Sensitivity in detecting osseous lesions depends on anatomic localization: planar bone scintigraphy versus 18F PET.

Radionuclide bone scanning (RNB) is considered to be the most practical screening technique for assessing the entire skeleton for skeletal metastases. However, RNB has been shown to be of lower sensitivity than MRI and CT in detecting osteolytic metastases. A prospective study was designed to evaluate the accuracy of planar RNB versus tomographic bone imaging with 18F-labeled NaF and PET (18F PET) in detecting osteolytic and osteoblastic metastases and its dependency on their anatomic localization. METHODS: Forty-four patients with known prostate, lung or thyroid carcinoma were examined with both planar RNB and 18F PET. A panel of reference methods including MRI of the spine, 1311 scintigraphy, conventional radiography and spiral CT was used as the gold standard. RNB and 18F PET were compared by a lesion-by-lesion analysis using a five-point score for receiver operating characteristic (ROC) curve analysis. RESULTS: 18F PET showed 96 metastases (67 of prostate carcinoma and 29 of lung or thyroid cancer), whereas RNB revealed 46 metastases (33 of prostate carcinoma and 13 of lung or thyroid cancer). All lesions found with RNB were also detected with 18F PET. Compared with 18F PET and the reference methods, RNB had a sensitivity of 82.8% in detecting malignant and benign osseous lesions in the skull, thorax and extremities and a sensitivity of 40% in the spine and pelvis. The area under the ROC curve was 0.99 for 18F PET and 0.64 for RNB. CONCLUSION: 18F PET is more sensitive than RNB in detecting osseous lesions. With RNB, sensitivity in detecting osseous metastases is highly dependent on anatomic localization of these lesions, whereas detection rates of osteoblastic and osteolytic metastases are similar. Higher detection rates and more accurate differentiation between benign and malignant lesions with 18F PET suggest the use of 18F PET when possible.     

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.     

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.     

Comparison of18FDG-PET with99mTc-HMDP scntigraphy for the detection of bone metastases in patients with breast cancer

OBJECTIVE: Bone is one of the most common sites of metastasis in breast cancer patients. Although bone scintigraphy is widely used to detect metastatic breast cancer, the usefulness of 18FDG-PET for detecting bone metastasis has not been clearly evaluated. The purpose of this study was to compare the diagnostic accuracy of 18FDG-PET with bone scintigraphy in detecting bone metastasis in breast cancer patients. METHODS: Forty-four women aged 35 to 81 years (mean, 56 years) with breast cancer were examined in this study. Both 18FDG-PET and bone scintigraphy were performed for each patient with 0-69 day intervals (mean, 11.5 days). The results of each image interpretation were compared retrospectively. Whole-body bones were classified into 9 anatomical regions. Metastases were confirmed at 45/187 regions in 14 patients by bone biopsy or clinical follow-up including other imaging techniques for a period of at least 6 months afterwards. RESULTS: On a region basis, the sensitivity, specificity, and accuracy of 18FDG-PET were 84%, 99% and 95%, respectively. Although these results were comparable to those of bone scintigraphy, the combination of 18FDG-PET and bone scintigraphy improved the sensitivity (98%) and accuracy (97%) of detection. False negative lesions of bone scintigraphy were mostly bone marrow metastases and those of 18FDG-PET were mostly osteoblastic metastases. 18FDG-PET was superior to bone scintigraphy in the detection of osteolytic lesions (92% vs. 73%), but inferior in the detection of osteoblastic lesions (74% vs. 95%). CONCLUSIONS: This study shows that 18FDG-PET tends to be superior to bone scintigraphy in the detection of osteolytic lesions, but inferior in the detection of osteoblastic lesions. 18FDG-PET should play a complementary role in detecting bone metastasis with bone scintigraphy.     

Detection of bone metastases in breast cancer by positron emission tomography

Positron emission tomography (PET) is able to demonstrate changes in the metabolism of malignant tumors and metastases before they become visible on anatomical imaging. The skeleton is the most common site of distant metastases of breast cancer. There is convincing evidence that FDG-PET is more sensitive in detecting osteolytic metastases than bone scintigraphy, whereas bone scintigraphy is more sensitive in detecting osteoblastic metastases. Because both types of metastases can occur in breast cancer, bone scintigraphy and FDG-PET should be considered as complementary and can currently be regarded as standard of care for staging in breast cancer patients, whereas the decision to use F-18 fluoride PET should be made individually for each patient, depending on the expected change of therapy management.     

