PURPOSE:To document the current prostate brachytherapy practice across the UK and Ireland and compare with previously published audit results. MATERIAL AND METHODS:Participants from 25 centers attending the annual UK & Ireland Prostate Brachytherapy Conference were invited to complete an online survey. Sixty-three questions assessed the center's experience and staffing, clinician's experience, clinical selection criteria and scheduling, number of cases per modality in the preceding three years, low-dose-rate (LDR) pre- and post-implant technique and high-dose-rate (HDR) implant technique. Responses were collated, and descriptive statistical analysis performed. RESULTS:Eighteen (72%) centers responded with 17 performing LDR only, 1 performing HDR only, and 6 performing both LDR and HDR. Seventy-one percent of centers have > 10 years of LDR brachytherapy experience, whereas 71% centers that perform HDR brachytherapy have > 5 years of experience. Thirteen centers have 2 or more clinicians performing brachytherapy with 61% of lead consultants performing > 25 cases (LDR + HDR) in 2016. The number of implants (range), that includes LDR and HDR, performed by individual practitioners in 2016 was > 50 by 21%, 25-50 by 38%, and < 25 by 41%. Eight centers reported a decline in LDR monotherapy case numbers in 2016. Number of center's performing HDR brachytherapy increased in last five years. Relative uniformity in patient selection is noted, and LDR pre- and post-implant dosimetry adheres to published quality guidelines, with an average post-implant D90 of > 145 Gy in 69% of centers in 2014 and 2015 compared to 63% in 2016. The median CT/US volume ratios were > 0.9 ≤ 1.0 (n = 4), > 1.0 ≤ 1.1 (n = 7), and > 1.1 (n = 2). CONCLUSION:There is considerable prostate brachytherapy experience in the UK and Ireland. An apparent fall in LDR case numbers is noted. Maintenance of case numbers and ongoing compliance with published quality guidelines is important to sustain high quality outcomes.

ConclusionIt is possible to decrease the dose in the neurovascular beam more than a 50% with our technique based on hyaluronic acid injection, however long-term follow-up will be necessary to determine the extent and benefit to the patient with this procedure.

Background to the audit: Whole brain radiotherapy (WBRT) is often used to treat brain metastases. A subgroup identified to have better prognosis includes patients with age (<65), controlled primary, no other metastases and Karnofsky performance status KPS >70.[1] In good prognosis groups an oligometastatic disease group has been identified in which locally aggressive therapy (surgery/stereotactic radiotherapy/SRS) improves disease control.[2]

ConclusionUp to October 2016, 42 patients have completed the treatment.More mature results seem to confirm the presented preliminary ones.Our preliminary data show the feasibility of an extremely hypofractionated schedule with concomitant boost on the mpMRI-identified DIL.The higher number of patients expected for the trial and a longer follow-up are needed to confirm these results.The secondary endpoints of the study, namely the evaluation of late toxicity, patient free survival, overall survival, quality of life and pattern of failure will be investigated when more mature follow-up data will be available.

Background to the audit: Anal squamous cell cancer affects approximately 1,100 patients in the UK annually. Outcomes for surgery and chemoradiotherapy (CRT) are comparable with CRT being the preferred modality to improve colostomy-free survival. Large radiation pelvic fields can lead to increased acute toxicity and long-term treatment-related sequelae.

146 Background: In patients treated with neoadjuvant lutenising hormone-releasing hormone agonist (LHRHa) therapy prior to radical prostate radiotherapy the PSA nadir in the first week of radiotherapy has been correlated with subsequent biochemical failure free survival (BFFS). Bicalutamide monotherapy (BC) is increasingly being used as a neoadjuvant therapy in place of LHRHa. We wished to compare the initial PSA response to neoadjuvant BC or LHRHa in this setting as well as examining subsequent biochemical failure rates. Methods: We retrospectively reviewed the case notes of consecutive men with prostate cancer treated with BC monotherapy prior to radical prostate radiotherapy from April 2004 to December 2008 and case-matched them to men treated with neoadjuvant LHRHa. PSA levels and kinetics prior to radiotherapy and subsequent BFFS were analysed. Results: Eighty nine men treated with BC with a median follow-up of 42 months were case matched to 89 men treated with LHRHa. There were no significant differences in age, initial PSA, Gleason, or T stage. The median nadir PSA on day 1 of radiotherapy was 2.2ng/mL (0.1-11.2) for BC patients and 0.9ng/mL (0.1-11.2) for LHRHa patients (p=0.0007). There were no significant differences in PSA velocity or doubling time during the neoadjuvant period. A PSA of <1.0ng/mL on day 1 of radiotherapy was seen in 29 (32%) and 47 (52%) of BC and LHRHa patients respectively. Biochemical failure was seen in 10 (11.2%) and 2 (2.2%) of BC and LHRHa patients respectively. PSA kinetics did not predict for subsequent BFFS at this duration of FU for men receiving neoadjuvant BC. Conclusions: In this case-matched study, neoadjuvant BC therapy does not provide the same level of pre-radiotherapy PSA suppression when compared to neoadjuvant LHRHa. Higher biochemical failure rates are seen in patients treated with BC than LHRHa however this may be a result of prolonged castration. No significant financial relationships to disclose.