Francavilla T L, Miletich R S, DeMichele D, Patronas N J, Oldfield E H, Weintraub B D, Di Chiro G
Neuroimaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.
Neurosurgery. 1991 Jun;28(6):826-33. doi: 10.1097/00006123-199106000-00007.
Positron emission tomography with [18F]fluorodeoxyglucose (FDG) was carried out in 24 patients with pituitary macroadenomas (32 studies) to assess the glucose utilization of these tumors in vivo. The adenoma metabolic index, which is the ratio of FDG uptake of tumor to a whole brain slice, was calculated. Comparisons were made between tumor uptake of FDG and hormone secretion and response to therapies. In each positron emission tomography study, the macroadenoma could be easily identified visually as an area of increased FDG uptake near the region of the sella. FDG uptakes were highest for nonfunctional adenomas, and the prolactin, growth hormone, and thyroid-stimulating hormone-producing groups displayed similar levels of glucose metabolism. The adenoma metabolic index for all tumors averaged 1.3, ranging from 0.3 for a thyroid-stimulating hormone adenoma to 3.5 for a nonfunctional tumor. Tumors did not exhibit metabolic rates that could characterize the type of hormone produced. Recurrent macroadenomas displayed metabolism similar to tumors not operated on, whereas irradiated adenomas showed lower glucose uptake than nonirradiated tumors. Drug therapy with bromocriptine or the long-acting somatostatin analogue octreotide also decreased the glucose utilization of the tumor. There was no correlation between the amount of hormone produced and the adenoma metabolic index when a group of tumors was analyzed. Patients scanned more than once, however, demonstrated changes in hormone levels that changed or did not change in parallel with tumor metabolism. Thus, positron emission tomography offers the potential capability for predicting and defining the growth of pituitary adenomas. This may be of particular value when plasma hormone assays and conventional imaging techniques prove inadequate for monitoring patient response to therapy.
对24例垂体大腺瘤患者（共进行32项研究）进行了[18F]氟脱氧葡萄糖（FDG）正电子发射断层扫描，以评估这些肿瘤在体内的葡萄糖利用情况。计算了腺瘤代谢指数，即肿瘤FDG摄取量与全脑切片的比值。对FDG肿瘤摄取量与激素分泌及治疗反应进行了比较。在每项正电子发射断层扫描研究中，大腺瘤可通过视觉轻松识别为蝶鞍区域附近FDG摄取增加的区域。无功能腺瘤的FDG摄取量最高，泌乳素、生长激素和促甲状腺激素分泌组的葡萄糖代谢水平相似。所有肿瘤的腺瘤代谢指数平均为1.3，范围从促甲状腺激素腺瘤的0.3到无功能肿瘤的3.5。肿瘤未表现出可表征所产生激素类型的代谢率。复发性大腺瘤的代谢与未手术的肿瘤相似，而接受放疗的腺瘤的葡萄糖摄取低于未接受放疗的肿瘤。用溴隐亭或长效生长抑素类似物奥曲肽进行药物治疗也降低了肿瘤的葡萄糖利用。在分析一组肿瘤时，所产生的激素量与腺瘤代谢指数之间无相关性。然而，多次扫描的患者显示激素水平的变化与肿瘤代谢的变化或不变化并行。因此，正电子发射断层扫描具有预测和界定垂体腺瘤生长的潜在能力。当血浆激素检测和传统成像技术不足以监测患者对治疗的反应时，这可能具有特别的价值。
