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.     

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.     

Frequent impact of [18F]fluorodeoxyglucose positron emission tomography on the staging and management of patients with indolent non-Hodgkin's lymphoma

[18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) is useful in staging aggressive non-Hodgkin's lymphoma (NHL). However, its role in indolent NHL has not been established. This retrospective study assessed the sensitivity and clinical impact of PET findings in patients with indolent NHL. Patients with indolent NHL who underwent FDG-PET scanning between May 1997 and August 2001 were identified. Case records were reviewed for FDG-PET and conventional staging/restaging results and compared for concordance. Forty-seven patients were identified. Twelve staging FDG-PET scans and 37 restaging FDG-PET scans were obtained. The FDG-PET case sensitivity rate was 98%. Forty-two percent of staging FDG-PET scans were concordant with conventional staging, with the remaining patients exhibiting more extensive disease on PET. At progression, FDG-PET and conventional assessments were discordant in 46% of cases. Positron emission tomography findings downstaged disease in 30% of these patients and upstaged disease in 16%. Computed tomography (CT) and FDG-PET identified 150 and 146 individual sites of disease, respectively. Among "definite" sites on structural imaging, 74% were also seen on PET. For equivocal lesions, only 19% were seen on both modalities. Clinical management was changed in 34% of patients as a result of FDG-PET findings. Of 22 discordant lesions in which true disease status could be evaluated, the PET findings were confirmed to be correct in 21 (95%; P < 0.0001). These findings demonstrate that FDG-PET has a high sensitivity for indolent NHL and often leads to alteration of disease staging and management. This high accuracy of FDG-PET in assessing discordant lesions suggests a greater diagnostic utility compared with CT.     

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.     

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.     

18氟-脱氧葡萄糖PET在儿童恶性淋巴瘤分期、疗效评估及随诊中的意义

 目的　探讨18氟-脱氧葡萄糖（18F-FDG）正电子发射计算机断层显像（PET）在儿童恶性淋巴瘤分期、疗效评估及随诊中的意义。方法　回顾性分析了88例儿童恶性淋巴瘤初诊时、化疗中期以及停药后随诊过程中18F-FDG-PET扫描结果,并与同期的CT扫描相比较。结果　67例初诊儿童淋巴瘤患者,化疗前共评估了1072个解剖部位,PET和CT均提示瘤灶阳性及阴性部位分别为11.10 %和77.52 %,PET阳性CT阴性的部位占6.81 %,而PET阴性CT阳性的占4.57 %,PET在化疗前受累部位的诊断方面优于CT扫描。对26例随诊患者,在治疗中期、停药时及停药后进行了35次PET检查,32例患儿瘤灶为阴性,PET扫描瘤灶真阴性为28例（87.50 %）,CT为16例（57.14 %）,在假阳性方面,CT比较高,为16例（50%）,而PET仅为4例（14.29 %）,临床吻合度PET大于CT。结论　PET对于儿童恶性淋巴瘤的临床分期、鉴别残余病灶的性质以避免不必要的过度治疗或二次活检,以及发现肿瘤的早期复发具有一定的意义。     

骨髓涂片免疫组织化学与骨髓活组织检查诊断非霍奇金淋巴瘤骨髓浸润的比较

目的：比较骨髓涂片免疫组织化学和骨髓活组织检查在检测非霍奇金淋巴瘤（NHL）骨髓受累中的优缺点。方法收集60例初治NHL患者,应用骨髓涂片免疫组织化学法和骨髓活组织检查检测是否骨髓受累,并将患者的年龄、临床分期、结外受累、B症状等临床因素与两种检测方法结果进行相关性分析。结果骨髓涂片免疫组织化学和骨髓活组织检查检测出的NHL骨髓受累阳性率分别为10.0%（6／60）、3.3%（2／60）（P＝0.008）;B细胞来源时,两者阳性率分别为6.6%（4／60）和3.3%（2／60）（P＝0.007）,T细胞来源时,阳性率分别为3.3%（2／60）、0（0／60）。经相关性分析,两种检测方法与患者性别、年龄、Karnofsky评分、B症状、结外累及、乳酸脱氢酶、血小板数、血红蛋白含量、中性粒细胞数、淋巴细胞数、分期均无关（均P＞0.05）。结论骨髓涂片免疫组织化学法检测NHL骨髓受累的阳性率高于活组织检查,进一步分析B细胞或T细胞来源时,骨髓涂片免疫组织化学法仍有相对优势。     

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.     

Computed tomography and 18F-FDG positron emission tomography for therapy control of Hodgkin's and non-Hodgkin's lymphoma patients: when do we really need FDG-PET?

