Positron emission tomography (PET) for staging low-grade non-Hodgkin's lymphomas (NHL)

Although positron emission tomography (PET) imaging is now recognized as a useful tool for staging intermediate and high-grade non-Hodgkin's lymphoma (NHL), few data are available regarding its accuracy in low grade NHL. We therefore studied 36 patients with histologically proven low-grade NHL. Whole-body 2-(fluorine-18) fluoro-2-deoxy-D-glucose (FDG) PET was performed at the time of initial diagnosis (n = 21) or for disease recurrence (n = 15) prior to any treatment. PET results were compared to those of physical examination and computed tomography (CT). PET studies were read without knowledge of any clinical data. Any focus of increased activity was described and given a probability of malignancy using a 5 point-scale (0: normal to 4: definitively malignant). An individual biopsy was available for a total of 31 lesions. The sensitivity and specificity were 87% and 100% for FDG-PET, 100% and 100% for physical examination and 90% and 100% for CT respectively. In addition, 42 of 97 peripheral lymph node lesions observed by FDG-PET were clinically undetected, whereas the physical examination detected 23 additional nodal lesions. PET and CT both indicated 12 extranodal lymphomatous localizations. FDG-PET showed 7 additional extranodal lesions while 5 additional unconfirmed lesions were observed on CT. Regarding bone marrow infiltration, PET and biopsy were concordant in 24 patients with 11 true positive (TP) and 13 true negative (TN). However PET was FN in 11 patients and no biopsy was performed in one patient. The combination PET/CT/physical examination seems to be more sensitive than the conventional approach for staging low grade NHL. Its sensitivity however is unacceptably low for diagnosing bone marrow infiltration.     

Exploring the role of FDG-PET in the assessment of bone marrow involvement in lymphoma patients as interpreted by qualitative and semiquantitative disease metabolic activity parameter

Bone marrow biopsy (BMB) is currently the standard method to evaluate marrow involvement in malignant lymphomas. However, there exist a number of pitfalls in this technique that can have important implications for initial staging, prognostification, and treatment of the disease. The present study was undertaken to investigate the utility of FDG-PET imaging in the detection of bone marrow involvement in untreated lymphoma patients. Forty untreated patients (36 males and 12 females) with either Hodgkin's disease (HD) (n = 17) or non-Hodgkin's lymphoma (NHL) (n = 31) underwent whole body FDG-PET study for disease evaluation. Bone marrow uptake of FDG was graded as absence or presence of disease activity at marrow sites by qualitative assessment. Semiquantitative analysis involved deriving disease metabolic index (DMI) using the following formula: DMI = SUV max of suitable circular ROI over PSIS or trochanteric region/ SUVmax of similar ROI over adjoining background. Findings of BMB and FDG-PET were compared for final analysis. Eleven out of 17 HD patients (12 males and 5 females) demonstrated concordance between FDG PET findings and BMB reports. Remaining 6 cases showed discordance of FDG-PET demonstrating presence of marrow involvement at marrow sites and uninvolved marrow on BMB. Twenty six of the 31 NHL cases (24 males and 7 females) demonstrated concordance between FDG PET findings and BMB reports. Remaining 5 cases showed discordance of FDG-PET demonstrating presence of marrow involvement at marrow sites and uninvolved marrow on BMB. All the BMB positive patients (2 of HD and 5 of NHL) demonstrated disease activity in bone marrow on FDG-PET study. All patients with absence of disease activity at marrow sites on FDG-PET scan (9 of HD and 21 of NHL) had histology proven uninvolved marrow. The quantitative assessment by DMI showed a mean of > 2.5 in HD and NHL patients at the PSIS region and the trochanteric region bilaterally in cases of bone marrow involvement by the disease. FDG-PET is a useful adjuvant to BMB for the evaluation of bone marrow involvement in lymphoma patients. The disease metabolic index of > 2.5 at the marrow sites can serve as a semiquantitative parameter for such diagnosis on FDG-PET in untreated patients of lymphoma.     

