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.     

18F-Fluoride PET/CT is highly effective for excluding bone metastases even in patients with equivocal bone scintigraphy

Purpose

Bone scintigraphy (BS) has been used extensively for many years for the diagnosis of bone metastases despite its low specificity and significant rate of equivocal lesions. ¹⁸F-Fluoride PET/CT has been proven to have a high sensitivity and specificity in the detection of malignant bone lesions, but its effectiveness in patients with inconclusive lesions on BS is not well documented. This study evaluated the ability of ¹⁸F-fluoride PET/CT to exclude bone metastases in patients with various malignant primary tumours and nonspecific findings on BS.

Methods

We prospectively studied 42 patients (34–88?years of age, 26 women) with different types of tumour. All patients had BS performed for staging or restaging purposes but with inconclusive findings. All patients underwent ¹⁸F-fluoride PET/CT. All abnormalities identified on BS images were visually compared with their appearance on the PET/CT images.

Results

All the 96 inconclusive lesions found on BS images of the 42 patients were identified on PET/CT images. ¹⁸F-Fluoride PET/CT correctly excluded bone metastases in 23 patients (68 lesions). Of 19 patients (28 lesions) classified by PET/CT as having metastases, 3 (5 lesions) were finally classified as free of bone metastases on follow-up. The sensitivity, specificity, and positive and negative predictive values of ¹⁸F-fluoride PET/CT were, respectively, 100?%, 88?%, 84?% and 100?% for the identification of patients with metastases (patient analysis) and 100?%, 82?% and 100?% for the identification of metastatic lesions (lesion analysis).

Conclusion

The factors that make BS inconclusive do not affect ¹⁸F-fluoride PET/CT which shows a high sensitivity and negative predictive value for excluding bone metastases even in patients with inconclusive conventional BS.     

Utility of 99mTc-MDP hybrid SPECT-CT for diagnosis of skull base osteomyelitis: comparison with planar bone scintigraphy, SPECT, and CT

Purpose

To evaluate single photon emission tomography–computed tomography (SPECT-CT) for diagnosis of skull base osteomyelitis (SBO) and to compare this technique with planar bone scintigraphy (BS), SPECT, and CT.

Methods

Data from 13 patients with known/suspected SBO were retrospectively analysed. Planar BS and SPECT images were evaluated by an experienced nuclear medicine physician, CT by and experienced radiologist, and SPECT-CT by the nuclear medicine physician and radiologist in consensus. On the basis of diagnostic confidence a score of 1–5 was given, with 1 being definitely osteomyelitis, 2 being probably osteomyelitis, 3 being equivocal, 4 being probably normal, and 5 being definitely normal. ROC analysis areas under the curves (AUC) were calculated. For diagnostic values a score of ≤2 was taken as positive. Clinical/imaging follow-up/microbiology was taken as reference standard.

Results

AUC was largest for SPECT-CT (0.977) followed by SPECT (0.909), CT (0.886), and planar BS (0.614). However, no significant difference was found between the techniques except for borderline significance between planar BS with SPECT-CT (P = 0.071) and CT (P = 0.072). Accuracy was 46 % for planar BS, 85 % for SPECT, 77 % for CT and 92 % for SPECT-CT.

Conclusion

SPECT-CT seems to be useful, but not superior to planar BS, SPECT, or CT, for diagnosis of SBO.     

Comparison of (18)F-FDG PET/CT and (99 m)Tc-MDP bone scintigraphy for detection of bone metastasis in osteosarcoma

Objective

We compared the diagnostic performance of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and (99 m)Tc-methylene diphosphonate bone scintigraphy (BS) for the detection of bone metastasis in osteosarcoma.

Materials and methods

We retrospectively reviewed 206 patients with stage II–IV osteosarcoma treated with surgery and chemotherapy as well as at least one paired PET/CT and BS scan (defined as an examination). PET/CT and BS images were interpreted separately. When analyzing the diagnostic yield of a combination of PET/CT and BS (PET/CT+BS), an examination was considered positive if either PET/CT or BS scored positive. The final diagnosis was obtained from histological findings or clinical follow-up with imaging studies for at least 6 months. Diagnostic performances of PET/CT, BS, and their combinations were calculated.

Results

Out of 833 examinations in 206 patients, 55 with 101 lesions in 38 patients were confirmed as bone metastases. The sensitivity, specificity, and diagnostic accuracy were 95, 98, and 98 %, respectively, for PET/CT; 76, 97, and 96 %, respectively, for BS; and 100, 96, and 97 %, respectively, for PET/CT+BS in an examination-based analysis. Lesion-based analysis demonstrated that the sensitivity of PET/CT+BS (100 %) was significantly higher than that of PET/CT (92 %) or BS (74 %) alone. BS detected significantly less bone metastases in the growth plate region than outside the growth plate region (22 vs. 77 %).

