FDG PET can replace bone scintigraphy in primary staging of malignant lymphoma.

Recent studies indicated that 18F-fluorodeoxyglucose (FDG) PET may be more accurate than CT in staging nodal and extranodal malignant lymphoma. The objective of this study was to compare conventional bone scintigraphy as an established skeletal staging procedure with PET using FDG in the detection of osseous involvement in malignant lymphoma. METHODS: Whole-body PET-based staging studies of 56 consecutive patients with proven Hodgkin's disease (n = 34) or non-Hodgkin's lymphoma (n = 22) were compared with the results of bone scintigraphy. Positive PET or bone scintigraphic findings were confirmed, if possible, by biopsy, MRI, CT or radiographic investigations. RESULTS: Of the 56 patients studied, 12 were found to have skeletal involvement on both studies (PET, 30 regions; bone scintigraphy, 20 regions). Findings were confirmed in all 12 patients. FDG PET detected an additional 12 involved regions in 5 patients. This was subsequently verified in 3 patients, although the other 2 cases remained unresolved. Conversely, bone scintigraphy revealed five abnormalities compatible with lymphoma in 5 patients. Three of these lesions were found to be erroneous; final evaluation of the remaining two findings was not possible. CONCLUSION: FDG PET is suitable for identifying osseous involvement in malignant lymphoma with a high positive predictive value and is thereby more sensitive and specific than bone scintigraphy.     

Earlier detection of bone metastases from pleomorphic liposarcoma in a pediatric patient by FDG PET/CT than planar 99mTc MDP bone scan

Bone scintigraphy using (99m)TC MDP (technetium-99m methylene diphosphonate) is a routine procedure for evaluation of osteoblastic metastases; however, its sensitivity compared with FDG PET/CT in a variety of malignancies remains to be established. We report a case of multiple osseous metastases revealed by FDG PET/CT in an 8-year-old girl with pleomorphic liposarcoma. Many of these osseous lesions were not visualized on the MDP planar bone scintigraphy performed 24 hours after PET/CT scan, becoming evident only on repeat bone scan performed 3 months later. The case suggests that FDG PET/CT has higher sensitivity in detecting osteoblastic metastases in pleomorphic liposarcoma.     

FDG-avid sclerotic bone metastases in breast cancer patients: a PET/CT case series

Distant metastases from breast cancer most frequently occur in the skeleton. Although 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET), with or without computed tomography (CT), is superior to bone scintigraphy for the detection of osteolytic bone metastases, it has been reported that sclerotic bone metastases frequently show no or only a low degree of FDG uptake on PET and PET/CT. Since both lytic and sclerotic metastases can occur in breast cancer patients, bone scintigraphy may remain of additional value in these patients. In this case series, we describe four breast cancer patients in whom FDG PET/CT has clearly visualized sclerotic bone metastases because of increased FDG uptake. Not so much the type of metastasis (sclerotic or lytic), but possibly the characteristics of the primary tumor or treatments prior to the FDG PET/CT scan might influence the degree of FDG uptake of bone metastases. The ability to detect sclerotic bone metastases based on increased FDG uptake supports the use of FDG PET/CT as a staging procedure in breast cancer patients, but knowledge of factors determining the visibility of bone metastases with FDG PET/CT is crucial.     

Staging of non-small-cell lung cancer by whole-body fluorine-18 deoxyglucose positron emission tomography

Positron emission tomography (PET) using fluorine-18 deoxyglucose (FDG), showing increased FDG uptake and retention in malignant cells, has been proven useful to differentiate malignant from benign tissue. We undertook a prospective study in 61 patients to compare the accuracy of whole-body FDG PET and conventional imaging (CI) methods for the staging of nonsmall-cell lung cancer (NSCLC). CI included chest and abdomen computed tomographic scanning and bone scintigraphy. When CI or PET study suggested metastatic disease, confirmation was obtained by biopsy or clinical or radiological follow-up. As compared to CI, PET correctly changed the N stage in 13 patients (21%) and the M stage in six patients (10%). There were three false-positive and no false-negative distant PET findings. Our preliminary results show that whole-body FDG PET can improve the diagnostic accuracy in the staging of NSCLC.     