FDG—PET显像技术在恶性淋巴瘤诊断与治疗中的应用

对大多数肿瘤而言，^18F—FDGPET具有敏感性高、特异性强的优点。在淋巴结和结外淋巴瘤的诊断检出率、淋巴瘤分期和再分期、疗效预测和评估、检测微小残留病灶、监测复发和预后判断均优于CT或^67Ga。PET常上调淋巴瘤分期（约40％），PET的检出效能随淋巴瘤的组织类型而变动，尤其对弥漫性大B细胞淋巴瘤（DLBCL）和霍奇金病诊断率高。对骨髓累及的检出PET／CT可补充骨髓活检（BMB），但不能取代BMB。PET较^67Ga对脾淋巴瘤有更高的检出率。治疗早中期PET／CT是无进展生存期和总生存期独立的预后指标。FDG并非肿瘤特异性物质，FDG—PET存在假阳性和假阴性，需注意鉴别，可能时进行组织活检。     

继发性骨淋巴瘤的18F-FDG PET/CT影像诊断及与骨髓活检诊断效能的比较

目的:分析继发性骨淋巴瘤的PET/CT影像特点,比较骨髓活检（bone marrow biopsy,BMB）及PET/CT诊断骨淋巴瘤各自的优势,探讨如何进一步提高骨淋巴瘤的检出率。方法:回顾性分析放化疗前在我院行PET/CT检查的68例继发性骨淋巴瘤影像及骨髓活检资料。所有病例均病理确诊为淋巴瘤。骨淋巴瘤病灶的诊断标准:BMB阳性或骨局灶性FDG代谢增高且治疗后代谢减低或消失。采用SPSS 16.0统计分析不同分组的SUVmax及诊断效能差异。结果:PET/CT与BMB诊断灵敏度比较:68例中63例行BMB。PET/CT的总体诊断灵敏度及对非惰性淋巴瘤的诊断灵敏度高于BMB（P＜0.05）,而对惰性淋巴瘤,BMB灵敏度略高于PET/CT(P＞0.05)。PET/CT表现与BMB结果:根据PET/CT所见分为骨质破坏组（18例）和骨髓浸润组（50例）,骨质破坏组的SUVmax明显高于骨髓浸润组（P＜0.01）。骨质破坏组以弥漫大B细胞淋巴瘤（diffuse large B cell lymphoma,DLBCL）为主,PET/CT均阳性。骨髓浸润组PET/CT阳性41例,表现为局灶性增高、弥漫不均匀性增高和弥漫均匀性增高,弥漫均匀性增高组的SUVmax明显低于其它两组。BMB阴性21例,其中骨质破坏组8例,局灶性骨髓浸润13例。病理类型与PET/CT表现:31例DLBCL、10例其它侵袭性非霍奇金淋巴瘤（non-Hodgkin's lymphoma,NHL）及6例霍奇金淋巴瘤（Hodgkin's lymphoma,HL）均PET/CT阳性;18例惰性淋巴瘤PET/CT仅11例阳性。DLBCL的SUVmax明显高于惰性淋巴瘤（P＜0.05）。结论:继发性骨淋巴瘤骨髓浸润多于骨质破坏。骨质破坏和局灶性骨髓浸润多见于侵袭性骨淋巴瘤,而弥漫性骨髓浸润更多见于惰性淋巴瘤。PET/CT对骨质破坏、局灶性骨髓浸润的诊断优于BMB,而BMB对弥漫性骨髓浸润的诊断优于PET/CT。联合BMB和PET/CT才能更准确地诊断骨淋巴瘤。     

Consistency of FDG-PET accuracy and cost-effectiveness in initial staging of patients with Hodgkin lymphoma across jurisdictions

