| PART I. Impact of18F-FDG PET/CT before intensity-modulated radiation therapy on treatment regimen in patients with esophageal cancerObjective The aim of this study is to investigate whether18F-FDG PET/CT has impact on intensity-modulated radiation therapy planning.Methods We retrospectively analyzed patients with esophageal cancer who were considered suitable for intensity-modulated radiation therapy after conventional imaging examinations and underwent PET/CT scans in our institution from December2006to December2012. The following were included:patients with pathologically proven esophageal cancer; patients without any treatment before PET/CT scans; patients without other synchronous neoplasms. Sixty patients were enrolled in this study, including49men and11women. Median age of the patients is61y (range41-90y). Conventional imaging examinations (37cases for EUS,52cases for esophagography,51cases for CT and46cases for B-mode ultrasound) were performed during the month before PET/CT scans. All patients underwent PET/CT imaging before radiation to evaluate whether the stage and therapeutic plans would be changed.Results PET/CT provided additional information and resulted in changes of clinical staging in12patients (20.0%). PET/CT imaging changed management from radiotherapy to chemotherapy in3patients (5.0%) for detecting much more distant metastases. The use of PET/CT changed target volumes in20of57patients (35.1%):16patients (28.1%) showed an increase in gross target volume or clinical target volume for more positive lymph nodes, and4patients (7.0%) exhibited target volumes reduction.Conclusions PET/CT imaging has advantages of detecting local lymph nodes and distant metastases and helping improve the accuracy of clinical staging which may lead to changes of therapeutic strategy. PART Ⅱ. Prognostic significance of18F-FDG PET/CT parameters in patients with esophageal cancerObjective18F-FDG PET/CT image-derived parameters of primary esophageal cancer, such as maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and PET tumor length (PTL), maybe useful in predicting survival in patients with esophageal cancer. The aim of this study is to investigate the prognostic value of these parameters in esophageal cancer patients who underwent radiotherapy or combined chemo-radiotherapy with or without surgery.Methods We retrospectively reviewed55patients with newly diagnosed esophageal cancer who underwent intensity-modulated radiotherapy and examined by PET/CT in our institution between December2006and December2012. The prognostic significances of patients’gender, age, tumor location, TNM stage, SUVmax, MTV, TLG, PTL and treatment modality were analyzed by Kaplan-Meier analysis and log-rank test. Receiver operating characteristic (ROC) curves were used to calculate the optima! thresholds for the four parameters and divided the patients into the SUVmax, MTV, TLG and PTL higher group and lower group, respectively.Results The estimated median survival time for all patients was19.1months (95%confidence interval,8.1-30.1). The overall1-,2-,3-,4-year survival rates for the entire group were59%,45%,35%,26%. Kaplan-Meier analysis shows that the survival rates of the higher SUVmax (≥11.4), MTV (≥8.27cm3), TLG (≥35.21) and PTL(≥5.8cm) groups were significantly different with the lower groups which were associated with a better prognosis. Other clinical characteristics including age and TNM stage were not significant in predicting overall survival.Conclusions SUVmax, MTV, TLG and PTL play a significant role in evaluating the prognosis of esophageal cancer, which may become useful stratification factors before radiotherapy to make out individualizing therapy and improve the overall survival rates. |
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