主要目标是提出一种基于MRI的筛查方案，研究不注射造影剂的MRI（双参数MRI，bpMRI）在前列腺癌（PCa）早期诊断中的作用，将MRI与前列腺特异性抗原（PSA）测试进行比较。出于这个原因，介绍了罗马第一大学前列腺癌二级筛查（PROSA）的初步结果，以研究基于MRI的筛查方案的效率。PROSA是一项前瞻性、随机、单中心的研究。目前已有351名男性参与并随机分配到两组：（A）无论PSA值如何，男性接受bpMRI检查（175名）；（B）参照临床实践，PSA升高者接受bpMRI检查（61名），而PSA正常者则不接受（112名）。MRI检查结果阳性者进行靶向活检。在A组中，检测到4例临床意义明显的PCa，而B组中没有发现任何病例（p = 0.046）。为评估筛查方案的效率，计算了实验事件率（EER，3.6%），对照事件率（CER，1.2%），绝对风险减少（ARR，2.5%）和需要治疗的人数（NNT，40.3）。PROSA在基于影像的PCa筛查领域中具有丰富的经验。该试验的初步数据凸显无造影MRI在早期检测PCa方面的潜力。进一步数据将最终验证最合适的筛查方案。 PROSA是一项在影像学为基础的前列腺癌筛查研究领域中有趣的经验。其初步数据凸显了无造影MRI作为早期检测PCa的筛查工具的潜力。 这种新的PCa筛查方法可以在降低不必要的前列腺活检和检测临床不显著前列腺癌的同时，促进临床意义明显前列腺癌的早期诊断。 版权所有©2023. 作者(们)以专属许可授予欧洲放射学会。

The main objective is to propose an MRI-based screening protocol, investigating the role of MRI without the injection of contrast media (bi-parametric MRI, bpMRI) as a secondary prevention test for prostate cancer (PCa) early diagnosis, comparing MRI with the prostate specific antigen (PSA) test. For this reason, preliminary results of Prostate Cancer Secondary Screening in Sapienza (PROSA) are presented, to investigate the efficiency of an MRI-based screening protocol. PROSA is a prospective, randomized, single-center study. To date, 351 men have been enrolled and blindly randomized into two different arms: (A) Men underwent a bpMRI regardless of their PSA values (175); (B) Men followed as per clinical practice: those with increased PSA (61) were referred to bpMRI, while those with normal PSA (112) were not. Men who screened positive on MRI were directed to MR-directed targeted biopsy. On arm A, 4 clinically significant PCa have been detected, while none was found on arm B (p = 0.046). To evaluate the efficiency of the screening protocol, we calculated the experimental event rate (EER, 3.6%), control event rate (CER, 1.2%.), absolute risk reduction (ARR, 2.5%), and number needed to treat (NNT, 40.3). PROSA represents an interesting experience in the field of imaging-based PCa screening. The preliminary data from this trial highlight the promising role of non-contrast MRI as a screening tool for early detection of PCa. Further data will finally validate the most appropriate screening program.PROSA depicts an interesting experience in the field of research focused on imaging-based prostate cancer screening. Its preliminary data highlight the promising role of non-contrast MRI as a screening tool for early detection of PCa.• Promotion of an MRI-based screening protocol, investigating the role of non-contrast MRI as a secondary prevention test for prostate cancer early diagnosis, comparing MRI with PSA test. • Prostate Cancer Secondary Screening in Sapienza (PROSA) represents an interesting experience in the field of research focused on imaging-based prostate cancer screening; its preliminary results indicate that it is possible to use non-contrast MRI as a screening tool for early detection of PCa. • This new approach to PCa screening could facilitate the early diagnosis of clinically significant prostate cancer while reducing the number of unnecessary prostate biopsies and the detection of clinically insignificant prostate cancer.© 2023. The Author(s), under exclusive licence to European Society of Radiology.