Impact of positron emission tomography on the management of patients with small-cell lung cancer: preliminary experience

Accurate staging is important in small-cell lung cancer (SCLC). Patients with limited stage may benefit from chemoradiation, whereas those with extensive stage conventionally receive chemotherapy. Prophylactic cranial irradiation may benefit those attaining complete remission (CR). 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) enhances accuracy of staging in non-SCLC. Its role in SCLC remains unclear. We reviewed 36 consecutive SCLC patients who underwent 47 PET studies between December 1996 and January 2001, for either staging (n = 11), restaging after therapy (n = 21), or both (n = 4). Conventional imaging was also performed. Of 15 patients who had PET for staging, 5 (33%) were upstaged from limited to extensive disease and treated without thoracic radiotherapy. Twenty-five patients underwent 32 restaging PET scans, of which 20 (63%) were discordant with conventional imaging. In 8 cases PET showed more extensive disease than conventional imaging, and in 12 cases PET-apparent disease appeared less extensive. In 13 patients, 14 untreated discordant lesions were evaluable; PET was confirmed accurate in 11 (79%) sites by last follow-up. Restaging PET influenced management in 13 cases (52%). PET-CR conferred longer median time to progression (13.7 months) than no CR (9.7 months). FDG-PET for SCLC was often discordant with conventional assessment and frequently influenced management.     

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.     

18F]fluorodeoxyglucose positron emission tomography scanning for staging, response assessment, and disease surveillance in patients with mantle cell lymphoma

BackgroundPositron emission tomography (PET) is an important imaging modality in the staging and response assessment of patients with lymphoma, but data on its specific use in mantle cell lymphoma (MCL) are lacking.Patients and MethodsThe records of 28 patients with MCL who had a total of 123 [¹⁸F]fluorodeoxyglucose (FDG) PET scans between March 1999 and November 2005 were reviewed. Nine patients had staging scans. The other scans were performed for response assessment or relapse surveillance.ResultsFDG-PET sensitivity was 100% for nodal disease in the 9 patients studied at baseline. Positron emission tomography scans performed for response assessment were concordant with conventional imaging in 47% and discordant in 53% of cases. Positron emission tomography scanning led to earlier diagnosis of relapse in 1 of 17 patients but produced a high rate of false-negative findings in the evaluation of gastrointestinal involvement.ConclusionFDG-PET appears to be a sensitive modality for staging and for response assessment in MCL but was not found to be useful in relapse surveillance or in the evaluation of gastrointestinal disease.     

Restaging of recurrent cervical carcinoma with dual-phase [18F]fluoro-2-deoxy-D-glucose positron emission tomography

BACKGROUND: The clinical value of positron emission tomography (PET) with [18F]fluoro-2-deoxy-D-glucose (FDG) for primary staging in cervical carcinoma appears to be promising. The authors sought to evaluate the diagnostic efficacy and benefit of PET in restaging cervical carcinoma at the time of first recurrence. METHODS: Forty patients with cervical carcinoma who experienced confirmed treatment failure but who were feasible candidates for curative salvage therapy were enrolled prospectively in the current study. Restaging was performed with PET and with computed tomography and/or magnetic resonance imaging (CT/MRI). Dual-phase PET was performed by adding 3-hour-delayed images to the 40-minute scans. The results of the PET and CT/MRI scans were compared. Lesion status was determined by pathologic findings or by clinical follow-up. The receiver operating characteristic curve method with calculation of area under the curve (AUC) was used to evaluate diagnostic efficacy. The primary endpoint was percent improvement in restaging (with improvement indicated by treatment modification) after PET. The secondary endpoint was 2-year overall survival among study participants compared with comparable previously treated patients who did not undergo disease restaging with PET. RESULTS: Twenty-two patients (55%) had their treatment modified due to PET findings. PET was significantly superior to CT/MRI (sensitivity: 92% vs. 60%; AUC: 0.962 vs. 0.771; P<0.0001) in identifying metastatic lesions. For individuals receiving primary surgery, a significantly better 2-year overall survival rate was observed among study participants compared with patients who underwent disease restaging without PET (HR, 0.21 [95% confidence interval, 0.05-0.83]; P=0.020). CONCLUSIONS: Dual-phase FDG-PET is superior to CT/MRI in the restaging of recurrent cervical carcinoma. Restaging with PET provides benefit by allowing the physician to offer optimal management of recurrent cervical carcinoma.     

