Department of Nuclear Medicine, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
Eur J Nucl Med Mol Imaging. 2012 Jan;39(1):39-49. doi: 10.1007/s00259-011-1936-4. Epub 2011 Sep 28.
The utility of combined metabolic and volumetric (18)F-FDG PET/CT indices for predicting tumour necrosis fractions following neoadjuvant chemotherapy has not been extensively studied in osteosarcoma. Furthermore, little is known of the early PET/CT responses after only one chemotherapy course.
Enrolled in the study were 20 children and young adults with resectable osteosarcoma who had undergone (18)F-FDG PET/CT scans before and after neoadjuvant chemotherapy. Maximum standardized uptake value (mSUV), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were measured. From among the 20 patients, 14 were prospectively recruited and underwent an additional PET/CT scan after one chemotherapy course. Histopathological necrosis fractions were compared with the above-mentioned PET/CT indices and their ratios.
MTV at the SUV threshold of 2 g/ml was closely correlated with the magnetic resonance image volumes before therapy (r = 0.91). In the prospective cohort, five patients were classified as good responders and nine as poor responders. All the metabolic indices (mSUV and its ratio) and combined metabolic/volumetric indices (MTV, TLG, and their ratios) except the mSUV ratio determined after therapy showed significant differences between good and poor responders (P <0.05). Differences were also noted for all of these indices determined after one chemotherapy course. Furthermore, most of these indices determined after therapy as well as after one chemotherapy course had good sensitivity, specificity, positive predictive value and negative predictive value with respect to predicting histological response to chemotherapy.
In our osteosarcoma patient population, (18)F-FDG PET/CT indices (either combined metabolic/volumetric or metabolic indices) determined after neoadjuvant chemotherapy were useful in predicting tumour responses. This held true after only one chemotherapy course.
在骨肉瘤中，尚未广泛研究联合代谢和容积（18）F-FDG PET/CT 指数预测新辅助化疗后肿瘤坏死分数的作用。此外，人们对仅接受一个化疗疗程后的早期 PET/CT 反应知之甚少。
本研究纳入了 20 名可切除骨肉瘤的儿童和年轻成人患者，他们在新辅助化疗前后接受了（18）F-FDG PET/CT 扫描。测量最大标准化摄取值（mSUV）、代谢肿瘤体积（MTV）和总病变糖酵解（TLG）。在这 20 名患者中，有 14 名前瞻性纳入并在一个化疗疗程后接受了额外的 PET/CT 扫描。组织病理学坏死分数与上述 PET/CT 指数及其比值进行了比较。
SUV 阈值为 2g/ml 时的 MTV 与治疗前的磁共振图像体积密切相关（r=0.91）。在前瞻性队列中，5 名患者被归类为良好反应者，9 名患者为不良反应者。除治疗后 mSUV 比值外，所有代谢指数（mSUV 及其比值）和联合代谢/容积指数（MTV、TLG 及其比值）在良好反应者和不良反应者之间均有显著差异（P<0.05）。在一个化疗疗程后，这些指数也有差异。此外，治疗后和一个化疗疗程后确定的大多数这些指数在预测化疗对组织学的反应方面具有良好的敏感性、特异性、阳性预测值和阴性预测值。
在我们的骨肉瘤患者群体中，新辅助化疗后确定的（18）F-FDG PET/CT 指数（无论是联合代谢/容积指数还是代谢指数）有助于预测肿瘤反应。这在仅接受一个化疗疗程后也成立。
