[Biochemical recurrence criteria after radiotherapy (external beam, brachytherapy). Natural history of the disease after radiotherapy]. / Criterios de recidiva bioquímica tras radioterapia (externa, braquiterapia ). Historia natural de la enfermedad después de radioterapia.

Prostate specific antigen (PSA) is the main tool in the follow-up of prostate cancer patients after definitive therapy. It's widely used as an early marker to value treatment success. Biochemical recurrence predicts metastatic disease progression and prostate cancer-specific mortality. In 1996, the American Society for Therapeutic Radiology and Oncology (ASTRO) provided a definition of biochemical failure after radiotherapy, based on three consecutive increases in PSA after nadir. As more experience was gained using the proposed definition and follow up duration in the PSA era matured, deficiencies and controversial issues emerged, so more recently proposed candidate definitions have provided consistent outcome. In view of the criticisms, a second consensus conference was held on 2005, with "nadir + 2 ng/ml" accepted as standard definition. The natural history and evidence of PSA kinetic parameters and different definitions of biochemical failure after external beam radiation therapy and/or brachytherapy are reviewed in the following article.

[Adjuvant radiotherapy after radical prostatectomy as preventive treatment for biochemical recurrence]. / Radioterapia adyuvante después de prostatectomía radical como tratamiento preventivo de la recidiva bioquímica.

Adjuvant radiotherapy (RT) has proven to be more effective in patients at high risk of relapse than salvage RT when this relapse occurs. To optimize its use we must identify the subset of patients at greater risk of residual microscopic disease after surgery, since in them the likelihood of 5-10 year biochemical failure can reach 60%. There are many studies on the subject in which these factors are identified, which in general are: presence of positive margins and capsular or seminal vesicle involvement (T3a-b). Of these, it seems that the presence of positive margins is the most powerful predictor of relapse. With regard to radiotherapy, there is variability in the dose to give and volume treated. In general, the dose in most series is ≥ 60 Gy, reaching some authors up to 70 Gy. As to the association or not hormone therapy (HT) and adjuvant radiotherapy, it is a subject of debate and so far no results of studies demonstrate a sufficient benefit, so it should be individualized, weighing potential benefits in high risk patients against side effects.