Li Fang-Lan, Su Ming-Gang, Shi Da-Zhi, Liang Fu-Ling, Li Lin
Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu 610041, China.
Sichuan Da Xue Xue Bao Yi Xue Ban. 2020 Mar;51(2):245-251. doi: 10.12182/20200360104.
To assess the staging, restaging, and treatment strategy determination of extranodal NK/T cell lymphoma (ENKT) by PET/CT real body (true whole-body, TWB) imaging, which is superior to PET/CT limitation of the whole body (limited whole-body, LWB, from skull vertex to upper thighs) by adding 'distal lower extremity' images.
TWB F-FDG PET/CT studies performed for staging and follow-up of ENKTL patients between January 2012 and September 2017 were retrospectively reviewed. Patients in staging group received TWB PET/CT evaluation for staging at the first diagnosis. In follow-up group, patients received follow-up evalution with TWB PET/CT and progressive disease (PD) in the LWB range with or without clinical diagnosis or suspicion before follow-up examination, and then divided into four subgroups: staging (+) PD (－), staging (+) PD (+), staging (－) PD (－), staging (－) PD (+). Then the percentage of unexpected ENKTL lesions found at the distal extremity (outside the LWB range) (P1), and the percentage of changes in the staging, restaging/outcome evaluation (P2) in each group were recorded.
Among the 225 patients in the staging group, 200 (88.9%) had tumors confined to LWB, while P1 was 11.1% (25 cases) and P2 was 0.4% (1 case). In the follow-up group, the P1 in staging (+) PD (－)( =85), staging (+) PD (+)( =4), staging (－) PD (－)( =43), staging (－) PD (+) goups ( =15) were 1.2%, 75.0%, 0%, 26.7%, and P2 were 1.2%, 0%, 0%, 13.3%, respectively. In the follow-up group, regardless of whether the TWB PET/CT examination was performed at the initial diagnosis stage, P1 in PD (－) group and PD (+) group was 0.8 vs. 36.8% ( <0.000 1), and P2 was 0.8% vs. 10.5% ( <0.000 1).
It is not recommended that the TWB PET/CT imaging from the top of the head to the bottom of the foot use for the first diagnosis of ENKTL patients. And for follow-up patients with no clinical evidence of tumor progression or with evidence of tumor progression but whose lesions were limited to LWB at the initial diagnosis of TWB PET/CT staging, LWB PET/CT from the top of the head to the middle of the thigh is recommended for routine follow-up. For ENKTL patients, TWB PET/CT was not performed at the initial stage of diagnosis to detect the condition of lower limbs. If the evidence of tumor progression in the LWB range appeared before the follow-up examination, TWB PET/CT was recommended for the follow-up evaluation to evaluate the systemic tumor involvement.
通过PET/CT真实全身（真正的全身，TWB）成像评估结外NK/T细胞淋巴瘤（ENKT）的分期、再分期及治疗策略的确定，该成像通过增加“下肢远端”图像优于PET/CT全身（有限全身，LWB，从颅顶到大腿上部）的局限性。
回顾性分析2012年1月至2017年9月期间为ENKTL患者进行分期和随访的TWB F-FDG PET/CT研究。分期组患者在首次诊断时接受TWB PET/CT评估以进行分期。在随访组中，患者接受TWB PET/CT随访评估，以及在随访检查前LWB范围内有或无临床诊断或怀疑的疾病进展（PD），然后分为四个亚组：分期（+）PD（－）、分期（+）PD（+）、分期（－）PD（－）、分期（－）PD（+）。然后记录在下肢远端（LWB范围外）发现的意外ENKTL病变的百分比（P1），以及每组分期、再分期/结果评估的变化百分比（P2）。
分期组的225例患者中，200例（88.9%）肿瘤局限于LWB，而P1为11.1%（25例），P2为0.4%（1例）。在随访组中，分期（+）PD（－）（=85）、分期（+）PD（+）（=4）、分期（－）PD（－）（=43）、分期（－）PD（+）组（=15）的P1分别为1.2%、75.0%、0%、26.7%，P2分别为1.2%、0%、0%、13.3%。在随访组中，无论在初始诊断阶段是否进行TWB PET/CT检查，PD（－）组和PD（+）组的P1分别为0.8% vs. 36.8%（<0.000 1），P2分别为0.8% vs. 10.5%（<0.000 1）。
不建议对ENKTL患者首次诊断时使用从头至脚的TWB PET/CT成像。对于随访时无肿瘤进展临床证据或有肿瘤进展证据但在TWB PET/CT分期初始诊断时病变局限于LWB的患者，建议常规随访采用从颅顶到大腿中部的LWB PET/CT。对于ENKTL患者，在诊断初期未进行TWB PET/CT以检测下肢情况。如果在随访检查前LWB范围内出现肿瘤进展证据，建议进行TWB PET/CT随访评估以评估全身肿瘤受累情况。