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.     

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 in limited-stage small-cell lung cancer: a prospective study.

PURPOSE: To determine how often positron emission tomography with [(18)F]fluoro-2-deoxy-D-glucose (FDG-PET) detects extensive-stage small-cell lung cancer (SCLC) in patients considered to have limited-stage disease based on conventional staging procedures, and to determine the impact of PET on treatment planning for presumed limited-stage SCLC. PATIENTS AND METHODS: We prospectively performed pretreatment FDG-PET on 24 patients determined by conventional staging methods to have limited-stage SCLC (defined as disease that could be encompassed within a reasonable radiotherapy portal, excluding bilateral supraclavicular disease). PET images were evaluated for evidence of extensive-stage disease. Tumor-node-metastasis system staging was also assigned for each patient, with and without PET information. RESULTS: FDG-PET demonstrated findings consistent with extensive-stage SCLC in three of 24 patients. FDG-PET correctly upstaged two (8.3%) of 24 patients to extensive-stage disease (95% CI, 1.03% to 27.0%). PET correctly identified tumor in each SCLC mass (primary or nodal) that was suspected on computed tomography (CT) imaging, thus giving a lesion-based sensitivity relative to CT of 100%. PET identified unsuspected regional nodal metastasis in six (25%) of 24 patients, and the radiation therapy plan was significantly altered to include the PET-positive/CT-negative nodes within the high-dose region in each of these patients. Brain PET images in 23 patients disclosed no evidence of brain metastasis. CONCLUSION: FDG-PET has high sensitivity for SCLC and appears to be of value for initial staging and treatment planning of patients with presumed limited-stage disease.     

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%.     

The role of Fluorine-18-Fluorodeoxyglucose positron emission tomography in staging and restaging of patients with osteosarcoma

Background

The objective of this study is to systematically review the role of positron emission tomography (PET) and PET/computed tomography (PET/CT) with Fluorine-18-Fluorodeoxyglucose (FDG) in patients with osteosarcoma (OS).

Methods

A comprehensive literature search of published studies through October 10^th, 2012 in PubMed/MEDLINE, Embase and Scopus databases regarding whole-body FDG-PET and FDG-PET/CT in patients with OS was performed.

Results

We identified 13 studies including 289 patients with OS. With regard to the staging and restaging of OS, the diagnostic performance of FDG-PET and PET/CT seem to be high; FDG-PET and PET/CT seem to be superior to bone scintigraphy and conventional imaging methods in detecting bone metastases; conversely, spiral CT seems to be superior to FDG-PET in detecting pulmonary metastases from OS

Conclusions

Metabolic imaging may provide additional information in the evaluation of OS patients. The combination of FDG-PET or FDG-PET/CT with conventional imaging methods seems to be a valuable tool in the staging and restaging of OS and may have a relevant impact on the treatment planning.     

Impact of 18F-fluorodeoxyglucose positron emission tomography in the staging and treatment response assessment of extra-pulmonary small-cell cancer

The aim of this study was to retrospectively evaluate the value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in extrapulmonary small-cell cancer (EPSCC). Patients with EPSCC who underwent PET for staging or response assessment between 1996 and 2007 were identified from a database. Patient records were reviewed. PET-based, and conventional staging and restaging results were compared. The binary staging classification of limited disease (LD) versus extensive disease (ED) was used. Patients with LD had tumours that could be encompassed within a tolerable radiation therapy (RT) volume. Of 33 eligible patients, 12 had staging PET scans, 11 had restaging scans and 10 had both. All known gross disease sites were FDG-avid. PET and conventional stage groupings were concordant in 21 of 22 cases. One patient was appropriately upstaged from LD to ED by PET. PET detected additional disease sites, without causing upstaging in three further patients. Restaging PET scans identified previously unrecognised persistent or progressive disease in 4 of 21 cases. In four further cases, persistent FDG uptake after treatment was either false positive (n = 2) or of uncertain (n = 2) aetiology. PPV was 100% for staging and 82% for restaging. In 8 of 43 imaging episodes (19%), PET appropriately influenced management in five cases by changing treatment intent from radical to palliative, and in three cases by altering the RT volume. PET has incremental value compared to conventional imaging for staging EPSCC, and may also be useful for restaging after therapy. PET influenced patient management in 19% of 43 imaging episodes.     

