BackgroundTreatment options for patients with recurrent disease after radical prostatectomy include salvage radiotherapy of the prostatic bed and/or androgen deprivation therapy. To establish an effective treatment strategy for recurrent disease after radical prostatectomy, we retrospectively analyzed the outcome of salvage radiation monotherapy in such cases.MethodsData from 61 men who had undergone salvage radiation monotherapy for biochemical recurrent disease after radical prostatectomy were retrospectively reviewed. In all patients, salvage radiotherapy consisted of iraradiation to the prostatic bed (70 Gy) using three-dimensional conformal radiotherapy techniques. Treatment outcome was analyzed to identify predictive factors of salvage radiotherapy.ResultsThe biochemical recurrence-free survival after salvage radiation monotherapy at 2 and 5 years was 55% and 38%, respectively. Cox proportional regression models revealed that the independent predictive factors for biochemical recurrence were Gleason Score ≥ 8, negative surgical margin, and PSA velocity ≥ 0.38 ng/mL/year. Negative surgical margin and PSA velocity ≥ 0.8 ng/mL/year were significantly associated with poor response in the serum PSA levels after salvage radiotherapy.ConclusionsBased on our findings, we propose a treatment strategy for biochemical recurrent disease after radical prostatectomy. Patients with Gleason score ≤ 7, positive surgical margin, and PSA velocity < 0.38 ng/mL/year are categorized the most favorable group, so that eradication by salvage radiation monotherapy could be expected. Other patients could be divided to two groups depending on surgical margin status and PSA velocity: 1) patients who might require combination of SRT and short-term androgen deprivation therapy and 2) patients who should be treated by androgen deprivation monotherapy.

BackgroundTo assess the biochemical recurrence (BCR)-free rate in patients who underwent prostate low-dose-rate brachytherapy (LDR-brachytherapy), using two different definitions (Phoenix definition and PSA ≥ 0.2 ng/mL).MethodsTwo hundreds and three patients who were clinically diagnosed with localized prostate cancer (cT1c-2cN0M0) and underwent LDR-brachytherapy between July 2004 and September 2008 were enrolled. The median follow-up period was 72 months. We evaluated the BCR-free rate using the Phoenix definition and the PSA cut-off value of 0.2 ng/mL, as in the definition for radical prostatectomy. To evaluate an independent variable that can predict BCR, Cox’s proportional hazard regression analysis was carried out.ResultsThe BCR-free rate in patients using the Phoenix definition was acceptable (5-year: 92.8%). The 5- year BCR-free rate using the strict definition (PSA ≥ 0.2 ng/mL) was 74.1%. Cox’s proportional hazard regression analysis showed that a higher biological effective dose (BED) of ≥180 Gy2 was the only independent variable that could predict BCR (HR: 0.570, 95% C.I.: 0.327-0.994, p = 0.048). Patients with a higher BED (≥180 Gy2) had a significantly higher BCR-free rate than those with a lower BED (<180 Gy2) (5-year BCR-free rate: 80.5% vs. 67.4%).ConclusionsA higher BED ≥180 Gy2 promises a favorable BCR-free rate, even if the strict definition is adopted.

