Letter to the Editor re: Positron Emission Tomography with [¹⁸F]-3′-Deoxy-3′fluorothymidine (FLT) as a Predictor of Outcome in Patients with Locally Advanced Resectable Rectal Cancer: a Pilot Study

Excerpt

Dehdashti et al. recently published the results of a pilot study testing the predictive value of [¹⁸F]-3′-Deoxy-3′fluorothymidine (FLT) in clinical outcome of patients with locally advanced resectable rectal cancer [1]. Such studies are methodologically challenging in all aspects and difficult to perform; so, we read with great interest their work that will hopefully contribute to the growing amount of data in the literature regarding the role of FLT as a predictive imaging biomarker. The authors concluded that pre-therapy 2-deoxy-2-[¹⁸F]fluoro-d-glucose uptake SUVmax ≥14.3, along with low FLT uptake (SUVmax < 2.2) and high percentage change in FLT uptake (≥60 %) after 2 weeks of treatment, was predictive of improved disease-free survival (DFS). No correlation was found between histopathological tumour regression and the change from baseline in FLT uptake. We would like, however, to raise a few issues associated with the methodology and analysis used. These have potential implications for future studies and reflect four major aspects of study design and analysis: …