Division of Endocrinology, Clinical Medicine Department, Faculty of Medical Sciences, University of Campinas, Rua Tessália Vieira de Camargo, 126, Campinas, São Paulo, 13084-971, Brazil.
Division of Nuclear Medicine, Radiology Department, Faculty of Medical Sciences, University of Campinas, Campinas, Brazil.
J Endocrinol Invest. 2021 Oct;44(10):2195-2202. doi: 10.1007/s40618-021-01523-6. Epub 2021 Feb 11.
Acromegaly is associated with many comorbidities and increased mortality. The first-line treatment is transsphenoidal surgery. However, many patients also need adjuvant drug treatment after surgery. Somatostatin analog (SSA), which suppresses GH secretion by somatotrophs by binding to the SSTR2 receptor, is the first choice. Nevertheless, 50% of patients are partially or totally resistant to SSA, so predictive factors of response are helpful to individualize drug treatment. GaDOTATATE PET/CT has emerged as the gold-standard method in the diagnosis and follow-up of gastroenteropancreatic neuroendocrine tumors, which also express SSTR. Our objective was to evaluate whether Ga-DOTATATE uptake (SUV max) at the pituitary region of patients on SSA therapy would be useful as a drug response predictor without the need of tumoral tissue.
Fifteen acromegalics patients on SSA treatment for at least 6 months were underwent to Ga-DOTATATE PET/CT at the nuclear medicine service. There was an SSA complete response group (n = 5), defined as GH < 1 µg/L and IFG-1 in the normal range for gender and age, and a group that did not meet these criteria (n = 10).
As a result, we did not find out a significantly higher SUV max in the complete response group (p = 0.0576) to SSA. However, we found a significant inverse relationship between postoperative GH values and the SUVmax at the sella turcica (p = 0.0188), probably reflecting tumor SSTR2 expression.
Thus, after this initial evaluation, GaDOTATATE PET/CT should be better studied to assess its usefulness in the follow-up of acromegalic patients.
肢端肥大症与许多合并症和死亡率增加有关。一线治疗方法是经蝶窦手术。然而，许多患者在手术后也需要辅助药物治疗。生长抑素类似物（SSA）通过与 SSTR2 受体结合抑制生长激素分泌，是首选药物。然而，有 50%的患者对 SSA 部分或完全耐药，因此反应的预测因素有助于个体化药物治疗。GaDOTATATE PET/CT 已成为胃肠胰腺神经内分泌肿瘤诊断和随访的金标准方法，这些肿瘤也表达 SSTR。我们的目的是评估 SSA 治疗患者的垂体区域 Ga-DOTATATE 摄取（SUVmax）是否可以作为一种无需肿瘤组织的药物反应预测指标。
15 例接受 SSA 治疗至少 6 个月的肢端肥大症患者在核医学科进行 Ga-DOTATATE PET/CT 检查。我们将患者分为完全缓解组（n=5），定义为 GH<1μg/L 和 IGF-1 在性别和年龄正常范围内，不符合这些标准的患者为未缓解组（n=10）。
我们发现完全缓解组的 SUVmax 并没有显著升高（p=0.0576）。然而，我们发现术后 GH 值与鞍区 SUVmax 之间存在显著的负相关（p=0.0188），这可能反映了肿瘤 SSTR2 的表达。
因此，在这项初步评估之后，应该更好地研究 GaDOTATATE PET/CT，以评估其在肢端肥大症患者随访中的有用性。
