18FDG positron emission tomography versus 67Ga scintigraphy as prognostic test during chemotherapy for non-Hodgkin's lymphoma

A prospective study was performed, comparing gallium scintigraphy (67Ga) and positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (18FDG), to monitor the response of aggressive non-Hodgkin's lymphoma during treatment. 67Ga and 18FDG scans were performed in 26 patients after two cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) therapy. The scans were reviewed independently by four experienced nuclear physicians, who were blinded for the alternative scan technique and follow-up. Eleven out of 26 patients remained free from progression with a mean follow up of 25 +/- 5 months, whereas 14 patients relapsed, and one died of lung cancer. Interobserver variation was significantly greater for 67Ga than for 18FDG PET. Some 64% of patients who had a negative early restaging 18FDG PET remained free from progression versus 50% of patients with negative 67Ga scans. Only 25% of patients with a positive PET remained disease free versus 42% of 67Ga-positive patients. Time to progression was associated with 18FDG PET results, but not with those by 67Ga. 18FDG PET had better test characteristics than 67Ga for the evaluation of early response in aggressive non-Hodgkin's lymphoma patients.     

Prognostic value of dual-time-point 18F-fluorodeoxyglucose positron emission tomography in patients with pulmonary sarcoidosis

Background and objective: The value of dual‐time‐ point ¹⁸F‐FDG PET was investigated to predict the prognosis of patients with pulmonary sarcoidosis. Methods: Twenty‐one patients with pulmonary sarcoidosis underwent ¹⁸F‐FDG PET examinations at two time points: an early scan at 60 min and a delayed scan at 180 min after injection of ¹⁸F‐FDG. Standardized uptake values (SUVs) at the two time points and the retention index (RI‐SUV) calculated from these were evaluated. To evaluate disease progression, all patients underwent chest CT 1 year after ¹⁸F‐FDG PET. Using these results, the accuracy of ¹⁸F‐FDG PET parameters and ⁶⁷Ga uptake for predicting disease persistence were compared, and the correlations between those parameters and serum markers were assessed. Results: RI‐SUV was significantly higher in patients with increased or unchanged pulmonary lesions at follow‐up CT (persistent group; 21.3 ± 9.6%) than in patients with improved pulmonary lesions (improved group; ?9.2 ± 28.6%, P = 0.0075). The diagnostic accuracy of RI‐SUV in the persistent group was significantly greater than that of early SUV or ⁶⁷Ga uptake, and serum soluble IL‐2 receptor showed a significant correlation with RI‐SUV. Conclusions: RI‐SUV showed better diagnostic accuracy compared with early SUV or ⁶⁷Ga uptake, in patients with persistent lung involvement at 1 year. It may be a useful measure of persistent inflammation in patients with pulmonary sarcoidosis.     

Diagnostic role of 18F-fluorodeoxyglucose positron emission tomography for follicular lymphoma with gastrointestinal involvement

