Evaluation of 18F-2-deoxy-2-fluoro-glucose positron emission tomography for gastric cancer screening in asymptomatic individuals undergoing endoscopy

(18)F-2-deoxy-2-fluoro-glucose Positron Emission Tomography (FDG-PET) has been recently proposed as a promising cancer-screening test. However, the validity of FDG-PET in cancer screening has not been evaluated. We investigated the sensitivity of FDG-PET compared with upper gastric endoscopy in gastric cancer screening for asymptomatic individuals. A total of 2861 consecutive subjects (1600 men and 1261 women) who were asymptomatic and who underwent both FDG-PET and upper gastrointestinal endoscopy between 1 February 2004 and 31 January 2005 were included in this study. Both endoscopists and a radiologist were unaware of the results of the other diagnostic tests. The FDG-PET images were examined using criteria determined by the pattern of FDG accumulation. Sensitivity and specificity of FDG-PET were calculated compared with endoscopic diagnosis as the gold standard. Among 2861 subjects enrolled in the study, there were 20 subjects with gastric cancer, of whom 18 were T1 in depth of cancer invasion. Positive FDG-PET results were obtained only in 2 of the 20 cancer subjects. The calculated sensitivity and specificity for overall gastric cancers were 10.0% (95% confidence interval (CI): 1.2-31.7%) and 99.2% (95% CI: 98.8-99.5%), respectively. (18)F-2-deoxy-2-fluoro-glucose Positron Emission Tomography was poorly sensitive for detection of gastric cancer in the early stages.     

Additional value of whole-body positron emission tomography with fluorine-18-2-fluoro-2-deoxy-D-glucose in recurrent colorectal cancer.

PURPOSE: To assess the additional value of the whole-body [18F]-2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) scan as a staging modality complementing conventional diagnostic methods (CDM) in patients suspected of having recurrent colorectal adenocarcinoma. PATIENTS AND METHODS: In 103 patients, the discordances between FDG-PET and CDM results were identified and related to the final diagnosis obtained by histopathology or clinical follow-up (> 1 year). All FDG-PET studies were reviewed with full knowledge of the CDM findings. RESULTS: In a region-based analysis, discordances between CDM and FDG-PET findings were found in 40 of 412 regions (10%). In these, FDG-PET had additional diagnostic value in 14 of 16 locoregional, six of seven hepatic, seven of eight abdominal, and eight of nine extra-abdominal regions. In a patient-based analysis, CDM categorized a subgroup of 60 patients as having resectable recurrent disease limited to the liver (n = 37) or locoregional region (n = 23). In 13 of these patients, there were discordant FDG-PET findings, detecting additional tumor sites in nine patients and excluding disease in three patients and yielding an additional diagnostic value in 20% of the patients. A second subgroup consisted of 13 patients with inconclusive CDM findings (n = 5) or with elevated plasma carcinoembryonic antigen levels and an otherwise negative conventional work-up (n = 8). In these patients, FDG-PET results were correct in eight of nine discordances, yielding a positive additional diagnostic value in 62% of the patients. CONCLUSION: Whole-body FDG-PET can have a clear impact on the therapeutic management in the follow-up of patients with colorectal cancer.     

Localised disease in cancer of unknown primary (CUP): The value of positron emission tomography (PET) for individual therapeutic management

Background:Two to four percent of cancer patients presentwith CUP syndrome. Median survival for localised disease is 20 and fordisseminated disease, seven months. For localised disease, curativetreatment is more likely and individual therapeutic strategies becomemore important. After conservative diagnostic procedures including MRI,the primary is detected in less than 25%. The diagnostic value ofPET and its influence on therapeutic strategies was evaluated. Patients and methods:Forty-two patients with localised CUPwere investigated from 5 of 98 to 10 of 2000. The presenting site waslymph node metastasis in 34 and visceral metastasis in 8 patients. Aftera median of 7 (3–11) diagnostic procedures without detection ofthe primary, but evidence of localised disease, PET was performed withfluorine-18-fluorodeoxyglucose. Results:In 26 of 42patients (62%), a primary was suggested by PET and confirmed in18 (43%). In 5 of 18 patients beyond localised disease,additional dissemination, not detected by previous diagnostic measures,was diagnosed by PET. Overall, dissemination was only detected only byPET in 16 of 42 patients (38%). In 29 of 42 patients(69%), the PET result influenced selection of the definitivetreatment. Conclusion:In CUP patients, PET has acertain impact on detection of the primary as well as of thedisseminated disease, and may also have a certain impact on therapeuticmanagement.     