Detection of unsuspected distant metastases and/or regional nodes by FDG-PET [corrected] scan in apparent limited-disease small-cell lung cancer

We retrospectively investigated the clinical usefulness of fluorodeoxyglucose positron emission tomography (FDG-PET) for evaluation of patients with limited-disease small-cell lung cancer (LD-SCLC) diagnosed by conventional staging procedures. Sixty-three patients received whole body FDG-PET scans after routine initial staging procedures. The findings of FDG-PET scans suggesting extensive-stage disease were confirmed by other imaging tests or by the patient's clinical course. FDG-PET scan findings indicated distant metastases in 6 of 63 patients. Metastatic disease was confirmed in five of these six patients (8%, 95% confidence interval: 3-18%). FDG-PET scan also detected regional lymph node metastases even in nine patients (14%) in whom computed tomography images had been negative, including contralateral lymph node metastasis in three patients. FDG-PET scan detected additional lesions in patients diagnosed as having LD-SCLC by conventional staging procedures. The therapeutic strategies were changed in 8% of patients based on the results of FDG-PET. FDG-PET scan is recommended as an initial staging tool for patients with this disease.     

Value of positron emission tomography with [F-18]fluorodeoxyglucose in patients with colorectal liver metastases: a prospective study.

PURPOSE: To assess prospectively the value of fluor-18-deoxyglucose (FDG) positron emission tomography (PET), in addition to conventional diagnostic methods (CDM), as a staging modality in candidates for resection of colorectal liver metastases. PATIENTS AND METHODS: In 51 patients analyzed for resection of colorectal liver metastases, clinical management decisions were recorded after a complete work-up with CDM. Afterward, FDG-PET scans were performed and any change of clinical management according to FDG-PET results was carefully documented. Discordances between FDG-PET and CDM results were identified and related to the final diagnosis by histopathology, intraoperative findings, and follow-up. RESULTS: In 10 (20%) out of 51 patients, clinical management decisions based on CDM were changed after FDG-PET findings were known. FDG-PET detected unresectable pulmonary (n = 5) and hepatic metastases (n = 1) and ruled out extrahepatic (n = 2) and hepatic disease (n = 2). Due to FDG-PET, eight patients were spared unwarranted liver resection or laparotomy and two other patients were identified as candidates for liver resection. When the results of FDG-PET were regarded as decisive in a retrospective analysis, potential change of management was 29% (15 patients). FDG-PET and CDM showed discordant extrahepatic results in 11 patients (22%) and discordant hepatic results in eight patients (16%). Compared with CDM, FDG-PET resulted in true upstaging (n = 11), true downstaging (n = 5), false upstaging (n = 1), and false downstaging (n = 2). The detection rate of liver metastases on a lesion basis was generally better for computed tomography than for FDG-PET (80% v 65%); this was related to tumor size. CONCLUSION: FDG-PET as a complementary staging method improves the therapeutic management of patients with colorectal liver metastases, especially by detecting unsuspected extrahepatic disease.     

Comparison of (18)F Flurodeoxyglucose PET with Ga-67 scintigraphy and conventional imaging modalities in pediatric lymphoma

Flurodeoxyglucose PET (FDG PET) is very useful for staging and restaging adult lymphomas. Its effectiveness in childhood lymphomas is less established. To evaluate the potential utility of FDG PET in the care of pediatric patients with lymphomas, we examined the clinical data and imaging findings of 26 patients, 8 - 19 years of age (14 HD, 12 NHL) who underwent 55 FDG PET studies. Results were compared with CT/MRI and gallium scans. FDG PET provided incremental, clinically important information in 21% of HD cases and 33% of NHL cases. It was especially useful in distinguishing scar tissue from residual disease at the end of therapy. In both HD and NHL, FDG PET had higher sensitivity (94%, 90%) and specificity (100%, 88%) than CT/MRI and gallium scanning. These results indicate that FDG PET is useful in the management of pediatric lymphomas.     

What Does PET Imaging Add to Conventional Staging of Head and Neck Cancer Patients?

