High-dose-rate interstitial brachytherapy as monotherapy in one fraction for the treatment of favorable stage prostate cancer: Toxicity and long-term biochemical results Pedro J. Prada a,⇑ , Juan Cardenal a , Ana García Blanco a , Javier Anchuelo a , María Ferri a , Gema Fernández c , Elisabeth Arrojo c , Andrés Vázquez b , Maite Pacheco b , José Fernández d a Department of Radiation Oncology; b Department of Radiation Physics, Hospital Universitario Marqués de Valdecilla, Santander; c Department of Radiation Oncology; and d Department of Radiation Physics, Hospital Universitario Central de Asturias, Oviedo, Spain article info Article history: Received 28 December 2015 Received in revised form 7 March 2016 Accepted 4 April 2016 Available online xxxx Keywords: Brachytherapy High dose rate Prostate cancer Monotherapy abstract Background: To evaluate acute and late genitourinary, the gastrointestinal toxicity and the long-term bio- chemical control after HDR monotherapy in one fraction (19 Gy). Patients and methods: Between April 2008 and October 2010, 60 consecutive patients were treated with favorable clinically localized prostate cancer; the median follow-up was 72 months (range 32–91). All patients received one implant and one fraction of HDR. Fraction dose was 19 Gy. Toxicity was reported according to the Common Toxicity Criteria for Adverse Event, Version 4.0 (CTAE v4.02) by the National Cancer Institute. Results: No intraoperative or perioperative complications occurred. Acute toxicity grade 2 or more was not observed in any patients. No chronic toxicity, such as incontinence, late urinary retention, urethral narrowing, rectal bleeding, anal ulcer and/or rectourethral fistula has been observed after treatment. The overall survival and failure in tumor-free survival (TFS) according to Kaplan–Meier estimates was 90% (±5%) and 88% (±5%) respectively at 6 years. The actuarial biochemical control was 66% (±6%) at 6 years. Conclusions: This protocol is feasible and very well tolerated with low genitourinary morbidity, no gas- trointestinal toxicity but no the same level of LDR biochemical control at 6 years. Ó 2016 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology xxx (2016) xxx–xxx Low dose rate (LDR) brachytherapy has rapidly gained popular- ity in the USA [1,2] and Europe [3,4] as an accepted, effective and safe therapy for localized prostate cancer. Many reports are now available which confirm good outcomes in selected patients with PSA relapse-free survivals that are equivalent to those achieved by surgery. The potential for a therapy that is equally efficient but less harmful than other interventions is especially attractive for patients with early prostate cancer. In 1999 we performed our first interstitial implant procedure with I-125 seeds; currently 120 patients are treated annually, with a total of 2100 recorded. On the other hand, treatment with temporary high dose rate (HDR) brachytherapy with 192-Ir as monotherapy has a number of advantages compared to LDR. The overall treatment time is decreased from many months with LDR to several minutes with HDR. Besides, HDR improves the dose distribution because of the possibility of accurately controlling the source and varying the source dwell time during treatment. The intraoperative optimiza- tion used with HDR allows better source position targeting with the potential for limiting toxicity. There are also advantages in radiation safety for both staff and patient who leave the treatment room without any radioactive implants. At Hospital Universitario Marqués de Valdecilla, we have used HDR brachytherapy as a boost in combination with pelvic external http://dx.doi.org/10.1016/j.radonc.2016.04.006 0167-8140/Ó 2016 Elsevier Ireland Ltd. All rights reserved. Abbreviations: AJCC, American Joint Committee on Cancer; BED, Biologically effective dose; CTAE v4.02, Common Toxicity Criteria for Adverse Event, version 4.02; CTV, Clinical target volume; D90, The dose that covers 90% volume of CTV; D100 urethra, Dose delivered to 100% of the urethra; DVH, Dose–volume histogram; GI, Gastrointestinal; GU, Genitourinary; HDR, High dose rate; IMRT, Intensity modulated radiotherapy; LDR, Low dose rate; PSA, Serum prostate-specific antigen; PTV, Planning target volume; PD, Prescribed dose; SPSS, Statistical analysis SPSS; SD, Standard deviations; TFS, Tumor-free survival; TRUS, The trans-rectal ultra- sound; V90-100-150-200, % of PTV receiving 90%, 100%, 150%, 200% of the PD); V120 urethra, Volume that received a dose of 120% of the urethra. ⇑ Corresponding author at: Department of Radiation Oncology, Hospital Univer- sitario Marques de Valdecilla, C/ Avd. Valdecilla s/n, Santander 39008 (Cantabria), Spain. E-mail address: pprada@telecable.es (P.J. Prada). Radiotherapy and Oncology xxx (2016) xxx–xxx Contents lists available at ScienceDirect Radiotherapy and Oncology journal homepage: www.thegreenjournal.com Please cite this article in press as: Prada PJ et al. High-dose-rate interstitial brachytherapy as monotherapy in one fraction for the treatment of favorable stage prostate cancer: Toxicity and long-term biochemical results. Radiother Oncol (2016), http://dx.doi.org/10.1016/j.radonc.2016.04.006