Conclusions

PET/CT is more sensitive and accurate than BS for diagnosing bone metastases in osteosarcoma. The combined use of PET/CT and BS improves sensitivity.     

Comparison of diagnostic ability between 99mTc-MDP bone scan and 18F-FDG PET/CT for bone metastasis in patients with small cell lung cancer

Objective

The aim of this study was to compare the diagnostic ability of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) with that of ^99mTc-methylene diphosphonate (^99mTc-MDP) bone scan for bone metastasis in staging patients with small cell lung cancer (SCLC).

Methods

Ninety-five patients with SCLC who underwent both ¹⁸F-FDG PET/CT and ^99mTc-MDP bone scan for initial staging work-up were retrospectively enrolled. All ¹⁸F-FDG PET/CT and bone scan images were visually assessed. Bone metastasis was confirmed by histopathological results and all available clinical information.

Results

Of 95 patients with SCLC, metastatic bone lesions were found in 30 patients, and 84 metastatic lesions were evaluated on a lesion-basis analysis. The sensitivity of ¹⁸F-FDG PET/CT was 100?% on a per-patient basis and 87?% on a per-lesion basis, and there was no false-positive lesion on PET/CT images. In contrast, the sensitivity of the bone scan was 37?% on a per-patient basis and 29?% on a per-lesion basis. The bone scan showed 11 false-positive lesions. The bone scan detected two metastatic lesions that were not detected by PET/CT, which were outside the region scanned by PET/CT. On follow-up bone scan, 21 lesions that were not detected by the initial bone scan but were detected by PET/CT were newly detected.

Conclusions

In patients with SCLC, ¹⁸F-FDG PET/CT showed higher detection rate of bone metastasis than ^99mTc-MDP bone scan. Thus, ¹⁸F-FDG PET/CT can replace bone scan in staging patients with SCLC.     

Diagnostic performance of 18F-dihydroxyphenylalanine positron emission tomography in patients with paraganglioma: a meta-analysis

Purpose

The aim of this study was to systematically review and conduct a meta-analysis of published data about the diagnostic performance of ¹⁸F-dihydroxyphenylalanine (DOPA) positron emission tomography (PET) in patients with paraganglioma (PG).

Methods

A comprehensive computer literature search of studies published through 30 June 2011 regarding ¹⁸F-DOPA PET or PET/computed tomography (PET/CT) in patients with PG was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of ¹⁸F-DOPA PET or PET/CT in patients with PG on a per patient- and on a per lesion-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of ¹⁸F-DOPA PET or PET/CT in patients with PG. Furthermore, a sub-analysis taking into account the different genetic mutations in PG patients was also performed.

Results

Eleven studies comprising 275 patients with suspected PG were included in this meta-analysis. The pooled sensitivity of ¹⁸F-DOPA PET and PET/CT in detecting PG was 91% [95% confidence interval (CI) 87–94%] on a per patient-based analysis and 79% (95% CI 76–81%) on a per lesion-based analysis. The pooled specificity of ¹⁸F-DOPA PET and PET/CT in detecting PG was 95% (95% CI 86–99%) on a per patient-based analysis and 95% (95% CI 84–99%) on a per lesion-based analysis. The area under the ROC curve was 0.95 on a per patient- and 0.94 on a per lesion-based analysis. Heterogeneity between the studies about sensitivity of ¹⁸F-DOPA PET or PET/CT was found. A significant increase in sensitivity of ¹⁸F-DOPA PET or PET/CT was observed when a sub-analysis excluding patients with succinate dehydrogenase subunit B (SDHB) gene mutations was performed.

Conclusion

In patients with suspected PG ¹⁸F-DOPA PET or PET/CT demonstrated high sensitivity and specificity. ¹⁸F-DOPA PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false-negative results should be kept in mind. Furthermore, SDHB gene mutations could influence ¹⁸F-DOPA PET or PET/CT diagnostic performance.     

Comparison of 131I whole-body imaging, 131I SPECT/CT, and 18F-FDG PET/CT in the detection of metastatic thyroid cancer

Purpose

The aim of this study was to compare ¹³¹I whole-body scintigraphy (WBS), WBS with ¹³¹I single photon emission computed tomography/computed tomography (SPECT/CT), and ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in the detection of distant metastases of differentiated thyroid cancer (DTC).

Methods

A total of 140 patients with 258 foci of suspected distant metastases were evaluated. ¹³¹I WBS, ¹³¹I SPECT/CT, and ¹⁸F-FDG PET/CT images were interpreted separately. The final diagnosis was obtained from histopathologic study, serum thyroglobulin level, other imaging modalities, and/or clinical follow-up.

