Table 1.
Patient demographics, cancer stage and grade.
Most patients had intermediate to high risk cancers and a Gleason score of 7a (159) or 7b (66). Whilst organ-confined cancers predominated (T1a –T2c, N = 313), 115 cases were non-organ confined (T3a –T4, approx. 27%). In 9 patients no Gleason score was available, as they had refused biopsy. In four patients d’Amico risk classification was impossible due to lack of biopsy, whereas in five patients a PSA exceeding 20 ng/ml or clinical stage of ≥ T2c resulted in a high-risk classification.
Table 2.
A. IRE treatment parameters of the presented patient cohort.
B. Ablation field extent. C. Procedure categories of patients with more than one IRE application.
Table 3.
A. Follow-up period of all treated patients.
B. Number of patients who completed the IIEF-5 Questionnaire. C. Number of patients who gave subjective feedback on their sexual functions. D. Number of patients who completed the IPSS-Questionnaire.
Table 4.
Adverse events after IRE for PCa.
Fig 1.
Erectile function after IRE for PCa.
A. Correlation between IIEF5-Score reduction with the ablation volume: less than 50% of the prostate treated (left, purple, -5.3 points), 50 to 90% of prostate volume ablated (middle, green, -7.73 points) and whole gland ablation (right, red, -11.1 points). B. Correlation between IIEF5-Score reduction and extent of neurovascular bundle (NVB) involvement in the IRE-field. The columns show the most recently obtained mean IIEF5-Score (where approx. 2/3 were within the first year after IRE): no NVB (left, purple, -1.57 points), one (left or right) NVB (middle, green, -6.42 points) and both NVB (right, red, -10.52 points). C. Reduction of the IIEF5-Score less than 18 months (left, red, -8.72 points) and more than one year after IRE (right, purple, -3.88 points). D. Outcome of subjective assessment of erectile dysfunction (ED). 52% had no ED, 45% experienced transient ED (occurrence of reduction of ED within 1 year after IRE), and 3% experienced persistent IRE-induced ED.
Fig 2.
Kaplan-Meier curves of recurrence free survival for PCa treated with IRE at 72 months follow-up; Gleason 6 (green), Gleason 7 (orange) and Gleason >7 (red), with 95% CI (dashed thin lines).
Recurrence-free survival rates were: Gleason 6: 94%, Gleason 7: 85%, Gleason >7: 60%. Number of observations were: Gleason 6: 3, Gleason 7: 18, Gleason >7: 26. In this diagram, any tumor re-ocurrence, including those outside the IRE treatment field, was included. Despite this conservative approach, which included PCa in untreated volumes of the prostate, the recurrence rates for high-grade (Gleason >7) cancers fall inside the corridor of the recurrence rates after prostatectomy (obtained from the Han Tables of Johns-Hopkins) for comparable cancer stages and PSA-levels (blue and magenta dots, CI shown as bars for ease of perception).
Fig 3.
Kaplan-Meier curves for recurrent PCa for Gleason 6 (green line), Gleason 7 (orange line) and Gleason > 7 (red line) with CI of 95% (dashed thin lines in the associated colors), considering only the recurrences inside or at the margin of the IRE treatment field, excluding the 20 PCa which were located within residual prostate tissue and thus classified as out-of-field recurrence.
Compared to the Kaplan-Meier curves in Fig 2, this analysis is more meaningful on the IRE technology specific aptitude for prostate cancer as it partly filters the diagnostic and focal therapy specific limitations. These were a total of 27 cases, with 1 patient Gleason 6, 10 patients Gleason 7, and 16 patients Gleason > 7. Here the recurrence rates after IRE are more similar to the recurrence rates after prostatectomy (values obtained from Han Tables [25], blue and magenta dots, CI shown as bars for ease of perception) for the lower stage cancers (organ confined disease, blue), even lower at 5-year follow-up: Gleason 6: 98% (64 months), Gleason 7: 93% (72 months), Gleason >7: 75% (72 months).