Advantages and limitations of FDG PET in the follow-up of breast cancer

18F-Fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) has been evaluated in breast cancer for the characterisation of primary tumours, lymph node staging and the follow-up of patients after surgery, chemotherapy and/or external radiotherapy. In contrast to both the low sensitivity and moderate specificity of FDG PET in the initial detection and characterisation of breast cancer and the low lesion-based sensitivity for lymph node staging, the results from use of FDG PET in re-staging breast cancer patients are very promising. A major advantage of FDG PET imaging compared with conventional imaging is that it screens the entire patient for local recurrence, lymph node metastases and distant metastases during a single whole-body examination using a single injection of activity, with a reported average sensitivity and specificity of 96% and 77%, respectively. In most studies the sensitivity of FDG PET is higher than that of a combination of conventional imaging methods. Limitations of FDG PET in the follow-up of breast cancer patients include the relatively low detection rate of bone metastases, especially in case of the sclerotic subtype, and the relatively high rate of false positive results. The rather low specificity of FDG PET can be improved/increased by utilising combined anatomical-molecular imaging techniques, such as a PET/CT tomograph. First results using PET/CT imaging in the follow-up of breast cancer patients demonstrate increased specificity compared with FDG PET alone. Both imaging modalities, however, offer to detect recurrent and metastatic breast cancer disease at an early stage and thus continue to demonstrate the efficacy of molecular imaging in patient management, despite the limited therapeutic options in recurrent and metastatic breast cancer.     

18F]fluorodeoxyglucose scintigraphy in diagnosis and follow up of treatment in advanced breast cancer

Seventeen patients with advanced breast cancer were imaged with a specially collimated gamma camera to study tumor uptake of 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) before and during therapy. Fourteen patients (82%) showed increased FDG accumulation in metastatic tumors, 6/8 (75%) of axillary, supra or infraclavicular metastatic lymph nodes were detectable. In one of these cases, FDG imaging was the first method to identify axillary metastasis causing nerve compression. Also, pulmonary and liver metastases could be imaged with FDG; both in two patients. The intra individual variability in uptake was considerable in bone metastases, and some lesions remained FDG negative: 99mTc-DPD was superior in detecting bone disease. Bone metastases of the osteolytic or mixed type were better visualized than sclerotic ones. Ten patients were reimaged later to assess the effect of therapy on FDG uptake. Increased uptake was associated with clinical progression, while unchanged or diminished uptake did not predict the course of disease as reliably. This study indicates that FDG can be used to image breast cancer metastases. FDG may be valuable in monitoring treatment response, but positron emission tomography (PET) would probably be more appropriate than planar imaging for this purpose.     

FDG-PET and CT patterns of bone metastases and their relationship to previously administered anti-cancer therapy

Purpose To assess ¹⁸F-fluorodeoxyglucose (FDG) uptake in bone metastases in patients with and without previous treatment, and compare positive positron emission tomography (PET) with osteolytic or osteoblastic changes on computed tomography (CT).Methods One hundred and thirty-one FDG-PET/CT studies were reviewed for bone metastases. A total of 294 lesions were found in 76 patients, 81 in untreated patients and 213 in previously treated patients. PET was assessed for abnormal FDG uptake localised by PET/CT to the skeleton. CT was evaluated for bone metastases and for blastic or lytic pattern. The relationship between the presence and pattern of bone metastases on PET and CT, and prior treatment was statistically analysed using the chi-square test.Results PET identified 174 (59%) metastases, while CT detected 280 (95%). FDG-avid metastases included 74/81 (91%) untreated and 100/213 (47%) treated lesions (p<0.001). On CT there were 76/81 (94%) untreated and 204/213 (96%) treated metastases (p NS). In untreated patients, 85% of lesions were seen on both PET and CT (26 blastic, 43 lytic). In treated patients, 53% of lesions were seen only on CT (95 blastic, 18 lytic). Of the osteoblastic metastases, 65/174 (37%) were PET positive and 98/120 (82%), PET negative (p<0.001).Conclusion The results of the present study indicate that when imaging bone metastases, prior treatment can alter the relationship between PET and CT findings. Most untreated bone metastases are PET positive and lytic on CT, while in previously treated patients most lesions are PET negative and blastic on CT. PET and CT therefore appear to be complementary in the assessment of bone metastases.     

