FDG PET/CT versus PET alone for pre-surgical detection of lymph node metastasis in esophageal carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To compare the combined FDG PET/CT with PET alone in the detection of lymph node metastasis (LNM) for esophageal carcinoma patient.</p><p><b>METHODS</b>From November 2003 to August 2005, 35 patients with esophageal carcinoma underwent FDG PET/CT before esophagectomy and lymph node (LN) dissection. The patients who had history of previous anticancer treatment or diabetes mellitus and inflammatory lung diseases as well as being inoperable for medical reasons were excluded. The results of LNM detection by PET/CT and PET alone were compared with pathological results.</p><p><b>RESULTS</b>Twenty-nine men and 6 women were eligible for this study, with a mean age of 57 years (range: 40 to 72 years). Of these 35 patients, 3 had lesion at the upper third thoracic esophagus, 22 at the middle third and 10 at the lower third. All patients underwent surgical resection successfully. Twenty-five patients and 65 out of 313 excised nodal groups were found to have metastases by pathological examination. The true positive and true negative LNM interpretation reached 61 and 229 LN groups on PET/CT versus 53 and 217 LN groups on PET alone. False negative LNM interpretation was found in 12 LN groups on PET alone, and 8 of them were corrected by PET/CT including one cervical LN, 4 paraesophageal LNs, one left gastric arterial LN, one left gastric cardia LN, one lesser gastric curve LN. False positive interpretations on PET alone were found in 31 LN groups, 12 of them were corrected by PET/CT which included 9 false-positive interpretations due to physical tracer uptake (2 in the cervical region and 7 in gastrointestinal tract ) and 3 lesions with heterogeneous tracer uptake in the primary tumor. The sensitivity, specificity and accuracy of LNM detection by PET alone was 81.54% (53/65), 87.50% (217/248), and 86.26% (270/313), whereas by PET/CT, which was 93.85% (61/65), 91.24% (229/248) and 92.65% (290/313), respectively. There were statistically significant differences in sensitivity and accuracy of LNM detection between PET/CT and PET alone (0.033 and 0.009).</p><p><b>CONCLUSION</b>Compared with FDG PET alone, FDG PET combined with CT can improve the sensitivity and accuracy in detection of lymph node metastasis in esophageal carcinoma.</p>

A comparative study on radiology and pathology target volume in non-small-cell lung cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>Defining the margin of clinical target volume (CTV) is very important for three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiation therapy (IMRT). In this study, according to the comparison between gross tumor volume (GTV) silhouetted by radiology and pathology in non-small-cell lung cancer (NSCLC), we tried to define the correlation of GTV by radiology and pathology, and assess the degree of correlation to local microscopic extension (ME) among different pathologic types of NSCLC, so as to define the margin of CTV precisely.</p><p><b>METHODS</b>From February 2001 to February 2002, forty-three NSCLC patients after surgical resection were studied. All patients had had CT scans of the chest before surgery and routine pathology examination after surgery. The tumor size at X (lateral direction), Y (ventrodorsal direction) and Z (craniocaudal direction) axes were measured on CT. Also by pathology examination, the tumor size at X, Y, Z axes and the degree of ME at X, Y, Z axes were measured, respectively.</p><p><b>RESULTS</b>Without taking into account the value of ME, there was almost total agreement on the GTV by radiology and pathology in three dimensions. The mean value of ME was 2.18 mm for adenocarcinoma (ADC) and 1.33 mm for squamous cell carcinoma (SCC) (P = 0.001). But, taking into account 95% of the ME, a margin of 7 mm and 5 mm must be allowed for ADC and SCC, respectively.</p><p><b>CONCLUSION</b>There exists a correlation of GTV by radiology and pathology. In the target volume defining for 3DCRT and IMRT, we could use the GTV by radiology instead of the GTV by pathology, with the ME being different for ADC and SCC. To cover 95% of the ME, the margin from GTV to CTV must be extended to 7 mm and 5 mm for ADC and SCC, respectively.</p>