Introduction: There is no consensus for the number of targeted biopsies taken from a single lesion on prostate MRI. There are studies which addressed this topic, but all are retrospective. Each single biopsy increases the risk for complication mainly infections and bleeding. We examined the incremental detection rate of prostate cancer in each subsequent biopsy from a single lesion, to find what is the ideal number of biopsies from a single lesion. Methods: The demographic, clinical and pathologic data from men who underwent trans rectal ultrasound (TRUS) fusion biopsy of the prostate was collected prospectively. Navigo fusion system was utilized. PI-RADS version 2.1 was utilized, a lesion PI-RADS 3 and more was targeted. From one Index lesion 5 sequential targeted biopsies were taken. Systematic biopsies were performed. Clinically significant prostate cancer was defined as Gleason grade =3+4. Patients with PSA above 20 ng/ml, status post local/systemic/hormonal therapy were excluded. Results: From May 2021 until March 2022, 127 men met the inclusion criteria. Mean age was 68.4± 8.18, mean PSA 7.1±3.49. Eighty-nine (70%) patients were diagnosed with prostate cancer. In 73(57%) patients cancer was detected in the targeted biopsies form the Index lesion: 53(41.7%) in the first biopsy, 59(46.5%) in the first two biopsies, 67(53%) in the first three biopsies and 73(57.4%) in all five biopsies. Clinically significant cancer was detected in 47(37%) of the first three biopsies, the 4th and 5th biopsies together added only 2(1.5%) cases of clinically significant cancer. There was a correlation between the size of the lesion and number of biopsies needed for the detection of prostate cancer, in a lesion >11mm only two biopsies are needed to detect 90% of the cancers. Conclusions: Most of the clinically significant cancers will be detected in the first three TRUS-Fusion biopsies from the index lesion, a negligible number of cancers will be added in the 4th and 5th biopsies. SOURCE OF Funding: None
