初诊Ⅳ期老年肿瘤患者全脑皮质^(18)氟-氟代脱氧葡萄糖摄取与肿瘤糖酵解总量的相关性及近期预后意义初探

Severe,diffuse decrease in global brain ^(18)F-fluorodeoxxglucose uptake,association with whole-body total lesion glycolysis and short-term prognostic significance in elderly patients with newly diagnosed stage Ⅳ cancer

目的探讨初诊IV期老年(≥60岁)肿瘤患者全脑皮质18氟-氟代脱氧葡萄糖(FDG)摄取弥漫明显减低征象与肿瘤糖酵解总量的相关性及其近期预后意义。方法回顾性总结24例^(18)F-FDGPET/CT显像全脑皮质表现为FDG摄取弥漫明显臧低的初诊IV期老年肿瘤患者(脑代谢诚低组)临床及FDG PET/CT资料,以16例全脑皮质未表现为FDG摄取弥漫明显减低的初诊IV期老年肿瘤患者(脑代谢未减低组)及25例年龄、性别大致匹配的健康查体受检者(正常对照组)作为对照,探讨全脑皮质FDG摄取与全身肿瘤负荷的相关性,随访脑代谢诚低组及未臧低组患者最终临床结局,总结该征象的近期预后意义。结果脑代谢减低组包括17例IV期淋巴瘤及7例IV期其他类型恶性肿瘤患者[男15例;年龄(73±9)岁],脑代谢未减低组包括8例IV期淋巴瘤及8例IV期其他类型恶性肿瘤患者[男12例;年龄(65±5)岁],正常对照组25例[男13例;年龄(65±6)岁]。脑代谢减低组较未减低组患者年龄更大(t=3.8,P=0.001)。全脑SUVmean分别为(4.9±1.8)及(10.9±2.0)(t=-9.8,P=0.000),全脑糖酵解总量(TG)分别为1786.5土1162.5及2868.4±1424.5(t=-2.6,P=0.012),全身肿瘤病灶糖酵解总量(TLG)分别为6825.5±4776.9及2919.5±2031.7(l=3.6,P=0.001)。Pearson相关性分析显示,脑FDG摄取与全身肿瘤病灶TLG存在负相关。随访两组患者生存结局,脑代谢减低组及未减低组中位随访时间分别为6个月和10个月(χ^(2)=3.7,P=0.054),脑代谢减低组14例(14/24)死亡,脑代谢未减低组9例死亡(9/16),(χ^(2)=0.017,P=0.896),但脑代谢减低组死亡者中有8例(8/14)在PET/CT检查后1月内死亡,脑代谢未减低组在1月内死亡者0例(χ^(2)=4.7,P=0.029)。结论初诊IV期老年肿瘤患者^(18)F-FDG PET/CT全脑皮质FDG摄取弥漫明显减低更常见于年龄更大者,其全身肿瘤负荷显著高于全脑皮质FDG摄取未见减低者,且在短期内病死率高,此征象提示近期预后不佳。

Objective To investigate the relationships between severe,diffuse decrease in global brain 18 F-fluorodeoxxglucose(FDG)uptake,whole-body total lesion glycolysis(TLG)and short-term death in elderly patients with newly diagnosed stageⅣcancer.Methods Clinical and 18 FFDG PET/CT data of 24 elderly patients newly diagnosed stageⅣcancer showing marked diffuse decrease in global brain FDG uptake(the decreased brain uptake group)were retrospectively enrolled.Sixteen elderly patients with newly diagnosed stage W cancer but without decreased global brain FDG uptake(the no decreased brain uptake group)and 25 healthy subjects were enrolled as the control groups.Correlations between brain FDG uptake and whole-body TLG were analyzed.We followed up the final outcomes of all patients and analyzed the short-term prognostic value of these manifestations.Results The decreased brain uptake group included 17 patients with stage Ⅳ lymphoma and 7 patients with stage Ⅳ malignant tumor of other types[15 males,age:(73±9)years],while the no decreased brain uptake group included 8 patients with stage Ⅳ lymphoma and 8 patients with stage Ⅳ malignant tumor of other types[12 males,age:(65±5)years]and the healthy control group included 25 subjects[13 males,age:(65±6)years].Patients were older in the decreased brain uptake group than in the no decreased brain uptake group(t=3.8,P=0.001).The global brain SUV means of the decreased brain uptake group and the no decreased brain uptake group were 4.9±1.8 and 10.9±2.0,respectively(t=-9.8,P=0.000).The global brain total glycolysis (TG)values of the two groups were 1786.5±1162.5 and 2868.4±1424.5,respectively(t=-2.6,P=0.012).The whole-body TLG values of the two groups were 6825.5±4776.9 and 2919.5±2031.7,respectively(t=3.6,P=0.001).Pearson correlation analysis showed that brain FDG uptake was adversely correlated with whole-body TLG.We followed up the survival outcomes of the two groups.The median follow-up lengths of the two groups were 6 months and 10 months,respectively(χ^(2)=3.7,P=0.054).Fourteen (14/24)patients died in the decreased brain uptake group while 9(9/16)died in the no decreased brain uptake group(χ^(2)=0.017,P=0.896).However,8 cases died within 1 month post PET/CT scan in the decreased brain uptake group while none died in the no decreased brain uptake group(χ^(2)=4.7,P=0.029).Conclusions Severe,diffuse decrease in ^(18)F-FDG PET/CT uptake in the whole cerebral cortex is more common in elderly patients with newly diagnosed stage Ⅳ cancer,whose total tumor load is significantly higher than that of cancer patients withol!t decrease in whole cerebral cortex FDG uptake.This uptake reduction may indicate poor short-term outcome and the probability of short-term death may be high.