IntroductionTwo hundred ten patients with newly diagnosed Hodgkin's lymphoma (HL) were consecutively enrolled in this prospective trial to evaluate the cost-effectiveness of fluorine-18 (¹⁸F)-fluoro-2-deoxy-D-glucose–positron emission tomography (FDG-PET) scan in initial staging of patients with HL.MethodsAll 210 patients were staged with conventional clinical staging (CCS) methods, including computed tomography (CT), bone marrow biopsy (BMB), and laboratory tests. Patients were also submitted to metabolic staging (MS) with whole-body FDG-PET scan before the beginning of treatment. A standard of reference for staging was determined with all staging procedures, histologic examination, and follow-up examinations. The accuracy of the CCS was compared with the MS. Local unit costs of procedures and tests were evaluated. Incremental cost-effectiveness ratio (ICER) was calculated for both strategies.ResultsIn the 210 patients with HL, the sensitivity for initial staging of FDG-PET was higher than that of CT and BMB in initial staging (97.9% vs. 87.3%; P < .001 and 94.2% vs. 71.4%, P < 0.003, respectively). The incorporation of FDG-PET in the staging procedure upstaged disease in 50 (24%) patients and downstaged disease in 17 (8%) patients. Changes in treatment would be seen in 32 (15%) patients. Cumulative cost for staging procedures was $3751/patient for CCS compared to $5081 for CCS + PET and $4588 for PET/CT. The ICER of PET/CT strategy was $16,215 per patient with modified treatment. PET/CT costs at the beginning and end of treatment would increase total costs of HL staging and first-line treatment by only 2%.ConclusionFDG-PET is more accurate than CT and BMB in HL staging. Given observed probabilities, FDG-PET is highly cost-effective in the public health care program in Brazil.     

The value of routine bone marrow biopsy in patients with diffuse large B-cell lymphoma staged with PET/CT: a Danish-Canadian study

BackgroundThe added diagnostic and prognostic value of routine bone marrow biopsy (BMB) in patients with diffuse large B-cell lymphoma (DLBCL) undergoing positron emission tomography combined with computed tomography (PET/CT) staging is controversial.Patients and methodsPatients with newly diagnosed DLBCL who underwent both staging PET/CT and BMB were retrospectively identified in British Columbia, Aalborg, and Copenhagen. Original written PET/CT and pathology reports were retrospectively reviewed to determine Ann Arbor stage and outcomes, with and without the contribution of BMB.ResultsA total of 530 patients were identified: 146 (28%) had focal bone marrow (BM) lesions on PET/CT and 87 (16%) had positive BMB. Fifty-two of 146 patients (36%) with positive PET/CT had a positive BMB [39 DLBCL, 13 indolent non-Hodgkin lymphoma (iNHL)], while 35 of 384 patients (9%) with negative PET/CT had positive BMB (12 DLBCL, 23 iNHL). BMB upstaged 12/209 (6%) of stage I/II patients to stage IV, although this was the case for only 3 (1%) patients with DLBCL in the BMB. PET/CT identified BM involvement by BMB with sensitivity 60%, specificity 79%, positive predictive value 36%, and negative predictive value 91%. Concordant histological involvement of the BM by DLBCL was associated with worse overall survival and progression-free survival than discordant or no involvement in univariate and multivariate analyses.ConclusionsIn patients with DLBCL, staging PET/CT can miss BM involvement with concordant DLBCL (less common) or discordant iNHL (more common). Routine BMB does not add relevant diagnostic or prognostic value over PET/CT alone in the majority of patients with DLBCL.     

Value of positron emission tomography for lung cancer staging.

OBJECTIVE: The therapeutic strategy in non-small-cell lung cancer (NSCLC) requires exact staging of tumour invasion (T) as well as differentiation between ipsi- and contralateral lymph node invasion (N1/2 vs N3). [18F]FDG-positron emission tomography (FDG-PET) has been shown to detect invaded N with high accuracy while correct determination of T appears to be unclear. The purpose of this prospective study was to evaluate benefit and necessity of 18FDG-PET as an additive to conventional staging modalities. METHODS: Forty patients with suspected non-small-cell lung cancer (NSCLC) were staged by means of computed tomography (CT), bronchoscopy, mediastinoscopy and bone scintigraphy. Additionally, attenuation corrected FDG-PET of the thorax was performed pre-operatively for analysis of T and N topography. After surgical resection with radical lymphadenectomy T and N staging results of CT and PET were compared with the pathological diagnoses. Specificity, sensitivity, positive predictive value and accuracy of CT and PET were calculated. RESULTS: Twenty three squamous cell carcinomas, 14 adenocarcinomas, and three non-malignant tumours were found. Accuracy of CT-T was 0.75 and of PET-T 0.78; accuracy of CT-N was 0.78 and of PET-N 0.80. By combination of CT-T and PET-T accuracy was 0.88. Combination of CT-N and PET-N yielded an accuracy of 0.90. In two out of three cases, PET correctly determined T0. In two cases non-malignant inflammatory lymph nodes were falsely staged as malignant by PET. CONCLUSIONS: Adequate pre-operative T- and N-staging is possible with both CT and FDG-PET. Accuracy can be improved by combination of CT and FDG-PET. FDG-PET is superior to CT in order to differentiate between malignant and benign tumours. However, acute inflammation can mimic malignant lymph node invasion. FDG-PET is justified as a supporting staging measure in cases presenting unclear differentiation between N2 and N3 after conventional staging and is helpful in cases with unclear cell type of the primary tumour.     