PURPOSE: To determine the value of PET scans in the staging of patients with head and neck carcinoma. METHODS AND MATERIALS: The charts of 25 patients who underwent neck dissection, computed tomography (CT) scan, and F-18-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging as part of their initial work-up for a head and neck squamous cell cancer between 2000-2003 were reviewed. All patients underwent clinical examination, triple endoscopy, and chest radiograph as part of their clinical staging, adhering to American Joint Commission for Cancer criteria. In addition to the clinical nodal (N) stage, PET findings were incorporated to determine a second type of N staging: clinical N + PET stage. The number of neck sides and nodal levels involved on CT or PET and on pathologic examination were recorded. RESULTS: The sensitivity and specificity for detection of nodal disease were similar for CT and FDG-PET. Positive and negative likelihood ratios were similar for both diagnostic tests. None of our 25 patients had unsuspected distant disease detected by PET. CONCLUSION: The addition of PET imaging did not improve diagnostic accuracy in our patients compared with CT. PET scanning did not alter clinical management in any of the patients.     

Whole body positron emission tomography in the treatment of Hodgkin disease

BACKGROUND: In Hodgkin disease (HD), accurate assessment of the extent of disease is essential because it provides the basis for different treatment strategies. In addition to conventional imaging methods (CIM), positron emission tomography with fluorine-18-fluorodeoxyglucose (FDG-PET) may permit reliable differentiation between lymphoma and nonmalignant tissue and thus improve determination of the stage of the disease. The aim of the current study was to assess the clinical value of FDG-PET for primary staging, treatment monitoring, and assessment in a suspected case of recurrent HD. METHODS: Eighty-one patients with HD underwent 106 FDG-PET studies using a dedicated whole body PET ring scanner. In 25 patients PET was part of the primary staging, 63 PET studies were undertaken for treatment monitoring after the completion of treatment, and in 18 patients PET was performed in cases of suspected recurrence of HD. PET scans were compared with CIM and verified histologically and/or by follow-up evaluation (mean follow-up duration, 20.4 months). RESULTS: With regard to primary staging, in a patient to patient analysis, both PET scans and CIM were positive (i.e., showed pathologic foci indicative of HD) in 24 of 25 cases. In a staging-relevant lesion to lesion analysis, accuracy in the determination of the stage of disease was 96% for PET versus 56% for CIM. PET led to a lower stage classification in 28% and a higher stage classification in 12% of cases, compared with the stage assumed with CIM. With regard to treatment monitoring, PET showed an accuracy of 91% compared with 62% for CIM. The negative predictive value of PET was 96%. With regard to suspected recurrence, PET findings were true-positive in 10 of 12 PET scans and true-negative in 5 of 6 PET scans, resulting in accuracy of 83%, which compares favorably with the accuracy rate of 56% for CIM. CONCLUSIONS: It may be concluded that FDG-PET is capable of determining the stage of HD with great accuracy and is capable of correctly detecting manifestations of HD in treatment monitoring and cases of suspected recurrence, in which CIM occasionally result in equivocal findings. The results of the current study suggest that FDG-PET should become a routine tool in the staging/restaging of HD.     

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.     

Combined PET and low-dose,noncontrast CT scanning obviates the need for additional diagnostic contrast-enhanced CT scans in patients undergoing staging or restaging for lymphoma

BackgroundPositron emission tomography (PET) is more accurate than computed tomography (CT) in staging and restaging of lymphoma, but both are considered necessary. Increasingly, PET is carried out with a low-dose CT scan. Many patients undergo both PET/CT and standard diagnostic CT. The clinical utility of performing both studies in patients with lymphoma was evaluated.Patients and methodsPatients with lymphoma who underwent concurrent PET/CT and diagnostic CT (a scan pair) were identified, and findings detected in either scan but not both were documented. Discrepancies were considered significant if they were related to either lymphoma or another disease process which potentially required intervention.ResultsEighty-seven scan pairs were identified. PET/CT detected additional lesions over diagnostic CT in 30 patients, of which 11 demonstrated increased clinical stage. Lymphoma therapy changed based on PET/CT in two patients, and one occult rectal cancer was detected. In contrast, diagnostic CT detected five relevant findings, including two incidental findings (venous thrombosis) and three patients with splenic lesions, none of which could be confirmed as lymphoma. No patient had change of stage or lymphoma therapy based on diagnostic CT.ConclusionIn our series, diagnostic CT did not add value to staging or restaging of lymphoma when carried out concurrently with PET/CT.     