[18F]Fluorodeoxyglucose scintigraphy in diagnosis and follow up of treatment in advanced breast cancer

Seventeen patients with advanced breast cancer were imaged with a specially collimated gamma camera to study tumor uptake of 2-[¹⁸F]-fluoro-2-deoxy-D-glucose (FDG) before and during therapy. Fourteen patients (82%) showed increased FDG accumulation in metastatic tumors, 6/8 (75%) of axillary, supra or infraclavicular metastatic lymph nodes were detectable. In one of these cases, FDG imaging was the first method to identify axillary metastasis causing nerve compression. Also, pulmonary and liver metastases could be imaged with FDG; both in two patients. The intra individual variability in uptake was considerable in bone metastases, and some lesions remained FDG negative:^99mTc-DPD was superior in detecting bone disease. Bone metastases of the osteolytic or mixed type were better visualized than sclerotic ones. Ten patients were reimaged later to assess the effect of therapy on FDG uptake. Increased uptake was associated with clinical progression, while unchanged or diminished uptake did not predict the course of disease as reliably. This study indicates that FDG can be used to image breast cancer metastases. FDG may be valuable in monitoring treatment response, but positron emission tomography (PET) would probably be more appropriate than planar imaging for this purpose.     

Bone metastases from breast cancer: associations between morphologic CT patterns and glycolytic activity on PET and bone scintigraphy as well as explorative search for influential factors

Background

This study aimed to compare the detection of bone metastases from breast cancer on F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and bone scintigraphy (BS). An explorative search for factors influencing the sensitivity or uptake of BS and FDG-PET was also performed.

Methods

Eighty-eight patients with bone metastases from breast cancer were eligible for this study. Histological confirmation of bone metastases was obtained in 31 patients. The bone metastases were visually classified into four types based on their computed tomography (CT) appearance: osteoblastic, osteolytic, mixed, and negative. The sensitivity of BS and FDG-PET were obtained regarding CT type, adjuvant therapy, and the primary tumor characteristics. The FDG maximum standardized uptake value (SUV_max) was analyzed.

Results

The sensitivities of the three modalities (CT, BS, and FDG-PET) were 77, 89, and 94%, respectively. The sensitivity of FDG-PET for the osteoblastic type (69%) was significantly lower than that for the other types (P < 0.001), and the sensitivity of BS for the negative type (70%) was significantly lower than that for the others. Regarding tumor characteristics, the sensitivity of FDG-PET significantly differed between nuclear grade (NG)1 and NG2–3 (P = 0.032). The SUV_max of the osteoblastic type was significantly lower than that of the other types (P = 0.009). The SUV_max of NG1 was also significantly lower than that of NG2–3 (P = 0.011). No significant difference in FDG uptake (SUV_max) was detected between different histological types.

Conclusion

Although FDG-PET is superior to BS for the detection of bone metastases from breast cancer, this technique has limitations in depicting osteoblastic bone metastases and NG1.

     

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.     

