[en] 3'-Deoxy-3'-Fluorothymidine (¹⁸F-FLT) is synthesized by 'BAThy' method at Tracerlab FX_f-N system. By using 5'-O-benzoyl-2,3-anhydro-thymidine (BAThy) as the precursor, ¹⁸F-FLT is obtained by two step reactions, including the nucleophilic fluoration and hydrolysis. The synthesis can be completed about 50 min. The radiochemical yield and radiochemical purity are about 10% and 95%, respectively. The procedure is guide simple and automated synthesis. (authors)

[en] Objective: To investigate the breast cancer and sentinel lymph node (SLN) with both ¹⁸F-FDG PET/CT and ⁹⁹Tc^m-SC SLN detection. Methods: 32 patients with breast mass without palpable lymph node involvement clinically were examined with ¹⁸F-FDG PET/CT. The breast masses and tissue of residual cavity were excised. 18 out of 32 patients were detected with ⁹⁹Tc^m-SC SPECT image and y -probe was applied to detect SLN during the operation. Histoimmunochemical and pathological analysis were also done after operation. Results: (1) The sensitivity, specificity and accuracy of primary breast lesion in 32 patients with ¹⁸F-FDG PET/CT image were 95.2%, 100% and 96.9%, respectively. (2) The lymph node metastasis were found in 5 out of 32 patients with PET/CT. The sensitivity, specificity and accuracy were 72.7%, 90.5% and 84.3%, respectively. (3) SPECT images showed SLN clearly in all of 18 patients. 1 out of 5 patients with metastatic SLN pathologically were also found axillary lymph nodes metastasis. No axillary lymph nodes metastasis were found in all the negative SLN patients. (4) Both of the majority negative coincidence and positive coincidence results were found in SLN detection and PET/CT image. Conclusion: SLN detection could predict the pathological state of following station of axillary lymph node. The effect in displaying primary breast lesion was superior to that of metastatic lymph node in PET/CT. There was better concordance in negative lymph node metastasis both with SLN detection and PET/CT but little false positive and false negative results could be found. (authors)

[en] Objective: The aim of this study was to investigate the value of ¹⁸F-fiuoroerythronitromidazole (FETNIM) in detecting tumor hypoxia in vivo. Methods: BALB/c nude mice were xenografted with SPCA-1 lung cancer cells. Tumors were allowed to grow to a diameter about 10 mm. In group A (n= 16), ¹⁸F-FETNIM (37 MBq) was injected from tail vein. Biodistribution of ¹⁸F-FETNIM was studied at 0.5, 1, 2, and 3 h after tracer injection. Blood, muscle, heart, liver, kidney, fat, lung, and tumor were moved and weighted. The radioactivity was measured with percentage activity of injection dose per gram of tissue (% ID/g) by a γ-counting well. In group B (n=14), the intratumoral PO₂ measurements were obtained by polar graphic oxygen needle probe. Results: The radioactivity was highest in kidney and lowest in fat and bone matrix. The maximum tumor to blood (T/B) and tumor to muscle(T/M) ratios were 1.69 ± 0.37 and 1.57 ± 0.47 at 2 h after injection. Intratumoral PO₂ measurements were ranged from 1.1 to 27.7 mm Hg (1 mm Hg=0.133 kPa) and were 30.2 to 40.5 mm Hg for normal tissue. Conclusion: A relatively high ¹⁸F-FETNIM retention ratio indicated ¹⁸F-FETNIM to be a potential agent for detecting tumor hypoxia in vivo. (authors)

