetries (133% and 260% for bladder and rectum respectively). The target volumen included was underestimated with the classical orthogonal film dosimetry. Conclusions: The orthogonal film dosimetry shows smaller accuracy than axial computarized tomography. The target volumens were not satisfactorily covered by the prescribed isodosis curve. The dose accumulated could, probably, be more prominent than the dose/fraction.