Results

Of the 140 patients with 258 foci, 46 patients with 166 foci were diagnosed as positive for distant metastasis. The sensitivity, specificity, and diagnostic accuracy of each imaging modality were 65, 55, and 59%, respectively, for ¹³¹I WBS; 65, 95, and 85% for ¹³¹I SPECT/CT, respectively; and 61, 98, and 86%, respectively, for ¹⁸F-FDG PET/CT in patient-based analyses. Lesion-based analyses demonstrated that both SPECT/CT and PET/CT were superior to WBS (p<0.001) in all patient groups. SPECT/CT was superior to WBS and PET/CT (p<0.001) in patients who received a single challenge of radioiodine therapy, whereas PET/CT was superior to WBS (p=0.005) and SPECT/CT (p=0.013) in patients who received multiple challenges.

Conclusion

Both SPECT/CT and PET/CT demonstrated high diagnostic performance in detecting metastatic thyroid cancer. SPECT/CT was highly accurate in patients who underwent a single challenge of radioiodine therapy. In contrast, ¹⁸F-FDG PET/CT presented the highest diagnostic performance in patients who underwent multiple challenges of radioiodine therapy.     

Role of 11C-choline PET/CT in the restaging of prostate cancer patients showing a single lesion on bone scintigraphy

Aim

To assess the utility of ¹¹C-choline PET/CT in the restaging of prostate cancer (PC) patients who showed a single finding on bone scintigraphy (BS) that was classified as equivocal or suspected for metastatic lesion.

Materials and methods

A total of 25 PC patients with biochemical failure (mean PSA value 11.1 ng/mL; median value 6.3 ng/mL; range 0.2–37.7 ng/mL) after primary treatment were included in this retrospective study. All of them showed a single lesion on BS reported as suspected for metastatic lesion or as equivocal finding. Patients underwent ¹¹C-choline PET/CT within 1–4 months from BS. Validation was established by follow-up for at least 6 months.

Results

On the basis of biopsy confirmation and/or 6-month follow-up, 22 of 25 patients were classified as positive for the presence of metastatic bone lesions: 13 with a single lesion and 9 with multiple lesions. ¹¹C-choline PET/CT was positive in 19/25 patients and, on a lesion basis, it showed 50 positive findings. BS results were confirmed in 8/25 (32%) patients. ¹¹C-choline PET/CT detected multiple sites of relapse in 11/25 (44%) patients: in 2/11, a single bone lesion associated with other extraosseous sites of relapse; in 6/11, multiple bone lesions; in 3/11, multiple bone lesions and other extraosseous localizations. Finally, 6/25 patients were negative on ¹¹C-choline PET/CT. In 3/6 patients, an osteoblastic lesion was seen on CT attenuation correction images (PET false negative; BS true positive), while in 3/6 patients only findings suggestive of the presence of degenerative disease were found (PET true negative; BS false positive). On a patient basis, ¹¹C-choline PET/CT showed a diagnostic sensitivity of 86% (19/22) and a specificity of 100% (19/19).

Conclusions

In our study, ¹¹C-choline PET/CT detected unknown lesions in 11/25 patients. Patients with a single equivocal finding on BS could have important additional information from ¹¹C-choline PET/CT study, especially in the detection of additional metastases, to choose an appropriate treatment.     

Clinical significance of 18F-α-methyl tyrosine PET/CT for the detection of bone marrow invasion in patients with oral squamous cell carcinoma: comparison with 18F-FDG PET/CT and MRI

Objective

L-3-[¹⁸F]-fluoro-α-methyl tyrosine (¹⁸F-FAMT) is an amino acid tracer for positron emission tomography/computed tomography (PET/CT) which specifically transported into cancer cells by L-type amino acid transporter 1 (LAT1). LAT1 overexpression in tumors is significantly correlated with cell proliferation and angiogenesis. ¹⁸F-FAMT PET/CT, fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) PET/CT and magnetic resonance imaging (MRI) were compared for their diagnostic performance in the detection of bone marrow invasion in patients with oral squamous cell carcinoma (OSCC).

Methods

Twenty-seven patients with OSCC on the upper or lower alveolar ridge underwent staging by MRI, ¹⁸F-FDG PET/CT and ¹⁸F-FAMT PET/CT studies before surgery. Post-surgical pathologic examination was used as the standard to determine the final diagnoses. The possibility of bone marrow invasion on MRI, ¹⁸F-FDG PET/CT and ¹⁸F-FAMT PET/CT were usually graded retrospectively into five-point score. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated according to the obtained scores.

Results

As the sensitivity of ¹⁸F-FDG PET/CT was highest (100 %) among that of MRI (95 %) and ¹⁸F-FAMT PET/CT (90 %), the specificity of ¹⁸F-FAMT PET/CT was highest (85.7 %) among that of MRI (57 %) and ¹⁸F-FDG PET/CT (14.3 %). The size of pathological tumor was accorded with that detected by ¹⁸F-FAMT PET/CT and was smaller than that detected by ¹⁸F-FDG PET/CT (P < 0.01). Significant difference was not found between ¹⁸F-FAMT PET tumor volume and pathological tumor volume.

