Marieke van Son

126 CHAPTER 7 Table 1 Continued Median (IQR) or number (%) Missing (%) Dorsolateral location of the tumor 132 (88%) Size of the CTV (cc) 8.5 (6 – 12.8) Size of the prostate # (cc) 31.4 (25.7 – 39.6) Baseline IPSS 8 (5 – 11) 16 (10.7%) Baseline IIEF 9 (4 – 18) 24 (16%) Baseline toxicity^ GU 0 1 2 3 73 (48.7%) 52 (34.7%) 19 (12.6%) 0 (0%) 6 (4%) GI 0 1 2 3 118 (78.7%) 24 (16%) 2 (1.3%) 0 (0%) 6 (4%) ED 0 1 2 3 23 (15.3%) 40 (26.7%) 54 (36%) 27 (18%) 6 (4%) Number of brachytherapy catheters used 9 (8 – 11) CTV D95% 18.8 (17.4 – 19.7) Urethra D10% (Gy) 15.2 (10.3 – 17.5) Bladder D1cc (Gy) 9.2 (5.2 – 11.6) Rectum D1cc (Gy) 10.2 (8.1 – 11.7) Legend: IQR: interquartile range, EBRT: external beam radiotherapy, LDR-BT: low-dose-rate brachytherapy, HDR-BT: high-dose-rate brachytherapy, ADT: androgen deprivation therapy, TURP: transurethral resection of the prostate, TNM-stage: tumor/node/metastasis stage, CTV: clinical target volume, IPSS: international prostate symptoms score, IIEF: international index of erectile function. * As part of primary treatment. # As measured on MRI. ^ As graded by the Common Terminology Criteria for Adverse Events (CTCAE) 4.0. Cumulative toxicity Over time, 48/150 (32%) patients had maximum new-onset grade 1 GU toxicity, mainly consisting of mild urinary tract pain, hematuria or frequency. A maximum of grade 2 GU toxicity was seen in 61/150 patients (41%), mostly within the subdomain urinary frequency (49/61), for which medication was usually prescribed. Five patients (3%) experienced grade 3 GU toxicity. One patient had grade 3 cystitis, for which he received intravenous antibiotics during a hospital admission. Two patients had grade 3 urinary retention (urethral stricture), which involved placement of a permanent suprapubic catheter after failed urethral stricture incision. Two patients had grade 3 urinary in-