BACKGROUND: The aim of this study was to evaluate the accuracy of computed tomography (CT) and [(18)F]fluoro-deoxy-d-glucose positron emission tomography (FDG-PET) for prediction of progression-free survival of Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) patients after completion of therapy. PATIENTS AND METHODS: CT and FDG-PET were performed in 40 HD, 17 indolent NHL and 44 aggressive NHL patients (29 women, 72 men; aged 41+/-14 years) in a median of 2 months after therapy. Progression-free survival was evaluated using the Kaplan-Meier method. Independent prognostic factors were identified by means of Cox proportional hazards model. RESULTS: CT imaging results were progressive disease (PD) in five, stable disease (SD) in 57, and partial response (PR) or complete remission (CR) in 39 patients. FDG-PET suggested residual lymphoma in 24 patients. Three-year progression-free survival rates after exclusion of five PD patients were: 100% (PET negative; CT: PR or CR), 81% (PET negative; CT: SD), 21% (PET positive; CT: SD) and 0% (PET positive; CT: PR). FDG-PET (P<0.0001) and bulky disease (P <0.05) were identified as independent prognostic variables. CONCLUSIONS: Among lymphoma patients with PR and SD on CT, FDG-PET discriminated those destined to progress into a low risk of < or =20% and a high risk for recurrence of > or =80%.     

Complete response to chemotherapy in primary hepatic lymphoma

Primary hepatic lymphoma is an uncommon lymphoid tumor with varied clinical presentations and treatment outcomes. The median age of involvement is 50 years (male preponderance) with median survival as 8-16 months. Here we report a 68-years-old female who presented with right hypochondriac pain and anorexia with hepatomegaly on physical examination. Ultrasonography (USG) with subsequent contrast enhanced computed tomography (CECT) of abdomen depicted a hypoechoic mass in the left lobe of liver. CECT of chest and neck showed no abnormality. Liver biopsy proved to be Non-Hodgkin lymphoma (NHL) diffuse large B cell type, CD20 positive. Bone marrow examination showed no infiltration by NHL. The patient was started on three weekly R-CHOP, given a total of 8 cycles. Patient attained a complete remission documented by negative computed tomography (CT) and positron emission tomography (PET) scans.     

FDG-PET/CT in the evaluation of anal carcinoma

PURPOSE: Surgical staging and treatment of anal carcinoma has been replaced by noninvasive staging studies and combined modality therapy. In this study, we compare computed tomography (CT) and physical examination to [(18)F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in the staging of carcinoma of the anal canal, with special emphasis on determination of spread to inguinal lymph nodes. METHODS AND MATERIALS: Between July 2003 and July 2005, 41 consecutive patients with biopsy-proved anal carcinoma underwent a complete staging evaluation including physical examination, CT, and 2-FDG-PET/CT. Patients ranged in age from 30 to 89 years. Nine men were HIV-positive. Treatment was with standard Nigro regimen. RESULTS: [(18)F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) detected 91% of nonexcised primary tumors, whereas CT visualized 59%. FDG-PET/CT detected abnormal uptake in pelvic nodes of 5 patients with normal pelvic CT scans. FDG-PET/CT detected abnormal nodes in 20% of groins that were normal by CT, and in 23% without abnormality on physical examination. Furthermore, 17% of groins negative by both CT and physical examination showed abnormal uptake on FDG-PET/CT. HIV-positive patients had an increased frequency of PET-positive lymph nodes. CONCLUSION: [(18)F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography detects the primary tumor more often than CT. FDG-PET/CT detects substantially more abnormal inguinal lymph nodes than are identified by standard clinical staging with CT and physical examination.     

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.     

PET in T-Cell Lymphoma

Most non-Hodgkin lymphomas (NHL) are of B-cell origin; only about 10% are T-cell or NK-cell lymphomas. The clinical features of T/NK-cell lymphomas differ from those of B-cell lymphomas: advanced stage and extranodal disease are more common and the prognosis is worse. Several studies have confirmed that 2-[fluorine-18]fluoro-2-deoxy-D-glucose (18FDG) uptake varies among different subtypes of lymphoma, a disparity that can be explained by the differences in histology, proliferation of tumor cells, and the ratio of viable tumor and reactive cells in the environment. These observations are based on investigation of B-cell lymphomas. Positron emission tomography (PET)/computed tomography (CT) was found to be useful both at staging and at measuring the therapeutic outcome after two to three cycles of chemotherapy (interim PET/CT). Several meta-analyses have confirmed the role of PET in evaluating the viability of the residual tumor mass after treatment. 18FDG-PET has been proved to have an excellent negative predictive value. Conversely, only a few studies have investigated the role of FDG-PET in T/NK-cell lymphomas. This paper summarizes the current information regarding the potential use of PET/CT in patients with T-cell lymphoma.     

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.     

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.     

