Targeted and systematic biopsy stands as the prevalent diagnostic approach for prostate cancer. Despite its widespread use, this method is characterized by a high volume of needle biopsies. A refined approach, termed targeted and index-lesion-ipsilateral systematic biopsy, as one of targeted and regional systematic biopsy methods, aim to reduce the number of biopsy cores while maintaining an adequate positive rate. However, the absence of robust evidence necessitates further investigation. This study employs a prospective, multicenter, paired, non-inferiority design to assess the diagnostic efficacy of targeted and index-lesion-ipsilateral systematic prostate biopsy in comparison with the conventional targeted and systematic biopsy for the detection of clinically significant prostate cancer (csPCa). Eligible participants were identified as those with target lesions on prostate MRI, who subsequently underwent targeted and systematic prostate biopsies. The index lesion was defined as the one with the highest Prostate Imaging Reporting and Data System (PI-RADS) score; in cases of multiple lesions with identical PI-RADS scores, the lesion with the greatest diameter was prioritized. Post-biopsy pathological data were collected and evaluated using the International Society of Urological Pathology (ISUP) grading system, which classifies patients with a grade of 2 or higher as having csPCa. The study's primary outcome was to calculate the confidence interval for the difference in csPCa detection rates between the two biopsy methods under a paired design. This interval was then compared against a pre-specified non-inferiority margin to determine whether the targeted and index-lesion-ipsilateral systematic biopsy method is non-inferior to the standard targeted and systematic biopsy in detecting csPCa.