RESULTS: The final diagnosis included 22 patients with ovarian cancer (n = 11), peritoneal cancer (n = 3), colon cancer (n = 2), liver cancer (n = 2), pancreatic cancer (n = 2), gastric cancer (n = 1), and fallopian tube cancer (n = 1). The diagnosis of the primary tumor using whole-body PET/CT was correct in 11 cases. Regional PET/MRI-assisted whole-body PET/CT diagnosis was correct in 18 cases, including 6 more cases of ovarian cancer and 1 more case of fallopian tube cancer. Among 4 cases that were not diagnosed correctly, 1 case had the primary tumor outside of the PET/MRI scan area, 2 cases were peritoneal cancer, and 1 case was colon cancer. The diagnostic accuracy of regional PET/MRI-assisted whole-body PET/CT was higher than PET/CT alone (81.8% vs. 50.0%, κ 2 = 5.14, p = 0.023). The primary tumor conspicuity score of PET/MRI was higher than PET/CT (3.67 ± 0.66 vs. 2.76 ± 0.94, P < 0.01). In the same scan area, more metastases were detected in PET/MRI than in PET/CT (156 vs. 86 in total, and 7.43 ± 5.17 vs. 4.10 ± 1.92 per patient, t = 3.89, P < 0.01). Lesion-to-background ratio in PET/MRI was higher than that in PET/CT (10.76 ± 5.16 vs. 6.56 ± 3.45, t = 13.02, P < 0.01).
CONCLUSIONS: Comparing to whole-body PET/CT alone, additional delayed regional PET/MRI with high soft tissue resolution is helpful in diagnosing the location of the primary tumor and identifying more metastases in patients with malignant ascites. Yet larger sample size in multicenter and prospective clinical researches is still needed.
结果:最终诊断包括22例卵巢癌患者(n=11),腹膜癌(n=3),结肠癌(n=2),肝癌(n=2),胰腺癌(n=2),胃癌(n=1),和输卵管癌(n=1)。全身PET/CT诊断原发肿瘤11例。18例区域PET/MRI辅助全身PET/CT诊断正确,其中卵巢癌6例,输卵管癌1例。在4例没有正确诊断的病例中,1例原发肿瘤位于PET/MRI扫描区域外,2例为腹膜癌,结肠癌1例。局部PET/MRI辅助全身PET/CT的诊断准确率高于单纯PET/CT(81.8%vs.50.0%,κ2=5.14,p=0.023)。PET/MRI原发肿瘤显著性评分高于PET/CT(3.67±0.66vs.2.76±0.94,P<0.01)。在同一扫描区域,在PET/MRI中检测到的转移瘤比在PET/CT中检测到的转移瘤多(156vs.共86个,和7.43±5.17vs.每位患者4.10±1.92,t=3.89,P<0.01)。PET/MRI的病变与背景比高于PET/CT(10.76±5.16vs.6.56±3.45,t=13.02,P<0.01)。
结论:与单独的全身PET/CT相比,在恶性腹水患者中,额外的具有高软组织分辨率的延迟区域PET/MRI有助于诊断原发肿瘤的位置和识别更多的转移。然而,在多中心和前瞻性临床研究中仍需要更大的样本量。