骨转移瘤18F—FDGPET／CT影像学表现分析

目的分析骨转移瘤的18F-脱氧葡萄糖（FDG）PET／CT影像学表现。方法140例18F—FDGPET／CT检查病例,按病灶的4种CT形态（成骨改变、溶骨改变、混合改变及无改变）分组,探讨肿瘤骨转移灶代谢表现与形态表现之间的关系,进一步治疗情况与转移灶代谢表现的关系。采用SPSS10．0软件,行Mann—Whitney检验及x2检验。结果140例患者分未治疗组78例（55．7％）,治疗（化疗及内分泌）组62例（44．3％）。共检出病灶1658个,CT示成骨病灶415个（25．0％）,溶骨病灶567个（34．2％）,混合病灶177个（10．7％）,无改变病灶499个（30．1％）。对未治疗组1045个病灶平均标准摄取值（SUVmax。）行Mann—Whitney检验,混合病灶、溶骨病灶SUVmax高于成骨病灶、无改变病灶（SUVmax。中位值分别为5．7,5．2,4．8及4．6,Z=-4．680,-6．067,-2．237,-4．635,P均〈0．05）;治疗组与未治疗组行,检验,未治疗组以溶骨性改变（39．6％）为多,治疗组以成骨性改变（35．9％）为多,组间病灶组成明显不同（x2=67．8,P〈0．05）,治疗组代谢水平明显低于未治疗组（SUVmax中位值分别为4．9及4．6,Z=-4．315,P〈0．05）。结论骨转移病灶形态表现不同,其代谢表现差异明显,溶骨病灶的SUVmax。明显大于无溶骨病灶;化疗及内分泌治疗能通过对病灶转归的改变影响病灶形态及相应代谢表现。     

Accuracy of fluorodeoxyglucose-positron emission tomography for diagnosis of single bone metastasis: comparison with bone scintigraphy

PURPOSE: The aim of this study was to compare the accuracy of fluorodeoxyglucose-positron emission tomography (FDG-PET) with bone scan for diagnosis of single bone metastasis using a semiquantitative method. MATERIAL AND METHODS: Seventy-six patients with suspected single bone metastasis, who underwent both FDG-PET and a bone scan, were selected. The number and location of lesions detected upon both FDG-PET and bone scan were recorded, and the lesions were compared using the McNemar test. For semiquantitative analysis, a maximum (max) standard uptake value (SUV) of 2.5 was used as the positive cutoff value for metastasis. The difference in max SUV value among 3 groups (osteolytic, osteoblastic, and benign lesions) was assessed using the Student-Newman-Keuls method. Biopsy results, other imaging findings (multirow detector computed tomography, magnetic resonance imaging), and the patient's clinical course were used as references. RESULTS: There were 47 single bone metastases and 29 benign lesions. The sensitivity, specificity, and accuracy of bone scans for diagnosing bone metastases were 89%, 41%, and 71%, respectively, and those of FDG-PET were 85%, 52%, and 72%, respectively. These data were not significantly different (P > 0.05). Using a max SUV of 2.5 as the positive cutoff value for metastasis, the specificity and accuracy of FDG-PET, 83% for each, improved. When classifying bone metastasis as osteoblastic or osteolytic, the max SUV was significantly higher in osteolytic metastasis than in osteoblastic and benign lesions (P = 0.001). CONCLUSIONS: Fluorodeoxyglucose-positron emission tomography (FDG-PET) using the semiquantitative parameter SUV improves the diagnostic ability to differentiate between single bone metastases and benign lesions.     

The role of 18F-fluoride PET-CT in the detection of bone metastases in patients with breast, lung and prostate carcinoma: a comparison with FDG PET/CT and 99mTc-MDP bone scan

Objectives

We aimed to compare the role of ¹⁸F-fluoride PET/CT, FDG PET/CT and ^99mTc-MDP bone scans in the detection of bone metastases in patients with lung, breast and prostate carcinoma.

Methods

This was a prospective study including patients for staging (S) and restaging (R). Seventy-two patients (23S, 49R) with infiltrating ductal breast carcinoma, 49 patients (25S, 24R) with prostate adenocarcinoma and 30 patients (17S, 13R) with non-small-cell lung carcinoma (NSCLC), without known bone metastases but with high risk/clinical suspicion for the same, underwent a ^99mTc-MDP bone scan, FDG PET/CT and ¹⁸F-fluoride PET/CT within 2 weeks. All scans were reviewed by two experienced nuclear medicine physicians, and the findings were correlated with MRI/thin-slice CT/skeletal survey. Histological verification was done wherever feasible.

Results

Sensitivity and negative predictive value (NPV) of ¹⁸F-fluoride PET/CT was 100 % in all three malignancies, while that of FDG PET/CT was 79 % and 73 % in NSCLC, 73 % and 80 % in breast cancer and 72 and 65 % in prostate cancer. Specificity and positive predictive value (PPV) of FDG PET/CT were 100 % in NSCLC and prostate and 97 % and 96 % in breast cancer. As compared to the ^99mTc-MDP bone scan, all parameters were superior for ¹⁸F-fluoride PET/CT in prostate and breast cancer, but sensitivity and NPV were equal in NSCLC. The MDP bone scan had superior sensitivity and NPV compared to FDG PET/CT but had low specificity and PPV.