AIM:To investigate the capacity for 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography(PET) to evaluate patients with gastrointestinal lesions of follicular lymphoma.METHODS:This retrospective case series consisted of 41 patients with follicular lymphoma and gastrointestinal involvement who underwent 18F-FDG-PET and endoscopic evaluations at ten different institutions between November 1996 and October 2011.Data for endoscopic,radiological,and biological examinations performed were retrospectively reviewed from clinical records.A semi-quantitative analysis of 18F-FDG uptake was performed for each involved area by calculating the maximum standardized uptake value(SUVmax).Based on the positivity of 18F-FDG uptake in the gastrointestinal lesions analyzed,patients were subdivided into two groups.To identify potential predictive factors for 18F-FDG positivity,these two groups were compared with respect to gender,age at diagnosis of lymphoma,histopathological grade,pattern of follicular dendritic cells,mitotic rate,clinical stage,soluble interleukin-2 receptor levels detected by 18F-FDG-PET,lactate dehydrogenase(LDH) levels,hemoglobin levels,bone marrow involvement,detectability of gastrointestinal lesions by computed tomography(CT) scanning,and follicular lymphoma international prognostic index(FLIPI) risk.RESULTS:Involvement of follicular lymphoma in the stomach,duodenum,jejunum,ileum,cecum,colon,and rectum was identified in 1,34,6,3,2,3,and 6 patients,respectively.No patient had esophageal involvement.In total,19/41(46.3%) patients exhibited true-positive 18F-FDG uptake in the lesions present in their gastrointestinal tract.In contrast,false-negative 18F-FDG uptake was detected in 24 patients(58.5%),while false-positive 18F-FDG uptake was detected in 5 patients(12.2%).In the former case,2/19 patients had both 18F-FDG-positive lesions and 18F-FDGnegative lesions in the gastrointestinal tract.In patients with 18F-FDG avidity,the SUVmax value of the involved gastrointestinal tract ranged from 2.6 to 17.4(median:4.7).For the 18F-FDG-negative(n = 22) and-positive(n = 19) groups,there were no differences in the male to female ratios(10/12 vs 4/15,P = 0.186),patient age(63.6 ± 2.4 years vs 60.1 ± 2.6 years,P = 0.323),presence of histopathological grade 1 vs 2(20/2 and 17/2,P = 1.000),follicular dendritic cell pattern(duodenal/nodal:13/5 vs 10/3,P = 1.000),mitotic rate(low/partly high,14/1 vs 10/3,P = 0.311),clinical stage according to the Ann Arbor system(stages ⅠE and ⅡE/other,15/7 vs 15/4,P = 0.499),clinical stage according to the Lugano system(stages Ⅰ and Ⅱ-1/other,14/8 vs 14/5,P = 0.489),soluble interleukin-2 receptor levels(495 ± 78 vs 402 ± 83,P = 0.884),LDH levels(188 ± 7 vs 183 ± 8,P = 0.749),hemoglobin levels(13.5 ± 0.3 vs 12.8 ± 0.4,P = 0.197),bone marrow involvement(positive/negative,1/8 vs 1/10,P = 1.000),detectability by CT scanning(positive/negative,1/16 vs 4/13,P = 0.335),and FLIPI risk(low risk/other,16/6 vs 13/6,P = 0.763),respectively in each case.CONCLUSION:These findings indicate that it is not feasible to predict 18F-FDG-avidity.Therefore,18FFDG-PET scans represent a complementary modality for the detection of gastrointestinal involvements in follicular lymphoma patients,and surveillance of the entire gastrointestinal tract by endoscopic examinations is required.     

18 F-fluorodeoxyglucose positron emission tomography to evaluate recurrent gastric cancer: a systematic review and meta-analysis

Background and Aim: We aimed to explore the role of the diagnostic accuracy of ¹⁸F‐fluorodeoxyglucose positron emission tomography (¹⁸F‐FDG PET) in detecting recurrent gastric cancer through a systematic review and meta‐analysis. Methods: The MEDLINE, EMBASE, Cancerlit, and Cochrane Library database, from January 2001 to July 2011, were searched for studies evaluating the diagnostic performance of ¹⁸F‐FDG PET in detecting recurrent gastric cancer. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR?), and constructed summary receiver operating characteristic curves. We also compared the performance of ¹⁸F‐FDG PET with computed tomography (CT) by analyzing studies that had also used these diagnostic methods on the same patients. Results: Across nine studies (526 patients), the overall sensitivity of ¹⁸F‐FDG PET was 0.78 (95% confidence interval [CI]: 0.68–0.86), and the overall specificity was 0.82 (95% CI: 0.76–0.87). Overall, LR+ was 3.52 (95% CI: 2.68–4.63) and LR? was 0.32 (95% CI: 0.22–0.46). In studies in which both ¹⁸F‐FDG PET and other diagnostic tests were performed, the sensitivity and specificity of ¹⁸F‐FDG PET were 0.72 (95% CI: 0.62–0.80) and 0.84 (95% CI: 0.77–0.90), respectively; of contrast CT, they were 0.74 (95% CI: 0.64–0.83) and 0.85 (95% CI: 0.78–0.90), respectively; and of combined PET and CT, they were 0.75 (95% CI: 0.67–0.82) and 0.85 (95% CI 0.79–0.90), respectively. Study sensitivity was not correlated with the prevalence of recurrent gastric cancer. Conclusion: ¹⁸F‐FDG PET has good diagnostic performance in the overall evaluation of recurrent gastric cancer, but still has some limited performance compared with contrast CT. ¹⁸F‐FDG PET combined with CT might improve the diagnostic performance in detecting recurrent gastric cancer.     