Negative predictive value of positron emission tomography and computed tomography for stage T1-2N0 non-small-cell lung cancer: a meta-analysis

BackgroundNodal staging of non–small-cell lung cancer (NSCLC) is crucial in evaluation of prognosis and determination of therapeutic strategy. This study aimed to determine the negative predictive value (NPV) of combined positron emission tomography and computed tomography (PET-CT) in patients with stage I (T1-2N0) NSCLC and to investigate the possible risk factors for occult nodal disease.MethodsStudies investigating the performance of PET in conjunction with CT in the nodal staging of stage I NSCLC were identified in the MEDLINE database. The initiative of standards for reporting of diagnostic accuracy (STARD) was used to ensure study quality. Pathologic assessments through mediastinoscopy or thoracotomy were required as the reference standard for evaluation of PET-CT accuracy. Stata-based meta-analysis was applied to calculate the individual and pooled NPVs.ResultsTen studies with a total of 1122 patients with stage I (T1-2N0) NSCLC were eligible for analysis. The NPVs of combined PET and CT for mediastinal metastases were 0.94 in T1 disease and 0.89 in T2 disease. Including both T1 disease and T2 disease, the NPVs were 0.93 for mediastinal metastases and 0.87 for overall nodal metastases. Adenocarcinoma histology type (risk ratio [RR], 2.72) and high fluorine-18 (¹⁸F) fluorodeoxyglucose (FDG) uptake in the primary lesion were associated with greater risk of occult nodal metastases.ConclusionsAlthough overall occult nodal metastases in clinical stage T1-2N0 NSCLC is not infrequent, combined PET and CT provide a favorable NPV for mediastinal metastases in T1N0 NSCLC, suggesting a low yield from routine invasive staging procedures for this subgroup of patients.     

The role of 18F-fluoro-deoxy-glucose positron emission tomography (FDG-PET) in the management of patients with colorectal cancer.

AIM: In patients with colorectal cancer an accurate diagnostic work-up is mandatory in order to perform the most specific treatment. At this moment 18F-fluoro-deoxy-glucose positron emission tomography (FDG-PET) is considered an accurate imaging technique in staging/restaging several malignancies. The aim of this paper is to review the scientific literature available about the role of FDG-PET in the management of patients with colorectal cancer. METHODS: An overview on Medline of scientific literature concerning FDG-PET and colorectal cancer was performed. The most relevant studies are reported. Advantages, limitations and new chances in using FDG-PET in these subsets of patients are summarized. RESULTS: FDG-PET is a useful tool in the evaluation of colorectal cancer. In comparison to conventional imaging technique, FDG-PET has an additional diagnostic value because it allows to metabolically characterize undetermined lesions suspected for recurrence of disease, to perform a complete pre-surgical staging and to identify occult metastatic disease. In clinical practice its use leads to a change in therapeutic choices in a high percentage of cases. CONCLUSIONS: FDG-PET should be considered an essential diagnostic tool in the management of patients with colorectal cancer, especially in recurrent disease evaluation.     

Unexplained rising carcinoembryonic antigen (CEA) in the postoperative surveillance of colorectal cancer: the utility of positron emission tomography (PET)

The aim of the study was to evaluate the use of positron emission tomography with [18F]-fluorodeoxyglucose (FDG-PET) in patients with unexplained rising carcinoembryonic antigen (CEA) in the postoperative surveillance of colorectal cancer. 50 consecutive patients with elevated CEA levels and a completely normal (n=31) or equivocal (n=19) conventional diagnostic work-up (CDW) were retrospectively selected. All PET images were reviewed with full knowledge of the CDW. The gold standard consisted of histology, or clinical follow-up of more than 1 year. Recurrent disease was established in 56 lesions in 43 patients. On a patient-based analysis, the sensitivity of FDG-PET was 34/43 (79%), and the positive predictive value 34/38 (89%). In 14/50 patients (28%), the FDG-PET findings led to a surgical resection with curative intent. On a lesion-based analysis, FDG-PET detected 42/56 lesions (sensitivity: 75%), the positive predictive value was 79% (42/53). These results demonstrate that FDG-PET can have a clear impact on patient management in patients with an unexplained elevation in CEA levels.     