Conclusion

To rule out bone metastases in cases where there is a high index of suspicion, ¹⁸F-fluoride PET/CT is the most reliable investigation. ¹⁸F-fluoride PET/CT has the potential to replace the ^99mTc-MDP bone scan for the detection of bone metastases.     

The detection of bone metastases in patients with high-risk prostate cancer: 99mTc-MDP Planar bone scintigraphy, single- and multi-field-of-view SPECT, 18F-fluoride PET, and 18F-fluoride PET/CT.

The aim of this study was to compare the detection of bone metastases by 99mTc-methylene diphosphonate (99mTc-MDP) planar bone scintigraphy (BS), SPECT, 18F-Fluoride PET, and 18F-Fluoride PET/CT in patients with high-risk prostate cancer. METHODS: In a prospective study, BS and 18F-Fluoride PET/CT were performed on the same day in 44 patients with high-risk prostate cancer. In 20 of the latter patients planar BS was followed by single field-of-view (FOV) SPECT and in 24 patients by multi-FOV SPECT of the axial skeleton. Lesions were interpreted separately on each of the 4 modalities as normal, benign, equivocal, or malignant. RESULTS: In patient-based analysis, 23 patients had skeletal metastatic spread (52%) and 21 did not. Categorizing equivocal and malignant interpretation as suggestive for malignancy, the sensitivity, specificity, positive predictive value, and negative predictive value of planar BS were 70%, 57%, 64%, and 55%, respectively, of multi-FOV SPECT were 92%, 82%, 86%, and 90%, of (18)F-Fluoride PET were 100%, 62%, 74%, and 100%, and of 18F-Fluoride PET/CT were 100% for all parameters. Using the McNemar test, 18F-Fluoride PET/CT was statistically more sensitive and more specific than planar or SPECT BS (P < 0.05) and more specific than 18F-Fluoride PET (P < 0.001). SPECT was statistically more sensitive and more specific than planar BS (P < 0.05) but was less sensitive than 18F-Fluoride PET (P < 0.05). In lesion-based analysis, 156 lesions with increased uptake of 18F-Fluoride were assessed. Based on the corresponding appearance on CT, lesions were categorized by PET/CT as benign (n = 99), osteoblastic metastasis (n = 46), or equivocal when CT was normal (n = 11). Of the 156 18F-Fluoride lesions, 81 lesions (52%), including 34 metastases, were overlooked with normal appearance on planar BS. SPECT identified 62% of the lesions overlooked by planar BS. 18F-Fluoride PET/CT was more sensitive and more specific than BS (P < 0.001) and more specific than PET alone (P < 0.001). CONCLUSION: 18F-Fluoride PET/CT is a highly sensitive and specific modality for detection of bone metastases in patients with high-risk prostate cancer. It is more specific than 18F-Fluoride PET alone and more sensitive and specific than planar and SPECT BS. Detection of bone metastases is improved by SPECT compared with planar BS and by 18F-Fluoride PET compared with SPECT. This added value of 18F-Fluoride PET/CT may beneficially impact the clinical management of patients with high-risk prostate cancer.     

Detection of bone metastases in thyroid cancer patients: bone scintigraphy or 18F-FDG PET?

