Denitive brachytherapy in localized prostate cancer – treatment outcomes and prognostic values of prostate- specic antigen

Brachytherapy in localized prostate cancer is alternative to radical prostatectomy, and the choice should be in accordance with the patient‘s decision when reporting the expected treatment results, complications and quality of life. The reported results of applying low-dose brachytherapy with permanent implant are more long-lasting and indicate a 15-year biochemical control, assessed by PSA values, in 85-88% of treated patients. Data from high dose rate brachytherapy with temporary radioactive implants are with shorter follow-up. The disadvantage of assessing the results of the studies in the treatment of prostate cancer is related to the assessment of the treatment results by biochemical control, and not mortality, as a more categorical indicator. This is due to the average age of the patients, the difficult differentiation of complications from frequently applied androgen deprivation therapy – hormonal treatment, concomitant diseases and the difficulty of distinguishing natural causes of the fatal outcome from specific tumor-related mortality. Prostate-specific antigen (PSA) values determine the prognosis during the course of the disease to a significant extent, as well as in monitoring the disease-free period. After radical prostatectomy, persistence of PSA is an expression of non-radical treatment behavior or undetected distant metastasis. While in radiotherapy and the various methods – external beam or brachytherapy due to the preservation of the parenchyma of the gland and the specific response to ionizing radiation depending on the size of the dose fraction, PSA continues to be detected long after the treatment. The pretreatment-initial level of the tumor marker is also important for this. The serious difficulty of using the marker in the follow-up of radiotherapy results has been demonstrated in numerous retrospective studies comparing local methods such as radical prostatectomy, percutaneous radiotherapy and brachytherapy or combined radiotherapy. The aim of the review is to present the results after different types of brachytherapy in localized prostate cancer and the data available in the literature on the follow-up of patients after brachytherapy with PSA values, their kinetics over time and their prognostic significance.