High SUV uptake on FDG–PET/CT predicts for an aggressive B-cell lymphoma in a prospective study of primary FDG–PET/CT staging in lymphoma

BackgroundData assessing the role of positron emission tomography (PET)/computed tomography (CT) imaging in lymphoma staging is still being accumulated and current staging is based primarily on CT. This study aims to compare the value of PET/CT over conventional CT and bone marrow biopsy (BMB) in the initial evaluation of patients with lymphoma.MethodsData on 122 patients with PET/CT scans as part of their initial staging were prospectively collected and reviewed. All patients had complete staging, including BMB.ResultsAmong the 122 patients, 101 had non-Hodgkin's lymphoma (NHL) and 21 had Hodgkin's lymphoma (HL). Compared with conventional CT, PET/CT upstaged 21 (17%) cases [B-cell non-Hodgkin's lymphoma (B-NHL), 12; T-cell non-Hodgkin's lymphoma (T-NHL), 3; HL, 6]. Of significance, in 13 patients with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG)-avid splenic lesions, four had normal CT findings. A maximum FDG uptake of >10 standardized uptake value (SUV) seems to significantly correlate with an aggressive B-cell lineage (odds ratio 2.47, 95% confidence interval 2.23–2.70). Overall, PET scan was concordant with BMB results in 108 (89%) and discordant in 14 (11%) cases. In HL, our data show that PET scan and marrow results agreed in 19 of the cases (90%), being concordantly negative in 18 cases and concordantly positive in one, giving a negative predictive value (NPV) of 100%, sensitivity of 100% and specificity of 90%. Of note, all 13 with early-stage HL had negative PET/CT scan and BMB. In NHL, all 17 cases of T-NHL had concordant PET and BMB results. In patients with aggressive B-NHL, BMB and PET/CT agreed in 58 patients (92%) and disagreed in five (8%), while the corresponding rates in indolent B-cell lymphoma were 14 (67%) and seven patients (33%), respectively. All seven were falsely negative.ConclusionsPET/CT upstages 17% of cases and detects occult splenic involvement. This may have potential therapeutic and prognostic implications. SUV >10 may predict for an aggressive histology. Except for indolent B-NHL, our data show that PET scans have a good overall NPV in excluding lymphomatous bone marrow involvement. This is particularly true of early-stage HL, suggesting that BMB may be safely omitted in this group.     

Positron Emission Tomography in Lymphoma: Comparison with Computed Tomography and Gallium-67 Single Photon Emission Computed Tomography

With the advent of positron emission tomography (PET), metabolic imaging has become a reality for tumor staging and monitoring response to therapy in lymphoma. Increased Fluorine-18 fluorodeoxyglucose ([¹⁸F]FDG) uptake in lymphomas has been well documented in the literature; it is based upon elevated glycolysis and longer residence time of FDG in malignant cells compared to most normal tissues. This suggests that in tumor staging, FDG-PET may be more sensitive and specific than the anatomic imaging modalities. Computed tomography (CT) is the standard imaging modality for the staging and restaging of lymphoma, and Gallium-67 (⁶⁷Ga) scintigraphy has played an important role in monitoring response to therapy and follow-up of patients. Published results suggest that FDG-PET is superior to ⁶⁷Ga imaging and may be equal or superior to CT for the detection of nodal as well as extranodal involvement in lymphoma.     

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 (PET) with 18F-fluorodeoxyglucose (18F-FDG) for the staging of low-grade non-Hodgkin's lymphoma (NHL).

