脂肪肉瘤的18F-氟代脱氧葡萄糖PET- CT显像特征

PET/CT imaging manifestations of different pathological subtypes of liposarcoma

目的:分析不同病理亚型脂肪肉瘤的18F-氟代脱氧葡萄糖(FDG) PET-CT显像特征,探讨PET-CT在脂肪肉瘤诊治中的应用价值。方法:回顾性分析13例经组织病理学检查证实的脂肪肉瘤患者的18F-FDG PET-CT显像资料。分析不同病理亚型脂肪肉瘤的PET-CT表现,比较不同病理亚型脂肪肉瘤FDG代谢程度的差异及代谢的均匀性。结果:高分化型脂肪肉瘤以脂肪密度为主,均为单发,内有絮状间隔和(或)不规则形软组织团片影伴轻度代谢;黏液样脂肪肉瘤为囊性或囊实性肿块,单发或多发,代谢均匀或不均匀、轻中度增高;去分化型脂肪肉瘤为软组织密度影为主的混杂密度肿块,代谢不均匀,软组织成分代谢增高明显,常伴有大片片状坏死区;混合型脂肪肉瘤为高分化型与去分化型的混合类型,多发病灶,两种类型的影像表现均有。局部脂肪浸润12例,其中1例复发性去分化型脂肪肉瘤患者发生肺转移,所有患者均无淋巴结转移。FNCCLE分级为G1、G2和G3级患者脂肪肉瘤的最大标准摄取值(SUVmax)分别为3.00、5.67和10.33,差异有统计学意义(P<0.05),其中G1与G3、G2与G3级间差异均有统计学意义(均P<0.05)。结论:不同病理亚型脂肪肉瘤患者的PET-CT表现不同,术前PET-CT检查能明确肿瘤侵犯范围、有无转移情况,有利于初步判断脂肪肉瘤的病理亚型和评估组织学分级,有助于手术计划的制订,为临床决策提供更多信息。

Objective: To analyze PET/CT imaging manifestations of different pathological subtypes of liposarcoma. Methods: The 18F-fluorodeoxyglucose(FDG) PET/CT features of 13 patients pathologically confirmed as liposarcoma were retrospectively reviewed. The metabolism degree and distribution of different subtypes of liposarcoma were compared. Results: The well-differentiated liposarcoma showed fat density mass with septa and irregular strip with mild FDG uptake. The myxoid liposarcoma showed cystic or cystic solid mass, single or multiple with mild-moderate FDG uptake heterogeneously or homogeneously. The dedifferentiated liposarcoma showed mixed soft tissue mass with high FDG uptake heterogeneously, larger lesion with necrosis centrally. The mixed type contained well differentiated type and dedifferentiated type, and showed multiple lesion with combined imaging manifestations. There were local invasions in 12 cases, no lymph node matastasis, and the recurrence of dedifferentiated liposarcoma with lung metastasis in 1 case. The maximum standard values(SUVmax) of FNCCLE grade G1, G2 and G3 liposarcoma were 3.00, 5.67 and 10.33, respectively;there was significant difference between G1 and G3 groups, G2 and G3 groups(all P<0.05). Conclusions: PET/CT manifestations of liposarcoma of various pathological subtypes are different. Preoperative PET/CT examination can clarify the pathological types, scope of tumor invasion and metastasis of liposarcoma, which provides more information for clinical decision-making and is helpful for the preparation of surgical plan.