Usefulness of 18F-fluorodeoxyglucose positron emission tomography in differential diagnosis and staging of cholangiocarcinomas

Background and Aim: ¹⁸F‐Fluoro‐2‐deoxy‐d ‐glucose positron emission tomography (¹⁸FDG‐PET) is promising for diagnosis and treatment of various malignancies. The aim of this study was to evaluate the clinical usefulness of ¹⁸FDG‐PET in differential diagnosis and staging of cholangiocarcinomas according to the intrahepatic, perihilar and common bile duct lesions and to compare with computerized tomography (CT) scan. Methods: From January 2000 to September 2003, 54 patients with suspected cholangiocarcinoma underwent abdominal CT scan and ¹⁸FDG‐PET within a 2‐week period. The PET images were analyzed visually and semiquantitatively. Results: The overall accuracy of ¹⁸FDG‐PET for discriminating malignant diseases of bile duct from benign conditions was slightly higher than that of CT scan (88.9% vs 81.5%). The sensitivity of ¹⁸FDG‐PET in perihilar cholangiocarcinoma was lower than the value of intrahepatic and common bile duct cancers (83.3% vs 91.3%, 90.9%); moreover, in cases of perihilar cancer, the sensitivity of ¹⁸FDG‐PET was lower than that of CT scans (83.3% vs 91.7%). ¹⁸FDG‐PET detected nine distant metastatic lesions not found by other imaging studies and excluded two patients who potentially had resectable condition in other imaging studies from unnecessary laparotomy. Conclusion: The clinical usefulness of ¹⁸FDG‐PET in differential diagnosis of bile duct cancers is related to the site of primary disease. Although it is a helpful method for differential diagnosis especially in cases of intrahepatic and common bile duct cancers, ¹⁸FDG‐PET can not provide confirmative clues in perihilar cholangiocarcinoma. ¹⁸FDG‐PET may hold promise in the detection of hidden distant metastasis and can play an additional role in the evaluation of resectability. ¹⁸FDG‐PET can be complementary to CT scan in diagnosing and staging of cholangiocarcinoma.     

Contribution of 18F-fluorodeoxyglucose positron emission tomography to the diagnosis of early pancreatic carcinoma

Background/Purpose

Pancreatic carcinoma has a poor prognosis, and early detection is essential to allow potentially curative resection. Despite the wide array of diagnostic tools available, the detection of small pancreatic tumors remains difficult. The aim of this study was to investigate the contribution of ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) to the diagnosis of early pancreatic cancer.

Methods

FDG-PET was performed in 56 patients with pancreatic cancer who underwent curative surgery. The standardized uptake value (SUV) for FDG was calculated in each patient and the relationships between the SUV and various clinicopathological factors were analyzed.

Results

The tumors ranged from 0.8 to 6.5 cm in diameter. When the cutoff value for the SUV was set at 2.5, 51 of the 56 patients (91%) had a positive FDG-PET study. The SUV did not show a significant difference in relation to tumor differentiation or pTS and pT factors. There was also no correlation between the SUV and the maximum tumor diameter (r = 0.22; P = 0.1). Five tumors had an SUV below the cutoff value, and all of these lesions had intermediate or scirrhous stroma rather than medullary stroma.

Conclusions

These results indicate that FDG-PET is useful for the detection of small early pancreatic cancers.     

Positron emission tomography scanning in the assessment of patients with lymphoma

BACKGROUND: The detection of lymphoma by computed tomography (CT) scanning is known to be improved by positron emission tomography (PET) and/or gallium scanning, although the direct comparative accuracy of these imaging modalities remains a subject of ongoing review. AIMS: The aim of the present study was to compare PET scanning with conventional imaging (CT and/or gallium scanning) in patients with lymphoma. METHODS: A retrospective study of 38 patients (25 men; 13 women; median age 39.5 years; range 18.0-81.0 years) who had had PET scans (24 scans at initial staging and 46 scans at restaging, including suspected disease relapse) was carried out. Thirty-one concurrent gallium scans had been performed. Disease was validated with clinical follow up or biopsy. RESULTS: The sensitivities of PET and CT at initial staging were 96 and 71%, respectively. PET identified additional sites of disease compared with CT in 29% of patients. Of the 15 patients who had had all three imaging modalities, the sensitivities of PET, CT and gallium were 93, 67 and 87%, respectively. At treatment completion, the positive predictive values of PET, CT and gallium scans for relapse given a residual mass were 100, 33 and 0%, respectively (P = 0.006 for PET and CT comparison). The negative predictive values of PET, CT and gallium were 76, 0 and 70%, respectively (P-value not significant). In suspected disease relapse, PET results changed management in 50% of patients. CONCLUSION: Compared with CT and gallium scans, PET has superior accuracy in staging and restaging, and its greatest value lies in its positive predictive value for relapse in patients with residual masses.     