In vivo evaluation of 5-[(18)F]fluoro-2'-deoxyuridine as tracer for positron emission tomography in a murine pancreatic cancer model

We used a murine tumor progression model for the evaluation of potential proliferation markers using positron emission tomography (PET). 5-[(18)F]-2'-deoxyuridine ([(18)F]FdUrd) was synthesized with >98% radiochemical purity and investigated in a pancreatic cancer model, transforming growth factor alpha transgenic mice crossbred to p53 deficient mice. Thymidylate synthase was increased already in premalignant lesions, whereas thymidine kinase 1 mRNA levels were up-regulated 4-fold in the pancreatic cancer specimen of these mice. PET imaging was performed after injection of 1 MBq of [(18)F]FdUrd and 1 MBq of [(18)F]fluoro-deoxyglucose. Animals with pancreatic cancer displayed focal uptake of both tracers. The [(18)F]FdUrd uptake ratio closely correlated with the proliferation index as evaluated in morphometric and fluorescence-activated cell sorter analysis. These results indicate the potential of our tumor model for the evaluation of PET tracers and suggest [(18)F]FdUrd as a tracer for the assessment of proliferation in vivo.     

Whole-body 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for accurate staging of Hodgkin's disease

Background: Staging of Hodgkin's disease (HD) is accomplished by a variety of invasive and non-invasive modalities. This prospective study was undertaken to investigate the value of whole-body positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) in defining regions involved by lymphoma compared with conventional staging methods in patients with HD.Patients and methods: Fourty-four newly diagnosed patients with HD underwent FDG-PET as part of their initial staging work-up. PET findings were correlated with findings of conventional staging including computed tomography, ultrasound, bone scanning, bone marrow biopsy, liver biopsy and laparotomy. When results of FDG-PET differed to those obtained by conventional methods reevaluation was performed by biopsy, if possible, or magnetic resonance imaging.Results: The results of FDG-PET were compared with three hundred twenty-one conventional staging procedures performed in 44 patients. FDG-PET was positive in 38 of 44 (86%) patients at sites of documented disease. PET detected additional lesions in five cases previously not identified by conventional staging methods. In another case a nodal lesion suspect on CT was negative at FDG-PET and was settled as true negative by biopsy. As a consequence of PET findings five patients had to be upstaged and one patient had to be downstaged, resulting in changes in treatment strategy in all six cases (14%). FDG-PET failed to visualize sites of HD in four patients. In two of our patients a false positive PET result was obtained.Conclusions: Our data indicate that FDG-PET provides an imaging technique that appears to visualize involved lesions in most patients with HD and is useful in the managment of these patients.     

Positron emission tomography agent 2-deoxy-2-[<Superscript>18</Superscript>F]fluoro-D-glucose has a therapeutic potential in breast cancer

Background  

Novel approaches are needed for breast cancer patients in whom standard therapy is not effective. 2-Deoxy-2-[¹⁸F]fluoro-D-glucose (¹⁸F-FDG) was evaluated as a potential radiomolecular therapy agent in breast cancer animal models and, retrospectively, in patients with metastatic breast cancer.     

TS和MMR联合检测在结直肠癌预后判断中的作用

目的:对133例结直肠癌患者临床病例资料进行回顾性分析,分析胸苷酸合成酶(thymidylate synthase,TS)蛋白与错配修复(mismatch repair,MMR)状态联合检测与结直肠癌患者临床病理特征及预后之间的关系.方法:免疫组化测定TS和MMR(MLH-1/MSH-2)蛋白表达.根据TS蛋白和MMR状态差异进行相应的配对组合,将纳入患者分为四组:TS蛋白高表达/MMR蛋白高表达(HtHm)组、TS蛋白低表达/MMR蛋白高表达(LtHm)组、TS蛋白低表达/MMR蛋白低表达(LtLm)组、TS蛋白高表达/MMR蛋白低表达(HtLm)组.分析TS和MMR联合检测与患者临床病理因素及预后的关系.结果:TS和MMR联合检测生存分析显示,LtHm组患者(39例)的3年生存率为69.2%,HtLm(20例)组患者的3年生存率为40.0%,两组总体生存率具有统计学差异(P=0.012),该差异在术后辅助化疗患者中仍存在(P=0.011).结论:辅助化疗组患者中LtHm组总体生存率显著高于HtLm组,LtLm组患者较HtHm组患者更易从氟尿嘧啶类药物辅助化疗中获益.     