BackgroundTo compare the periodical incidence rates of genitourinary (GU) and gastrointestinal (GI) toxicity in patients who underwent prostate low-dose-rate brachytherapy between the monotherapy group (seed implantation alone) and the boost group (in combination with external beam radiation therapy (EBRT)).MethodsA total of 218 patients with a median follow-up of 42.5 months were enrolled. The patients were divided into 2 groups by treatment modality, namely, the monotherapy group (155 patients) and the boost group (63 patients). The periodical incidence rates of GU and GI toxicity were separately evaluated and compared between the monotherapy group and the boost group using the National Cancer Institute - Common Terminology Criteria for Adverse Events, version 3.0. To elucidate an independent factor among clinical and postdosimetric parameters to predict grade 2 or higher GU and GI toxicity in the acute and late phases, univariate and multivariate logistic regression analyses were carried out.ResultsOf all patients, 78.0% showed acute GU toxicity, and 7.8% showed acute GI toxicity, while 63.8% showed late GU toxicity, and 21.1% showed late GI toxicity. The incidence rates of late GU and GI toxicity were significantly higher in the boost group. Multivariate analysis showed that the International Prostate Symptom Score (IPSS) before seed implantation was a significant parameter to predict acute GU toxicity, while there were no significant predictive parameters for acute GI toxicity. On the other hand, combination with EBRT was a significant predictive parameter for late GU toxicity, and rectal volume (mL) receiving 100% of the prescribed dose (R100) was a significant predictive parameter for late GI toxicity.ConclusionsThe boost group showed higher incidence rates of both GU and GI toxicity. Higher IPSS before seed implantation, combination with EBRT and a higher R100 were significant predictors for acute GU, late GU and late GI toxicity.

BackgroundTo evaluate the effect of two different alpha-1 adrenoceptor antagonists on lower urinary tract symptoms in patients who underwent LDR-brachytherapy.MethodsA total of 141 patients who had been clinically diagnosed with localized prostate cancer and underwent LDR-brachytherapy were enrolled. Patients were randomized and allocated to two groups (silodosin 8 mg vs. naftopidil 75 mg). The primary endpoint was a change in the international prostate symptom score (IPSS) at 3 months after seed implantation. Secondary endpoints included the recovery rate of IPSS at 12 months after seed implantation, the change in IPSS and overactive bladder symptom score, uroflowmetric parameters, and frequency volume chart (FVC). To determine independent variables that can predict IPSS recovery, logistic regression analysis was carried out.ResultsThe mean change in the IPSS at 3 months after seed implantation in both groups was ⊿10.6 (naftopidil) and ⊿10.4 (silodosin), respectively. There was not a significant difference between the two groups (p=0.728). An increase in urinary frequency and a decrease in total urinated volume and mean voided volume were observed in FVC for 12 months after seed implantation. Multivariate analysis revealed that the urethral dose (UD30) was an independent predictive parameter of IPSS recovery. Patients with UD30 < 200Gy showed a higher recovery rate of IPSS at 12 months after seed implantation.ConclusionThere was no significant difference of serial change in IPSS between silodosin and naftopidil during the first year after seed implantation. A lower dose on the urethra was an independent predictor of IPSS recovery at 12 months after seed implantation.

BackgroundTo compare the PSA value at the last follow-up of patients who underwent prostate low-dose rate brachytherapy (LDR-BT) with that of patients who underwent intensity-modulated radiation therapy (IMRT).MethodsA total of 610 prostate cancer patients (cT1c-3bN0M0) were enrolled, and 445 of them underwent LDR-BT, while 165 received IMRT (74–76 Gy). The median follow-up period of these two groups was 75 months (LDR-BT) and 78 months (IMRT), respectively. We also evaluated the biochemical recurrence (BCR)-free rate using two definitions (Phoenix definition and PSA ≥ 0.2 ng/mL).ResultsThe percentage of patients who achieved PSA < 0.2 ng/mL at the last follow-up was 77.5% in the LDR-BT group and 49.7% in the IMRT group (p < 0.001). Among patients with a normal testosterone level at the last follow-up, the percentage of those who achieved PSA < 0.2 ng/mL at the last follow-up was 79.2% in the LDR-BT group and 32.1% in the IMRT group (p < 0.001). The 5-year BCR-free rate by the Phoenix definition in the IMRT and LDR-BT groups was 89.5 and 95.0% (p < 0.001), respectively. On the other hand, the 5-year BCR-free rate using the definition of PSA ≥ 0.2 ng/mL was 59.1 and 80.1% in the IMRT and LDR-BT groups, respectively (p < 0.001).ConclusionsThe PSA value at the last follow-up of LDR-BT was significantly lower than that of IMRT, and this result was particularly marked in patients with a normal testosterone level at the last follow-up.