BACKGROUND: Similar to the situation in other tumour types, it is currently unclear whether fluorodeoxyglucose (FDG) positron emission tomography (PET) is adequate in the detection of bone metastases of thyroid cancer. The purpose of this retrospective study was to evaluate the performance of bone scans in comparison with FDG PET in the detection of bone metastases in patients with differentiated thyroid cancer (DTC). MATERIALS AND METHODS: Twenty-four patients had undergone both FDG PET and bone scans within 6 months because of suspected bone metastases. All scans were re-evaluated using all available additional imaging and clinical data for verification. Scan findings were scored as positive, negative or doubtful. RESULTS: Bone metastases were present in eight of 24 (33%) patients. Only bone scintigraphy but not FDG PET suggested the presence of bone metastases in three patients, all confirmed with magnetic resonance imaging (MRI)/X-ray. Five patients were identified with bone metastases on both bone scan and FDG PET, which was confirmed by computed tomography (CT)/MRI/X-ray in four. Five patients had doubtful findings on bone scans whereas FDG PET scans were negative. MRI showed degenerative disorders in two of five and was normal in two. Eleven patients had both a negative bone scan and FDG PET scan. CONCLUSION: In three of eight (38%) thyroid cancer patients bone metastases were only identified on bone scans. Therefore, bone scans are still valuable in detecting bone metastases in patients with DTC and can not be replaced by FDG PET.     

Diagnostic value of MRI in comparison to scintigraphy, PET, MS-CT and PET/CT for the detection of metastases of bone

The initial localization of metastases in the bone in patients with solid tumors has a relatively good prognosis in comparison with visceral metastasization. The early detection of bone marrow metastases allows for a rapid initiation of therapy and a subsequent reduction in the morbidity rate. Modern MRI is superior to the 30-year-old skeletal scintigraphy and bone marrow scintigraphy with respect to sensitivity, specificity, as well as the extent of osteal metastasis. MRI provides substantial, therapy-relevant additional information. MSCT plays an important role in the management of cancer patients in clinical routine and gives an excellent survey of the axial skeleton by demonstrating osteolytic and osteoblastic metastases. Extensive comparative studies of MRI with 18F-FDG-PET and 18F-fluoride-PET have not yet been carried out. Whole body MRI is a very promising new staging method for the oncological diagnosis of solid tumors and the detection of osteal metastases. The adoption of 18F-FDG-PET and 18F-fluoride-PET FDG as well as the side by side PET-CT image fusion and the two in one PET/CT examinations appears to be slightly less sensitive to whole body MRI in the detection of osteal metastases. Larger, prospective multicenter studies are necessary to establish these as new, promising methods for the detection of osteal metastases.     

Diagnostic accuracy of FDG PET imaging for the detection of recurrent or metastatic gynecologic cancer

PURPOSE: This study evaluated the diagnostic role and accuracy of positron emission tomography (PET) using 2-[F-18]fluoro-2-deoxy-D-glucose (FDG) for the detection of tumor foci in patients with suspected recurrent or metastatic lesions of gynecologic cancers. MATERIALS AND METHODS: FDG PET imaging was performed on 51 patients with a previous history of gynecologic cancer who were referred for a clinical suspicion of recurrent disease. PET acquisition was started 50-60 min after the intravenous injection of 5-6 MBq/kg FDG in all patients. The PET images were interpreted visually, and tracer uptake was quantitated as the standardized uptake value adjusted to body weight (SUV) in the lesions showing FDG uptake. The accuracy of the PET results was assessed by a consensual verdict based on histology, cytology, other imaging and clinical follow-up. RESULTS: FDG PET correctly diagnosed 33 of 36 patients with recurrent disease and 12 of 15 patients without recurrence. On patient-based analysis, the sensitivity, specificity and accuracy of FDG PET were 91.7%, 80.0% and 88.2%, respectively, depending on the selected scheme for visual scoring of the lesions. The area index in receiver-operating characteristic analysis was 0.95 for patient detection. Malignant lesions accumulated significantly more FDG than the benign ones (the mean SUVs were 3.7 +/- 1.9 and 1.6 +/- 1.1, respectively, p = 0.004). The sensitivity and specificity in correct identification of tumor recurrence or metastases using a threshold SUV 1.9 were 88.8% and 66.7% in contrast to the visual analysis (sensitivity 96.4%, specificity 50%) on a lesion-based analysis. The partial volume effect of SUV in a few small lesions and the presence of bone lesions in which FDG uptake was relatively low might be the reason for the lower sensitivity in SUV analysis. FDG PET was valuable when CT/MRI was negative or inconclusive, and in patients with elevated tumor marker levels as well as with normal tumor marker levels when recurrence was suspected clinically. However, PET failed to visualize some small metastatic lesions in lung and bone, and showed falsely high FDG uptake in some benign lesions. CONCLUSION: The results indicated that FDG PET is a reliable and accurate diagnostic method for detecting recurrent or metastatic gynecologic cancer particularly lymph node metastases. Although the sensitivity of PET for detecting small metastases was relatively limited, the overall sensitivity of FDG PET was significantly higher than morphologic imaging.     