Background:Although PET has been shown to be highlysensitive in the primary staging of lymphoma, previous studies withsmall numbers of patients indicated that low-grade NHL may not always beadequately detected by PET. We undertook this study to determine factorsinfluencing the detection of lesions by PET in low-grade NHL and toevaluate the utility of PET in this indication. Patients and methods:Forty-two patients underwentconventional staging procedures (clinical examination,oto-rhino-laryngologic examination, computed tomography of the chest,abdomen and pelvis, gastroscopy and bone marrow biopsy as well aswhole-body non-attenuation corrected ¹⁸F-FDG-PET. Results:PET detected 40% more abnormal lymph nodeareas than conventional staging in follicular lymphoma but wasinappropriate for the staging of small lymphocytic lymphoma where itdetected less than 58% of abnormal lymph node areas. PET showedmore lesions than conventional staging for peripheral (34% morelymph node areas detected) and thoracic lymph node (39% more)areas but not for abdominal or pelvic lymph nodes (26% fewerareas detected). The sensitivity to detect bone marrow infiltration wasunacceptably low for PET. In contrast, PET was as effective as standardprocedures for the detection of other extranodal localizations, althougha few localizations were detected only by PET and a few others only byconventional procedures. Conclusions:PET may contribute to the management ofpatients with low-grade follicular NHL. For the other low-grade lymphomasubtypes, the role of PET is less evident. Further studies using PET toevaluate the results of treatment or to diagnose disease recurrence arewarranted in low-grade follicular NHL.     

2-Fluorine-18-fluoro-2-deoxy-D glucose positron emission tomography in the pretreatment staging of Hodgkin's disease: Influence on patient management in a single institution

Purpose:Optimum therapy for patients with Hodgkin's disease (HD)is determined by a number of prognostic factors, one of which is an accuratedefinition of extent of disease (stage). Computerised tomography is widelyused in staging but cannot reliably evaluate normal sized lymph nodes and someextranodal sites, e.g., liver, spleen and bone marrow.2-Fluorine-18-fluoro-2-deoxy-D glucose (FDG) has been shown to concentratepreferentially in lymphoma sites (whether in nodal or extranodal tissue) andtherefore may have a useful role in staging patients with HD. This studycompares concurrent computerized tomography (CT) and FDG positron emissiontomography (PET) in the staging of Hodgkin's disease and assesses thefrequency of stage migration and possible changes in therapy related to theuse of PET scanning. Patients and methods:This was a single centre retrospective studyof 44 patients with Hodgkin's disease who underwent both staging CT and PETprior to treatment between September 1993 and August 1998 at St. Thomas'Hospital. The number and sites of disease were assessed for each patient,documenting any stage and therapy modification prompted by PET findings. Results:One hundred fifty-nine sites of disease were demonstratedin forty-four patients by FDG–PET compared with eighty-four by CT. Asa result, 18 (40.9%) patients were upstaged, nine of these byFDG-uptake in splenic or extranodal sites not visualised on CT. Only threepatients were downstaged by PET results. Eleven patients (25%) hadtreatment modified by PET scan findings. Conclusions:Significantly more sites of disease were identifiedby PET than CT resulting in stage changes and a modification of therapy in25% of patients. This has important implications not only for currentpatient management but also for the design of future clinical trials.     

Systematic review and meta-analysis on the diagnostic performance of FDG-PET/CT in detecting bone marrow involvement in newly diagnosed Hodgkin lymphoma: is bone marrow biopsy still necessary?

BackgroundThis study aimed to systematically review and meta-analyze published data on the diagnostic performance of ¹⁸F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT) in detecting bone marrow involvement in newly diagnosed Hodgkin lymphoma, and to determine whether FDG-PET/CT can replace blind bone marrow biopsy (BMB) in these patients.Patients and methodsThe PubMed/Medline and Embase databases were systematically searched for relevant studies. Methodological quality of each study was assessed. Sensitivities and specificities of FDG-PET/CT in individual studies were calculated and underwent meta-analysis with a random effects model. A summary receiver operating characteristic curve (sROC) was constructed with the Moses–Shapiro–Littenberg method. The weighted summary proportion of FDG-PET/CT-negative patients with a positive BMB among all cases was calculated under the fixed effects model.ResultsNine eligible studies, comprising a total of 955 patients with newly diagnosed Hodgkin lymphoma, were included. Overall, the studies were of moderate methodological quality. The sensitivity and specificity of FDG-PET/CT for the detection of bone marrow involvement ranged from 87.5% to 100% and from 86.7% to 100%, respectively, with pooled estimates of 96.9% [95% confidence interval (CI) 93.0% to 99.0%] and 99.7% (95% CI 98.9% to 100%), respectively. The area under the sROC curve was 0.9860. The weighted summary proportion of FDG-PET/CT-negative patients with a positive BMB among all cases was 1.1% (95% CI 0.6% to 2.0%).ConclusionAlthough the methodological quality of studies that were included in this systematic review and meta-analysis was moderate, the current evidence suggests that FDG-PET/CT may be an appropriate method to replace BMB in newly diagnosed Hodgkin lymphoma.     

