Significance of dual-time-point 18F-FDG PET imaging in evaluation of hilar and mediastinal lymph node metastasis in non-small-cell lung cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the diagnostic value of dual-time-point 18F-FDG PET-CT imaging in detecting hilar and mediastinal lymph node metastasis in non-small-cell lung cancer (NSCLC).</p><p><b>METHODS</b>Forty-six patients with NSCLC underwent standard whole body single-time 18F-FDG PET-CT scans and a delayed imaging for the thorax alone before surgery, meanwhile, the standard uptake value (SUV) and retention index (RI) were calculated.</p><p><b>RESULTS</b>A total number of 584 lymph nodes were excised in the 46 patients. Of these, 134 metastatic lymph nodes were pathologically confirmed in 31 patients. There were 189 lymph nodes detected and suspected to be metastatic by standard single-time 18 F-FDG PET-CT imaging, and 161 by dual-time-point imaging. Therefore, the sensitivity, specificity, diagnostic accuracy, positive predictive value and negative predictive value in the detection of hilar and mediastinal lymph node metastasis were 87.3%, 84.0%, 84.8%, 61.9% and 95.7% by standard single-time 18F-FDG PET-CT imaging, versus 94.8%, 92.2%, 92.8%, 78.9% and 98.1%, respectively, by dual-time-point imaging. There was a statistically significant difference in the detection of lymph node metastasis between the standard single-time imaging and dual-time-point 18F-FDG PET-CT imaging.</p><p><b>CONCLUSION</b>Dual-time-point 18F-FDG PET-CT imaging is more sensitive, specific and accurate than standard single-time 18F-FDG PET-CT imaging in the detection of hilar and mediastinal lymph node metastasis, and may provide more information for diagnosis, staging and treatment of non-small cell lung cancer.</p>

Preliminary study of 18F-FDG PET-CT in defining lymph node radiation target volume for non-small-cell lung cancer patients / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the value of 18F-FDG PET-CT in detecting metastatic lymph node and radiation planning for patient with non-small-cell lung cancer (NSCLC).</p><p><b>METHODS</b>The data of 58 NSCLC patients were retrospectively analyzed. Preoperatively, Both 18F-FDG PET-CT and CT scan were performed for all patients. Blinded interpretation of these images was then carried out. The gross tumor volume defined by radiation oncologist based on imaging results of either PET-CT or CT alone was compared with pathological results eventually.</p><p><b>RESULTS</b>The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of detecting metastatic lymph node in the mediastinum was 56.0%, 54.2%, 54.8%, 38.9%, 70.3% by CT alone, and 88.0%, 85.4%, 86.3%, 75.9%, 93.2% by PET-CT, respectively. There was a statisticalty significant difference between two methods(P < 0.05). However, statisticalty no significant difference in detecting hilar lymph nodes was observed. The radiation target volume defined by CT was identical to that by PET-CT in 31(53.5%) cases, but changed in the other 27 (46.5%) cases when 18F-FDG PET data was added. The accuracy was 75.9% in detecting metastatic lymph nodes in the radiation target volume defined by PET-CT, while it was much lower by CT alone (48.3%) with a statistically significant difference between two methods (P < 0.05).</p><p><b>CONCLUSION</b>18F-FDG PET-CT is more accurate than CT alone in assessment of mediastinal lymph nodes for NSCLC patients. It may be recommended as a method in defining the radiation target volume.</p>