Specificity Of Bone Scintigraphy Research Articles

A single centre pilot experience with 18F-JK-PSMA-7 PET-CT in the staging of prostate cancer

Background: The sensitivity and specificity of bone scintigraphy and thoraco-abdominopelvic CT scans traditionally used for the staging of prostate cancer don’t meet clinical requirements. In 2020 18F-JK-PSMA-7 positron emission tomography-computed tomography (PET-CT) became available in our country for routine clinical diagnostics. Methods: As part of our self-assessment, we retrospectively analysed the results of 24 PSMA PET-CTs realised for our patients up to 31 December 2020. Results: The indication of the examination was biochemical recurrence after radical prostatectomy (prostate specific antigen (PSA) >0.2 ng/mL) for 16 patients and primary staging (PSA range: 5.2–70 ng/mL) for 8 patients. Biochemical recurrence was related to local relapse in 2 cases, regional lymph node involvement in 5 cases, oligo- and multi-metastatic spread in 1 and 3 cases respectively. 5 patients had no detectable lesion. Patients with PSA <1 ng/mL showed no extrapelvic enhancement. At primary staging 3 patients presented distant metastases. There was no correlation between PSA level and disease extent. In total PSMA PET-CT results changed the treatment strategy for 7 patients. Conclusions: 18F-JK-PSMA-7 PET-CT is a useful diagnostic tool. The examination can lead to change the treatment decision at primary staging as well as at biochemical recurrence. The results of this pilot study may support the strategy that patients with biochemical recurrence following radical prostatectomy receive salvage radiotherapy to the prostate bed and the pelvic lymphatic regions without any imaging examination when PSA <1 ng/mL.

Two cases of gastrointestinal stromal tumor of the small intestine with liver and bone metastasis.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. These tumors most commonly occur in the stomach (60%), jejunum and ileum (30%). Metastasis is characteristically the malignant behavior of the GISTs. GISTs most frequently metastasize to the liver and peritoneum, whereas bone and lung metastases are uncommon sites. Here, we described two cases of bone and liver metastases in patients with advanced GISTs. Both of them showed liver metastasis at disease presentation and bone metastasis in early time after the diagnosis. Bone metastases involved the lumber spine and right femur in first patient and L2 vertebral body in the second case. All of the lesions presented a lytic pattern. These cases are presented because of the rare incidence of bone metastasis to femur and vertebral bodies. More attention should be paid to the diagnosis of bone metastases from GISTs in clinical practice despite the shortage of available data on the sensitivity and specificity of bone scintigraphy and PET-CT.

Reply to the letter “Choline PET/CT compared with bone scintigraphy in the detection of bone metastases in prostate cancer patients”

Dear Sir, We thank Beheshti and Langsteger [1] for their interest in our paper “[C]Choline PET/CT detection of bone metastases in patients with PSA progression after primary treatment for prostate cancer: comparison with bone scintigraphy” [2] and for raising important issues; we would like to reply to the comments presented. We agree that the comparison between tomographic and planar modalities has an intrinsic bias due to the different potentials of the two techniques. Knowing that it has already been demonstrated that single photon emission computed tomography (SPECT) and/or SPECT/CT significantly improve the specificity of bone scintigraphy (BS) [3, 4], in the present paper the clinical advantages and limitations of one technique over the other have been described exclusively based on a clinical point of view, and the comparison between the two modalities to evaluate the potential benefits that PET/CT could offer over BS have been performed. We are aware that the comparison of bone metastases may be of limited value because [C]choline PET/CTstudies were performed from the base of the skull. This limitation is due to the retrospective nature of the study; thus, [C]choline PET/ CT scans were acquired according to a standard protocol. In particular, only two lesions, one at the skull, and categorized at BS as malignant, and one at an arm, and categorized at BS as equivocal, could not be validated because the anatomical localizations were outside the field of view of PET/CT and thus excluded from lesion-based analysis. Regarding the low choline uptake in sclerotic bone lesions, our opinion is that further studies are required to clarify the meaning of this phenomenon. At present we cannot distinguish between the low uptake due to a regression of bone disease in response to therapy or due to a false-negative [C] choline PET/CT finding. Until this crucial concept has been clarified, the monitoring of bone metastatic disease should be based on a conventional bone scan. At present the low choline uptake in sclerotic bone lesions can be considered a limitation of [C]choline PET/CT but, once the metabolic meaning of this finding is clarified, it could potentially become a prognostic tool with significant clinical relevance. In our series, there were 24 of 78 patients with bone metastases on [C]choline PET/CT and 19 of 78 patients on BS. In our opinion the relevance of these results is the following: if a patient undergoes [C]choline PET/CT for biochemical recurrence for restaging his disease and a pathological bone uptake occurs, due to the high positive predictive value of [C]choline PET/CT, the clinician may be confident in considering that pathological uptake as a bone metastatic lesion. Moreover, the absence of [C]choline uptake in degenerative changes of the skeleton is another issue that emphasizes the potential superiority of this technique over BS. In response to the comment of Beheshti and Langsteger [1], we would also like to remark that [C]choline PET/CT, being a whole-body modality, presents the great advantage M. Picchio (*) : F. Fallanca Nuclear Medicine Department, Scientific Institute San Raffaele, Milan, Italy e-mail: picchio.maria@hsr.it

