¹⁸F-FDG PET as a Routine Posttreatment Surveillance Tool in Oral and Oropharyngeal Squamous Cell Carcinoma: A ProspectiveStudy

Abstract

The purpose of this study was to evaluate the role and timing of serial 18 F-FDG PET scans as routine surveillance for detecting early locoregional recurrence, distant metastases, and second primary tumors in patients treated for advanced squamous cell carcinoma (SCC) in the oral cavity or oropharynx during the first year after completion of their curative treatment. Methods: Forty-eight consecutive patients with SCC in the oral cavity or oropharynx were included after completing their initial therapy with curative intent. Prospective follow-up of the participants was 2-fold: regular follow-up (history and physical examination) and serial 18 F-FDG PET scans. Patients underwent standard follow-up and 18 F-FDG PET at 3, 6, 9, and 12 mo after initial treatment. Findings were validated by histopathology or 18 mo of clinical follow-up and imaging after initial treatment. Results: Incidence of recurrences and second primary tumors was 27% and 10%, respectively. 18 F-FDG PET was significantly (P 5 0.035) more often in agreement with the gold standard than was regular follow-up. 18 F-FDG PET showed a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 43%, 51%, and 100%, respectively. For regular followup, these values were 0%, 60%, 0%, and 50%, respectively. 18 F-FDG PET accounted for a change in diagnostics or treatment in 63% of the patients and regular follow-up in 25% of the patients. Sensitivity and specificity of 18 F-FDG PET were both irrespective of timing of 18 F-FDG PET. For the 3-and 6-mo posttherapy results combined, 18 F-FDG PET detected malignancy in 16 of the 18 patients. Conclusion: 18 F-FDG PET is a suitable routine posttreatment surveillance tool in oral and oropharyngeal SCC patients and detects malignancy before clinical suggestion by the regular follow-up arises. The best timing of a systematic 18 F-FDG PET scan is between 3 and 6 mo after treatment.

Osteoradionecrosis after Radiation Therapy for Head and Neck Cancer: Differentiation from Recurrent Disease with CT and PET/CT Imaging

“…Multiple prior studies have also found the relative unreliability of an elevated SUV in differentiating recurrent tumor from ORN. 11,12,[16][17][18] While recurrent tumor does, in general, demonstrate higher SUV mean and SUV max values compared with ORN, there is significant overlap, which makes differentiating the 2 entities on a case-by-case basis extremely unreliable. This overlap is presumably responsible for previous reports of false-positive results in PET scans attributed to osteoradionecrosis.…”

18F-FDG PET for Routine Posttreatment Surveillance in Oral and Oropharyngeal Squamous Cell Carcinoma

“…We read with great interest the recent article by Krabbe et al (1), in which the authors prospectively evaluated the impact and timing of 18 F-FDG PET for posttreatment surveillance of oral and oropharyngeal squamous cell cancer. Forty-eight patients were included after completing their initial therapy with curative intent.…”

Evaluation of neck node response after radiotherapy: minimizing equivocal results

“…Another option for improving response evaluation might be to repeat PET scans during follow-up. Although in the study by Sjövall et al [17] this seemed not to improve the response evaluation, in the study by Krabbe et al [19] the detection of residual neck disease improved. Preliminary data [20] have indicated that a combination of 18 F-FDG PET and DW-MRI may be an attractive option for optimizing the decision making to perform a neck dissection following chemoradiotherapy.…”

“…Marcus et al [18] recently proposed the five-point BHopkins scale^based on intensity (similar to the Deauville scale, but using the jugular vein rather than the mediastinal blood pool), adding a description of aspects of residual uptake (focal or diffuse). Krabbe et al [19] graded the confidence of image interpretation using a five-point scale (0 definitely no tumour, 1 probably no tumour, 2 equivocal, 3 probably tumour, and 4 definite tumour). Schouten et al [20] used a similar system based on aspect and intensity.…”