Disease staging with positron emission tomography or gallium scanning and use of rituximab predict outcome for patients with diffuse large B-cell lymphoma treated with autologous stem cell transplantation

Tumor status, as determined by positron emission tomography or gallium scanning (PET/G), may be an important predictor of outcome for patients with diffuse large B-cell lymphoma (DLBCL) undergoing autologous stem cell transplantation (ASCT). ASCT conditioning regimens that include rituximab may reduce the rate of relapse. We evaluated the influence of rituximab on overall and progression-free survival in patients with DLBCL based on PET/G status before ASCT. A retrospective review of all patients with chemosensitive DLBCL who underwent ASCT in the context of research protocols at our institution between 1995 and 2005 was performed. Our study included 174 patients. Disease status before ASCT, according to PET/G, was negative in 136 patients (78%), positive in 29 patients (17%), and unknown in nine patients (5%). PET/G status and rituximab use were the only factors predictive of progression-free survival in multivariate analyses: the hazard ratios for relapse were 2·9 for PET/G-positive versus -negative patients ( P  <   0·001) and 0·4 for rituximab versus no rituximab use ( P  =   0·001). We conclude that evidence of disease on PET/G scanning prior to transplantation is associated with an increased risk for relapse after ASCT. Transplantation regimens containing rituximab can reduce this risk, regardless of PET/G status.     

A pathophysiologic study of tako-tsubo cardiomyopathy with F-18 fluorodeoxyglucose positron emission tomography.

AIMS; Our study aims to investigate the pathophysiologic mechanism underlying tako-tsubo cardiomyopathy using F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET). METHODS AND RESULTS: Fifteen patients with tako-tsubo cardiomyopathy were enrolled in this study. Plasma catecholamines, cardiac troponin T (cTnT), and D-dimer were serially evaluated in all patients. Thallium-201 ((201)Tl) single-photon emission computed tomography (SPECT) and F-18 FDG PET were performed in 10 and eight patients, respectively. Emotional or physical stress occurred in 12 (80.0%) patients. ST-T segment abnormalities existed in all patients. Thirteen patients exhibited mildly elevated cTnT, although coronary angiography did not reveal significant stenosis in any patient. Endomyocardial biopsy specimens (n = 9) demonstrated contraction-band necrosis (n = 4) and mononuclear cell infiltration (n = 3). The levels of norepinephrine and epinephrine peaked on admission (744 +/- 452 and 140 +/- 166 pg/mL, respectively). There was severely reduced uptake at the apex on F-18 FDG PET image, despite slightly reduced uptake of (201)Tl. Elevation of D-dimer was observed in nine patients. CONCLUSION: The extent of metabolic defect involving apical akinetic area was more severe than perfusion abnormality. Our data suggest that sudden emotional or physical stress may cause a catecholamine-induced metabolic disorder in the myocardium, which is probably central to this syndrome.     

Prognostic utility of pre-transplantation [18F] fluorodeoxyglucose positron emission tomography/computed tomography in patients with diffuse large B-cell lymphoma who underwent rituximab,dexamethasone, high-dose cytarabine,carboplatin salvage chemotherapy

We analysed the outcomes of 62 patients with refractory/relapsed diffuse large B-cell lymphoma (rrDLBCL) who had pre-transplantation fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) after R-DHAC (rituximab, dexamethasone, high-dose cytarabine, carboplatin) salvage chemotherapy, and were evaluated using Deauville criteria and total lesion glycolysis (TLG). A positive pre-transplantation PET/CT with Deauville score of 5 was associated with shorter progression-free survival (PFS) (P = 0·01), while a Deauville score of 4 was not predictive of outcome. Only pre-transplant TLG was significantly associated with both PFS (P = 0·005) and overall survival (P = 0·03). TLG deserves to be further investigated in prospective studies.     

