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Objective To investigate the diagnostic value and the impact on treatment decision of 18F-FDG PET/CT in differentiated thyroid carcinoma (DTC) patients with elevated serum thyroglobulin (Tg) levels and negative radioiodine 131I post-therapy whole body scan (131I-RxWBS).Methods Totally 72 patients with DTC who had elevated serum Tg levels and negative 131I-RxWBS were enrolled,and 18F-FDG PET/CT was performed.The imaging results of 18F-FDG PET/CT were compared with the clinical results of surgical pathology or 6 to 36 months follow up.The diagnostic efficacy of 18F-FDG PET/CT in detection of recurrence and/or metastasis of DTC with elevated Tg levels and negative 131I-RxWBS was evaluated.Results The accuracy,sensitivity,specificity,positive prediction value and negative prediction value of 18F-FDG PET/CT in diagnosis of DTC with elevated Tg levels and negative 131I-RxWBS was 83.33％ (60/72),89.47％ (34/38),76.47％ (26/34),80.95％ (34/42) and 86.67％ (26/30),respectively.18F-FDG PET/CT changed the treatment strategies of 35 patients (35/72,48.61 ％) among 72 patients,while recurrence or metastasis of DTC was not found during clinical follow-up in 23 of these 35 patients (23/35,65.71％) who underwent reoperation,but was detected in the other 12 patients (12/35,34.29％).Conclusion 18F-FDG PET/CT is a valuable method for detection of recurrence and/or metastasis of DTC with elevated Tg levels and negative 131I-RxWBS,also for guiding the follow-up treatment strategy.
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Purpose To explore the clinical value of131I-whole body scan (131I-WBS) and 18F-FDG PET/CT on the metastatic management of patients with differentiated thyroid cancer (DTC) after operation.Materials and Methods Serum thyroglobulin (Tg) of 27 patients after DTC surgery was measured one day before131I therapy, and the patients underwent131I-WBS on 3-5 days after131I therapy. According to the results of Tg and 131I-WBS, all the patients were divided into 4 types as follows: type I: Tg (+),131I-WBS (-); type II: Tg (+),131I-WBS (+); type III: Tg (-),131I-WBS (+); and type IV: Tg (-), 131I-WBS (-). Then the patients received18F-FDG PET/CT scan within a week after 131I-WBS. The results of131I-WBS and18F-FDG PET/CT scan were analyzed according to histopathologic findings or clinical and imaging follow-up of at least 6 months as diagnosis standard.Results The examinations uncovered that metastasis occurred in 52 lesions of 22 cases out of the 27 cases.131I-WBS revealed 24 metastatic lesions (46.2%) in 8 cases (36.4%), and18F-FDG PET/CT showed 35 metastatic lesions (67.3%) in 15 cases (68.2%), the difference with statistic significance (χ2=4.46 and 4.74,P0.05). Based on that, therapeutic plans were modified for 13 patients with type I metastasis and 1 patient with type IV metastasis.Conclusion131I-WBS and18F-FDG PET/CT are complementary for detecting metastatic lesion and help to decide the following treatment of DTC patients after surgery. Moreover,18F-FDG PET/CT shows advantages in detecting metastatic lesion in Tg-positive and negative131I-WBS type of DTC patients after surgery, thus can provide an important clinical guidance for this type of patients.
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Objective To investigate the biodistribution of intratumoral administerd~(131)Ⅰ-labeled human-mouse chimeric monoclonal antibody (chTNT) in patients with advanced lung carcinoma. Methods Eleven patients enrolled had cytological and histological confirmed diagnoses of either stage Ⅲ b or stage Ⅳ inoperable lung carcinoma. Intratumoral injection was directed by thoracic CT-guided catheter using a multi-holed needle. The dose for each patient was 18.5 - 37 MBq/cm~3 tumor mass. Blood samples were drawn at different time intervals for up to 13 days, and urine samples were collected for up to 11 days after injection for pharmacokinetic studies. In vivo stability was examined by HPLC by analyzing serum and urine, which were found to contain~(131)Ⅰ-chTNT. Whole body images were taken for quantitative organ and tumor biodistribution studies. Results In all 11 patients,~(131)Ⅰ-chTNT was the major component of the radiolabel in serum. Within 96 hours after administration, it was 100% stable. Plasma disappearance curves of ~(131)Ⅰ-chTNT were best fit by a two-exponential model in all patients with T_(1/2kα) of (0. 89±0. 17) h and T_(1/2β) of (86.88 ± 25.97)h. Free Ⅰ was the only metabolite of Ⅰ-chTNT that appeared in urine. A biodistribution study demonstrated excellent localization of the radioactivity in tumors. The accumulated radioactivity in urine at 264 h was (58.37 △Corresponding author E-mail:chen. shaoliang@zs-hospital. sh. cn±17.45) % of the injection dose. There was (51.05±8.41)%ID ,~(131)Ⅰ-chTNT in the tumor at 30 min after injection, and the tumor/lung (T/N) ratio was 63.87 ± 25.71. It remained (3.47 ± 3.27) %ID at 264 h,and the T/N ratio was 9. 61 ± 11.00. Among the main target organs, accumulation of the radiolabeled antibody was mainly found in lungs, liver, heart, kidneys, spleen and thyroid.Conclusions Pharmacokinietics of ~(131)Ⅰ-chTNT follows a two-exponential model. According to its long preservation in tumor tissue, intratumoral injection of~(131)Ⅰ-chTNT is good for tumor therapy.
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<p><b>BACKGROUND</b>To analysis and evaluate the efficacy of I-131 labeled chimeric TNT antibody ( ¹³¹I-chTNT MAb) targeting therapy in advanced lung cancer, and then choose the best way of administration.</p><p><b>METHODS</b>Forty-three patients with advanced lung cancer were treated by 3 different protocols using ¹³¹I-chTNT MAb. Their diagnosis was confirmed by histology and there were 30 cases in stage IIIB and 13 cases in stage IV, 32 cases were newly diagnosed and 11 cases were retreated. All patients were divided into three groups and treated with different methods: (1)iv infusion (n=22); (2) intratumoral injection (n=16); and (3) combination iv (25% of total dosage) and intratumoral (75%) infusion (n=5). All patients received radiolabeled MAb at a total dosage of 2.96×10⁷ Bq/kg on days 1 and 14.</p><p><b>RESULTS</b>There were 2 complete response (4.7%), and 11 partial response (25.6%), the total response rate was 30.2% (13/43) in all patients. For those patients receiving iv injection alone, the response rate was 9.1%. For those patients receiving intratumoral injection alone, the response rate was 56.3%. There was significant difference between them (P < 0.01 ). The main toxicity was reversible bone marrow suppression, 2 cases (4.7%) with grade III leukopenia and 3 cases (7.0%) grade III thrombocytopenia.</p><p><b>CONCLUSIONS</b>¹³¹I-chTNT has significant therapeutic effects on advanced lung cancer and the intratumoral injection is the best way of administration.</p>