Conclusions

¹⁸F-FAMT PET/CT was useful and more specific than MRI or ¹⁸F-FDG PET/CT in the detection of bone marrow invasion of OSCC and may contribute to minimize the extent of resection in oral surgery patient.     

Role of 18F-fluoride PET/CT in the assessment of multiple myeloma: initial experience

Purpose

The aim of this study was to report our early experience with ¹⁸F-fluoride PET/CT for detecting lesions and evaluate the usefulness of this modality in the assessment of multiple myeloma (MM).

Materials and methods

¹⁸F-fluoride PET/CT and ^99mTc-MDP bone scintigraphy (BS) studies from 7 myeloma patients (4 male and 3 female, mean age 55 years) diagnosed according to standard criteria were reviewed retrospectively. Two reviewers visually and quantitatively analyzed the images and recorded their findings after reaching a consensus. Diagnostic certainty regarding the presence or absence of myeloma lesions was evaluated according to the reference standard consisting of whole-body magnetic resonance imaging and whole-body X-ray.

Results

A total of 93 affected areas were definite according to the reference standard. Of these, 83 affected areas (89 %) were identified on ¹⁸F-fluoride PET/CT, whereas 54 affected areas (58 %) were found on BS. Mean SUVmax in the affected areas was 9.8 ± 3.2 (standard deviation) ranging from 5.0 to 21.2. A total of s17 lesions with bone fracture were also detected by ¹⁸F-fluoride PET/CT and 2 lesions (12 %) were negative on BS.

Conclusion

Our result showed that ¹⁸F-fluoride PET was a possible modality to detect areas of lesions in patients with MM.     

Comparison of bone scintigraphy and <Superscript>68</Superscript>Ga-PSMA PET for skeletal staging in prostate cancer

Purpose

The aim of our study was to compare the diagnostic performance of ⁶⁸Ga-PSMA PET and ^99mTc bone scintigraphy (BS) for the detection of bone metastases in prostate cancer (PC) patients.

Methods

One hundred twenty-six patients who received planar BS and PSMA PET within three months and without change of therapy were extracted from our database. Bone lesions were categorized into benign, metastatic, or equivocal by two experienced observers. A best valuable comparator (BVC) was defined based on BS, PET, additional imaging, and follow-up data. The cohort was further divided into clinical subgroups (primary staging, biochemical recurrence, and metastatic castration-resistant prostate cancer [mCRPC]). Additionally, subgroups of patients with less than 30 days delay between the two imaging procedures and with additional single-photon emission computed tomography (SPECT) were analyzed.

Results

A total of 75 of 126 patients were diagnosed with bone metastases. Sensitivities and specificities regarding overall bone involvement were 98.7–100 % and 88.2–100 % for PET, and 86.7–89.3 % and 60.8–96.1 % (p?<?0.001) for BS, with ranges representing results for ‘optimistic’ or ‘pessimistic’ classification of equivocal lesions. Out of 1115 examined bone regions, 410 showed metastases. Region-based analysis revealed a sensitivity and specificity of 98.8–99.0 % and 98.9–100 % for PET, and 82.4–86.6 % and 91.6–97.9 % (p?<?0.001) for BS, respectively. PSMA PET also performed better in all subgroups, except patient-based analysis in mCRPC.

Conclusion

Ga-PSMA PET outperforms planar BS for the detection of affected bone regions as well as determination of overall bone involvement in PC patients. Our results indicate that BS in patients who have received PSMA PET for staging only rarely offers additional information; however, prospective studies, including a standardized integrated x-ray computed tomography (SPECT/CT) protocol, should be performed in order to confirm the presented results.

     

Compared to <Superscript>123</Superscript>I-MIBG SPECT/CT, <Superscript>18</Superscript>F-DOPA PET/CT provides accurate tumor extent in patients with extra-adrenal paraganglioma

Aim

The aim of this study was to compare the accuracy of ¹²³I-MIBG SPECT/CT with that of ¹⁸F-DOPA PET/CT for staging extra-adrenal paragangliomas (PGLs) using both functional and anatomical images (i.e., combined cross-sectional imaging) as the reference standards.

Methods

Three men and seven women (age range 26–73 years) with anatomical and/or histologically proven disease were included in this study. Three patients had either metastatic head-and-neck paragangliomas (HNPGLs) or multifocal PGL, and seven patients had nonmetastatic disease. Comparative evaluation included morphological imaging with CT, functional imaging with ¹⁸F-DOPA PET, and ¹²³I-MIBG imaging including SPECT/CT. Imaging results were analyzed on a per-patient and per-lesion basis.