Predictive value of early 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) during salvage chemotherapy in relapsing/refractory Hodgkin lymphoma (HL) treated with high-dose chemotherapy

This retrospective study evaluated whether early 2-[fluorine-18]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) after two cycles of salvage chemotherapy (PET2) could predict survival after high-dose chemotherapy (HDC). Twenty-four Hodgkin lymphoma (HL) patients were included. PET2 was negative in 58% and positive in 42% of patients. Ninety per cent of patients (9/10) with positive PET2 relapsed after HDC while all but one patient with negative PET2 maintained a complete remission. The 2-year progression-free survival was 93% vs. 10% for patients with negative and positive PET2, respectively ( P  < 0.001). This study shows that interim PET can predict the outcome after high-dose chemotherapy in HL patients.     

18F-FDG PET/CT纳入肝细胞癌肝移植标准的趋势与价值

肝移植是治疗肝细胞癌(HCC)的有效方法,为降低HCC肝移植术后可能出现较高肿瘤复发率,有学者率先提出著名的Milan标准。但该标准过于严格,部分患者因其肿瘤病变较大或多个结节,虽其生物行为相对“温良”,也被排除在等待肝移植名单之外,随之世界各地出现了众多的“扩大Milan版标准”。HCC组织病理学的微血管侵犯(MVI)、肿瘤组织低分化与HCC肝移植术后较高复发率有显著相关性。复习总结了近年来国内外18氟-脱氧葡萄糖(18F-FDG)PET/CT在HCC肝移植方面的应用文献,发现18F-FDG在HCC病变部位不同的摄取程度,反映了肿瘤组织生物学行为特征即侵袭性的差异;18F-FDG高摄取与HCC病变的MVI、低分化呈正相关;18F-FDG还能敏感、准确地发现HCC肝外转移灶。认为术前18F-FDG PET/CT结果对HCC肝移植预后评估有巨大价值,将其结果纳入HCC肝移植标准是趋势所归,也有望统一“扩大Milan版标准”。建议新的肝移植标准可定义为,原则上遵循Milan标准;对超出Milan标准者,满足HCC病变18F-FDG PET/CT阴性,且排除大血管侵犯和肝外转移。     

Emerging role of ~(18)F-fluorodeoxyglucose positron emission tomography for guiding management of hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is one of major causes of cancer mortality worldwide. For decades, ~(18)F-fluorodeoxyglucose(FDG) positron emission tomography(PET) has been widely used for staging, predicting prognosis, and detecting cancer recurrence in various types of malignant diseases. Due to low sensitivity of FDG PET for detecting intrahepatic HCC lesions, the clinical value of FDG PET in HCC patients has been limited. However, recent studies with diverse analytic methods have shown that FDG PET has promising role in aiding management of HCC patients. In this review, we will discuss the clinical role of FDG PET for staging, predicting prognosis, and evaluating treatment response in HCC. Further, we will focus on recent clinical studies regarding implication of volumetric FDG PET parameters, the significance of FDG uptake in HCC for selecting treatment and predicting treatment response, and the use of radiomics of FDG PET in HCC.     

18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) does not visualize follicular lymphoma of the duodenum

<p>18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) has been used as a potential tool for imaging nodal follicular lymphoma (FL) and extranodal spread. As primary intestinal FL is increasingly being recognized, we have performed a study to investigate the usefulness of 18F-FDG-PET for staging of extranodal FL within the gastrointestinal tract. In eight patients with a diagnosis of FL localized in the duodenum (six cases in stage I and one each in stages II and IV, respectively) whole body 18F-FDG-PET scans were performed. Seven patients with duodenal FL were rated WHO grade 1 and one had FL grade 3, while both patients with secondary spread had FL WHO grade 1. All patients were imaged before initiation of therapy. None of the patients with primary duodenal FL showed pathologically elevated 18F-FDG uptake. 18F-FDG-PET findings were not influenced by histological grade or proliferative activity of FL. These findings suggest that 18F-FDG-PET is not useful for clinical assessment of primary duodenal FL.     

Fluorine‐18 FDG imaging in hepatocellular carcinoma using positron coincidence detection and single photon emission computed tomography

