Prostate cancer generally occurs multifocally. The lesions of the largest size and highest-grade are often concordant, and defined as an index tumor. However, these factors sometimes do not coincide within one lesion. In such discordant cases, not the largest size lesion but the highest-grade lesion is known to determine the prognosis. We focused on the multiparametric magnetic resonance imaging (mpMRI) detectability of the highest-grade tumors in discordant cases. We investigated the detectability of the highest-grade tumor using preoperative mpMRI in 50 discordant patients who underwent radical prostatectomy. The radiologist was informed of the tumor location on the pathological tumor map, and mpMRI interpretation for each tumor was performed. Prostate Imaging-Reporting and Data System (PI-RADS) scores of 1, 2, 3, 4, and 5 on preoperative mpMRI were assigned to 13, 1, 9, 16, and 11 of the largest tumors, respectively. On the other hand, scores of 1, 2, 3, 4, and 5 were assigned to 23, 0, 7, 19, and 1 of the highest-grade tumors, respectively. The difference between them was statistically significant (p=0.007). We also found that the largest anterior tumor frequently hid the ipsilateral posterior highest-grade tumor; the detection rate of the highest-grade tumor in this pattern was 42.1% (8 of 19 cases) We found that mpMRI detectability of the highest-grade tumor in discordant cases was inferior to that of the largest tumor with low malignant potential. Our results suggest that the risk of high-grade tumors which determine patient prognosis being overlooked.

中文翻译：

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通过多参数磁共振成像检测多灶性不一致前列腺癌的最高级病变

前列腺癌通常是多灶性发生的。最大尺寸和最高级别的病变通常是一致的，并被定义为指标肿瘤。然而，这些因素有时在一个病变内并不同时存在。在这种不一致的病例中，确定预后的不是最大尺寸的病变，而是最高等级的病变。我们重点关注不一致病例中最高级别肿瘤的多参数磁共振成像 (mpMRI) 可检测性。我们在 50 名接受根治性前列腺切除术的不一致患者中使用术前 mpMRI 研究了最高级别肿瘤的可检测性。放射科医生被告知肿瘤在病理肿瘤图上的位置，并对每个肿瘤进行 mpMRI 解释。术前 mpMRI 的前列腺成像报告和数据系统 (PI-RADS) 评分分别为 1、2、3、4 和 5 分，分别分配给 13、1、9、16 和 11 个最大的肿瘤。另一方面，1、2、3、4和5的分数分别分配给23、0、7、19和1个最高级别的肿瘤。它们之间的差异具有统计学意义（p=0.007）。我们还发现最大的前部肿瘤经常隐藏同侧后部最高级别的肿瘤；该模式中最高级别肿瘤的检出率为 42.1%（19 例中的 8 例）我们发现，不一致病例中最高级别肿瘤的 mpMRI 检出率低于具有低度恶性潜力的最大肿瘤的检出率。我们的结果表明，决定患者预后的高级别肿瘤的风险被忽视了。