Application of standardized uptake value for FDG PET-CT in predicting radiation pneumonitis / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the correlation of radiation pneumonitis (RP) with standardized uptake value (SUV) for fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET-CT) in lung cancer patients treated with radiation therapy.</p><p><b>METHODS</b>Fourty patients with unresectable non-small cell lung cancer (NSCLC) received FDG PET-CT before and after radiotherapy. The average SUV of the lung tissue irradiated with a dose of < or = 5 Gy, 5.1 approximately 15 Gy, 15.1 approximately 35 Gy, 35.1 approximately 60 Gy, >60 Gy were measured. The correlation between SUV and RP was analyzed by comparing the SUV in the patients with RP and without. The SUV ratio of the irradiated lung tissue to that of the non-irradiated lung tissue (L/B) was also calculated.</p><p><b>RESULTS</b>Of the 40 patients, 8 developed RP, including 6 cases of grade 2 and 2 cases of grade 3. The SUV of irradiated lung tissues with a dose of 35.1 approximately 60 Gy was significantly correlated with RP. When SUV > or =1, the RP incidence rate was 41.7% versus 20.0% in the whole group, with a statistically significant difference. (chi2 = 3.96, P < 0.05). The sensitivity and specificity of SUV in predicting RP was 62.5% and 78.1%, respectively. When the value of L/B > or = 2.5, the RP incidence rate was 40.7% in this group versus 20.0% in the whole group, with a statistical significance (chi(2) = 4.92, P < 0.05). If taking L/B > or = 2.5 as a threshold value, the sensitivity and specificity in predicting RP was 72.7% and 90.9%, respectively. No statistically significant difference was found in predicting radiation pneumonitis between SUV > or =1 and L/B > or = 2.5 (chi2 = 0.002, P > 0.05).</p><p><b>CONCLUSION</b>The standardized uptake value (SUV) and the SUV ratio of the irradiated lung tissue to that of the non-irradiated lung tissue (L/B) for FDG PET-CT are positively correlated with radiation pneumonitis, and clinicians may use it to predict the occurrence of radiation pneumonitis.</p>

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>

Thermal dosimetric study on hyperthermia combined with radiotherapy for deep seated pelvic malignancies / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To ascertain a clinically meaningful thermal dose unit-temperature equivalent minute (TEM) 42.5 degrees C and the relationship between TEM 42.5 degrees C and tumor response rate.</p><p><b>METHODS</b>From August 1998 to December 2002, 49 patients with recurrent or metastatic malignancies in the pelvis were treated with hyperthermia combined with conventional radiotherapy. Direct thermometry with high resistance lead needle was used whenever possible to measure the temperature by inserting Teflon catheter into the tumor. TEM 42.5 degrees C was used as the thermal dose unit and the relationship between TEM 42.5 degrees C and tumor response rate was monitored.</p><p><b>RESULTS</b>There was a positive correlation between response rate TEM 42.5 degrees C and the radiation dose. The tumor volume and number of heat treatment showed no influence on response.</p><p><b>CONCLUSION</b>Both univariate analysis and multivariate logistic regression analysis indicate that there is a positive correlation between the response rate, TEM 42.5 degrees C and the radiation dose. TEM 42.5 degrees C may act as a useful thermal dose unit in the combination of hyperthermia and radiotherapy. To lower the incidence of complications in thermometry, direct thermometry with high resistance lead needle can be used to measure the temperature by inserting Teflon catheter into the deep-seated malignancies.</p>

Value of ~(18)FDG PET-CT in defining the length of esophageal cancer / 中华放射肿瘤学杂志

Objective To assess the value of 18-fluoro-deoxy-glucose positron emission-CT(FDG PET-CT) in defining the length of primary esophageal cancer.Methods Thirty-two patients had underg- one esophagoscopy,esophagography and FDG PET-CT scans one week before esophagectomy.There was one tumor located in the upper thoracic esophagus,22 in the middle thoracic esophagus,and 9 in the lower tho- racic esophagus.The location and length of primary lesion of the tumor was determined by esophagoscopy, esophagography,and FDG PET-CT.The length of the abnormality seen on the CT portion of the PET-CT scan was determined separately and independently by two radiologists.All results were compared with the resected specimen.Results According to esophagography,CT and PET-CT,all lesion lengths were compared with that of the resected specimen.It was found that the tumor location determined by esophagoscopy was not in accordance with the resected specimen in 2 patients.The mean length of the primary tumor,being from short to long,were (3.8?1.4),(4.1?1.5),(4.4?1.6),(5.3?1.9) and (4.7?1.7) cm,as determined by esophagoscopy,esophagography,CT,actral length of the resected specimen and PET-CT.Compared with the resected specimen,there was obvious difference (P=0.000,0.007,0.025,0.001).Considering that there might be some kind of shrinkage in the resected specimen (about 83.59%,as reported by Ma et al), we rectified the length of resected specimen and compared with other findings again.It was found that insig- nificant difference existed between PET-CT and rectified length value of the resected specimen (P=0.082). Conclusions FDG PET-CT is effective in the length determination of primary esophageal cancer.It may he used to determine the length of esophagus to be resected for patients indicated for esophagectomy.It may also be used to ac- curately delineate the gross tumor volume for patients eligible for radiotherapy.