Evaluation of Bone Metastasis from Hepatocellular Carcinoma Using 18F-FDG PET/CT and 99mTc-HDP Bone Scintigraphy: Characteristics of Soft Tissue Formation

Purpose

Bone metastasis from hepatocellular carcinoma (HCC) can present with soft tissue formation, resulting in oncologic emergency. Contrast-enhanced FDG PET/CT and bone scintigraphy were compared to evaluate characteristics of bone metastases with or without soft tissue formation from HCC.

Methods

Of 4,151 patients with HCC, 263 patients had bone metastases. Eighty-five patients with bone metastasis from HCC underwent contrast-enhanced FDG PET/CT. Fifty-four of the enrolled subjects had recent ^99mTc-HDP bone scintigraphy available for comparison. Metastatic bone lesions were identified with visual inspection on FDG PET/CT, and maximum standardized uptake value (SUV_max) was used for the quantitative analysis. Confirmation of bone metastasis was based on histopathology, combined imaging modalities, or serial follow-up studies.

Results

Forty-seven patients (55%) presented with soft tissue formation, while the remaining 38 patients presented without soft tissue formation. Frequent sites of bone metastases from HCC were the spine (39%), pelvis (19%), and rib cage (14%). The soft-tissue-formation group had more frequent bone pain (77 vs. 37%, p < 0.0001), higher SUV_max (6.02 vs. 3.52, p < 0.007), and higher incidence of photon defect in bone scintigraphy (75 vs. 0%) compared to the non-soft-tissue-formation group. FDG PET/CT had higher detection rate for bone metastasis than bone scintigraphy both in lesion-based analysis (98 vs. 53%, p = 0.0015) and in patient-based analysis (100 vs. 80%, p < 0 .001).

Conclusions

Bone metastasis from HCC showed a high incidence of soft tissue formation requiring emergency treatment. Although the characteristic findings for soft tissue formation such as photon defect in bone scintigraphy are helpful in detection, overall detectability of bone metastasis is higher in FDG PET/CT. Contrast-enhanced PET/CT will be useful in finding and delineating soft-tissue-forming bone metastasis from HCC.     

Value of FDG PET in papillary thyroid carcinoma with negative 131I whole-body scan.

The management of metastatic thyroid carcinoma patients with a negative 131I scan presents considerable problems. Fifty-four athyrotic papillary thyroid carcinoma patients whose 1311 whole-body scans were negative underwent 18F-fluorodeoxyglucose (FDG) PET; the purpose was to determine whether this procedure could localize metastatic sites. We also assessed its usefulness in the management of these patients. METHODS: Whole-body emission scan was performed 60 min after the injection of 370-555 MBq 18F-FDG, and additional regional attenuation-corrected scans were obtained. Metastasis was pathologically confirmed in 12 patients and was confirmed in other patients by overall clinical evaluation of the findings of other imaging studies and of the subsequent clinical course. RESULTS: In 33 patients, tumor had metastasized, whereas 21 patients were in remission. FDG PET revealed metastases in 31 patients (sensitivity 93.9%), whereas thyroglobulin levels were elevated in 18 patients (sensitivity 54.5%). FDG PET was positive in 14 of 15 metastatic cancer patients with normal thyroglobulin levels. In 20 of 21 patients in remission, FDG PET was negative (specificity 95.2%), whereas thyroglobulin levels were normal in 16 patients (specificity 76.1%). The sensitivity and specificity of FDG PET were significantly higher than those of serum thyroglobulin. In patients with negative 1311 scans, FDG PET detected cervical lymph node metastasis in 87.9%, lung metastasis in 27.3%, mediastinal metastasis in 33.3% and bone metastasis in 9.1%. In contrast, among 117 patients with 131I scan-positive functional metastases, 131I scan detected cervical lymph node metastasis in 61.5%, lung metastasis in 56.4%, mediastinal metastasis in 22.2% and bone metastasis in 16.2%. In all 5 patients in whom thyroglobulin was false-negative with negative antithyroglobulin antibody, PET showed increased 18F-FDG uptake in cervical lymph nodes, mediastinal lymph nodes, or both. Among patients with increased 18F-FDG uptake only in the cervical lymph nodes, the nodes were dissected in 11. Metastasis was confirmed in all, even in normal-sized lymph nodes. CONCLUSION: FDG PET scan localized metastatic sites in 131I scan-negative thyroid carcinoma patients with high accuracy. In particular, it was superior to 131I whole-body scan and serum thyroglobulin measurement for detecting metastases to cervical lymph nodes. FDG PET was helpful for determining the surgical management of these patients.     