F-18 fluorodeoxyglucose positron-emission tomography in the diagnosis of tumor recurrence and metastases in the follow-up of patients with breast carcinoma: a comparison to conventional imaging

AIM: To evaluate the role of F-18-fluorodeoxyglucose positron-emission tomography (F-18 FDG PET) in the follow-up of breast carcinoma in case of clinical suspicion of local recurrence or distant metastases and/or tumor marker increase in correlation to conventional imaging. MATERIAL AND METHODS: Retrospective analysis of the results of F-18 FDG PET (ECAT ART(R), Siemens CTI MS) of 62 patients (age 58.5 +/- 12.8) with surgically resected breast carcinoma (time interval after surgery, 86 +/- 82 months, mean follow-up 24 +/- 12.6 months). Patient- and lesion-based comparison with conventional imaging (CI) including mammography (MG), ultrasonography (US), computerized tomography (CT), magnetic resonance imaging (MRI), radiography (XR) and bone scintigraphy (BS). Furthermore, we evaluated the influence on tumor stage and therapeutic strategy. A visual qualitative evaluation of lesions was performed. RESULTS: On a patient base, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for detecting local recurrence or distant metastases were calculated to be 97%, 82%, 87%, 96% and 90% compared with 84%, 60%, 73%, 75% and 74% with CI. On a lesion base, significantly more lymph node (84 vs. 23, P < 0.05) and fewer bone metastases (61 vs. 97, P < 0.05) could be detected by using F-18 FDG PET compared with CI. Sclerotic bone lesions were predominantly detected by BS. On the other hand, there were several patients with more FDG positive bone lesions and also mixed FDG positive/Tc-99m methylenediphosphonate (MDP) negative and FDG negative/Tc-99m MDP positive metastases. In case of normal tumor markers, sensitivity, specificity, PPV, NPV and accuracy for detecting local recurrence or distant metastases were calculated to be 100%, 85.0%, 78.6%, 100% and 90.3% for FDG PET and 80%, 50%, 50%, 80% and 61.5% for CI. An upstaging could be observed in 9.7% (6/62) and downstaging in 12.9% (8/62), leading to a change in therapeutic regimen in 13 patients (21%). CONCLUSIONS: F-18 FDG PET demonstrates apparent advantages in the diagnosis of metastases in patients with breast carcinoma, compared with conventional imaging on a patient base. On a lesion base, significantly more lymph node and less bone metastases can be detected by using F-18 FDG PET compared with conventional imaging, including bone scintigraphy. In patients with clinical suspicion but negative tumor marker profile, too, F-18 FDG PET seems to be a reliable imaging tool for detection of tumor recurrence or metastases. Considering the high predictive value of F-18 FDG PET, tumor stage and therapeutic strategy will be reconsidered in several patients.     

Impact of whole-body 18F-FDG PET on staging and managing patients with breast cancer: the referring physician's perspective.

FDG PET has emerged as an important clinical imaging modality for diagnosing and staging cancer. However, the impact of FDG PET on staging and managing patients with breast cancer from the referring physician's point of view is unknown. METHODS: The referring physicians of 160 breast cancer patients received standardized questionnaires inquiring if and how PET findings altered their patient's stage and their clinical management decisions. Management changes were classified as intermodality if the change was from one modality to another (e.g., medical to surgical, surgical to radiation, medical to no treatment, and vice versa) or as intramodality if the change was within the same modality (e.g., altered medical or radiotherapy approach). RESULTS: Fifty of the 160 surveys were completed (31% response rate). PET changed the clinical stage in 36% of patients (28% upstaged, 8% downstaged) and resulted in intermodality changes in 28% of patients and intramodality changes in 30% of patients. CONCLUSION: The results of this prospective survey show that FDG PET has a major impact on the management of breast cancer patients, influencing both clinical stage and management in more than 30% of patients.