Timo Soeterik

50 CHAPTER 3 FIGURE 3. Percentages of patients with overall PRIAS-concordant follow-up (PSA monitoring and biopsy testing) * Patients underwent the minimum number of scheduled repeat biopsies depending on their follow-up time. PSA testing was regarded as PRIAS compliant if ≥75% of required PSA tests were performed depending on AS follow-up time. Repeat biopsies and overall PRIAS concordant follow-up Protocol adherence regarding scheduled prostate biopsies also differed between hospitals. As can be seen in Figure 2, the highest percentage of patient compliance with the first scheduled repeat biopsy was observed in hospital 2 (79%), while the lowest was in hospital 1 (48%). In the overall population, 473/912 patients (52%) were compliant with all scheduled repeat biopsies during their follow-up. At an institutional level, the highest percentage was found in hospital 2 (68%) and the lowest in hospital 1 (40%). There was also great variation between hospitals regarding the percentage of patients with overall PRIAS concordant follow-up; hospital 4 had the lowest proportion of patients with overall concordant follow-up (34%) and hospital 2 had the highest (60%; Figure 3). MRI for follow-up MRI of the prostate was performed during follow-up in 449/1000 patients (45%). The proportion of patients undergoing prostate MRI during AS varied significantly among institutions. The highest percentage was observed in hospital 6 (104/186, 56%) and the lowest in hospital 5 (22/78, 28%; p < 0.001). In some cases, MRI was performed instead of repeat biopsy. In a total of 41 patients, MRI of the prostate was performed instead of the first repeat biopsy. If we consider patients as compliant if MRI was performed instead of the scheduled biopsy, the total number of patients with PRIAS-concordant repeat biopsy (or MRI) follow-up would increase from 473/912 (52%) to 537/912 (59%). Prostate MRI increasingly replaced prostate biopsies over time. Of all patients diagnosed in 2008, 2/90 (2%) underwent MRI instead of the first repeat biopsy. Among patients diagnosed in 2014, this was performed in 15/126 cases (12%).