This study aimed to explore the predictive value of intratumoral heterogeneity of 18F-FDG uptake in pharyngeal cancer treated with chemoradiotherapy.
These analyses included 52 consecutive patients with pharyngeal cancer who underwent 18F-FDG PET/CT before definitive chemoradiotherapy. The heterogeneity factor (HF) was defined as the derivative (dV/dT) of a volume-threshold function for a primary tumor and metastatic lymph nodes, respectively. The relationships between clinical parameters and HF in primary tumor (pHF) and metastatic lymph nodes (nHF) were analyzed.
The HF ranged from -1.367 to -0.027 (median -0.152) in primary tumor. The pHF was significantly correlated with SUVmax, metabolic tumor volume, total lesion glycolysis. Response to induction chemotherapy was not correlated with pHF while response to radiotherapy was significantly better in patients with high pHF (low heterogeneity). Consistently, the 2-year locoregional recurrence-free survival was significantly better in patients with high pHF (82.9% in -0.152 < pHF versus 30.5% in -0.152 > pHF, log-rank p = 0.009). However, nHF (ranged from -1.067 to -0.039 (median -0.160)) was not significantly correlated with response to radiotherapy and locoregional recurrences.
The pHF was a significant predictive value of radiation response and locoregional recurrence in pharyngeal cancer while nHF was not a significant predictive factor.
Clinical trial identification
All authors have declared no conflicts of interest.