Yuko Uchiyama1,2, Kenji Hirata3,4, Shiro Watanabe1,2, Shozo Okamoto5, Tohru Shiga6, Kazufumi Okada7, Yoichi M Ito7, Kohsuke Kudo1,8,9. 1. Department of Diagnostic Imaging, Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan. 2. Department of Nuclear Medicine, Hokkaido University Hospital, Sapporo, Japan. 3. Department of Diagnostic Imaging, Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan. khirata@med.hokudai.ac.jp. 4. Department of Nuclear Medicine, Hokkaido University Hospital, Sapporo, Japan. khirata@med.hokudai.ac.jp. 5. Department of Radiology, Obihiro-Kosei General Hospital, Obihiro, Japan. 6. Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima, Japan. 7. Data Science Center, Promotion Unit, Institute of Health Science Innovation for Medical Care, Hokkaido University Hospital, Sapporo, Japan. 8. Department of Diagnostic Imaging and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan. 9. Faculty of Medicine, Global Center for Biomedical Science and Engineering, Hokkaido University, Sapporo, Japan.
Abstract
BACKGROUND: Although patients with differentiated thyroid cancer (DTC) generally have a good prognosis, patients with a large metabolic tumor volume (MTV) on FDG-PET may experience poor clinical courses. We measured organ-based MTVs and tested its prognostic performance in comparison to conventional MTV (cMTV). METHODS: We retrospectively analyzed the cases of 280 patients who received their first I-131 therapy in 2003-2014 at our hospital and showed an FDG-avid metastatic lesion. We randomly divided the patients into training (n = 190) and validation (n = 90) datasets. We classified the MTVs as MTVneck-node, MTVdistant-node, MTVlung, MTVbone, and MTVother-organs and tested with/without dichotomization vis-à-vis overall survival (OS). Based on the estimated weighting coefficients of the organ-based MTVs, we propose a new index: the adjusted whole-body MTV (aMTV). Using the validation dataset, we compared the aMTV with cMTV for predicting OS. RESULTS: In a univariate analysis, MTVdistant-node and MTVother-organs were more strongly correlated with the OS than the dichotomized forms, whereas the dichotomized forms of MTVneck-node, MTVlung, and MTVbone were more strongly correlated with OS than the continuous variables. The aMTV was thus expressed as 0.69 × dic(MTVneck-node) + 0.02 × MTVdistant-node + 1.05 × dic(MTVlung) + 1.58 × dic(MTVbone) + 0.01 × MTVother-organs, where dic(x) represents 0 or 1 based on the optimized cut-off. In the model evaluation using the validation group, aMTV was a significant predictor of OS with a higher c-index (0.7676) than cMTV (0.7218). CONCLUSION: In DTC patients with FDG-avid metastasis before I-131 therapy, all organ-based MTVs were significant predictors of prognosis. As the aMTV outperformed the cMTV for predicting prognoses, we recommend measuring the MTV on an organ basis.
BACKGROUND: Although patients with differentiated thyroid cancer (DTC) generally have a good prognosis, patients with a large metabolic tumor volume (MTV) on FDG-PET may experience poor clinical courses. We measured organ-based MTVs and tested its prognostic performance in comparison to conventional MTV (cMTV). METHODS: We retrospectively analyzed the cases of 280 patients who received their first I-131 therapy in 2003-2014 at our hospital and showed an FDG-avid metastatic lesion. We randomly divided the patients into training (n = 190) and validation (n = 90) datasets. We classified the MTVs as MTVneck-node, MTVdistant-node, MTVlung, MTVbone, and MTVother-organs and tested with/without dichotomization vis-à-vis overall survival (OS). Based on the estimated weighting coefficients of the organ-based MTVs, we propose a new index: the adjusted whole-body MTV (aMTV). Using the validation dataset, we compared the aMTV with cMTV for predicting OS. RESULTS: In a univariate analysis, MTVdistant-node and MTVother-organs were more strongly correlated with the OS than the dichotomized forms, whereas the dichotomized forms of MTVneck-node, MTVlung, and MTVbone were more strongly correlated with OS than the continuous variables. The aMTV was thus expressed as 0.69 × dic(MTVneck-node) + 0.02 × MTVdistant-node + 1.05 × dic(MTVlung) + 1.58 × dic(MTVbone) + 0.01 × MTVother-organs, where dic(x) represents 0 or 1 based on the optimized cut-off. In the model evaluation using the validation group, aMTV was a significant predictor of OS with a higher c-index (0.7676) than cMTV (0.7218). CONCLUSION: In DTC patients with FDG-avid metastasis before I-131 therapy, all organ-based MTVs were significant predictors of prognosis. As the aMTV outperformed the cMTV for predicting prognoses, we recommend measuring the MTV on an organ basis.
Authors: W Wang; S M Larson; M Fazzari; S K Tickoo; K Kolbert; G Sgouros; H Yeung; H Macapinlac; J Rosai; R J Robbins Journal: J Clin Endocrinol Metab Date: 2000-03 Impact factor: 5.958