ABSTRACT
Objective To synthesize 18F labeled N-(2-18 F-fluoropropionyl)-L-glutamine (18 F-FPGLN) for tumor PET imaging,and to perform its biodistribution study on normal mice and PC-3 tumorbearing nude mice.Methods 4-nitrophenyl-2-18F-fluoropropionate (18F-NFP) was synthesized on the MF2V-IT-I synthesizer and was purified by semi-preparative HPLC.Anhydrous 18F-NFP was added to a solution of L-glutanine t-butyl ester to synthesize 18F-FPGLN t-butyl ester,which was hydrolyzed by HCl (3 mol/L) and neutralized with NaOH (2 mol/L) solution.18F-FPGLN product was collected for further study.Biodistribution study was performed on normal Kunming mice and PC-3 prostate cancer tumor-bearing nude mice,respectively.Results 18F-FPGLN was synthesized with 10％-15％ (decay uncorrected) overall radiochemical yield after 130 min of radiosynthesis.The radiochemical purity was higher than 96％.Rapid and high uptake of radiotracer was observed within the kidneys,and was quickly excreted through the urinary bladder.The uptake in kidney reached (35.0±1.2) ％ID/g at 5 min post-injection,and descended to (1.5±0.3) ％ID/g at 120 min.The liver,lung,heart and small intestine showed relatively moderate uptake of radioactivity.The uptake in the pancreas,muscle,spleen,stomach and brain was low,and the lowest uptake of (1.5±0.3) ％ID/g was found in the brain at 30 min post injection.High accumulation of 18F-FPGLN in PC-3 xenograft was observed,and the tumor/muscle ratio reached 2.07 at 60 min post injection.Conclusion A novel N-position 18F-labeled glutamine analogs 18F-FPGLN,with favorable pharmacokinetic characteristics,is synthesized successfully,which makes it possible to perform tumor PET imaging using 18F-FPGLN subsequently.
ABSTRACT
Objective To investigate the prognosis of patients with nasal NK/T cell lymphoma receiving different treatment modalities. Methods From 1990 to 2004, 85 patients with stage ⅠE and ⅡE primary nasal NK/T cell lymphomas were retrospectively studied. Twenty patients received chemotherapy of CHOP regimen alone, 11 patients received radiotherapy only, 6 patients received radiotherapy followed by more than 2 cycles of chemotherapy, and 48 patients received more than 2 cycles of chemotherapy followed by radiotherapy. Survival analysis was performed by the Kaplan-Meier method, the difference between groups was evaluated by the Log-rank test, and the Cox regression model was used for multivariate analysis. Results The 5-year overall survival rate (OS) was 40%. The 5-year OS was 57% and 28% for limited stage ⅠE and extended stage ⅠE(X2 =8. 87, P =0. 003), and 23% for stage ⅡE, which was similar to extended stage ⅠE (X2 =0. 19, P-0. 664). The 5-year OS was 13%, 54% and 47% for chemotherapy alone, radiotherapy followed with or without chemotherapy, and chemotherapy followed by radiotherapy, respectively. The last two groups had better OS than chemotherapy alone (P = 0. 030 and 0.049). The 5-year OS was 58% and 12% for patients achieving complete response (CR) and uncomplete response (X2 = 30.68, P = 0. 000).The CR rate was 56% and 86% for radiotherapy of ≤50 Gy and >50 Gy (X2 =6.11, P=0. 013). The corresponding 5-year relapse-free survival rate was 89% and 84% (X2 =0.36, P=0.551). Of 68 patients receiving initial chemotherapy, the CR rate of those who received ≤2, 3-4 and ≥5 cycles was 0, 20%and 3 3 % , respectively (X2 = 7.65 , P = 0. 022) . For 5 0 patients who received ≥ 3 cycles of initial chemotherapy and 17 patients who received initial radiotherapy of ≥40 Gy, the CR rate was 28% and 88%(χ2= 18. 75, P= 0. 000). In patients with pathological nodular and ulcer type, the CR rates with radiotherapy were higher than with chemotherapy (100%: 38%, χ2 = 7.92, P = 0. 005; and 100%: 11%,χ2 = 14.40, P = 0. 000). Multivariate analysis showed that stage and recent effect were the independent prognostic factors. Conclusions The initial radiotherapy with 50 Gy is appropriate for early stage nasal NK/T cell lymphomas. Combined chemotherapy could be used for extended stage ⅠE and ⅡE, but the outcome of CHOP regimen is poor.