Whole-body MR imaging for detection of bone metastases in children and young adults: comparison with skeletal scintigraphy and FDG PET.

OBJECTIVE: The purpose of this study was to compare the diagnostic accuracy of whole-body MR imaging, skeletal scintigraphy, and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for the detection of bone metastases in children. SUBJECTS AND METHODS: Thirty-nine children and young adults who were 2--19 years old and who had Ewing's sarcoma, osteosarcoma, lymphoma, rhabdomyosarcoma, melanoma, and Langerhans' cell histiocytosis underwent whole-body spin-echo MR imaging, skeletal scintigraphy, and FDG PET for the initial staging of bone marrow metastases. The number and location of bone and bone marrow lesions diagnosed with each imaging modality were correlated with biopsy and clinical follow-up as the standard of reference. RESULTS: Twenty-one patients exhibited 51 bone metastases. Sensitivities for the detection of bone metastases were 90% for FDG PET, 82% for whole-body MR imaging, and 71% for skeletal scintigraphy; these data were significantly different (p < 0.05). False-negative lesions were different for the three imaging modalities, mainly depending on lesion location. Most false-positive lesions were diagnosed using FDG PET. CONCLUSION: Whole-body MR imaging has a higher sensitivity than skeletal scintigraphy for the detection of bone marrow metastases but a lower sensitivity than FDG PET.     

Comparison of fluorodeoxyglucose positron emission tomography and "conventional diagnostic procedures" for the detection of distant metastases in breast cancer patients

The presence of distant metastases is the main prognostic factor in patients with breast cancer and has a significant influence in the choice of therapy. Therefore, chest X-ray, bone scintigraphy and ultrasound of the abdomen are performed to detect distant metastases at diagnosis and follow-up. Fluorodeoxyglucose positron emission tomography (FDG PET) has been shown to provide sensitive detection of primary tumour and metastases for many tumour entities, but little information is available about the diagnostic value for breast cancer patients. This study retrospectively compared FDG PET for detection of metastatic disease with chest X-ray, bone scintigraphy and ultrasound of the abdomen, referred to as "conventional diagnostic procedures" (CDPs), in 50 breast cancer patients. Imaging procedures were analysed in a blinded fashion with the results classified as "no evidence of metastases", "equivocal" and "evidence of metastases". Clinical follow-up and the results of other imaging modalities including computed tomography and magnetic resonance imaging were used to determine if metastases were present. FDG PET identified metastatic disease with a sensitivity and specificity of 86% and 90% as compared to 36% and 95% for CDPs, respectively. Regarding "equivocal" and "evidence of metastases" as positive, the sensitivity of CDPs increased to 57% with a corresponding specificity of 81%, whereas sensitivity and specificity of FDG PET remained unchanged. Regarding different localities of metastases the sensitivity of FDG PET was superior in the detection of pulmonary metastases and especially of lymph node metastases of the mediastinum in comparison to chest X-ray, whereas the sensitivity of FDG PET in the detection of bone and liver metastases was of the same magnitude as compared with bone scintigraphy and ultrasound of the abdomen.     

