Patients and study design
This study was approved by the Chang Gung Medical Foundation Institutional Review Board (IRB) for data analysis, and the serial number is 100-1264B. The data were analyzed retrospectively and anonymously. From May 2008 to December 2013, patients with clinically localized prostate cancer (T stage ≦T3a, N0, M0) were reviewed. The clinical stage is decided by Gleason score, digital rectal examination, initial prostate-specific antigen (iPSA), and image studies (bone scan, pelvic computed tomography or magnetic resonance imaging). Among these patients, we excluded the patients undergoing treatments other than the four treatment modalities: (1) Radical retropubic prostatectomy (RRP), (2) High dose rate brachytherapy (HDRBT), (3) Cryoablation and (4) High-intensity focused ultrasound (HIFU). The non-randomized treatment selection was made by the surgeon and patient’s discussion and preference. Finally, there were four treatment groups: (1) RRP (N = 97), (2) HDRBT (N = 161), (3) Cryoablation (N = 114), and (4) HIFU (N = 120).
The perioperative parameters such as age, preoperative prostate volume, iPSA, Gleason score, T stage, D’Amico risk group, the 5-item version of the international index of erectile function (IIEF-5), international prostate symptom score (IPSS) and related quality of life (QoL) score at baseline were collected for demographic data.
Besides, postoperative PSA nadir, time to PSA nadir, PSA biochemical recurrence (for radical retropubic prostatectomy, PSA ≥ 0.2 ng/mL; for the other three treatments, PSA ≥ PSA nadir + 2 ng/mL), salvage treatment-free rate, and metastasis-free rate were checked for oncological outcomes.
In addition, we recorded urethral stricture, second transurethral resection of the prostate (TURP) or optic internal urethrotomy (OIU), urinary incontinence defined one or more daily absorbent pads use, epididymitis, scrotal edema, rectal injury, irradiation cystitis, irradiation proctitis, series of IIEF-5, IPSS and related QoL scores at 6, 12, 18, and 24 months postoperatively for functional outcomes. Postoperative erectile dysfunction was defined by patients with preoperative IIEF-5 ≥ 17 and postoperative IIEF-5 < 17 (moderate to severe erectile dysfunction) at 1 year.
Radical retropubic prostatectomy (RRP)
Radical retropubic prostatectomy was performed through a low midline incision and extraperitoneal approach. The extent of radical retropubic prostatectomy included the entire prostate gland, bilateral seminal vesicles and pelvic lymph nodes. Neurovascular bundle sparing technique was not intentionally used.
High dose rate brachytherapy (HDRBT)
High dose rate brachytherapy was first performed by urologists in conjunction with radiation oncologists. Iridium radioisotopes (Ir192) were introduced by the radiation oncologists through transperineal needles implanted by urologists in three fractions on two consecutive days. The dose rate was individually designed for each patient on the basis of the results of the examination of important organs such as the urethra, bladder, and rectum, or any defect caused by TURP. The needles were removed after delivering the final HDR fraction. HDR brachytherapy (dose, 4–5.6 Gy per fraction) was performed as a boost followed by external beam radiation therapy (EBRT) (dose, 45–57.6 Gy) 2–3 weeks later. We did not give perioperative androgen deprivation therapy in all the patients (Chiang et al. 2004).
Whole-gland cryoablation was performed by fourth-generation cryosurgical technology (Endocare Cryocare Surgical System, Heathtronics Inc., Austin, TX, USA) under the guidance of transrectal ultrasonography with thermal sensor monitoring, urethral warming, and Denonvilliers’ fascia normal saline instillation to avoid urethral and rectal injury (Liu et al. 2015).
High-intensity focused ultrasound (HIFU)
Whole-gland HIFU was performed by Ablatherm® Integrated Imaging (EDAP TMS SA, Vaulx-en-Velin, France) under the guidance of transrectal ultrasonography. In addition, all of the HIFU patients underwent transurethral resection of the prostate (TURP) before operation. If preoperative prostate volume was <30 mL, TURP and HIFU would be performed simultaneously. If preoperative prostate volume was ≥30 mL, HIFU would be performed 4 weeks later after TURP (Liu and Chiang 2016).
All the data was analyzed according to treatment types. Continuous variables were compared by one-way ANOVA test. Categorical variables were compared by Chi square test. Survival analysis was conducted by Kaplan–Meier survival curves and Log Rank test. All analyses were performed using SPSS Statistics version 17.0 (SPSS Inc., Chicago, IL, USA). p values <0.05 were considered significant.