伴PET/CT骨髓弥漫性糖代谢增高的淋巴瘤患者骨髓浸润情况及相关因素分析

背景与目的：正电子发射计算机断层显像技术(positron emission tomography-computed tomography,PET/CT)在淋巴瘤的诊断、治疗和随访中发挥着越来越重要的作用。该研究旨在探索PET/CT显示骨髓弥漫性糖代谢异常增高的淋巴瘤患者骨髓有无浸润、淋巴瘤病理类型以及其他临床特点。方法：回顾性分析复旦大学附属中山医院62例经病理确诊为淋巴瘤且PET/CT显示骨髓弥漫性糖代谢增高患者的临床资料、病理以及PET/CT详细数据,并行统计学分析。结果：PET/CT显示有骨髓弥漫性糖代谢异常增高的患者,其淋巴瘤病理类型分布与国内所报道各亚型淋巴瘤发病比例基本一致;侵袭性与惰性淋巴瘤之间［标准摄取值(standard uptake value,SUV)分别为8.43与5.38,P=0.048］、有或无B症状之间(SUV分别为8.30与5.72,P=0.033)、有或无骨髓浸润之间(SUV分别为8.78与6.96,P=0.020),SUV的差异均有统计学意义。32例(51.6%)患者经骨髓活检病理证实骨髓受累。骨髓受累者其淋巴瘤病理类型的分布上与未受累者差异有统计学意义(P=0.001);骨髓受累者套细胞淋巴瘤、结内边缘区B细胞淋巴瘤、伯基特淋巴瘤和间变大细胞淋巴瘤者比例较高,而骨髓未受累者弥漫大B细胞淋巴瘤、外周T细胞淋巴瘤、肠病相关性T细胞淋巴瘤和NK/T细胞淋巴瘤(鼻型)者比例较高。PET/CT骨摄取假阳性可能与发热、贫血等有关。结论：PET/CT骨髓弥漫性糖代谢异常增高虽然对临床诊疗有一定的提示,但应结合PET/CT骨糖代谢异常增高的特点、患者的临床因素及病理亚型综合分析,以减少误诊与漏诊,更精确地指导分期及治疗。     

The incremental effect of positron emission tomography on diagnostic accuracy in the initial staging of esophageal carcinoma

BACKGROUND: The purpose of the current study was to assess whether [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) provides incremental value (e.g., additional information on lymph node involvement or the presence of distant metastases) compared with computed tomography (CT) in patients with esophageal carcinoma. METHODS: The authors examined 149 consecutive patients with thoracic esophageal carcinoma. Eighty-one patients underwent radical esophagectomy without pretreatment, 17 received chemoradiotherapy followed by surgery, 3 underwent endoscopic mucosal resection, and the remaining 48 patients received definitive radiotherapy and chemotherapy. The diagnostic accuracy of FDG-PET and CT was evaluated at the time of diagnosis. RESULTS: The primary tumor was visualized using FDG-PET in 119 (80%) of 149 patients. Regarding lymph node metastases, FDG-PET had 32% sensitivity, 99% specificity, and 93% accuracy for individual lymph node group evaluation and 55% sensitivity, 90% specificity, and 72% accuracy for lymph node staging evaluation. PET exhibited incremental value over CT with regard to lymph node status in 14 of 98 patients who received surgery: 6 patients with negative CT findings were eventually shown to have lymph node metastases (i.e., they had positive PET findings and a positive reference standard [RS]); 6 patients with positive CT findings were shown not to have lymph node metastases (i.e., they had negative PET findings and a negative RS); and 2 patients were shown to have cervical lymph node metastases in addition to mediastinal or abdominal lymph node metastases. Among the remaining patients, PET showed incremental value over CT with regard to distant organ metastases in six patients. The overall incremental value of PET compared with CT with regard to staging accuracy was 14% (20 of 149 patients). CONCLUSIONS: FDG-PET provided incremental value over CT in the initial staging of esophageal carcinoma. At present, combined PET-CT may be the most effective method available for the preoperative staging of esophageal tumors.     

