Jonmarker Olof, Axelsson Rimma, Nilsson Ted, Gabrielson Stefan
CLINTEC, Department of Radiology, Karolinska Institutet, 171 77 Stockholm, Sweden.
ME Radiology Huddinge, Karolinska University Hospital, 141 86 Stockholm, Sweden.
Diagnostics (Basel). 2021 Mar 31;11(4):630. doi: 10.3390/diagnostics11040630.
In prostate cancer, the early detection of distant spread has been shown to be of importance. Prostate-specific membrane antigen (PSMA)-binding radionuclides in positron emission tomography (PET) is a promising method for precise disease staging. PET diagnostics depend on image reconstruction techniques, and ordered subset expectation maximization (OSEM) is the established standard. Block sequential regularized expectation maximization (BSREM) is a more recent reconstruction algorithm and may produce fewer equivocal findings and better lesion detection.
Ga PSMA-11 PET/CT scans of patients with de novo or suspected recurrent prostate cancer were retrospectively reformatted using both the OSEM and BSREM algorithms. The lesions were counted and categorized by three radiologists. The intra-class correlation (ICC) and Cohen's kappa for the inter-rater reliability were calculated.
Sixty-one patients were reviewed. BSREM identified slightly fewer lesions overall and fewer equivocal findings. ICC was excellent with regards to definitive lymph nodes and bone metastasis identification and poor with regards to equivocal metastasis irrespective of the reconstruction algorithm. The median Cohen's kappa were 0.66, 0.74, 0.61 and 0.43 for OSEM and 0.61, 0.63, 0.66 and 0.53 for BSREM, with respect to the tumor, local lymph nodes, metastatic lymph nodes and bone metastasis detection, respectively.
BSREM in the setting of Ga PMSA PET staging or restaging is comparable to OSEM.
在前列腺癌中，远处转移的早期检测已被证明具有重要意义。正电子发射断层扫描（PET）中与前列腺特异性膜抗原（PSMA）结合的放射性核素是一种用于精确疾病分期的有前景的方法。PET诊断依赖于图像重建技术，有序子集期望最大化（OSEM）是既定的标准。块序贯正则化期望最大化（BSREM）是一种更新的重建算法，可能会产生更少的模糊结果和更好的病变检测效果。
对初发或疑似复发性前列腺癌患者的镓 PSMA - 11 PET/CT扫描图像，使用OSEM和BSREM算法进行回顾性重新格式化。由三位放射科医生对病变进行计数和分类。计算组内相关系数（ICC）和评估者间可靠性的科恩kappa系数。
共评估了61例患者。BSREM总体上识别出的病变略少，模糊结果也更少。无论采用哪种重建算法，在明确的淋巴结和骨转移识别方面，ICC都很好，但在模糊转移方面则较差。对于肿瘤、局部淋巴结、转移淋巴结和骨转移的检测，OSEM的科恩kappa中位数分别为0.66、0.74、0.61和0.43，BSREM的分别为0.61、0.63、0.66和0.53。
在镓 PMSA PET分期或再分期中，BSREM与OSEM相当。