Results

On a per-patient basis, ¹⁸F-DOPA PET’s detection rate for both nonmetastatic and metastatic/multifocal disease was 100%, whereas that of planar ¹²³I-MIBG imaging alone was 10.0% and that of ¹²³I-MIBG SPECT/CT was 20.0%. Overall, on a per-lesion basis, ¹⁸F-DOPA PET showed a sensitivity of 69.2% (McNemar p?<?0.001) compared with anatomical imaging. Sensitivity of planar ¹²³I-MIBG scintigraphy was 5.6%, and that of SPECT/CT was 11.1% (McNemar p?<?0.0001). Overall, ¹⁸F-DOPA PET identified 18 lesions, and anatomical imaging identified 26 lesions; planar ¹²³IMIBG imaging identified only 1 lesion, and SPECT/CT, 2 lesions.

Conclusion

¹⁸F-DOPA PET is more sensitive than is ¹²³I-MIBG imaging, including SPECT/CT, for staging HNPGL. Combined functional and anatomical imaging (PET/CT) is indicated to exclude metastatic disease in extra-adrenal PGL.

     

18F-FDG PET as a single imaging modality in pediatric neuroblastoma: comparison with abdomen CT and bone scintigraphy

Objective

The purpose of this study was to evaluate the diagnostic performance of ¹⁸F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) as a single imaging agent in neuroblastoma in comparison with other imaging modalities.

Methods

A total of 30 patients with pathologically proven neuroblastoma who underwent FDG PET for staging were enrolled. Diagnostic performance of FDG PET and abdomen CT was compared in detecting soft tissue lesions. FDG PET and bone scintigraphy (BS) were compared in bone metastases. Maximal standardized uptake value (SUVmax) of primary or recurrent lesions was calculated for quantitative analysis.

Results

Tumor FDG uptake was detected in 29 of 30 patients with primary neuroblastoma. On initial FDG PET, SUVmax of primary lesions were lower in early stage (I–II) than in late stage (III–IV) (3.03 vs. 5.45, respectively, p = 0.019). FDG PET was superior to CT scan in detecting distant lymph nodes (23 vs. 18 from 23 lymph nodes). FDG PET showed higher accuracy to identify bone metastases than BS both on patient-based analyses (100 vs. 94.4 % in sensitivity, 100 vs. 77.8 % in specificity), and on lesion-based analyses (FDG PET: 203 lesions, BS: 86 lesions). Sensitivity and specificity of FDG PET to detect recurrence were 87.5 % and 93.8, respectively.

Conclusion

FDG PET was superior to CT in detecting distant LN metastasis and to BS in detecting skeletal metastasis in neuroblastoma. BS might be eliminated in the evaluation of neuroblastoma when FDG PET is performed.     

A meta-analysis of ¹⁸FDG-PET-CT, ¹⁸FDG-PET, MRI and bone scintigraphy for diagnosis of bone metastases in patients with lung cancer

Background and purpose

Lung cancer is the most common cause of cancer related death among both men and women worldwide. The skeleton is the most common site of cancer metastasis. Early detection is crucial for prognosis. To evaluate and compare the capability for bone metastasis assessment of [¹⁸F] fluoro-2-d-glucose positron emission tomography with computed tomography (¹⁸FDG-PET–CT), [¹⁸F] fluoro-2-d-glucose positron emission tomography (¹⁸FDG-PET), magnetic resonance imaging (MRI) and bone scintigraphy (BS) in lung cancer patients, a meta-analysis is preformed.

Methods

We searched MEDLINE, OVID, EMBASE and the Cochrane Library for studies evaluating diagnosis validity of ¹⁸FDG-PET–CT, ¹⁸FDG-PET, MRI and BS between January 1990 and August 2010. Meta-analysis methods were used to pool sensitivity, specificity, diagnostic odd ratios (DORs) and to construct a summary receiver-operating characteristic curve (SROC).

Results

A total of 17 articles (9 ¹⁸FDG-PET–CT studies, 9 ¹⁸FDG-PET studies, 6 MRI studies and 16 BS studies) that included 2940 patients who fulfilled all of the inclusion criteria were considered for inclusion in the analysis. The pooled sensitivity for the detection of bone metastasis in lung cancer using ¹⁸FDG-PET–CT, ¹⁸FDG-PET, MRI and BS were 0.92 (95% CI, 0.88–0.95), 0.87 (95% CI, 0.81–0.92), 0.77 (95% CI, 0.65–0.87) and 0.86 (95% CI, 0.82–0.89), respectively. The pooled specificity for the detection of bone metastasis from lung cancer using ¹⁸FDG-PET–CT, ¹⁸FDG-PET, MRI and BS were 0.98 (95% CI, 0.97–0.98), 0.94 (95% CI, 0.92–0.96), 0.92 (95% CI, 0.88–0.95), 0.88 (95% CI, 0.86–0.89), respectively. The pooled DORs estimates for ¹⁸FDG-PET–CT 449.17 were significantly higher than for ¹⁸FDG-PET (118.25, P < 0.001), MRI (38.27, P < 0.001) and BS (63.37, P < 0.001). The pooled sensitivity of BS was not correlated with the prevalence of bone metastasis.

