Dados do Trabalho

Título

PSA NADIR PREDICTS BIOCHEMICAL RECURRENCE AFTER EXTERNAL BEAM RADIATION THERAPY COMBINED TO HIGH DOSE RATE BRACHYTHERAPY IN THE TREATMENT OF PROSTATE CANCER

Resumo

Introduction: Prostate cancer (PCa) is the second most prevalent neoplasm among men in the world. Its treatment has a wide spectrum of alternatives and variables, ranging from active surveillance through radio and/or brachytherapy, to surgery. Objective: The present work aimed to identify the predictive factors for biochemical recurrence and to evaluate the toxicity of the treatment using the association of external beam radiation therapy (eRT) with high dose rate brachytherapy (HDRB) applied in the treatment of patients with prostate cancer. Methods: Longitudinal retrospective study, using a prospectively collected database between 2005 and 2014 of 186 consecutive patient records with a diagnosis of low, intermediate, or high-risk prostate cancer treated with eRT combined with HDRB, in a single medical institution located in the city of Campinas, SP, Brazil (Radium Institute). PSA increase over 2 ng/ml above the nadir PSA was considered as biochemical recurrence, following the definition of the Phoenix Consensus. Continuous and clinically relevant categorical variables (age, initial PSA, delivered dose in eRT, number of needle implants, number of positive cores in a transrectal biopsy, use of hormone blockade, Gleason score, TNM staging, post-treatment PSA, and PSA Nadir) were evaluated with absolute (n) and percentage (%) values using multiple logistic regression and receiver operating characteristic (ROC) curve. Results: Post-treatment PSA was the only independent predictor of biochemical recurrence, p<0.0001. The lower the PSA nadir the lower the biochemical recurrence risk (p = 0.0009). ROC curve analysis showed PSA nadir >1 as the best cutoff (p=0.018) determinant of biochemical recurrence. The incidence of grade 3 late toxicity to the genitourinary tract was 0.6%, and there were no cases of severe complications to the gastrointestinal tract. Conclusion: External Beam Radiation Therapy conjugated to Brachytherapy in the treatment of Prostate Cancer has demonstrated low toxicity into both GU and GI tracts and biochemical recurrence rates, mainly when PSA nadir <1.

Palavras Chave ( separado por ; )

External Radiotherapy, High Dose Rate Brachytherapy, Prostate Cancer, Biochemical Relapse, Toxicity, Efficacy