[en] Objective: The accumulation of a new PET tracer, ¹¹C-4-(3-bromoanilino)-6,7-dime-thoxyquinazoline (PD153035), was found related to the expression level of epidermal growth factor receptor (EGFR) in tumor tissues. The aim of the study was to explore the potential of the tracer for PET imaging. Methods: The relationship of cellular uptake of ¹¹C-PD153035 and the EGFR expression was detected in vitro in MDA-MB-468, A-549 and MDA-MB-231 cell lines. PET imaging was carried out in 9 tumor-bearing mice, 3 for each cell-line, at 0, 5, 10, 20, 30, 40, 50 and 60 min post ¹¹C-PD153035 injection. The uptake ratio of tumor to non-tumor (T/NT) was calculated using region of interest (ROI) method, and then the nude mice were sacrificed with tumors excised. The exvivo ¹¹C-PD153035 accumulation and the EGFR expression of different tumors were detected, respectively. Results: Both in vitro and ex vivo studies proved that the accumulation of ¹¹C-PD153035 closely correlated with the EGFR expression of the tumor cells (r²=0.78, P=0.001; r²=0.64, P=0.005). The T/NT ratio was observed correlated to EGFR (r²=0.65, P0.004) too. Conclusion: This study showed that the uptake of ¹¹C-PD153035 closely correlated with EGFR expression, and the potential for both diagnostic and therapy-monitoring applications. (authors)

[en] Objective: PET with ¹⁸F-fluorodeoxyglucose (FDG) has been used to beth detect and stage a variety of malignancies. The aim of this retrospective study was to evaluate the clinical value of ¹⁸F-FDG PET/CT for recurrence and metastasis in gastric carcinoma patients after total gastrectomy. Methods: A total of 45 gastric carcinoma patients who underwent total gastrectomy were included. PET/CT scans were obtained for restaging. The ' gold standard' of ¹⁸F-FDG PET/CT diagnostic accuracy was based on either histopathology or clinical follow-up. By using the t-test from SPSS 11.5, the cut-off of maximum standardized uptake values (SUV_max) from ¹⁸F-FDG to differentiate benign from malignant lesion at stomach were determined and calculated. Results: (1) Of the 45 patients, 22 were suspicion recurrent lesion at stomach. Of the 22 patients, 12 were confirmed to have recurrent lesions. The diagnostic accuracy were 100.0% (12/ 12) for sensitivity, 70.0% (7/10) for specificity, and 86.4% (19/22) for accuracy, respectively. A higher SUV_max in malignant than benign lesion was noted (6.27 ± 3.42 vs 3.92 ± 2.24), though not reached to the significance (t = 1. 862, P > 0.05). (2) For extra-gastric lesion detection, the sensitivity, specificity, and accuracy for region lymph nodes were 78.9% (15/19), 92.3% (24/26), and 86.7% (39/ 45), for peritoneal spreading were 6/9, 97.2% (35/36), 91. 1% (41/45), and for distant sites were 86.7%(13/15), 93.3% (28/30), 91.1% (41/45). (3) False positive were found in eight sites. All were either inflammatory or physiological uptake at intestine. False negative were found in nine sites. Either due to small in size (less than 1.0 cm in diameter), well differentiation of the tumor cell or with a nature of signet ring. Conclusion: ¹⁸F-FDG PET/CT had a potential to detect local, regional, and distant metastasis in gastric cancer. (authors)

[en] Objective: To evaluate the accuracy of coregistration of PET/CT images in patients with pulmonary carcinoma and the affecting factors, and to investigate the difference between two methods for measuring coregistration accuracy. Methods: Twenty-four patients with well-circumscribed pulmonary carcinoma were examined by integrated PET/CT. Thirty-one lesions with the diameter of 1.0-5.0 cm were analyzed. The registration accuracy of PET/CT was measured with two methods, volume measure and center of geometry (COG) measure. The volume of interest of each lesion was defined separately on PET, CT and the images were fused (V_PET, V_CT, V_PET+CT). The overlap volume of PET and CT images was calculated with the formula: V_PET/CT=V_PET + V_CT - V_PET+CT. The percentage of V_PET/CT on V_PET+CT, P_PET/CT, was used to assess the fusion accuracy of PET and CT images. The COG was assessed. The distance of COGs between the PET image and the CT image, D_COG, was measured. The coregistration accuracy was compared between lesions classified according to the lesion location and volume. Results: The mean D_COG was (4.39 ± 2.33) mm (range, 1.00-8.68 mm). P_PET/CT was (36.18 ± 22.66)% (range, 0%-80.53%). Misregistration tended to be profounder in the lower lungs [D_COG=(4.63 ± 2.37) mm, P_PET/CT=(32.25 ± 18.40)%] than in the upper lungs [D_COG=(4.11±2.36) mm, P_PET/CT=(40.95 ± 26.91)%, P=0.30]. Misregistration also tended to be slightly profounder in the left lung [D_COG=(5.18 ± 3.08) mm, P_PET/CT=(33.01 ± 20.21)%] than in the right lung [D_COG=(4.02 ± 1.87) mm, P_PET/CT=(37.68 ± 24.07)%, P=0.78]. There was no statistical difference among lesions located at different lung regions (the apex, peripheral, central, and base of lung) while using two indexes. As for the lesions with different volumes as ≤2 cm³, 2.1-9.9 cm³ or ≥10 cm³, the P_PET/CT were (14.11 ± 10.64)%, (41.64 ± 16.22)% and (53.77 ± 17.71)%, respectively (P<0.01). Conclusions: The registration of the pulmonary lesion in PET/CT images is usually accurate, but spatial misregistration does occur, especially for the smaller lesions. The combination of different methods for measuring coregistration accuracy may be more valuable in defining this kind of misregistration. (authors)