Conclusion

The results showed that both ¹⁸FDG-PET–CT and ¹⁸FDG-PET were better imaging methods for diagnosing bone metastasis from lung cancer than MRI and BS. ¹⁸FDG-PET–CT has higher diagnostic value (sensitivity, specificity and DORs) for diagnosing bone metastasis from lung cancer than any other imaging methods.     

Clinical value of 18F-fluorodihydroxyphenylalanine positron emission tomography/computed tomography (18F-DOPA PET/CT) for detecting pheochromocytoma

Purpose

In detecting pheochromocytoma (PHEO), positron emission tomography (PET) with the radiolabelled amine precursor ¹⁸F-fluorodihydroxyphenylalanine (¹⁸F-DOPA) offers excellent specificity, while computed tomography (CT) provides high sensitivity and ability to localize lesions; therefore, the combination of these modalities could be advantageous in this setting. The aim of this study was to investigate whether combined ¹⁸F-DOPA PET/CT more accurately detects and localizes PHEO lesions than does each modality alone.

Methods

¹⁸F-DOPA PET, CT and ¹⁸F-DOPA PET/CT images of 25 consecutive patients undergoing diagnostic scanning of suspected sporadic or multiple endocrine neoplasia type 2 syndrome-associated PHEO were reviewed retrospectively in randomized sequence. Two blinded observers scored the images regarding the likelihood of PHEO being present and localizable. Results were correlated with subsequent clinical history and, when available, histology.

Results

Of the 19 lesions detected by all three modalities, PET identified each as positive for PHEO, but was unable to definitively localize 15 of 19 (79%). CT could definitively localize all 19 lesions, but could not definitively diagnose or exclude PHEO in 18 of 19 (95%) lesions. Furthermore, CT falsely identified as negative for PHEO one lesion which was judged to be positive for this tumor by both PET and PET/CT. Only in PET/CT scans were all 19 lesions accurately characterized and localized. On a per-patient basis, the sensitivity of ¹⁸F-DOPA PET/CT for PHEO was 100% and the specificity 88%, with a 100% positive predictive value and an 88% negative predictive value.

Conclusion

¹⁸F-DOPA PET/CT more accurately diagnoses and localizes adrenal and extra-adrenal masses suspicious for PHEO than do ¹⁸F-DOPA PET or CT alone.     

The diagnostic and prognostic value of 18F-FDG PET/CT in the initial assessment of high-grade bone and soft tissue sarcoma. A retrospective study of 89 patients

Purpose

To evaluate the feasibility of ¹⁸F-FDG PET/CT for initial assessment in high-grade bone sarcomas (BS) and soft tissue sarcomas (STS).

Methods

During the years 2001–2010, 89 patients (30 BS, 59 STS) referred for further evaluation and surgical treatment of a high-grade BS or STS also had a PET/CT scan performed for staging preoperatively (n?=?68) or within 1?month of surgery (n?=?21). Metastatic lesions suggested on the PET/CT scan were confirmed or rejected by histological evaluation, by additional imaging or by follow-up. In 68 patients (28 BS, 40 STS) the relationship between the maximal standardized uptake value (SUVmax) of the primary tumour and survival was examined.

Results

The PET/CT scan suggested the presence of 13 metastatic lesions in BS patients (5 lymph node, 8 distant) and 21 metastatic lesions (6 lymph node, 15 distant) in STS patients. The calculated sensitivity (SE) and specificity (SP) were 95?% and 96?% for detection of distant metastases, and the predictive value (PV) of a positive or a negative test was 87?% and 98?%, respectively. SE and SP were 100?% and 90?% for detection of lymph node metastases, and the PV of a positive or a negative test was 27?% and 100?%, respectively. The 5-year survival was 81?% among patients with SUVmax below the median value (≤10), but was 33?% among those with SUVmax >10.

Conclusion

FDG PET/CT for the initial assessment of patients with high-grade BS or STS was feasible with high SE and SP, but in those with lymph node metastases the PV of a positive test was low. The SUVmax of the primary tumour was a strong prognostic factor for survival.     

Clinical impact of “true whole-body” 18F-FDG PET/CT: lesion frequency and added benefit in distal lower extremities

Objectives

The purpose of this study was to evaluate the lesion frequency and incremental added benefit with “true whole-body” ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) of distal lower extremities. We compared this field of view with the typical whole-body view, from head to upper thighs, in numerous patients with known or suspected malignancy.