Comparison of FDG-PET/CT and bone scintigraphy for detection of bone metastases in breast cancer

Bone scintigraphy is the standard procedure for the detection of bone metastases in breast cancer patients. FDG-PET/CT has been reported to be a sensitive tool for tumor staging in different malignant diseases. However, its accuracy for the detection of bone metastases has not been compared to bone scintigraphy. To compare whole-body FDG-PET/CT and bone scintigraphy for the detection of bone metastases on a lesion basis in breast cancer patients. Twenty-nine consecutive women (mean age 58 years, range 35-78 years) with histologically proven breast cancer were assessed with bone scintigraphy and whole-body FDG-PET/CT. Twenty-one patients (72%) were suffering from primary breast cancer and eight patients (28%) were in aftercare with a history of advanced breast cancer. Both imaging procedures were assessed for bone metastases by a radiologist and a nuclear medicine physician. Concordant readings between bone scintigraphy and FDG-PET/CT were taken as true. Discordant readings were verified with additional MRI imaging in all patients and follow-up studies in most patients. A total of 132 lesions were detected on bone scintigraphy, FDG-PET/CT or both. According to the reference standard, 70/132 lesions (53%) were bone metastases, 59/132 lesions (45%) were benign, and three lesions (2%) remained unclear. The sensitivity of bone scintigraphy was 76% (53/70) compared to 96% (67/70) for FDG-PET/CT. The specificity of bone scintigraphy and FDG-PET/CT was 95% (56/59) and 92% (54/59), respectively. According to the reference standard bone metastases were present in eight out of the 29 patients (28%), whereas 20 patients (69%) were free of bone metastases. One (3%) patient had inconclusive readings on both modalities as well as on MRI and follow-up studies. Bone scintigraphy and FDG-PET/CT correctly identified seven out of eight patients with bone metastases and 20 out of 20 patients free of metastases. On a lesion-basis whole-body FDG-PET/CT is more sensitive and equally specific for the detection of bone metastases compared with bone scintigraphy.

Scintigraphie osseuse dans le bilan d’extension des carcinomes épidermoïdes des voies aérodigestives supérieures