Fluorodeoxyglucose-positron-emission tomography findings in mantle cell lymphoma

ObjectiveMantle cell lymphoma (MCL) is an aggressive type of non-Hodgkin lymphoma with a propensity for extranodal involvement. The role of fluorodeoxyglucose (FDG)–positron emission tomography (PET) imaging in common types of lymphoma has been well-established. However, there is limited information in the literature about the utility of FDG-PET imaging in patients who have MCL. The aim of this study was to determine the role of FDG-PET imaging in assessment of disease activity in MCL compared with conventional imaging techniques such as computerized tomography/magnetic resonance imaging (CT/MRI).MethodsFDG-PET images of 20 patients with MCL who were referred to our center for assessment of extent of disease were reviewed retrospectively. The FDG-PET findings were compared with those of CT/MRI and were correlated with clinical information, histopathology, and outcome.ResultsThe diagnostic sensitivity for PET was 90% (17/19), and specificity was 100% (1/1). For CT/MRI, the sensitivity was 87% (14/16) and specificity was 50% (2/4). PET was better than CT/MRI in detecting nodal involvement. With respect to extranodal involvement, PET detected more cases of spleen involvement than CT/MRI. PET was equivalent to conventional imaging in detecting bowel involvement.ConclusionsPET imaging has a high sensitivity in detecting both nodal and extranodal involvement in patients who have MCL. Based on the available data in patients who had other subtypes of non-Hodgkin lymphoma, the specificity of PET also appears to be superior to anatomic imaging techniques. FDG-PET imaging may prove to be the single most effective method for detection.     

Value of [18F]fluorodeoxyglucose-positron emission tomography in managing patients with aggressive non-Hodgkin's lymphoma

An increased glucose metabolic rate is observed with various degrees of intensity in different subtypes of aggressive lymphomas. [(18)F]Fluorodeoxyglucose (FDG)-positron emission tomography (PET; FDG-PET) allows functional imaging of this phenomenon through 3-dimensional tomographic slices, which are now easily fused with computed tomography (CT) images. [(18)F]Fluorodeoxyglucose-PET staging appears superior to conventional staging modalities for detecting nodal and extranodal lymphoma. When performed after first-line chemotherapy, FDG-PET is more efficient than CT and conventional diagnostic methods to predict the disease outcome. Some studies have reported that the relapse rate is 100% in patients with positive PET findings after treatment and 17% in patients with negative PET findings. This imaging modality can also assess early response after 1-2 cycles of chemotherapy, thus identifying responders from patients whose cancer will fail to respond to first-line therapy or will relapse shortly after having exhibited a partial or complete remission. [(18)F]Fluorodeoxyglucose-PET also seems useful for an accurate selection of patients who will benefit from highly intensive treatment.     

Role of fluorine-18 fluoro-deoxyglucose positron emission tomography scan in the evaluation and follow-up of patients with low-grade lymphomas

BACKGROUND: Fluorine-18 fluoro-deoxyglucose positron emission tomography (FDG-PET) scanning has excellent sensitivity and specificity for staging non-Hodgkin lymphomas, but to the authors' knowledge few studies to date have evaluated FDG-PET in low-grade lymphomas only. METHODS: A retrospective study was performed on patients with biopsy-proven nontransformed and transformed follicular lymphoma (FL), B-cell small-cell lymphocytic lymphoma (SLL/CLL), or marginal zone lymphoma (MZL) who underwent PET and computed tomography (CT) scans within 3 weeks. Standard uptake values (SUV) of all abnormal foci were measured. RESULTS: In FL, PET demonstrated 94% sensitivity and 100% specificity for staging. PET was more specific than CT for detecting recurrence or assessing therapeutic responses (91% vs. 50%). FDG avidity among patients with WHO Grades 1, 2, and 3 disease was not significantly different (analysis of variance [ANOVA]). For MZL staging, PET had moderate sensitivity (71%) and outperformed CT alone in the depiction of extranodal sites (85% vs. 57% sensitivity). In SLL/CLL, PET sensitivity was 53% and underestimated disease extent in 5 of 19 patients (26%) compared with CT. PET did not affect initial management but confirmed suspected recurrences in 75% of patients. Nontransformed FL had a higher SUV (ANOVA, P < .05) compared with MZL and SLL/CLL. SUV was higher in transformed than in nontransformed tumors (P < .001, Student t test). CONCLUSIONS: PET usefulness in staging low-grade lymphomas varies depending on histology. PET sensitivity is excellent in FL and moderate in MZL. PET is more specific than CT for follow-up in all types. PET has limited usefulness for SLL/CLL staging. However, a suggestive pattern of hazy and mild uptake was often noted in positive scans. In all low-grade lymphomas, the emergence of foci of intense uptake should raise suspicion of conversion to high-grade disease.     

