Prediction Model of Chemotherapy Response in Osteosarcoma by ¹⁸F-FDG PET and MRI

Abstract

Response to neoadjuvant chemotherapy is a significant prognostic factor for osteosarcoma; however, this information can be determined only after surgical resection. If we could predict histologic response before surgery, it might be helpful for the planning of surgeries and tailoring of treatment. We evaluated the usefulness of 18 F-FDG PET for this purpose. Methods: A total of 70 consecutive patients with a high-grade osteosarcoma treated at our institute were prospectively enrolled. All patients underwent 18 F-FDG PET and MRI before and after neoadjuvant chemotherapy. We analyzed the predictive values of 5 parameters, namely, maximum standardized uptake values (SUVs), before and after (SUV2) chemotherapy, SUV change ratio, tumor volume change ratio, and metabolic volume change ratio (MVCR) in terms of their abilities to discriminate responders from nonresponders. Results: Patients with an SUV2 of less than or equal to 2 showed a good histologic response, and patients with an SUV2 of greater than 5 showed a poor histologic response. The histologic response of a patient with an intermediate SUV2 (2 , SUV2 # 5) was found to be predictable using MVCR. A patient with an MVCR of less than 0.65 is likely to be a good responder, whereas a patient with an MVCR of greater than or equal to 0.65 is likely to be a poor responder. According to our model, the predictive values for good responders and poor responders were 97% (31/32) and 95% (36/38), respectively. Conclusion: We found that combined information on 18 F-FDG PET and MRI scans, acquired before and after chemotherapy, could be used to predict histologic response to neoadjuvant chemotherapy in osteosarcoma.

Usefulness of Combined Metabolic–Volumetric Indices of 18F-FDG PET/CT for the Early Prediction of Neoadjuvant Chemotherapy Outcomes in Breast Cancer

“…[12][13][14][15][16][17]. Moreover, these indices demonstrated the possibility of predicting chemotherapy effect in osteogenic sarcoma, not only at the end of the neoadjuvant chemotherapy [18,19], but also after the second cycle [20].…”

The Role of 18F-FDG PET/CT as a Prognostic Factor in Patients with Synovial Sarcoma

“…During the past decade, 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( monitoring of various malignancies [9][10][11]. 18 F-FDG PET provides physiologic information that enables cancer to be diagnosed on the basis of altered glucose metabolism [12].…”

Combination of 18F-FDG PET/CT and Diffusion-Weighted MR Imaging as a Predictor of Histologic Response to Neoadjuvant Chemotherapy: Preliminary Results in Osteosarcoma

“…18 F-FDG PET enables the assessment of glucose metabolism and hence also the metabolic activity of cancer tissue by calculating a standardized uptake value (SUV). Change in SUV after neoadjuvant chemotherapy has been reported to be useful in predicting tumor response in osteosarcoma (9)(10)(11). Diffusion-weighted MR imaging (DWI) represents in vivo images of biologic tissues weighted with the local microstructural characteristics of water diffusion.…”

“…However, because tumor necrosis can be assessed only in the resected specimens after the completion of neoadjuvant chemotherapy, the continuation of ineffective chemotherapy can cause the development of resistant clones (3). To overcome these limitations, noninvasive imaging modalities including bone scintigraphy (5), CT (6), MR imaging (2,3,7,8), and 18 F-FDG PET (9)(10)(11) have been investigated to predict the effect of neoadjuvant chemotherapy. 18 F-FDG PET enables the assessment of glucose metabolism and hence also the metabolic activity of cancer tissue by calculating a standardized uptake value (SUV).…”