[Single fraction boost with high dose rate interstitial brachytherapy in conservative treatment of breast carcinoma]. / Sobreimpresión en fracción única con braquiterapia intersticial de alta tasa en el tratamiento conservador del carcinoma de mama.

INTRODUCTION: We evaluated the effectiveness of interstitial high dose rate brachytherapy as a single fraction boost to the surgical bed in patients with breast cancer undergoing conservative treatment. The comparison was with the alternative of electron boost. MATERIALS AND METHODS: Between April 1999 and December 2000, we conducted a prospective study of 84 patients with infiltrative breast carcinoma treated with conservative surgery, with free margins. This was followed by external radiotherapy to the breast of up to 46 Gy and one application of brachytherapy with needles inserted into the surgical bed, and administering 7 Gy to 90% with high dose rate (HDR). RESULTS: With a mean follow-up of 43 months, only one patient had therapeutic failure in the implant area, and local control was 98.5%. Another patient had a 2nd tumour in a different quadrant and 3 developed metastasis. Survival at 5 years was 98.7%. Acute toxicity was minimal, with excellent or good cosmetic appearance in 95%. CONCLUSIONS: Brachytherapy with high dose rate as single fraction boost in conservative treatment of breast carcinoma is simple, fast, well tolerated, with excellent local control, good cosmetic appearance, and with minimal late-onset toxicity.

Sobreimpresión en fracción única con braquiterapia intersticial de alta tasa en el tratamiento conservador del carcinoma de mama / Single fraction boost with high dose rate interstitial brachytherapy in conservative treatment of breast carcinoma

Introducción. Evaluamos la eficacia de la sobreimpresión del lecho quirúrgico con braquiterapia intersticial de alta tasa de dosis, en fracción única en pacientes con cáncer de mama, tratadas con tratamiento conservador, como alternativa a la sobreimpresión con electrones. Material y métodos. Entre abril de 1999 y diciembre de 2000, hemos realizado un estudio prospectivo sobre 84 pacientes con carcinoma infiltrante de mama sometidas a cirugía conservadora, con márgenes libres, seguida de radioterapia externa sobre la mama hasta 46 Gy y una aplicación de braquiterapia con agujas en el lecho quirúrgico, dando 7 Gy al 90% con alta tasa. Resultados. Con un seguimiento medio de 43 meses, sólo una paciente ha recaído en zona de implante siendo el control local del 98,5%. Otra paciente presentó un segundo tumor en un cuadrante distinto y tres desarrollaron metástasis. La supervivencia a 5 años es del 98,7%. La toxicidad aguda ha sido mínima, con estética excelente o buena en el 95%. Conclusiones. La braquiterapia con alta tasa en fracción única, como sobreimpresión en el tratamiento conservador del cáncer de mama, es bien tolerada, sencilla y rápida, consiguiendo un control local excelente, con buen resultado estético y una mínima toxicidad tardía

Introduction. We evaluated the effectiveness of interstitial high dose rate brachytherapy as a single fraction boost to the surgical bed in patients with breast cancer undergoing conservative treatment. The comparison was with the alternative of electron boost. Materials and methods. Between April 1999 and December 2000, we conducted a prospective study of 84 patients with infiltrative breast carcinoma treated with conservative surgery, with free margins. This was followed by external radiotherapy to the breast of up to 46 Gy and one application of brachytherapy with needles inserted into the surgical bed, and administering 7 Gy to 90% with high dose rate (HDR). Results. With a mean follow-up of 43 months, only one patient had therapeutic failure in the implant area, and local control was 98.5%. Another patient had a 2nd tumour in a different quadrant and 3 developed metastasis. Survival at 5 years was 98.7%. Acute toxicity was minimal, with excellent or good cosmetic appearance in 95%. Conclusions. Brachytherapy with high dose rate as single fraction boost in conservative treatment of breast carcinoma is simple, fast, well tolerated, with excellent local control, good cosmetic appearance, and with minimal late-onset toxicity