The purpose of this study was to report the outcomes of high-dose-rate (HDR) brachytherapy and hypofractionated external beam radiotherapy (EBRT) combined with long-term androgen deprivation therapy (ADT) for National Comprehensive Cancer Network (NCCN) criteria-defined high-risk (HR) and very high-risk (VHR) prostate cancer. Data from 178 HR (n = 96, 54%) and VHR (n = 82, 46%) prostate cancer patients who underwent 192Ir-HDR brachytherapy and hypofractionated EBRT with long-term ADT between 2003 and 2008 were retrospectively analyzed. The mean dose to 90% of the planning target volume was 6.3 Gy/fraction of HDR brachytherapy. After five fractions of HDR treatment, EBRT with 10 fractions of 3 Gy was administered. All patients initially underwent ≥6 months of neoadjuvant ADT, and adjuvant ADT was continued for 36 months after EBRT. The median follow-up was 61 months (range, 25–94 months) from the start of radiotherapy. The 5-year biochemical non-evidence of disease, freedom from clinical failure and overall survival rates were 90.6% (HR, 97.8%; VHR, 81.9%), 95.2% (HR, 97.7%; VHR, 92.1%), and 96.9% (HR, 100%; VHR, 93.3%), respectively. The highest Radiation Therapy Oncology Group-defined late genitourinary toxicities were Grade 2 in 7.3% of patients and Grade 3 in 9.6%. The highest late gastrointestinal toxicities were Grade 2 in 2.8% of patients and Grade 3 in 0%. Although the 5-year outcome of this tri-modality approach seems favorable, further follow-up is necessary to validate clinical and survival advantages of this intensive approach compared with the standard EBRT approach.

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Purpose: The aim of this report is dosimetric evaluation for an intraoperative fusion computed tomography (CT) as a superior predictor of 1-month CT based dosimetry in comparison to transrectal ultrasound (TRUS) in permanent interstitial prostate brachytherapy.Material and methods: Data of 65 patients treated with seed implantation were analyzed. All procedures has been performed with patients in the lithotomy position inside the O-arm system. An end-fine probe is used as a landmark to fuse TRUS and O-arm-based CT images. There was no difference in the patient's position, probe position, and timing of image acquisition between the two imaging modalities. Dose-volume histogram (DVH) parameters such as the dose to 90% of prostate volume (D 90 ) has been analyzed.Results: The area under the curve of the receiver operating characteristic tended to be larger on fusion CT than on TRUS for most DVH parameters (71.85% vs. 59.59% for D 90 ; p = 0.07). Significant relationships between fusion CT and 1-month CT were confirmed using Pearson's correlation coefficients for most DVH parameters (R = 0.48, p < 0.01 for D 90 ), although the relationship between TRUS and 1-month CT was poor. Large dose reduction (35 Gy for D 90 ) was seen from TRUS to fusion CT, especially in patients with high body weight and small prostate volume.Conclusions: Intraoperative fusion CT appears to have higher predictive power for 1-month CT-based dosimetry than TRUS. A prospective trial using fusion CT-based planning is warranted.J Contemp Brachytherapy 2016; 8, 1: 7-16 DOI: 10.5114/jcb.2016.57817Key words: brachytherapy, intraoperative CT, low dose rate, O-arm system, prostate cancer. PurposeTransrectal ultrasound (TRUS) is the standard imaging tool for interstitial prostate brachytherapy [1]. The prostate, urethra, and rectum are usually contoured on TRUS images, and treatment is planned based on these contours. In addition, these contours could be modified in a realtime manner during surgery. Meanwhile, it is a wellknown fact that ultrasound is not suitable for imaging implanted seeds [2,3]. Although computed tomography (CT) is not available in the usual operating room, the guideline of the American Brachytherapy Society recommended CT as the gold standard for detecting seed position and calculating post-implant dose volume histograms (DVHs) [4].The O-arm ® surgical imaging system (Medtronic, Dublin, Ireland) was developed to provide real-time, intraoperative CT imaging with a large field-of-view. This system permits patients to be in the lithotomy position even during image acquisition because the bore diameter of this system (965 mm) is significantly larger than that of conventional CT (700-800 mm). However, soft tissues such as the prostate or rectum are difficult to delineate with this system because of its lower contrast resolution compared to conventional CT, although high-density structures such as bone or seeds that are made from titanium can be clearly imaged.Therefore, we combined O-arm-based CT and TRUS during surgery as a new...