Impact of FDG PET on the preoperative staging of newly diagnosed breast cancer

Purpose The main objective of this study was to determine the efficacy of ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG PET) to assess the impact of this technique in staging of patients with newly diagnosed breast cancer. Methods Two hundred and seventy-one consecutive patients (median age = 51 ± 11 years) with biopsy-proven primary breast cancer who were examined by FDG PET were enrolled in this prospective preoperative staging study. Whole-body FDG-PET images were acquired approximately 60 min after the intravenous administration of FDG (5.2 MBq/kg). Visual assessment and the maximum standardized uptake value (SUVmax) of breast lesions for semiquantitative analysis were carried out. The PET results were compared with the histopathology results. Results For the tumor, node, metastases (TNM) staging, 240 patients (250 breasts) were considered eligible based on the criteria that were established for this analysis. Significant differences were noted in SUVmax of lesions according to the TNM staging (p < 0.05). The average SUVmax of the primary tumor was calculated in patients with axillary involvement (n = 58) and for the ones without axillary metastasis (n = 79), and SUVmax were 4.1 ± 3.5 and 2.8 ± 2.3, respectively, with a significant difference between the two groups (p = 0.03). PET imaging revealed pathological FDG uptake in 54% (46/85) of patients with axillary lymph node metastases. The sensitivities of FDG PET for detecting axillary lymph node metastasis were found 41% in pN1, 67% in pN2, and 100% in pN3, and the specificity was 89% for pN0 stage. Detection of extra-axillary regional node or distant metastatic lesions revealed by PET scan in 22 of 24 patients resulted in a significant change in the TNM stage. Distant metastasis without axillary lymph node metastasis was noted in 21% (5/24) of patients. The results revealed that FDG PET upgraded TNM stage in 9.2% (22/240) of patients and 7.5% (18/240) of patients were diagnosed as having one or more distant metastases. Conclusion FDG PET was able to identify extra-axillary regional nodal and distant lesions in newly diagnosed patients with breast cancer; FDG PET may alter the staging and management of therapy in patients with newly diagnosed breast cancer.     

Usefulness of <Superscript>18</Superscript>F-FDG PET in intrahepatic cholangiocarcinoma

Surgical resection is the only curative treatment strategy for intrahepatic cholangiocarcinoma (CC). Therefore, accurate staging is essential for appropriate management of patients with CC. We assessed the usefulness of 2-[¹⁸F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in the staging of CC. We undertook a retrospective review of FDG PET images in 21 patients (10 female, 11 male; mean age 57 years) diagnosed with CC. Ten patients had hilar CC and 11, peripheral CC. Patients underwent abdominal magnetic resonance imaging (MRI) (n=20) and computed tomography (CT) (n=12) for the evaluation of primary tumours, and chest radiography and whole-body bone scintigraphy for work-up of distant metastases. For semi-quantitative analysis, the maximum voxel standardised uptake value (SUV_max) was obtained from the primary tumour. All peripheral CCs showed intensely increased FDG uptake, and some demonstrated ring-shaped uptake corresponding to peripheral rim enhancement on CT and/or MRI. In nine of the ten patients, hilar CCs demonstrated increased FDG uptake of a focal nodular or linear branching appearance. The remaining case was false negative on FDG PET. One patient with a false negative result on MRI demonstrated increased uptake on FDG PET. Among the ten hilar CCs, FDG uptake was intense in only two patients and was slightly higher than that of the hepatic parenchyma in the remaining patients. For the detection of lymph node metastasis, FDG PET and CT/MRI were concordant in 16 patients, and discordant in five (FDG PET was positive in three, and CT and MRI in two). FDG PET identified unsuspected distant metastases in four of the 21 patients; all of these patients had peripheral CC. FDG PET is useful in detecting the primary lesion in both hilar and peripheral CC and is of value in discovering unsuspected distant metastases in patients with peripheral CC. FDG PET could be useful in cases of suspected hilar CC with non-confirmatory biopsy and radiological findings.     

