Long Term Negative Predictive Value of Post-Treatment FDG PET/CT Scan in Nasopharyngeal Carcinoma

Adham Hijab, Ilit Turgeman, Shorook Na'ara and Salem Billan

Rambam Health Care Campus, Israel
Israel Institute of Technology, Israel
Departmentof Otolaryngology, Head and Neck Surgery, Israel Institute of Technology, Israel

^*Correspondance to: Salem Billan 

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Abstract:

Objectives: Accurate assessment of response to treatment in Nasopharyngeal Carcinoma (NPC) is important for early administration of salvage therapy and to avoid futile invasive diagnostic investigations. This study assessed the Negative Predictive Value (NPV) of the post-therapy FDG-PET/CT scan throughout a prolonged follow-up period.Patients and Materials: We reviewed our NPC patients’ database from March 2005 to August 2015. A cohort of patients with initial post-treatment negative FDG-PET/CT scan was identified. A scan was considered negative if no non-physiological uptake was seen. Follow-up data was retrospectively analyzed.Results: Forty-six patients with negative post-treatment PET/CT scans were identified. Median follow-up was 44.1 months. Forty patients were disease-free at last follow-up (e.g., NPV 87%). Mean age at diagnosis of patients who had recurrence was 65.17 years compared to 44.65 years for patients who were disease-free. Based on COX regression analysis, patients who were 65 years old or older had a significant risk for disease recurrence (Hazard Ratio [HR] 10.67, 95% Confidence Interval [CI] 1.95-58.4, p=0.006) compared to younger patients. NPV of patients under 65 was 94% compared to 50% for patients older than 65. Four of six patients who relapsed had T4 disease and the remaining two had T3. There were no recurrences in the group of T1-2 (NPV 100%).Conclusion: The NPV of PET/CT scans is high and can predict recurrent disease in T1-2 NPC patients and in those younger than 65 years, regardless of T stage. Larger studies are warranted to validate our findings.

Keywords:

Nasopharyngeal carcinoma; PET/CT; Follow-up; Recurrence

Cite the Article:

Hijab A, Turgeman I, Na'ara S, Billan S. Long Term Negative Predictive Value of Post-Treatment FDG PET/CT Scan in Nasopharyngeal Carcinoma. Clin Oncol. 2018; 3: 1557.