The role of changes in maximum standardized uptake value of FDG PET-CT for post-treatment surveillance in patients with head and neck squamous cell carcinoma treated with chemoradiotherapy: preliminary findings.

Objective: No clear consensus exists regarding the optimal interval and frequency of follow-up positron emission tomography (PET)-CT in patients with head and neck squamous cell carcinoma (HNSCC) treated with chemoradiotherapy (CRT). Here, we sought to clarify whether the changes in the maximum standardized uptake value (ΔSUV _max ) may be a valid parameter to help decision-making for surveillance management after CRT.
Methods: 40 patients underwent PET-CT at pre-treatment and 3 months after CRT. Patients were followed by sequential PET-CT for 2 years after CRT. The ΔSUV _max of the primary tumour and the metastatic nodes were calculated between pre-treatment and 3 months after the CRT, and we evaluated the associations between ΔSUV _max and the manifestation of recurrence, time to recurrence and the patient survival.
Results: The ΔSUV _max of the primary tumour was significantly lower for the lesions with recurrence than that for those with non-recurrence for both the primary site and the nodal site (p = 0.007, 0.02). A significant correlation was found between the time to recurrence and the ΔSUV _max of the primary tumour (r = 0.63, p < 0.05). The threshold ΔSUV _max of the primary tumour of 1.04 revealed 76.9% sensitivity and 86.4% specificity for distinguishing recurrence from non-recurrence. The progression-free survival and overall survival of the two patient groups divided by the ΔSUV _max of the primary tumour at 1.04 showed a significant difference (p = 0.003, 0.02). The ΔSUV _max of the metastatic nodes did not show a significant association with recurrence or patient survival.
Conclusion: The ΔSUV _max of the primary tumour showed a significant association with recurrence and patient survival. Advances in knowledge: The ΔSUV _max of the primary tumour may be a valid clinical parameter to help decision-making for the surveillance management of patients with HNSCC after CRT.