[en] The domestic C-11 multifunction module was used to establish a simple, rapid, efficient synthetic technology for the fully automated synthesis of ¹¹C-acetate. Methyl magnesium bromide Grignard (0.1 mL of 1.5 mol/L) was used as a precursor to react with the ¹¹C-CO₂ in the Loop ring to produce intermediate acetyl bromide. The intermediate was first hydrolysis by acetic, and then purified, elution, and hydrochloric with acid. Then, the unreacted ¹¹C-CO₂ was removed by nitrogen. Finally, the product was neutralized with sodium phosphate and purified with sterile filtration membrane. The total synthesis time was about 10 minutes. The synthesis yield of ¹¹C-acetate was (58.5 ± 6.7)% (decay corrected), and the radiochemical purity was more than 99%. The residual solvents were analyzed by gas chromatography. Analysis results indicated that concentration of the acetonitrile and acetone were (0.007 ± 0.002)% and (0.005 ± 0.002)%, respectively. The whole synthesis process was automatically completed, and the operation was simple and flexible with high synthesis efficiency and radiochemical purity, it was suitable for clinical performance of PET. (authors)

[en] Objective: To investigate a feasibility of treatment planning in thoracic esophageal carcinoma with 3-deoxy-3-fluorothymidine (FLT) PET-CT and to compare with fluorodeoxyglucose (FDG) PET-CT based on dosimetric analysis. Methods: Twenty-two patients with esophageal squamous cell carcinoma detected by FLT and FDG PET-CT were enrolled. The gross tumor volumes (GTV), clinical target volume (CTV) and planning target volume (PTV) were delineated using treatment planning system of Philips Pinnacle³ based on the optimal threshold of FLT and FDG PET-CT respectively,and to make two groups simulation treatment planning. The parameters of dose-volume histograms in two groups planning were compared in the similar direction and ensuring prescribed dose line surround 95% target volume. Results: The values of GTV, CTV and PTV in FLT PET-CT planning were less than those of FDG, that was 29.03 cm³ : 33.05 cm³ (t=-2.62, P<0.05), 244.22 cm³ : 257.01 cm³ (t=-3.53, P<0.05) and 351.29 cm³ : 379.85 cm³ (t=-4.01, P<0.05), respectively. There were no significantly difference in conformity index and homogeneity index in two planning, that was 0.74 : 0.72 (t=0.89, P>0.05) and 1.09 : 1.11 (t=1.41, P>0.05), respectively. The values of V₂₀ of bilateral lung, V₄₀ of heat and maximal dose received by spinal cord in two planning were not significantly yet (t=-1.60, -1.55, all P>0.05). While, the values in mean lung dose, V₅, V₁₀, V₃₀, V₄₀ and V₅₀ of bilateral lung, mean heart dose, and V₃₀ of heart in FLT PET-CT planning were significant lower than those of FDG (t=-5.442 - -2.637, all P<0.05). Conclusions: Compared with FDG, FLT PET-CT based treatment planning brings potential benefits for lungs and heart. (authors)