Early prediction of response to first-line chemotherapy by sequential [18F]-2-fluoro-2-deoxy-D-glucose positron emission tomography in patients with advanced colorectal cancer

Background: To evaluate [¹⁸F]-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET), for early evaluation of response to palliative chemotherapy and for prediction of long-term outcome, in patients with metastatic colorectal cancer (mCRC).Patients and methods: In a randomized trial, patients with mCRC received irinotecan-based combination chemotherapy. FDG–PET was carried out before treatment and after two cycles in 51 patients at two centers. Visual changes in tumor FDG uptake and changes measured semi-automatically, as standard uptake values (SUVs), were compared with radiological response after four and eight cycles.Results: The mean baseline SUV for all tumor lesions per patient was higher in nonresponders than in responders (mean 7.4 versus 5.6, P = 0.02). There was a strong correlation between metabolic response (changes in SUV) and objective response (r = 0.57, P = 0.00001), with a sensitivity of 77% and a specificity of 76%. There was no significant correlation between metabolic response and time to progression (P = 0.5) or overall survival (P = 0.1).Conclusions: Although metabolic response assessed by FDG–PET reflects radiological tumor volume changes, the sensitivity and specificity are too low to support the routine use of PET in mCRC. Furthermore, PET failed to reflect long-term outcome and can, thus, not be used as surrogate end point for hard endpoint benefit.     

99mTcOAADT]-(CH2)2-NEt2: a potential small-molecule single-photon emission computed tomography probe for imaging metastatic melanoma

Evaluation of [99mTc]oxotechnetium(V) complexes of the amine-amide-dithiol (AADT) chelates containing tertiary amine substituents as small-molecule probes for the diagnostic imaging of metastatic melanoma has shown that technetium-99m-labeled AADT-(CH2)2-NEt2 (99mTc-1) has the highest tumor uptake and other favorable biological properties. We have, therefore, assessed this agent in a more realistic metastatic melanoma model in which, after i.v. tail injection, a highly invasive melanoma cell line, B16F10, forms pulmonary tumor nodules in normal C57BL6 mice. Small melanotic lesions develop in the lungs and, on histologic examination, appear as small black melanoma colonies, increasing in size and number with time after tumor cell injection. Groups of mice received tumor cell inocula of 2 x 10(5), 4 x 10(5), or 8 x 10(5) B16F10 cells; 14 days later, 2 hours after 99mTc-1 administration, lung uptake of 2.83 +/- 0.21%, 3.63 +/- 1.07%, and 4.92 +/- 1.61% injected dose per gram of tissue (% ID/g), respectively, was observed, compared with normal lung uptake of 2.13 +/- 0.2% ID/g (P < 0.05). Additionally, a higher level of 99mTc-1 accumulation was seen 17 days after tumor cell inoculation as the lung lesions grew. These in vivo studies coupled with additional in vitro and ex vivo assessment show that 99mTc-1 has high and specific uptake in melanoma metastases in lungs and can potentially follow the temporal growth of these tumors.     

Comparison between positron emission tomography using 2-[fluorine-18]fluoro-2-deoxy-D-glucose,conventional imaging and computed tomography for staging of breast cancer

BackgroundThe presence, extent and localization of distant metastases are key prognostic factors in breast cancer patients and play a central role in therapeutic decision making. The aim of this study was to compare the diagnostic performance of positron emission tomography using 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG–PET) with that of computed tomography (CT) and conventional imaging including chest radiography, abdominal ultrasound and bone scintigraphy.Patients and methodsA total of 119 consecutive patients with newly diagnosed locally advanced disease (n = 69) or previous history of breast cancer (n = 50) who had clinical suspicion of metastatic disease underwent FDG–PET, CT and conventional imaging procedures. Imaging results were retrospectively compared with histopathology and clinical follow-up which served as a reference standard.ResultsFDG–PET detected distant metastases with a sensitivity of 87% and a specificity of 83%. In contrast, the sensitivity and specificity of combined conventional imaging procedures were 43% and 98%, respectively. CT revealed a sensitivity of 83% and a specificity of 85%.ConclusionsIn breast cancer, FDG–PET is superior to conventional imaging procedures for detection of distant metastases. Although FDG–PET and CT provided similar diagnostic accuracy, the information was often found to be complementary. With increasing availability of FDG–PET/CT, prospective studies are needed to determine whether it could potentially replace the array of conventional imaging procedures used today.     