Methods

True whole-body ¹⁸F-FDG PET/CT, from the top of the head to the bottom of the feet, was performed on 4574 consecutively registered patients with known or suspected malignancy. Using a variable sampling method, the PET images of head and torso were acquired for 90 s per bed position, and the images of lower extremities were acquired for 30 s per position, thus requiring between 22 and 24 min of emission scanning per patient. A log was maintained to record cases of abnormal findings in distal lower extremities outside the typical whole-body field of view. Suspected malignant lesions in distal lower extremities were verified by correlation with pathological findings and clinical follow-up.

Results

Abnormal findings in distal lower extremities were found in 647 (14.1 %; 95 % CI 13.1–15.2 %) of 4574 examinations. Increased FDG uptake was found in 559 examinations (12.2 %; 95 % CI 11.3–13.2 %). Lesions appeared malignant or equivocal in 67 examinations (1.5 %; 95 % CI 1.1–1.8 %) on the PET images. In 42 (0.9 %; 95 % CI 0.6–1.2 %) of 4574 examinations, these lesions were pathologically or clinically proven to be malignant. Detection of these malignancies resulted in changing clinical management in 21 (50 %) of 42 examinations. Definitive benign lesions were found in 492 examinations (10.7 %; 95 % CI 9.9–11.7 %) on the PET images. Abnormal findings were noted in 90 examinations (2.0 %; 95 % CI 1.6–2.4 %) consisting of 88 benign and 2 malignancies on the CT images alone.

Conclusion

True whole-body ¹⁸F-FDG PET/CT was not of high yield and appears to offer little additional benefit, as to detection of additional metastases and involvement, but it may affect clinical management in patients with known or suspected malignancy.     

Comparison of 18F-fluoride PET/CT, 18F-FDG PET/CT and bone scintigraphy (planar and SPECT) in detection of bone metastases of differentiated thyroid cancer: a pilot study

Objective:

We compared the efficacies of ¹⁸F-fluoride positron emission tomography (¹⁸F-fluoride PET)/CT, ¹⁸F-fludeoxyglucose PET (¹⁸F-FDG PET)/CT, and ^99mTc bone scintigraphy [planar and single photon emission CT (SPECT)] for the detection of bone metastases in patients with differentiated thyroid carcinoma (DTC).

Methods:

We examined 11 patients (8 females and 3 males; mean age ± standard deviation, 61.9 ± 8.7 years) with DTC who had been suspected of having bone metastases after total thyroidectomy and were hospitalized to be given ¹³¹I therapy. Bone metastases were verified either when positive findings were obtained on both ¹³¹I scintigraphy and CT or when MRI findings were positive if MRI was performed.

Results:

Metastases were confirmed in 24 (13.6%) of 176 bone segments in 9 (81.8%) of the 11 patients. The sensitivities of ¹⁸F-fluoride PET/CT and ^99mTc bone scintigraphy (SPECT) were significantly higher than those of ¹⁸F-FDG PET/CT and ^99mTc bone scintigraphy (planar) (p < 0.05). The accuracies of ¹⁸F-fluoride PET/CT and ^99mTc bone scintigraphy (SPECT) were significantly higher than that of ^99mTc bone scintigraphy (planar) (p < 0.05).

Conclusion:

The sensitivity and accuracy of ¹⁸F-fluoride PET/CT for the detection of bone metastases of DTC are significantly higher than those of ^99mTc bone scintigraphy (planar). However, the sensitivity and accuracy of ^99mTc bone scintigraphy (planar) are improved near to those of ¹⁸F-fluoride PET/CT when SPECT is added to a planar scan. The sensitivity of ¹⁸F-FDG PET/CT is significantly lower than that of ¹⁸F-fluoride PET/CT or ^99mTc bone scintigraphy (SPECT).

Advances in knowledge:

