What Is the Contribution of Brachytherapy in Tailoring Local Therapy?

Abstract

Brachytherapy is a generic term to describe radionuclide “curietherapy,” usually performed with iridium 192 or contact X-ray 50 kV (CXRT) to deliver radiation dose with a short (brachy) FSD (focus skin distance) of 6 cm or less for rectal cancer. Iridium 192 can be used either with an endoluminal approach or with an interstitial perineal implant. CXRT is delivered through a rigid proctoscope under direct control of the vision. The advantage of brachytherapy is an excellent geographical accuracy delivering a very high dose into a small volume. The result is a high rate of tumor response with little toxicity, allowing hypofractionation. In an era of treatment tailoring for rectal cancer, brachytherapy should play an increasing role mainly to improve the chances of conservative treatment. In operable patient, it can be used to cure T1N0 either after local excision or with irradiation alone. In T2N0 in combination with external beam radiotherapy (± chemotherapy), it can be used for organ preservation within the frame of clinical prospective trial. In inoperable frail patients, brachytherapy should play a major role to cure early rectal tumors or to palliate more advanced lesions.