Tassinari Elisa, Conci Nicole, Battisti Giacomo, Porta Francesco, Di Scioscio Valerio, Pirini Maria Giulia, de Biase Dario, Nigro Maria Concetta, Iezza Miriam, Castagnetti Fausto, Lovato Luigi, Fanti Stefano, Pantaleo Maria Abbondanza, Nannini Margherita
Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy.
Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna-Policlinico di Sant'Orsola, Bologna, Italy.
Front Oncol. 2023 Dec 20;13:1310452. doi: 10.3389/fonc.2023.1310452. eCollection 2023.
Positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) has proven to be highly sensitive in the early assessment of tumor response in gastrointestinal stromal tumors (GIST), especially in cases where there is doubt or when the early prediction of the response could be clinically useful for patient management. As widely known, kinase mutations have an undoubtful predictive value for sensitivity to imatinib, and the inclusion of KIT and PDGFRa mutational analysis in the diagnostic workup of all GIST is now considered standard practice.
Herein, we described in detail a case of an exon 11 KIT mutated-metastatic GIST patient, who presented an unexpected metabolic progression at the early FDG-PET evaluation after 1 month of first-line imatinib, unconfirmed at the liver biopsy performed near after, which has conversely shown a complete pathological response.
This report aims to highlight the existence of this metabolic pseudoprogression in GIST at the beginning of imatinib therapy in order to avoid early treatment discontinuation. Therefore, an early metabolic progression during a molecular targeted therapy always deserves to be evaluated in the context of the disease molecular profiling, and in case of a discordant finding between functional imaging and molecular background, a short-term longitudinal control should be suggested.
正电子发射断层扫描（PET）联合18-氟脱氧葡萄糖（FDG）已被证明在胃肠道间质瘤（GIST）肿瘤反应的早期评估中具有高度敏感性，特别是在存在疑问的情况下，或者当反应的早期预测对患者管理具有临床实用性时。众所周知，激酶突变对伊马替尼敏感性具有毋庸置疑的预测价值，目前在所有GIST的诊断检查中纳入KIT和PDGFRa突变分析被视为标准做法。
在此，我们详细描述了一例11号外显子KIT突变的转移性GIST患者，该患者在一线伊马替尼治疗1个月后的早期FDG-PET评估中出现了意外的代谢进展，随后不久进行的肝脏活检未证实这一点，相反，活检显示为完全病理缓解。
本报告旨在强调伊马替尼治疗开始时GIST中存在这种代谢假性进展，以避免过早停止治疗。因此，在分子靶向治疗期间的早期代谢进展总是值得在疾病分子谱的背景下进行评估，并且在功能成像和分子背景之间发现不一致的情况下，建议进行短期纵向对照。
