C11 BODIPY 581/591 br Results br The bPFS local recurrence free survival
The bPFS, local recurrence-free survival, and metastases-free survival (MFS) at 5 years were 87.1%, 95.5%, and 96.3%, respectively. The prostate cancer-specific survival and OS at 5 years were 100% and 92%, respectively. As shown in Table 2, we were unable to establish any predictors of bPFS, MFS, or OS on univariate analysis. Four patients had biochemical recurrence occurring at 24, 42, 58, and 104 months after initial presentation. Two patients had sem-inal vesicle recurrences detected on prostate-specific mem-brane antigen positron emission tomographic scans when their biochemical recurrence was confirmed (58 and 104 months). One patient had an oligometastasis detected
Characteristics N ¼ 31 cT Stage
Favourable 10 Unfavourable 21 ADT
cT, clinical tumor; ISUP, International Society for Urological Pathology; ADT, androgen deprivation therapy. Table 2
Univariate Analysis of Clinical Factors That May Influence bPFS, MFS, and r> OS
Clinical Prognostic Factors bPFS MFS OS
Intermediate-Risk Group .82 .55 .44 (Favourable vs. Unfavourable)
bPFS, biochemical progression-free survival; MFS, metastases-free sur-vival; OS, overall survival; cT, clinical tumor; ISUP, International Society for Urological Pathology; ADT, androgen deprivation therapy.
on his prostate-specific membrane antigen positron emission tomographic scan 10 months after his biochemical recurrence (24 months) and subsequently had stereotactic body radio-therapy directed at the oligometastasis. The final patient has not developed any detectable local recurrence or metastases 73 months after his biochemical recurrence (42 months).
The incidence of late grade 1 and 2 GU toxicities were 54.8% and 6.5%, respectively. The most common late grade 1 toxicities were urinary urgency, urinary tract pain, urinary retention, and urinary frequency. The incidence of late grade 3 GU toxicity was 6.5% with urinary retention occurring in two patients requiring either a C11 BODIPY 581/591 neck incision (BNI) or transurethral resection of the prostate (TURP). Of the four patients who had BNI or TURP before their treatment, one patient who had a prior BNI developed further retention with urethral stricture and required a subsequent TURP. The incidence of any late GU toxicity was 80% in the 3DCRT with bone matching IGRT cohort vs. 43% in the IMRT with fiducial marker cohort.
The incidence of late grade 1 and 2 gastrointestinal (GI) toxicities were 19.4% and 6.5%, respectively. The grade 2 toxicities were rectal bleeding and radiation proctitis. No pa-tients developed grade 3 GI toxicity. There was no difference in late GI toxicity with two grade 1 toxicity (20%) reported in the 3DCRT with bone matching IGRT cohort vs. five grade 1 toxicity (24%) in the IMRT with fiducial marker IGRT cohort.
Three randomized studies have now shown a significant bPFS advantage for brachytherapy plus EBRT over EBRT alone [1–3]. Two older studies employed high dose rate (HDR) brachytherapy boosts with Iridium 192 implants plus EBRT vs. nondose-escalated EBRT alone(2, 3). Both studies demonstrated a significant improvement in bPFS for the brachytherapy arms. The 5-year bPFS was improved by 32% (71% vs. 39%) in Sathya et al , and the 7-year bPFS was improved by 18% (66% vs. 48%) in Hoskin et al . However, the EBRT doses employed were lower than current recommended guidelines, with Sathya et al 
using 66 Gy and Hoskin et al  using 55 Gy in their EBRT alone arms. The ASCENDE-RT study  compared LDR-PB boost vs. dose-escalated EBRT (78 Gy) with significant improvement in 7 and 9 year bPFS demonstrated for the brachytherapy arm. This difference was 11% at 7 years (86% vs. 75%), rising to an estimated 21% at 9 years (83% vs. 62%) despite the use of contemporary radiation doses. Even further dose escalation with EBRT may not achieve the outcomes provided by a brachytherapy boost with Spratt et al  reporting inferior 7 year bPFS with EBRT alone to 86.4 Gy vs. EBRT plus LDR boost (81.4% vs. 92%). Extreme dose escalation beyond 86.4 Gy has proven to be difficult to achieve with normal tissue constraints being the limiting factor. There is only one randomized study comparing EBRT plus brachytherapy vs. brachytherapy alone. The NRG Oncology/RTOG0232 study  randomized