Focal irreversible electroporation for prostate cancer: functional outcomes and short-term oncological control

Background:current data on the use of irreversible electroporation (ire) in the treatment of prostate cancer (pca) is limited. we aim to evaluate the safety, short-term functional and oncological outcomes of focal ire in low-intermediate risk pca.methods:between february 2013 and may 2014, 32 consecutive men underwent ire at a single centre. patients with low-intermediate risk pca who had not received previous pca treatment were included for analysis. the tumour was ablated using 3–6 electrodes, ensuring a minimum 5-mm safety margin around the visible magnetic resonance imaging (mri) lesion. follow-up included recording clavien complications, expanded prostate cancer index composite (epic) questionnaires (baseline, 1.5, 3, 6 months), 6-month multi-parametric mri (mp-mri) and 7-month biopsy. findings on mp-mri and biopsy were sub-divided into infield, adjacent or outfield of the treatment zone.results:twenty-five men were included for final analysis. safety follow-up revealed one clavien grade 3 complication and five grade 1 complications. functional follow-up confirmed no significant change in american urological association urinary symptom score, sexual or bowel function. infield, there were no suspicious findings on mp-mri (n=24) or biopsy (n=21) in all patients. adjacent to the treatment zone, five (21%) had suspicious findings on mp-mri with four (19%) proving to be significant on biopsy. outfield, there were two (8%) with suspicious findings on mp-mri and one (5%) significant finding on biopsy. for the five patients with significant findings on follow-up biopsy, one is awaiting repeat ire, one had radical prostatectomy and three remained on active surveillance.conclusions:in selected patients with low-intermediate risk pca, focal ire appears to be safe with minimal morbidity. there were no infield recurrences and 76% of patients were histologically free of significant cancer at 8 months. almost all recurrences were adjacent to the treatment zone, and this was addressed by widening the treatment margins.