Comparative study of FDG PET/CT and conventional imaging in the staging of rhabdomyosarcoma

Objective  The current study was conducted to compare the diagnostic accuracy between ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/computed tomography (CT), and conventional imaging (CI) for the staging and re-staging of patients with rhabdomyosarcomas. Methods  Thirty-five patients who underwent FDG PET/CT prior to treatment were evaluated retrospectively. CI methods consisted of ^99mTc-hydroxymethylene diphosphonate bone scintigraphy, chest radiograph, whole body CT, and magnetic resonance imaging of the primary site. The images were reviewed and two boardcertified radiologists reached a diagnostic consensus. Tumor stage was confirmed by histological examination and/or follow-up examinations. Results  Interpretation on the basis of FDG PET/CT, and CI, diagnostic accuracies of the T and N stages were similar. Using FDG PET/CT, the M stage was correctly assigned in 31 patients (89%), whereas the accuracy of CI in M stage was 63%. TNM stage was correctly assessed with FDG PET/CT in 30 of 35 patients (86%) and with CI in 19 of 35 patients (54%). The overall TNM staging and M staging accuracies of FDG PET/CT were significantly higher than that of CI (P < 0.01). Conclusions  FDG PET/CT is more accurate than CI regarding clinical staging and re-staging of patients with rhabdomyosarcomas.     

FDG PET and immunoscintigraphy with 99mTc-labeled antibody fragments for detection of the recurrence of colorectal carcinoma.

The aim of this study was to compare FDG PET with a new monoclonal antibody-based imaging agent that comprises an anti-carcinoembryonic antigen (CEA) monoclonal antibody Fab' fragment directly labeled with 99mTc. METHODS: Twenty-eight patients who were previously treated for colorectal carcinoma and in whom recurrence was suspected were examined with FDG PET and immunoscintigraphy. The most common indications were an elevation of serum CEA (13 patients), suggestive lesions documented by CT (9 patients), sonography (4 patients), and severe constipation (2 patients). Planar imaging and SPECT were performed 4-6 h after intravenous injection of the new imaging agent. Whole-body PET was performed 45-60 min after intravenous injection of FDG. The findings were confirmed by conventional diagnostic modalities, surgery, and histology. RESULTS: Histology confirmed local tumor recurrence in 9 of 28 patients. Clinical follow-up or CT confirmed the presence of liver metastases in 9 patients and lymph node involvement, lung metastases, and bone metastases in 2 patients each. The new agent correctly detected 8 of 9 local recurrences, whereas FDG PET was able to detect all 9 cases and in 1 case was false-positive. Liver metastases were confirmed in 9 patients by FDG PET but in only 1 patient by the new agent. Two cases with lymph node metastases and 2 cases with lung metastases were correctly identified by FDG PET, but none were detected by the new agent. Finally, bone metastases were identified in 1 patient by FDG PET but not with the new agent, whereas bone marrow infiltration (n = 1) was diagnosed by both imaging modalities. CONCLUSION: These results indicate that FDG PET and 99mTc-labeled anti-CEA Fab' are suitable for the diagnosis of local recurrence of colorectal carcinoma but that FDG PET is clearly superior in the detection of distant metastases (liver, bone, and lung) and lymph node involvement.     

Nodal metastases of nasopharyngeal carcinoma: patterns of disease on MRI and FDG PET

The patterns of nodal spread of nasopharyngeal carcinoma (NPC) have an important influence on treatment planning, but have not yet been fully addressed. We prospectively used MRI and FDG PET to document the patterns of nodal spread in NPC. One hundred and one patients with newly diagnosed NPC were studied with MRI and FDG PET. On MRI, nodes were considered as metastatic according to criteria regarding size, the presence of nodal necrosis, and extracapsular spread. FDG PET images were interpreted visually, and nodes were considered metastatic if they showed prominent FDG uptake against the background. Nodal metastases were found in 89 of our 101 patients. Analysis of the distributions of nodal metastases in these 89 patients showed that retropharyngeal nodes were less frequently involved than cervical nodes (82.0% vs 95.5%). The vast majority of cervical nodal metastases were to the internal jugular chain, including nodes at levels II, III, and IV, with decreasing incidences of 95.5%, 60.7%, and 34.8%, respectively. Level V nodal involvement was found in 27% of patients. Supraclavicular fossa nodal metastases were not uncommon and occurred in 22.5% of patients. Skip metastases in the lower-level nodes or supraclavicular fossa nodes occurred in 7.9% of patients. Mediastinal and abdominal metastatic adenopathy was present in 4.5% and 3.4% of patients, respectively, and was associated with advanced nodal metastasis in the supraclavicular fossa. Level VI (2.2%), level VII (1.1%), submandibular (2.2%), and parotid (3.4%) nodal metastases were uncommon and were always associated with advanced ipsilateral nodal metastases of the neck. We conclude that the combined use of FDG PET and MRI can comprehensively depict the pattern of nodal metastasis in NPC patients. Nodal metastases principally affected level II nodes, from which lymphatic spread extended down in an orderly manner to involve level III, level IV, and the supraclavicular fossa nodes, or extended posteriorly to involve level V nodes. The frequency of skip metastases was 7.9%. Distant spread to mediastinal or abdominal nodes was found in 3–5% of patients, usually in association with supraclavicular nodal metastases.     