This article has demonstrated first the high efficacy of ¹⁸F-fluoride PET/CT for the detection of bone metastases of DTC.Differentiated thyroid carcinoma (DTC) shows a relatively good prognosis compared with carcinomas of other organs, and the 10-year survival rate of DTC is >80% because of treatments such as total thyroidectomy and ablation of remnants with radioiodine.¹ However, metastases of DTC develop in 7–23% of patients; the distant metastases occur commonly in the lungs, bones and brain, and the bones are the second most common site of metastases of DTC.² Bone scintigraphy using ^99mTc-labelled phosphate compounds [^99mTc-methylene diphosphonate (^99mTc-MDP) or ^99mTc-hydroxymethylene diphosphonate (^99mTc-HMDP)] has been widely used for detecting and evaluating bone metastases of various kinds of carcinomas because of its overall high sensitivity and the easy evaluation of the entire skeleton.³ However, there were often false-positive cases in ^99mTc bone scintigraphy, because degenerative or inflammatory foci were often confused with metastatic lesions. The addition of single photon emission CT (SPECT) to planar acquisition of ^99mTc bone scintigraphy has been shown to exhibit a beneficial effect on the detection and evaluation of bone metastases.^4–6 Skeletal imaging by ¹⁸F-fludeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT has been shown to be useful in the detection of bone metastases of various carcinomas including DTC.⁷Previously, we compared the efficacies of ¹⁸F-FDG PET and planar ^99mTc bone scintigraphy for the detection of bone metastases in patients with DTC.⁸ We found that the specificity and the overall accuracy of ¹⁸F-FDG PET for the detection of bone metastases in patients with DTC were higher than those of planar ^99mTc bone scintigraphy, whereas the difference in the sensitivity of both examinations was not statistically significant, and concluded that ¹⁸F-FDG PET is superior to planar ^99mTc bone scintigraphy because of its lower incidence of false-positive results in the detection of bone metastases of DTC.⁸¹⁸F-fluoride is a positron-emitting bone-seeking radiotracer, which has a similar uptake mechanism to ^99mTc-MDP and ^99mTc-HMDP. As the availability of PET systems was increasing, ¹⁸F-fluoride has been used for skeletal PET imaging since 1990s. PET or PET/CT with ¹⁸F-fluoride have been shown to be more sensitive than planar ^99mTc bone scintigraphy for the detection of bone metastases of lung,⁹ breast,^10,11 hepatocellular,¹² prostate,^11,13,14 colon and bladder¹¹ cancers. However, to the best of our knowledge, there have been no systematic comparative studies on the efficacies of ¹⁸F-fluoride PET/CT, ¹⁸F-FDG PET/CT and ^99mTc bone scintigraphy (planar and SPECT) for the detection of bone metastases of DTC. This study was conducted to compare ¹⁸F-fluoride PET/CT, ¹⁸F-FDG PET/CT and ^99mTc bone scintigraphy (planar and SPECT) in the detection of bone metastases of DTC.     

Molecular imaging in musculoskeletal infections with <Superscript>99m</Superscript>Tc-UBI 29-41 SPECT/CT

Objective

To determine the added value of CT over planar and SPECT-only imaging in the diagnosis of musculoskeletal infection using ^99mTc-UBI 29-4.

Materials and methods

184 patients with suspected musculoskeletal infection who underwent planar and SPECT/CT imaging with ^99mTc-UBI 29-41 were included. Planar, SPECT-only and SPECT/CT images were reviewed by two independent analysts for presence of bone or soft tissue infection. Final diagnosis was confirmed with tissue cultures, surgery/histology or clinical follow-up.

Results

^99mTc-UBI 29-41 was true positive in 105/184 patients and true negative in 65/184 patients. When differentiating between soft tissue and bone infection, planar?+?SPECT-only imaging had a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 95.0, 74.3, 84.8, 91.3 and 86.9%, respectively, versus 99.0, 94.5, 92.5, 98.5 and 94.5% for SPECT/CT. SPECT/CT resulted in a change in reviewers’ confidence in the final diagnosis in 91/184 patients. Inter-observer agreement was better with SPECT/CT compared with planar?+?SPECT imaging (kappa 0.87, 95% CI 0.71–0.85 versus kappa 0.81, 95% CI 0.58–0.75).

Conclusion

Addition of CT to planar and SPECT-only imaging led to an increase in diagnostic performance and an improvement in reviewers’ confidence and inter-observer agreement in differentiating bone from soft tissue infection.

     

F-18 Sodium Fluoride Positron Emission Tomography/Computed Tomography for Detection of Thyroid Cancer Bone Metastasis Compared with Bone Scintigraphy

Objective

The aim of the study was to compare the diagnostic performances of F-18 sodium fluoride positron emission tomography/computed tomography (bone PET/CT) and bone scintigraphy (BS) for the detection of thyroid cancer bone metastasis.

Materials and Methods

We retrospectively enrolled 6 thyroid cancer patients (age = 44.7 ± 9.8 years, M:F = 1:5, papillary:follicular = 2:4) with suspected bone metastatic lesions in the whole body iodine scintigraphy or BS, who subsequently underwent bone PET/CT. Pathologic diagnosis was conducted for 4 lesions of 4 patients.

Results

Of the 17 suspected bone lesions, 10 were metastatic and 7 benign. Compared to BS, bone PET/CT exhibited superior sensitivity (10/10 = 100% vs. 2/10 = 20%, p = 0.008), and accuracy (14/17 = 82.4% vs. 7/17 = 41.2%, p < 0.025). The specificity (4/7 = 57.1%) of bone PET/CT was not significantly different from that of BS (5/7 = 71.4%, p > 0.05).

Conclusion

Bone PET/CT may be more sensitive and accurate than BS for the detection of thyroid cancer bone metastasis.