Second-look PET-CT following an initial incomplete PET-CT response to (chemo)radiotherapy for head and neck squamous cell carcinoma

Abstract

This is a repository copy of Second-look PET-CT following an initial incomplete PET-CT response to (chemo)radiotherapy for head and neck squamous cell carcinoma.

A cost‐utility analysis comparing CT surveillance, PET‐CT surveillance, and planned postradiation neck dissection for advanced nodal HPV‐positive oropharyngeal cancer

“…In our cost‐utility model, novel PET‐CT surveillance was the dominant strategy across a wide range of variables compared with traditional PET‐CT, likely as a result of a 40% lower neck dissection rate. Novel and standard PET‐CT strategies showed similar survival and locoregional control, consistent with the findings of other studies 6‐8 . Our findings corroborate the value of a stepwise approach with a second PET‐CT in equivocal responders.…”

“…Consequently, newer studies have advocated for the use of an interval PET‐CT scan to improve the diagnostic performance of PET‐CT and reduce the rate of false positives leading to unnecessary neck dissection. Prestwich et al 7 evaluated patients with head and neck squamous cell carcinoma who underwent an interval PET‐CT performed roughly 3 months after the initial 3‐month posttreatment scan of patients with an incomplete/equivocal response. On interval PET‐CT, they found that 74% patients with initial incomplete/equivocal response converted to a complete nodal response.…”

“…Nevertheless, our study showed that both the standard and novel PET‐CT approaches were cost effective over CT surveillance. Finally, this study evaluated patients with HPV+ OPC and did not include patients with HPV– disease, which is associated with more persistent nodal disease and a higher rate of locoregional recurrence 3,6,7,13 . Inclusion of HPV– OPC would increase the rate of positive imaging findings and subsequent neck dissection, resulting in increased cost and decreased effectiveness of image‐guided surveillance approaches.…”

“…Some authors have advocated for the use of interval PET‐CT reimaging (ie, repeat PET‐CT after 6 months) for select patients with incomplete or equivocal responses on initial scan 6‐8 . These studies have reported a 60% to 74% rate of conversion to complete response with repeat PET‐CT 12 to 16 weeks after the initial scan, without detriment to survival or regional control 6,7 . These contemporary data have not been previously evaluated in cost‐effectiveness analyses.…”

Post-treatment FDG PET-CT in head and neck carcinoma: comparative analysis of 4 qualitative interpretative criteria in a large patient cohort

“…Porceddu et al recommend a further repeat PET-CT 4-6 weeks later (16 weeks post treatment) if the first one shows indeterminate response, with no subsequent cases of nodal failure 12 . Similarly a recent publication from our group highlighted that a second-look PET-CT 13 weeks median duration from the first response assessment PET-CT (median 30 weeks post treatment) found the majority of incomplete response cases convert to a complete metabolic response 30 . Follow-up imaging at an earlier time point results in a higher number of false positive results 31 .…”