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.     

Comparison of fluorine-18 fluorodeoxyglucose positron emission tomography and Ga-67 scintigraphy in evaluation of lymphoma

BACKGROUND: The accuracy of fluorodeoxyglucose positron emission tomography (FDG-PET; dual-head camera with attenuation correction) and Ga-67 scintigraphy was compared to identify disease sites in patients with Hodgkin disease (HD) and intermediate and high-grade non-Hodgkin lymphoma (NHL) at initial diagnosis or clinical recurrence. METHODS: Fifty-one contemporaneous FDG-PET and Ga-67 scintigraphies were performed on patients with NHL (35 intermediate grade, 3 high grade) or HD (13 patients). Sites of disease were correlated on a site-by-site basis on FDG-PET and Ga-67 images. Tumor-to-background (T/B) ratios were obtained for both techniques. Discordant FDG-PET and Ga-67 findings were correlated with computed tomography findings or clinical evaluation including repeat FDG-PET scans obtained after therapy. RESULTS: Fluorodeoxyglucose positron emission tomography was positive at all 158 sites in 51 patients compared with 113 sites in 41 positive studies with Ga-67 scintigraphy (single positron emission computed tomography [SPECT] and/or planar images). In 44 patients who had complete Ga-67 SPECT data on all tumor sites, FDG-PET was positive at 126 sites and Ga-67 SPECT was positive at 81 sites. Ga-67 SPECT failed to demonstrate disease at 45 sites (35.7%). In 10 of 44 patients, Ga-67 SPECT completely failed to detect any disease at 22 of 45 sites (17.5%) and partially identified disease sites at 23 of 45 sites (18.2%) in 11 patients regardless of the tumor site and histology. In these patients, the lesions measured between 0.6 and 14.0 cm by CT. Fluorodeoxyglucose positron emission tomography revealed higher stage disease in 13 patients compared with Ga-67 imaging. Tumor-to-background ratios were statistically different between the two techniques with higher ratios obtained with FDG-PET (P < 0.0001). CONCLUSIONS: In imaging aggressive lymphoma and HD before therapy, FDG-PET has significantly higher site and patient sensitivity than Ga-67 scintigraphy (100% vs. 71.5% and 100% vs. 80.3%, respectively). The change in disease stage by FDG-PET may result in a change in therapy strategy.     

Utility of positron emission tomography for the staging of patients with potentially operable esophageal carcinoma.

PURPOSE: A prospective study of preoperative tumor-node-metastasis staging of patients with esophageal cancer (EC) was designed to compare the accuracy of 18-F-fluoro-deoxy-D-glucose (FDG) positron emission tomography (PET) with conventional noninvasive modalities. PATIENTS AND METHODS: Seventy-four patients with carcinomas of the esophagus (n = 43) or gastroesophageal junction (n = 31) were studied. All patients underwent attenuation-corrected FDG-PET imaging, a spiral computed tomography (CT) scan, and an endoscopic ultrasound (EUS). RESULTS: FDG-PET demonstrated increased activity in the primary tumor in 70 of 74 patients (sensitivity: 95%). False-negative PET images were found in four patients with T1 lesions. Thirty-four patients (46%) had stage IV disease. FDG-PET had a higher accuracy for diagnosing stage IV disease compared with the combination of CT and EUS (82% v 64%, respectively; P: =.004). FDG-PET had additional diagnostic value in 16 (22%) of 74 patients by upstaging 11 (15%) and downstaging five (7%) patients. Thirty-nine (53%) of the 74 patients underwent a 2- or 3-field lymphadenectomy in conjunction with primary curative esophagectomy. In these patients, tumoral involvement was found in 21 local and 35 regional or distant lymph nodes (LN). For local LN, the sensitivity of FDG-PET was lower than EUS (33% v 81%, respectively; P: =.027), but the specificity may have been higher (89% v 67%, respectively; P: = not significant [NS]). For the assessment of regional and distant LN involvement, compared with the combined use of CT and EUS, FDG-PET had a higher specificity (90% v 98%, respectively; P: =. 025) and a similar sensitivity (46% v 43%, respectively; P: = NS). CONCLUSION: PET significantly improves the detection of stage IV disease in EC compared with the conventional staging modalities. PET improves diagnostic specificity for LN staging.