Abstract: Background/aims: We prospectively evaluated whether fluorine‐18 deoxyglucose (FDG) positron coincidence detection (PCD) or FDG single‐photon emission computed tomography (SPECT) provides additional benefits to our conventional preoperative evaluation of lesion detection in patients suspected to have hepatocellular carcinoma (HCC). Methods: Thirteen consecutive patients with a suspected HCC underwent conventional preoperative evaluation with ultrasonography (US), triple‐phase helical computed tomography (CT), superparamagnetic iron oxides (SPIO) enhanced magnetic resonance imaging (MRI) and serum α‐fetoprotein (AFP) level. All 13 patients had an FDG‐PCD and SPECT. These results were evaluated to assess the value of FDG‐PCD and SPECT in addition to US, SPIO‐enhanced MRI and triple‐phase helical CT. Results: Ten of the 13 (77%) patients had at least one histologically confirmed HCC without extrahepatic abdominal spread. The tumors ranged in size from 1 to 8 cm and the serum AFP ranged from 3 to 30 000 µg/l. Of these 10 patients, two patients had an increased tumor F‐FDG uptake (sensitivity of 20%); one patient with an AFP of 5 µg/l and a tumor size of maximum 4.5 cm and one patient with an AFP of 249 µg/l and a tumor size of maximum 2 cm. In three patients with a benign liver mass, FDG imaging with either PCD or SPECT was negative. There was no false positive finding. Conclusions: We found poor sensitivity of FDG‐PCD and FDG‐SPECT for the detection of HCC. There were no clear relations between AFP or tumor size and FDG uptake. Therefore, we conclude that FDG imaging with PCD or SPECT has no value in the preoperative work‐up for HCC in patients with cirrhosis.     

The prognostic value of interim positron emission tomography scan in patients with classical Hodgkin lymphoma

The prognostic value of interim positron emission tomography (PET) was evaluated after 2 cycles of doxorubicin, bleomycin, vinblastin and dacarbazine in classical Hodgkin lymphoma patients (n = 229), based on Deauville criteria. In early stage non‐bulky disease, bulky stage II disease, advanced stage low International Prognostic Score (IPS ≤2) and advanced stage (IPS ≥3), 3‐year progression‐free survival rates in PET2‐negative vs. PET2‐positive groups were 95·9% vs. 76·9% (P < 0·0018), 83·3% vs. 20·0% (P = 0·017), 77·0% vs. 30·0% (P < 0·001) and 71·0% vs. 44·4%(P = 0·155), respectively. The outcome after positive PET2 was better than previously reported. The results from non‐randomized studies of PET2‐guided therapy would be valuable with careful interpretation.     

Predictive value of early 18F-fluoro-deoxyglucose positron emission tomography in chemosensitive relapsed lymphoma

18F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) might be a better tool than computerized tomography (CT) in predicting long-term treatment outcome in patients with relapsed chemosensitive lymphoma who are candidates for autologous stem cell transplantation (ASCT). We studied patients with recurrent or persistent aggressive non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD), who were treated with three courses of second-line induction chemotherapy [DHAP-VIM (dexamethasone, cytarabine, cisplatin followed by etoposide, iphosphamide and methotrexate)-DHAP], followed by myeloablative therapy and ASCT if chemosensitive. FDG-PET was performed in parallel to conventional diagnostic methods before starting, and after two courses of, second-line therapy. Of 68 relapsed lymphoma patients, 46 chemosensitive patients (33 NHL and 13 HD) were included, of whom 39 were transplanted. After DHAP-VIM, the second PET scan was normalized in 15/46 patients; progression-free survival at 2 years was 62% for PET-negative patients versus 32% for PET-positive patients (P = 0.048). The relative risk for progressive disease in patients with < 90% intensity reduction was 2.85 (95% confidence interval 1.15-7.05, P = 0.018). Early FDG-PET may help to predict the long-term treatment outcome of ASCT in chemosensitive patients with relapsed lymphoma and identify those patients who need extra or alternative treatment. Disappearance or > 90% reduction of intensity of abnormal FDG uptake after two courses of reinduction therapy was correlated with a favourable outcome.     

~(18)F-Fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma

AIM To compare ~(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(~(18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma.METHODS Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent ~(18)F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions,including FDG avidity,pattern(focal/diffuse),and intensity [maximal standard uptake value:(SUVmax)]. The correlation of SUVmax with gastricclinicopathological variables was investigated by χ~2 test,and receiver-operating characteristic(ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. RESULTS Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients(94.23%) with gastric lymphoma and 65 patients(89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type Ⅰ and type Ⅱ lesions,whereas gastric carcinoma patients mainly had type Ⅲ lesions. The SUVmax(13.39 ± 9.24 vs 8.35 ± 5.80,P 0.001) and SUVmax/THKmax(maximal thickness)(7.96 ± 4.02 vs 4.88 ± 3.32,P 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone.CONCLUSION PET/CT features differ between gastric lymphoma and carcinoma,which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma.