To assess whether primary tumor and nodal 18F-FDG uptake may predict prognosis in patients with salivary gland carcinoma.
We conducted a 2-center, retrospective study on 117 patients with salivary gland carcinoma who underwent 18F-FDG PET/CT before treatment and were subsequently treated with curative intent between 2004 and 2014. Pretreatment SUVmax of the primary tumor (SUVmax-T) and that of positive nodes (SUVmax-N) were analyzed in relation to clinical outcomes.
Patients were followed up for a median of 61 months. The following 5-year rates were observed: locoregional control (LRC), 78%; distant metastasis-free survival (DMFS), 67%; progression-free survival (PFS), 62%; and overall survival (OS), 68%. A cutoff value of 7.0 maximized the prognostic impact of both SUVmax-T and SUVmax-N for PFS. Compared with patients with SUVmax-T and SUVmax-N values below the optimal cutoff, those with SUVmax-T and SUVmax-N of 7 or greater showed less favorable 5-year LRC (P < 0.001 and P < 0.001), DMFS (P < 0.001 and P < 0.001), PFS (P < 0.001 and P < 0.001), and OS (P < 0.001 and P < 0.001) rates. Both SUVmax-T of 7 or greater and SUVmax-N of 7 or greater were identified as independent predictors of LRC (P = 0.010 and 0.022), DMFS (P = 0.001 and P = 0.001), PFS (P < 0.001 and P = 0.007), and OS (P = 0.007 and P = 0.002) in multivariable analysis. We therefore devised a prognostic scoring system based on these 2 variables, which was found to be strongly associated with 5-year LRC (P < 0.001), DMFS (P < 0.001), PFS (P < 0.001), and OS (P < 0.001) rates.
SUVmax of the primary tumor and SUVmax-N on pretreatment 18F-FDG PET/CT images may be a useful guide in predicting treatment outcomes, especially when combined in a prognostic scoring system.
From the Departments of *Radiation Oncology and
†Head and Neck Oncology Group, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, Republic of China;
‡Division of Radiation Oncology, Department of Experimental Radiation Oncology, and
§UTHealth Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX;
∥Department of Nuclear Medicine and Molecular Imaging Center, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan;
¶Department of Nuclear Medicine, Keelung Chang Gung Memorial Hospital, Keelung; and
Departments of **Medical Oncology and
‡‡Particle Physics and Beam Delivery Core Laboratory, Institute for Radiological Research, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, Republic of China.
Received for publication June 29, 2018; revision accepted August 15, 2018.
Conflicts of interest and sources of funding: This study was financially supported by research grants CMRPG3F0061-2 and CORPG3G0961 from Chang Gung Medical Foundation. None declared to all authors.
Correspondence to: Chien-Yu Lin, MD, PhD, Department of Radiation Oncology, Chang Gung Memorial Hospital at Linkou, No. 5, Fuxing St, Guishan District, Taoyuan City 333, Taiwan, Republic of China. E-mail: email@example.com.
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