Comparison of 18F-fluoro-2-deoxyglucose positron emission tomography and gallium-67 citrate scintigraphy for detecting malignant lymphoma

This study evaluates and compares the accuracy of positron emission tomography with 18F-fluoro-2-deoxyglucose (FDG-PET) and gallium-67 citrate (Ga-67) scintigraphy in identifying disease sites in patients with malignant lymphoma at initial diagnosis or relapse. Histology subgroups included low (n=5), intermediate (n=6), high-grade (n=5) non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD) (n=14). Ann-Arbor staging included 7 patients in stage I, 8 in stage II, 9 in stage II, 6 in stage IV and 11 extra-nodal. In this study, before any therapy, 25 contemporaneous FDG-PET and Ga-67 scintigraphies were performed on patients with either NHL (16) or HD (14). One hundred and eleven sites of disease were correlated on a site-by-site basis in corresponding areas of FDG-PET and Ga-67 scintigraphy. Discordant FDG-PET and Ga-67 scintigraphic findings were correlated with CT/MRI and clinical evaluation. FDG-PET detected malignant lymphoma in 24/25 patients (sensitivity: 96.0%). There was a false-negative FDG-PET result in only 1 patient with low-grade gastric malignant lymphoma. Ga-67 scintigraphy detected malignant lymphoma in 18/25 patients (sensitivity: 72.0%). There were false-negative Ga-67 scintigraphic results in 4 cases with low-grade non-Hodgkin's lymphoma, 2 cases with bone or bone marrow involvement, and 3 smaller disease sites. FDG-PET upstaged 6 patients in whom Ga-67 scintigraphy detected disease sites partially. In imaging lymphoma prior to therapy, FDG-PET had a higher sensitivity and detected significantly more disease sites when compared with Ga-67 scintigraphy in the initial evaluation of this group of patients. Upstaging of patients with FDG-PET may result in a change in treatment strategy. However, evaluation of the final sensitivity, specificity and accuracy of these imaging modalities will need a further study with a larger patient number.     

18F-FDG PET-CT在非霍奇金淋巴瘤结外病灶检测及精确分期中的应用

目的 探讨18F-FDG PET-CT在检测非霍奇金淋巴瘤(NHL)结外病灶及精确分期中的应用价值.方法 回顾性分析94例初诊NHL患者的PET-CT结果,比较PET-CT与其他影像学检查对NHL结外病灶检出的一致性以及精确分期情况.结果 PET-CT检出受累病灶432处,其中淋巴组织及器官占73.8％(319/432),最大标准摄取值(SUVmax)平均13.4(3.4～33.4);结外病灶占26.2％(1 13/432),SUVmax平均13.5(3.1～55.0).PET-CT与CT对于淋巴组织及器官病灶的检出一致率为95％,而对于结外病灶的检出一致率仅为54.9％.PET-CT对于软组织、骨骼以及胃肠道病灶的检出率高于CT,但对于骨髓病灶的检出率低于骨髓细胞学检查.根据PET-CT结果再分期,29例(31.0％)调整分期,其中分期上调者占75.9％(22/29),引起分期上调的原因主要是PET-CT对于软组织、骨骼等病灶的检出率高;分期下调者占24.1％(7/29),引起分期下调的原因主要是PET-CT对于非肿瘤性原因引起的淋巴结及脾脏增大或浆膜腔积液的分辨力强.结论 18F-FDG PET-CT能够提高NHL结外病灶的检出率,特别是对于骨和软组织等弥漫性非肿块型病灶,有利于精确分期.