2-18fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) for postchemotherapy seminoma residual lesions: a retrospective validation of the SEMPET trial

Background2-¹⁸fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) has been recommended in international guidelines in the evaluation of postchemotherapy seminoma residuals. Our trial was designed to validate these recommendations in a larger group of patients.Patients and methodsFDG-PET studies in patients with metastatic seminoma and residual masses after platinum-containing chemotherapy were correlated with either the histology of the resected lesion(s) or the clinical outcome.ResultsOne hundred and seventy seven FDG-PET results were contributed. Of 127 eligible PET studies, 69% were true negative, 11% true positive, 6% false negative, and 15% false positive. We compared PET scans carried out before and after a cut-off level of 6 weeks after the end of the last chemotherapy cycle. PET sensitivity, specificity, negative predictive value (NPV), and positive predictive value were 50%, 77%, 91%, and 25%, respectively, before the cut-off and 82%, 90%, 95%, and 69% after the cut-off. PET accuracy significantly improved from 73% before to 88% after the cut-off (P = 0.032).ConclusionsOur study confirms the high specificity, sensitivity, and NPV of FDG-PET for evaluating postchemotherapy seminoma residuals. When carried out at an adequate time point, FDG-PET remains a valuable tool for clinical decision-making in this clinical setting and spares patients unnecessary therapy.     

The expression of thymidylate synthase (TS) and excision repair complementing-1 (ERCC-1) protein in patients with unresectable colorectal cancer treated with mFOLFOX6 therapy

Thymidylate synthase (TS) and excision repair complementing-1 (ERCC-1) were known to be important biomarkers to predict a tumor response to 5-fluorouracil (5-FU) and oxaliplatin, but the relationship between these expressions and tumor response were still unclear. The aim of this study was to determine whether the expression of TS and ERCC-1 protein predict a tumor response in patients with unresectable colorectal cancer treated with mFOLFOX6 therapy as first-line treatment. Fifty patients with unresectable colorectal cancer treated with mFOLFOX6 therapy were enrolled in this study. The expression of TS and ERCC-1 protein in primary cancer cells were examined using immunohistochemistry. There were no significant differences between response rate and the expression of TS or ERCC-1 protein (TS: p>0.99, ERCC-1: p= 0.50). There were no significant differences between progression-free survival time and the expression of TS or ERCC-1 protein (TS: p=0.60, ERCC-1: p=0.60). In this study, the expression TS and ERCC-1 protein may not be useful for the prediction of tumor response in patients with unresectable colorectal cancer treated with mFOLFOX6 therapy.     

Clinical relevance of fusion images using (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography in local recurrence of rectal cancer

Local recurrence of rectal cancer is a critical issue. Anatomical images, such as computed tomography (CT) or magnetic resonance imaging (MRI), are sometimes insufficient for preoperative evaluation. A useful modality for diagnosis of local recurrence of rectal cancer is (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET), but it does not give adequate information about anatomy. To utilize the advantages of these techniques, this study was done to validate the accuracy of using fused images and their usefulness in the decision making for surgical intervention of local recurrence of rectal cancer by directly comparing the fused images with resected specimens. PET and CT/MRI were performed for patients suspected of local recurrence of rectal cancer (n=4). PET image data were re-calculated to fit CT/MRI images and manually superimposed on the anatomical images. Fusion images were compared with resected specimens. Radical operation was carried out for three patients. Fusion images provided information on precise tumor location, and extent of tumor invasion as well as the diagnosis of tumor recurrence. All patients underwent curative operation with negative surgical margins, and the information provided by the fusion images was confirmed by comparison with resected specimens. In all cases, preoperative evaluation of tumor recurrence with fusion images provided more useful clinical information for the management of patients than the anatomical images alone. PET images, when combined with MRI or CT, may prove to be a useful adjunct in the management of patients being evaluated for resection of local recurrence of rectal cancer.     