Staging of lymph nodes with FDG dual-headed PET in patients with non-small-cell lung cancer

Accurate assessment of mediastinal lymph node involvement in patients with non-small-cell lung cancer (NSCLC) is necessary to select patients for direct surgical treatment. The aims of the present study were to assess the feasibility of staging NSCLC with FDG using a dual-headed positron emission tomographic (PET) camera and to compare this non-invasive technique with computed tomography (CT) and lymph node sampling, since both modalities are currently used for staging NSCLC. Thirty-three patients (29 men and 4 women, mean age 60 years) with newly diagnosed NSCLC were studied. In all patients, CT, FDG dual-headed PET and mediastinoscopy were performed within 4 weeks. The results of mediastinoscopy were used to select patients for thoracotomy. For both the assessment of individual lymph node involvement and the patient-based classification, the results of FDG dual-headed PET and CT were compared using the McNemar test. Thirty-one of 187 lymph nodes studied contained tumour metastases. FDG dual-headed PET showed a significantly higher sensitivity (P < 0.001) and specificity (P < 0.001) than CT. FDG dual-headed PET and CT correctly staged 27 and 20 patients, respectively. Due to the significantly higher negative predictive value of FDG dual-headed PET versus CT (P = 0.012), it was a better non-invasive diagnostic tool for selecting patients for surgery. In seven of eight patients, additional intrapulmonary sites of increased uptake were found, which revealed malignancy on histological examination. CT was false-negative in three of these patients. In one patients, increased FDG uptake was caused by an infection. In conclusion, it is possible to stage mediastinal lymph nodes in patients with NSCLC using a dual-headed PET camera. The high negative predictive value of FDG dual-headed PET suggests that mediastinoscopy may be omitted in patients with NSCLC.     

Metastatic myxoid liposarcomas: imaging and histopathologic findings

Objective The objective was to describe the imaging and histopathologic characteristics of metastatic myxoid liposarcomas. Materials and methods This retrospective study was approved by the institutional review board and complied with HIPAA guidelines. The study group comprised 12 patients with metastatic myxoid liposarcoma who underwent MRI, CT, or FDG-PET. The location and imaging characteristics of the metastatic lesions were recorded, and the histopathology of all metastatic lesions was reviewed. Results There were 23 histologically proven metastases in 12 patients. Based on imaging criteria, there were 41 metastases. The mean time from the diagnosis of primary tumor to the first metastasis was 4.4 years. Sixty-seven percent of patients had bone and soft tissue metastases, 33% had pulmonary metastases, 33% had liver metastases, 25% had intra-abdominal, and 16% retroperitoneal metastases. CT demonstrated well-defined lobulated masses with soft tissue attenuation in all cases, without macroscopic fat component. In cases of osseous metastases, CT showed mixed lytic and sclerotic foci, with bone destruction in advanced cases. MRI demonstrated fluid-like signal intensity with mild heterogeneous enhancement in cases of soft tissue metastases. In osseous metastases, MRI showed avid heterogeneous enhancement. FDG-PET showed no significant FDG uptake for all metastases. MRI was the most useful imaging modality for osseous and soft tissue metastases. Conclusion Myxoid liposarcomas are soft tissue sarcomas, with a high prevalence of extrapulmonary metastases. The bones and soft tissues were the most common site of involvement, followed by the lungs and liver. MRI was the most sensitive modality in the detection of osseous and soft tissue metastases, and is the recommended modality for the diagnosis and follow-up of bone and soft tissue involvement.     

