Table 1.

Definitions and consensus statements

Definition	Consensus statement regarding definition
General definitions
Focal therapy (FT)	An anatomy-based (zonal) treatment strategy (e.g. targeting a quadrant, a lobe or both lobes sub-totally)
Targeted FT	A lesion-based focal treatment strategy targeting the identified tumors plus a safety margin
The aim of (targeted) FT for PCa	Eradication of all significant cancer(s)
Subtotal ablation	Any ablation where less than the whole gland is treated
Extended-hemiablation	An ablation where one lobe is completely treated plus a margin of the other lobe regardless of shape
Index lesion	The single dominant lesion in terms of grade and size where grade is more important. There can be only 1 index lesion. The term index lesion itself may be of limited use in the context of FT. It is more important to have an overview of all significant lesions that warrant treatment rather than a single defined index lesion
Salvage FT	Salvage FT refers to the situation where FT is applied to the prostate after whole-gland therapy, or in the same region of the prostate as previous FT. The prostate gland has to be in place
Success and failure in focal therapy
Ablation failure	Ablation failure is a failure of the technique to destroy the tissue in the treated zone, evidenced by tumor found within the treated zone. Ablation failure is just one of the causes that can lead to failure of FT as a whole. Other types of failure include targeting failure and selection failure. Must be confirmed by targeted biopsy
Radiographic suspicion of ablation failure	A suspicion on imaging of tumor presence within the treated zone. mpMRI a suitable imaging modality to determine ablation failure
Residual disease	Cancer remaining in the target zone after FT
Selection failure	FT was inappropriately indicated, evidenced by short-term post-treatment identification of metastatic or locally advanced disease. There is no agreement on whether significant PCa in short-term biopsies taken inside or outside the treatment zone and the need for whole-gland treatment during follow-up constitute selection failure
Biochemical progression after targeted FT	PSA is the best marker to monitor the disease after targeted FT. However, there is currently no data on how to use PSA, i.e. there is no data to support any of the definitions for biochemical recurrence in the context of (targeted) FT
Pathological progression	An increase in Gleason score or tumor volume evidenced by a larger number of positive biopsies or larger per-core tumor involvement
Baseline and outcome functional measures
Functional success of FT	The maintenance of voiding pattern, erectile function and quality of life assessed after 12 months
Erectile function	A qualitative definition of impotency exists: the persistent inability to attain and maintain an erection sufficient for satisfactory sexual performance. For reporting research the panel recommends defining significant erectile dysfunction using the IIEF-5 score <21, determined at 1 year
Sexually active	Patient-reported regular sexual activity
Urinary incontinence	The need to use pads or patient-reported leakage. More comprehensive data could be gathered by requesting patients to complete a micturition diary including the parameters: number of pads, leakage and urge
Significant deterioration of urinary function	An increase in IPSS >5 points
Quality of life	A quality-of-life questionnaire should be administered and both the UCLA-EPIC and the EORTC-QLQ-c-30 tools can be used although neither one is validated for the specific context of focal therapy
Bowel toxicity/GI side effects	The occurrence of: a change in stool frequency, fistula formation, soiling and/or blood in the stool after FT should constitute bowel toxicity/GI side effects. There is no consensus on whether mucus in the stool should also be included. The use of one of the existing grading systems for bowel toxicity is recommended
Intraoperative complications	Complications that cause damage to the patients’ health or require intervention to prevent damage
Short-term side effects	Side effects within 90 days of the procedure
Serious side effects	Clavien–Dindo-scale with 3 or greater as “serious” side effects
Procedural outcomes
Procedure time	From the completion of anesthetic induction until the treating physician is finished
Hospital stay	The time from admittance until discharge
FT in day-care	Admittance, treatment and discharge on the same day
Catheterization time	The time from inserting the catheter until its removal, including time spent on the OR and the recovery-unit

All statements were accepted with >80 % consensus unless stated other otherwise