Objective. To predict late toxicity of radiotherapy in patients who were treated with prostate cancer may be useful to individualize treatment and to select patients for dose escalation. The aim of this study is to determine if the radiation-induced apoptosis is useful in patients with prostate cancer. Methods. Between March 2005 and June 2007 we included in a prospectively study 237 patients, were analyzed with a follow-up of 8 year for late toxicity. We performed a rapid assay in peripheral blood irradiated with 8Gy before the patient treatment. We study the grade of radio-induced apoptosis which was quantified by flow cytometry. Toxicity was defined according to the scale of the RTOG. We compared the toxicity of patients with the grade of radio-induced apoptosis in CD4 and CD8 T lymphocytes. Results. The median age was 70 years, 37% were T1c, 33% were T2, 26.6% were T3 and 3.4% were failures, 46% of patients had Gleason score < 7 and 54%≥7. The late GU toxicity was 32%. The overall survival was 95% and the specific survival was 98%. It was found a relationship between CD4 T lymphocytes radio-induced apoptosis and late genitourinary (GU) toxicity grade≥1, this is an inverse relationship, the lower percentage of apoptosis with higher late toxicity. The percentage of patients with a apoptosis≤30 are more likely to have genitourinary late toxicity (p = 0.03). No relationship was found with CD8 T lymphocytes neither other toxicity. Conclusions. The rapid assay of radiation-induced lymphocyte apoptosis can predict late GU toxicity in patients with prostate cancer. The study was financed with a grant of the Agència per l'Avaluaciá de la Tecnologia I Recerca Mèdica (AATRM) no. 085/08/2004 de la Generalitat de Catalunya.
Foro, P., Bellosillo, B., Lozano, J., Rodriguez, N., Sanz, X., Reig, A., … Algara, M. (2013). Radiation-induced apoptosis as predictor of genitourinary toxicity. Reports of Practical Oncology & Radiotherapy, 18, S99. https://doi.org/10.1016/j.rpor.2013.03.818