Objectives To determine the value of technetium-99 m bone scintigraphy in the screening of bone metastases in the systematic initial extension assessment of upper aerodigestive tract suamous cell carcinomas; to identify risk factors of these bone metastases for better screening. Material and methods In this prospective study, the initial assessment of tumoral extension was systematically associated with bone scintigraphy. Only patients with no malignant tumors were included in the study. Any skeletal fixation identified was then analyzed with standard radiography and/or tomodensitometry and with the patient's clinical progression to confirm whether or not the fixation was metastatic. The sensitivity and specificity of bone scintigraphy was then calculated. A correlation between bone pain or hypercalcemia and confirmed bone metastases was also systematically sought to determine whether these factors were predictive of bone metastases so as to better target the screening. Results Among the 55 patients included in the study, three had confirmed bone metastases. All were detected by the bone scintigraphy, with a sensitivity of 100%. However, the 20 false-positive results gave a low specificity of 62%. Bone pain was described by two patients, but they were among the three metastatic patients. Specificity was 100%, but the sensitivity was only 67%. Three patients had hypercalcemia: the three metastatic patients. The sensitivity and specificity were 100%. In the tumoral status of the three patients with bone metastasis, tumors were small, classified as T1 or T2, but with substantial node involvement, classified N3, and with invasion of the internal jugular vein in two cases. Conclusion The incidence of bone metastases in the initial extension assessment was low; consequently, they are not sought systematically. However, their presence radically changes the prognosis and the therapeutic management, raising the question of screening. The technetium-99 m bone scintigraphy has limits, with many false-positive resulting the need for additional investigations. Defining the risk factors for bone metastases would improve screening. Two questions remain: what factors are involved? The bone pain and the hypercalcemia must be analyzed with a larger number of cases, but they seem to be nonspecific. The node involvement stage could be a more reliable parameter, in particular in cases of jugular vein invasion; what method should be used? In the future, the PET scan could be the key procedure not only in the locoregional extension assessment, but also for general extensions, in a single procedure investigating the whole body.

The Current Status of Bone Scintigraphy in Malignant Diseases

For the past few decades, planar bone scintigraphy has been the most frequently performed imaging study in the evaluation of metastatic bone disease. Although scintigraphic findings alone are often nonspecific for skeletal pathologies, this technique reportedly has an exquisite sensitivity. However, recently accumulated data on the efficacy of positron emission tomography with fluorine-18 fluorodeoxyglucose and fluorine-18 sodium fluoride as well as magnetic resonance imaging for evaluating skeletal metastatic disease now indicate that conventional planar bone scintigraphy is not very sensitive in the detection of metastatic bone lesions in selected malignancies. Nevertheless, bone scintigraphy still remains the primary imaging modality for evaluation of metastatic bone disease owing mainly to its cost effectiveness and wide availability. In addition, recently introduced hybrid imaging systems combining single-photon emission computed tomography and spiral computed tomography, although not widely available yet, increase considerably both the sensitivity and specificity of bone scintigraphy. This article focuses primarily on the current role of bone scintigraphy and its strengths and weaknesses in assessing different types of malignant diseases relative to other imaging modalities in selected malignancies.

Bone scintigraphy of hip prostheses. Can analysis of patterns of abnormality improve accuracy?

The patterns of abnormality (both site and intensity of uptake) on bone scintigraphy in 76 total hip replacements were studied and graded to determine whether specific patterns of abnormality were associated with greater accuracy in deciding the need for revision surgery. Patients were divided into three groups: 1) 45 hips were considered to have required surgery, 2) in 15 hips surgery was retrospectively considered unnecessary, and 3) 16 prostheses were painless. There was a trend for fewer abnormal sites and a lower intensity of abnormality from group 1 to group 3. By considering patterns of uptake, the specificity of bone scintigraphy could be improved from 65% to 95%, but at the expense of lower sensitivity, falling from 90% to 75%. The most accurate criteria for determining the need for revision surgery (sensitivity 88%, specificity 85%) were increased uptake at the tip or a total scintigraphy score of greater than 3.

Bone scintigraphy in patients suspected of having meniscus tears

The sensitivity and specificity of bone scintigraphy in the evaluation of meniscus tears was investigated in a prospective study of 44 younger patients referred for arthroscopy with a suspected meniscus tear. We found a sensitivity of 0.74 and a specificity of 0.76 for pure meniscus pathology; thus, the test cannot so far be recommended as a routine in evaluating meniscus pathology. However, the test was highly sensitive if used to divide the patients into 2 groups: a potential surgery‐demanding group with meniscus pathology, osteochondritis, degenerative joint disease or rotational instability, and a group with synovitis, hot patella or a healthy knee where surgery (arthroscopy) could be avoided. The accuracy in this division was 0.92. We find the test valuable if used this way.