Clinical Application Of18F-fluorodeoxyglucose PET And Involved-field In Concurrent Chemoradiation Of Esophageal Carcinoma

Background And Purpose Published literatures indicated that metabolic response of tumor18F-FDG is able to predict histopathologic response after chemoradiation in esophageal cancer. But all kinds of metabolic parameters and thresholds vary from different clinical trials, including post-radiation SUVmax (post-SUVmax), a decrease percentage of SUVmax on pre-and post-radiation (%DetaSUVmax), and a change percentage of tumor length according to SUVmax (â–³L), et al. Disputes exist in how to evaluate and analysize the indexes and values. The aim of this trial is to observe the differences about the parameters predicting histopathologic response and survival curve of these after stratification patients according to histopathologic and metabolic response.Material and Methods A total of60patients with squamous esophageal cancer were enrolled in this trial. All patients received chemoradiation followed by esophagectomy and18FDG-PET examination twice on pre-and post-radiation. Then metabolic indexes post-SUVmax,%DetaSUVmax andâ–³L are calculated and all patients are classified to metabolic complete response (CMR) or metabolic nonresponse (non-CMR) according to post-SUVmax3.0,%DetaSUVmax75%andâ–³L33%. Histopathologic response in esophageal sections was observed to determine and classify to pathologic complete response (CR) or pathologic non-response (non-CR). Survival curves were compared to the difference after classification according to histopathologic and metabolic response.Results For all kinds of PET-based indexes, only%DetaSUVmax75%andâ–³L33%predicted histopathologic response and correlated to local control time and overall survival time (Correlation coefficient R:0.747/0.704and0.705/0.684, P<0.05). And the accuracy is higher with the the sensitivity91.6%and81.4%and the specificity86.7%and89.5%. Analysis of Cox Proportional Hazards Model for overall survival and local control indicated that two parameters had a significant survival advantage (hazard ratio [HR]=0.897and0.813, P<0.01). Survival curve after stratification according to a threshold of75%of%DetaSUVmax was minor difference to that of histopathologic response.Conclusion%DetaSUVmax75%andâ–³L33%in all metabolic indexes were optical to predict the histopathologic response, with a minor difference in survival curve after stratification. Objective The aim of this trial was to study whether a decrease percentage of tumor FDG uptake correlate with overall survival and local control times for patients with esophageal cancer, and who would benefit from a late-course accelerated hyperfractionated (LCHF) radiation scheme.Material and Methods A total of50eligible patients with squamous esophageal cancer received PET examination three times and were treated with the LCHF radiation scheme with a dose of68.4Gy/41fractions in6.5weeks. A decrease percentage of FDG uptake (%DeltaSUVmax) was calculated and patients were stratified into high radiosensitive (HR), moderate radiosensitive (MR) and low radiosensitive (LR) subgroups according to%DeltaSUVmax in the CF scheme. Then a linear correlation was calculated between patients'survival time and%DeltaSUVmax. Local control and overall survival were compared after stratification.Results Only in the MR subgroup there was no linear correlation for%DetaSUVmax between the CF and LCHF scheme (Correlation coefficients R<0.4, P values>0.05). And other%DeltaSUVmax after radiation correlated to overall survival or local control times (Correlation coefficients R>0.5, and P value<0.05), including between the CF and LCHF scheme in the HR and LR subgroups.3-year local control rates in the HR, MR and LR subgroups were100%,81.5%and0%respectively (P<0.001). And3-year overall survival rates were92.4%,58.8%and0%for HR, MR and LR subgroups respectively (P<0.001).Conclusion%DetaSUVmax on postradiation positively correlated to patients'survival time for esophageal cancer. Patients who benefited from LCHF schedules were patients with a30%-60%decrease of tumor FDG uptake after the completion of CF radiation. Objective To investigate the feasibility of involved-field irradiation (IFI) for the treatment of cervical and upper-thoracic esophageal cancer with concurrent chemoradiation.Material and Methods A total of102eligible patients with cervical and upper-thoracic esophageal cancer were treated with concurrent chemoradiation and randomized into either an IFI or elective nodal irradiation (ENI) group. Before chemoradiation, PET/CT scan was used to all patients. All patients received a dose of59.4Gy/33fractions in5.5weeks. A total of2cycles of cisplatin-based chemotherapy were delivered for patients.Results Total acute toxicities didn't reach a statistical significance for the IFI versus the ENI group(P=0.203), but hematologic toxicity included infect ion (27.4%v64.7%) and nausea (25.4%v54.9%)were a statistical significance group(P=0.008and0.028). There was no statistical difference for late radiation reaction. The cumulative incidence of local/regional failure (13.7%v17.6%) was lower in the ENI versus the IFI group in three years, with no statistical significance(P=0.837). Regional lymph failure was9.8%for the IFI group versus7.8%for the ENI group(P=0.837). And out-field lymph failure only2%for the IFI group. The1-,2-, and3-year survival rates were100%,84.0%, and41.3%for the ENI group, and100%,74.7%, and32.0%for the IFI group, respectively (P=0.336). The1-,2-, and3-year local control rates were90.0%,80.1%, and80.1%in the IFI group, and92.8%,92.8%, and85.7%in the ENI group(P=0.583), respectively.Conclusion IFI as treatment for cervical and upper-thoracic esophageal cancer did not cause significant failure in lymph node regions. IFI remains an acceptable and toxicity-minimizing method of treatment.