Pharmacokinetic evaluation of N-[2-(dimethylamino)ethyl]acridine-4-carboxamide in patients by positron emission tomography.

PURPOSE: To evaluate tumor, normal tissue, and plasma pharmacokinetics of N-[2-(dimethylamino)ethyl]acridine-4-carboxamide (DACA). The study aimed to determine the pharmacokinetics of carbon-11-labeled DACA ([11C]DACA) and evaluate the effect of pharmacologic doses of DACA on radiotracer kinetics. PATIENTS AND METHODS: [11C]DACA (at 1/1,000 phase I starting dose) was administered to 24 patients with advanced cancer (pre-phase I) or during a phase I trial of DACA in five patients. Positron emission tomography (PET) was performed to assess pharmacokinetics and tumor blood flow. Plasma samples were analyzed for metabolite profile of [11C]DACA. RESULTS: There was rapid systemic clearance of [11C]DACA over 60 minutes (1.57 and 1.46 L x min(-1) x m(-2) in pre-phase I and phase I studies, respectively) with the production of several radiolabeled plasma metabolites. Tumor, brain, myocardium, vertebra, spleen, liver, lung, and kidneys showed appreciable uptake of 11C radioactivity. The area under the time-versus-radioactivity curves (AUC) showed the highest variability in tumors. Of interest to potential toxicity, maximum radiotracer concentrations (Cmax) in brain and vertebra were low (0.67 and 0.54 m(2) x mL(-1), respectively) compared with other tissues. A moderate but significant correlation was observed for tumor blood flow with AUC (r = 0.76; P =.02) and standardized uptake value (SUV) at 55 minutes (r = 0.79; P =.01). A decrease in myocardial AUC ( P =.03) and splenic and myocardial SUV ( P =.01 and.004, respectively) was seen in phase I studies. Significantly higher AUC, SUV, and Cmax were observed in tumors in phase I studies. CONCLUSION: The distribution of [11C]DACA and its radiolabeled metabolites was observed in a variety of tumors and normal tissues. In the presence of unlabeled DACA, pharmacokinetics were altered in myocardium, spleen, and tumors. These data have implications for predicting activity and toxicity of DACA and support the use of PET early in drug development.     

2-(fluorine-18)fluoro-2-deoxy-D-glucose positron emission tomography in the detection and staging of malignant lymphoma. A bicenter trial

BACKGROUND: The authors undertook a prospective evaluation of the clinical value of 2-fluoro [18-]-2-deoxyglucose positron emission tomography (FDG-PET) in the detection and staging of malignant lymphoma compared with computed tomography (CT) and bone marrow biopsy (BMB). METHODS: Fifty-two consecutive patients with untreated malignant lymphoma were evaluated prospectively in a bicenter study. FDG-PET, CT, and BMB were performed for investigating lymph node/extranodal manifestations and bone marrow infiltration. Thirty-three percnt of the discrepant results were verified by biopsy, magnetic resonance imaging, or clinical follow-up (range, 4-24 month). RESULTS: Altogether, 1297 anatomic regions (lymph nodes, organs, and bone marrow) were evaluated. FDG-PET and CT scans were compared by receiver operating characteristic (ROC) curve analysis. The area under the ROC curve were as follows: lymph nodes, 0.996 (PET) and 0.916 (CT); extranodal, 0.999 (PET) and 0.916 (CT); supradiaphragmatic, 0.996 (PET) and 0.905 (CT); and infradiaphragmatic, 0.999 (PET) and 0.952 (CT). In these analyses, FDG-PET was significantly superior to CT (P < 0.05), except in infradiaphragmatic regions, in which the two methods produced equivalent results. In detecting bone marrow infiltration, FDG-PET was superior to CT and was equivalent to BMB. In 4 of 52 patients (8%), FDG-PET led to an upstaging and a change of therapy. CONCLUSIONS: Noninvasive FDG-PET is very accurate in the staging of malignant lymphoma. Compared with standard staging modalities (CT and BMB), PET was significantly superior and led to changes in the therapy regimen for 8% of patients.