[en] Angiogenesis is an essential step in tumour development and metastasis. Integrin αvβ3 plays a major role in angiogenesis, tumour growth and progression. A new tracer, "1"8F-AL-NOTA-PRGD2, denoted as "1"8F-alfatide, has been developed for positron emission tomography (PET) imaging of integrin αvβ3. This is a pilot study to test the safety and diagnostic value of "1"8F- arginine-glycine-aspartic acid (RGD) PET/computed tomography (CT) in suspected lung cancer patients. Twenty-six patients with suspected lung cancer on enhanced CT underwent "1"8F-alfatide RGD PET/CT examination before surgery and puncture biopsy. Standard uptake values (SUVs) and the tumour-to-blood ratios were measured, and diagnoses were pathologically confirmed. RGD PET/CT with "1"8F-alfatide was performed successfully in all patients and no clinically significant adverse events were observed. The "1"8F-alfatide RGD PET/CT analysis correctly recognized 17 patients with lung cancer, 4 patients (hamartoma) as true negative, and 5 patients (4 chronic inflammation and 1 inflammatory pseudotumour) as false positive. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of "1"8F-alfatide RGD PET/CT for the diagnosis of suspected lung cancer patients was 100, 44.44, 80.77, 77.27, and 100 %, respectively. The area under a receiver operating characteristic (ROC) curve was 0.75 (P = 0.038), and ROC analysis suggested an SUVmax cut-off value of 2.65 to differentiate between malignant lesions and benign lesions. The SUV for malignant lesions was 5.37 ± 2.17, significantly higher than that for hamartomas (1.60 ± 0.11; P < 0.001). The difference between the tumour-to-blood ratio for malignant lesions (4.13 ± 0.91) and tissue of interest-to-blood ratio for hamartomas (1.56 ± 0.24) was also statistically significant (P < 0.001). Neither the SUVmax nor the tumour-to-blood ratio was significantly different between malignant lesions and inflammatory lesions or inflammatory pseudotumours (P > 0.05). Sixteen of 26 patients later underwent successful surgery, and pathologic examination confirmed nodes positive for metastasis in 14 of 152 lymph nodes. The sensitivity, specificity, accuracy, PPV, and NPV of PET/CT for lymph nodes was 92.86, 95.65, 95.40, 61.90, and 99.25 %, respectively. Our results suggest that RGD PET/CT with the new tracer "1"8F-alfatide is safe and potentially effective in the diagnosis of non-small cell lung cancer. It may be used in the diagnosis of lung cancer, successfully distinguishing malignant lesions from hamartoma. However, it is difficult to clearly differentiate inflammatory or inflammatory pseudotumours from malignant lesions. Additional studies with a larger number of patients are needed to validate our findings. (orig.)

[en] Purpose: To prospectively evaluate whether maximal microscopic extensions (MEmax) correlate with maximal standardized uptake value (SUVmax) and metabolic tumor volume (MTV) at 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) images in non–small-cell lung cancer (NSCLC). Methods and Materials: Thirty-nine patients with Stage I–IIIA NSCLC underwent surgery after FDG-PET/CT scanning. SUVmax and MTV were calculated on the PET/CT images. The maximum linear distance from the tumor margin to the farthest extent of the tumor in every dimension was measured at the tumor section. The correlations among MEmax, SUVmax, MTV and other clinical pathologic parameters were analyzed. Results: MEmax for all patients had a significant correlation with SUVmax (r = 0.777, p = 0.008) and MTV (r = 0.724, p < 0.001). When expressed in terms of the probability of covering ME with respect to a given margin, we suggested that margins of 1.93 mm, 3.90 mm, and 9.60 mm for SUVmax ≤5, 5–10, and >10 added to the gross tumor volume would be adequate to cover 95% of ME. Conclusions: This study demonstrated that tumors with high SUVmax and MTV have more MEmax and would therefore require more margin expansion from gross tumor volume to clinical target volume. FDG-PET/CT, especially for SUVmax, is promising and effective and merits additional study in noninvasive delimiting of the clinical target volume margin for NSCLC.