Background Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy (STAMPEDE) trial showed the survival benefit for prostate radiotherapy in newly diagnosed prostate cancer patients with a low metastatic burden. The result raises the next question whether additional radiotherapy to metastatic sites could improve the survival in those with a low metastatic burden. Methods We evaluated the efficacy and safety of prostate‐directed radiotherapy (PDRT) with or without metastasis‐directed radiotherapy (MDRT) in newly diagnosed oligometastatic patients who underwent combination of high‐dose‐rate prostate brachytherapy, external beam radiotherapy, and androgen deprivation therapy. Forty patients with bone metastasis and node positive prostate cancer were retrospectively analyzed. Of these, 22 (55%), 3 (7%), and 15 (38%) patients had N1M0, M1a, and M1b, respectively. Eighteen patients (45%) received MDRT to all metastatic sites. All patients initially underwent ≧6 months of androgen deprivation therapy. Oligometastatic disease was defined as presence of five or fewer metastatic lesions. Median follow‐up period was 62.5 months. Results Of the 40 patients, the 5‐year castration‐resistant prostate cancer (CRPC)‐free survival rate and cancer‐specific survival was 64.4% and 87.9%, respectively. Pre‐ or post‐treatment predictive value including prostate‐specific antigen (PSA) at diagnosis ≥20 ng/mL, Gleason grade group 5, positive biopsy core rate ≥51%, PSA nadir level of ≥0.02 ng/mL after the radiotherapy, and no MDRT were significantly associated with progression to CRPC. Patients with MDRT had significantly higher probability of achieving a PSA level of <0.02 ng/mL than those without the therapy (88.8% vs 54.5%, P = 0.0354) and consequently had a better CRPC‐free survival than those without the therapy (HR 0.319, 95%CI: 0.116‐0.877). Comparing PDRT alone, PDRT with MDRT did not significantly increase the incidences of genitourinary and gastrointestinal toxicities. Conclusions This single‐institutional study revealed the feasibility of combining prostate brachytherapy and MDRT for newly diagnosed oligometastatic prostate cancer. This combined approach has potential to prolong CRPC‐free survival.

Background: Local impedance (LI) can indirectly measure catheter contact and tissue temperature during radiofrequency catheter ablation (RFCA). However, data on the effects of catheter contact angle on LI parameters are scarce. This study aimed to evaluate the influence of catheter contact angle on LI changes and lesion size with two different LI-sensing catheters in a porcine experimental study. Methods: Lesions were created by the INTELLANAV MiFi™ OI (MiFi) and the INTELLANAV STABLEPOINT™ (STABLEPOINT). RFCA was performed with 30 W and a duration of 30 s. The contact force (CF) (0, 5, 10, 20, and 30 g) and catheter contact angle (30°, 45°, and 90°) were changed in each set (n = 8 each). The LI rise, LI drop, and lesion size were evaluated. Results:The LI rise increased as CF increased. There was no angular dependence with the LI rise under all CFs in the MiFi. On the other hand, the LI rise at 90°was lower than at 30°under 5 and 10 g of CF in STABLEPOINT. The LI drop increased as CF increased. Regarding the difference in catheter contact angles, the LI drop at 90°was lower than that at 30°for both catheters. The maximum lesion widths and surface widths were smaller at 90°than at 30°, whereas there were no differences in lesion depths. Conclusion:The LI drop and lesion widths at 90°were significantly smaller than those at 30°, although the lesion depths were not different among the 3 angles for the MiFi and STABLEPOINT.