18 F-FDG PET显像与99Tcm-MDP全身骨显像诊断肿瘤远处转移的比较

目的　评价18F 脱氧葡萄糖 (FDG)PET肿瘤显像与99Tcm 亚甲基二膦酸盐 (MDP)全身骨显像对检出骨和远处转移的价值。方法　对 16例恶性肿瘤放化疗后的患者进行18F FDGPET显像和99Tcm MDP全身骨显像 ,并对两种结果进行了比较。结果　 16例肿瘤患者中18F FDGPET显像皆阳性 ,其中 14例患者有远处转移 ,转移病灶共 62处 ,其中骨转移病灶 2 0处 ;在全身骨显像中 ,11例有局限性异常放射性浓聚 ,其中 2例为单一病灶 ,9例为多发病灶 ,共检出病灶 5 7处 ,另 5例骨显像正常。结论　18F FDGPET对恶性肿瘤的诊断具有较高的准确性和特异性 ,但对骨转移灶的诊断价值相对较差 ;99Tcm MDP显像阴性或单一病灶的可疑转移瘤患者有必要进行18F FDGPET检查 ,以明确诊断其他远处转移灶     

Preoperative assessment of cervical lymph nodes in head and neck cancer with fluorine-18 fluorodeoxyglucose using a dual-head coincidence camera: a pilot study

The aim of this study was to investigate whether in patients with head and neck cancer, staging is possible with fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) using a dual-head positron emission tomography (PET) camera. Twenty patients (ten men, ten women; mean age: 60 years) were studied using 185 MBq (5 mCi) ¹⁸F-FDG. Two of these patients who were suspected of having recurrence in the neck were restaged 19 and 12 months, respectively, after the resection of the primary tumour. The images were visually analyzed and the results were correlated with computed tomography (CT) (n = 18), ultrasonography (n = 17) and pathological findings. With respect to the primary tumour, FDG dual-head PET and CT revealed a sensitivity of 100% and 59%, respectively (P<0.001). In seven patients lymph node metastases were found in the neck specimen. Two of them had bilateral metastases. FDG dual-head PET correctly identified all nine pathological neck sides whereas CT and ultrasonography depicted eight of nine and seven of eight pathological sides, respectively. In three patients, false-positive FDG uptake was seen, which was due to a preceding biopsy in two cases. The sensitivity of FDG dual-head PET, CT and ultrasonography in the identification of pathological neck sides was 100%, 89% and 87%, respectively, and the specificity was 90%, 93% and 50%, respectively. With knowledge of the preceding biopsies, the specificity of FDG dual-head PET would have been 97%. The smallest lymph node metastasis detected by FDG dual-head PET that was missed by CT had a diameter of 0.6 cm. Measurement of ¹⁸F-FDG with a dual-head PET camera is very sensitive in the detection of primary head and neck cancers and accurate in the preoperative assessment of lymph node metastases. The results justify a prospective study on the identification of metastases in patients with head and neck cancer. In addition, it is justified to start a study on the detection of unknown primary tumours in patients with cervical metastases. Received 19 October and in revised form 18 December 1998     

Sensitive detection of mediastinal lymph node metastasis of lung cancer with 11C-choline PET.

11C-choline and FDG are PET tracers used to visualize various malignancies. In this study, we compared their capabilities in detecting mediastinal lymph node metastasis originating from non-small cell lung cancer (NSCLC). METHODS: Twenty-nine patients with biopsy-proven NSCLC were studied with PET. 11C-choline PET and FDG PET were performed from 5 and 40 min, respectively, after injection of 370 MBq tracer. PET data were analyzed in terms of the standardized uptake value (SUV). After the PET study, the patients underwent lung resection and mediastinal lymph node dissection. The resected specimens were examined pathologically, and the PET data were analyzed in reference to the pathologic data. RESULTS: With 11C-choline, the SUV in metastasis was similar to the SUV in the primary tumor, where the similarity of the SUV was 100% allowing for a 40% difference. With FDG, small metastases were invisible on the PET image. The SUV of FDG in metastasis was much smaller than that in the primary tumor, and the similarity of the SUV was only 19% allowing for a 40% difference. When pathologic findings were used as standards, the sensitivities of 11C-choline PET and FDG PET in detecting mediastinal lymph node metastasis were 100% and 75%, respectively. CONCLUSION: 11C-choline PET was very effective in detecting lymph node metastases in the mediastinum originating from NSCLC, with a sensitivity of 100%. 11C-choline PET promises to be useful not only before surgery but also after surgery.     