Value of FDG-PET/CT Examinations in Different Cancers of Children, Focusing on Lymphomas

The aim of the study was to assess sensitivity and specificity of FDG-PET/CT in different forms of childhood cancer. We retrospectively evaluated the results dedicated of 162 FDG-PET/CT examinations of 86 children treated with: Hodgkin lymphoma (HL; n?=?31), non-Hodgkin lymphoma (NHL; n?=?30) and other high grade solid tumors (n?=?25). Patients were admitted and treated in two departments of pediatric hematology and oncology in Hungary. FDG-PET/CT was performed for staging (n?=?25) and for posttreatment evaluation (n?=?137). Imaging was performed in three FDG-PET/CT Laboratories, using dedicated PET/CT scanners. False positive results were defined as resolution or absence of disease progression over at least 1 year on FDG-PET/CT scans without any intervention. In some cases histopathological evaluation of suspicious lesions was performed. Fals negative results were defined as negative FDG-PET/CT results in case of active malignancy. Positive predictive values (PPV) and negative predictive values (NPV) were calculated. NPV was 100 %. The highest PPV was observed in high grade solid tumors (81 %), followed by HL (65 %) and NHL (61 %). There was a major difference of PPV in different histological types of HL (50 % in HL of mixed-cellularity subtype, 90 % in nodular sclerosing, and 100 % in lymphocyte-rich and lymphocyte depleted HL). We treated one patient with nodular lymphocyte predominant HL, who had 5 false positive FDG-PET/CT results. PPV of T- and B-lineage NHL were similar (60 % and 62 %, respectively). We observed an interesting difference of PPV in different stages of HL and NHL. In HL PPV was higher in early than in advanced disease forms: 66 % in stage II HL and 60 % in stage III HL, whereas there was an inverse relationship between PPV and disease stages in NHL 0 % in stage I and II patients, 67 % in stage III and 100 % in stage IV patients. PPV was lower in males (54 %) than in females (65 %). PPV were 64 % vs. 58 % in patients under vs. over 10 years of age. Negative FDG-PET/CT results during follow-up reliably predict the absence of malignancy. Positive FDG-PET/CT scan results in general have a low PPV. The relatively high PPV in patients with histologically proven high grade solid tumors, advanced stages of NHL and with nodular sclerosing, lymphocyte-rich and lymphocyte depleted subtypes of HL warrant a confirmation by biopsy, whereas the watch-and-wait approach can be used in other forms of childhood cancer patients with a positive FDG-PET/CT result in course of follow-up examinations.     

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.     

A prospective study of PET/CT in initial staging of small-cell lung cancer: comparison with CT, bone scintigraphy and bone marrow analysis.

BACKGROUND: Small-cell lung cancer (SCLC) accounts for 15%-20% of all lung cancer cases. Accurate and fast staging is mandatory when choosing treatment, but current staging procedures are time consuming and lack sensitivity. PATIENTS AND METHODS: A prospective study was designed to examine the role of combined positron emission tomography/computed tomography (PET/CT) compared with standard staging (CT, bone scintigraphy and immunocytochemical assessment of bone marrow biopsy) of patients with SCLC. Thirty-four consecutive patients were included. Twenty-nine patients received initial PET/CT. RESULTS: PET/CT caused change of stage in 5/29 (17%). Excluding patients with unconfirmed findings or pleural effusion, the sensitivity for accurate staging of patients with extensive disease was the following: for standard staging 79%, PET 93% and PET/CT 93%. Specificity was 100%, 83% and 100%, respectively. CONCLUSION: The results from this first study on PET/CT in SCLC indicates that PET/CT can simplify and perhaps even improve the accuracy of the current staging procedure in SCLC. A larger clinical trial, preferably with consequent histological confirmation in case of discordance, however, is warranted.     

Predictive role of positron emission tomography (PET) in the outcome of lymphoma patients

An extensive analysis of the reliability of positron emission tomography (PET) after induction treatment in patients with Hodgkin's disease (HD) or aggressive non-Hodgkin's lymphoma (NHL). In all, 75 untreated patients with HD (n=41) or aggressive NHL (n=34) were studied with both PET and CT scans following standard chemotherapy induction therapy (ABVD or MACOP-B) with/without radiotherapy. Histopathological analysis was performed when considered necessary. After treatment, four out of five (80%) patients who were PET(+)/CT(-) relapsed, as compared with zero out of 29 patients in the PET(-)/CT(-) subset. Among the 41 CT(+) patients, 10 out of 11 (91%) who were PET(+) relapsed, as compared with 0 out of 30 who were PET(-). The actuarial relapse-free survival (RFS) rates were 9 and 100% in the PET(+) and PET(-) subsets, respectively (P=0.00001). All five patients who were PET(+)/CT(-) underwent a lymph node biopsy: in four (80%) cases, persistent lymphoma and was confirmed at histopathological examination. Two HD patients who were PET(-)/CT(+) (with large residual masses in the mediastinum or lung) were submitted to biopsy, which in both cases revealed only fibrosis. In HD and aggressive NHL patients, PET positivity after induction treatment is highly predictive for the presence of residual disease, with significant differences being observable in terms of RFS. PET negativity at restaging strongly suggests the absence of active disease; histopathological verification is important in patients who show PET positivity.     

Value of [18F]Fluorodeoxyglucose–Positron Emission Tomography in Managing Adults with Aggressive Non-Hodgkin's Lymphoma

An increased glucose metabolic rate is observed with various degrees of intensity in different subtypes of aggressive lymphomas. [¹⁸F]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. [¹⁸F]Fluorodeoxyglucose–positron emission tomography 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. [¹⁸F]Fluorodeoxyglucose–PET also seems useful for an accurate selection of patients who will benefit from highly intensive treatment.