Comparison of FDG-PET findings of brain metastasis from non-small-cell lung cancer and small-cell lung cancer

OBJECTIVE: We compared the F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) findings of brain metastasis between patients with non-small-cell lung cancer (NSCLC) and small cell lung cancer (SCLC). METHODS: A whole-body FDG and a brain PET were performed in 48 patients (31 men, 17 women; 57 +/- 9 years, 42 NSCLC, 6 SCLC), who had brain metastasis on magnetic resonance (MR). All primary lung lesions were detected by FDG-PET and confirmed pathologically. We analyzed the PET findings, lesion sizes, and the pathological result of primary lung cancer. RESULTS: Of the 48 patients, 31 (64.6%) showed hypermetabolic lesions on FDG-PET of the brain image, and 14 (29.2%) showed hypometabolic lesions. Three patients (6.3%) had both hypermetabolic and hypometabolic lesions. On the lesion-based analysis, 74 lesions (67.3%) showed hypermetabolism on FDG-PET, and 36 lesions (32.7%) showed hypometabolism. All primary lung lesions were hypermetabolic on FDG-PET. When the FDG findings of metastatic brain lesions were analyzed with the pathological types of primary lung cancer, NSCLC was more frequently associated with hypermetabolic metastatic brain lesions than SCLC (80% and 26.7%, respectively, P < 0.01). On comparing the sizes of metastatic lesions between SCLC (1.3 +/- 1.2 cm) and NSCLC (1.8 +/- 1.2 cm), lesions of <1 cm were more frequent in SCLC than in NSCLC (P = 0.012). But no significant relationship was found between the size and PET finding of metastatic lesion (P = 0.412). CONCLUSIONS: Even when the primary lesion of lung cancer showed hypermetabolism in FDG-PET, FDG accumulation in metastatic brain lesions was variable. One-third of brain metastases from lung cancer showed hypometabolism. NSCLC was more frequently associated with hypermetabolic metastatic brain lesions than SCLC. The PET findings of brain lesions were affected not only by the size of lesion but also by its biological characteristics.     

Staging non-small cell lung cancer with whole-body PET.

PURPOSE: To compare the accuracies of whole-body 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) and conventional imaging (thoracic computed tomography [CT], bone scintigraphy, and brain CT or magnetic resonance [MR] imaging) in staging bronchogenic carcinoma. MATERIALS AND METHODS: Within 20 months, 100 patients with newly diagnosed bronchogenic carcinoma underwent whole-body FDG PET and chest CT. Ninety of these patients underwent radionuclide bone scintigraphy, and 70 patients underwent brain CT or MR imaging. For each patient, all examinations were completed within 1 month. A radiologic stage was assigned by using PET and conventional imaging independently and was compared with the pathologic stage. The accuracy, sensitivity, specificity, and negative and positive predictive values were calculated. RESULTS: PET staging was accurate in 83 (83%) patients; conventional imaging staging was accurate in 65 (65%) patients (P < .005). Staging with mediastinal lymph nodes was correct by using PET in 67 (85%) patients and by using CT in 46 (58%) patients (P < .001). Nine (9%) patients had metastases demonstrated by using PET that were not found with conventional imaging, whereas 10 (10%) patients suspected of having metastases because of conventional imaging findings were correctly shown with PET to not have metastases. CONCLUSION: Whole-body PET was more accurate than thoracic CT, bone scintigraphy, and brain CT or MR imaging in staging bronchogenic carcinoma.