Conventional Bone Scintigraphy Research Articles

Conventional Imaging, MRI and 18F-FDG PET/MRI for N and M Staging in Patients with Newly Diagnosed Breast Cancer.

Background: This study compares the diagnostic potential of conventional staging (computed tomography (CT), axillary sonography and bone scintigraphy), whole-body magnetic resonance imaging (MRI) and whole-body 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET/)MRI for N and M staging in newly diagnosed breast cancer. Methods: A total of 208 patients with newly diagnosed breast cancer were prospectively included in this study and underwent contrast-enhanced thoracoabdominal CT, bone scintigraphy and axillary sonography as well as contrast-enhanced whole-body 18F-FDG PET/MRI. The datasets were analyzed with respect to lesion localization and characterization. Histopathology and follow-up imaging served as the reference standard. A McNemar test was used to compare the diagnostic performance of conventional staging, MRI and 18F-FDG PET/MRI and a Wilcoxon test was used to compare differences in true positive findings for nodal staging. Results: Conventional staging determined the N stage with a sensitivity of 80.9%, a specificity of 99.2%, a PPV (positive predictive value) of 98.6% and a NPV (negative predictive value) of 87.4%. The corresponding results for MRI were 79.6%, 100%, 100% and 87.0%, and were 86.5%, 94.1%, 91.7% and 90.3% for 18F-FDG PET/MRI. 18F-FDG PET/MRI was significantly more sensitive in determining malignant lymph nodes than conventional imaging and MRI (p < 0.0001 and p = 0.0005). Furthermore, 18F-FDG PET/MRI accurately estimated the clinical lymph node stage in significantly more cases than conventional imaging and MRI (each p < 0.05). Sensitivity, specificity, PPV and NPV for the M stage in conventional staging were 83.3%, 98.5%, 76.9% and 98.9%, respectively. The corresponding results for both MRI and 18F-FDG PET/MRI were 100.0%, 98.5%, 80.0% and 100.0%. No significant differences between the imaging modalities were seen for the staging of distant metastases. Conclusions:18F-FDG PET/MRI detects lymph node metastases in significantly more patients and estimates clinical lymph node stage more accurately than conventional imaging and MRI. No significant differences were found between imaging modalities with respect to the detection of distant metastases.

Inter-observer variability between readers in detection of bone metastases comparing different modalities; PET/CT, SPECT/CT and planar bone scintigraphy.

To assess the inter-observer variability between readers in the detection of bone metastases for different modalities [planar bone scintigraphy (BS), single photon emission computed tomography/computed tomography (SPECT/CT), and fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) (F-18 FDG PET/CT)]. Patients with known primary tumors referred for metastatic workup either by F-18 FDG PET/CT or conventional planar BS and SPECT/CT were enrolled in this prospective study. The three modalities (BS, SPECT/CT, and PET/CT) were acquired for each patient. Interpretation was done by two independent nuclear medicine physicians separately and blindly; reader 1 (R1) and reader 2 (R2). A three-point subjective scale was used (1 = negative for bone metastases, 2 = equivocal, and 3 = positive). The findings were compared to the final patient status based on clinical and radiological follow-up for at least 6 months. The Kappa test was used to assess the degree of agreement between readers in their interpretation of each modality. A total of 54 patients (39 females and 15 males, ages 26-76; mean: 54.7 ± 12) were eligible for this study. Fair agreement 0.372 between R1 and R2 in interpretation of BS was noticed that improved to 0.847 after addition of SPECT/CT. Perfect agreement was achieved between R1 and R2 while interpreting PET/CT images (kappa = 0.964, P < 0.001). F-18 FDG PET/CT significantly improved the inter-observer variability between readers, allowing for better diagnosis of bone metastases in known cancer patients. Also, it was superior to BS and SPECT/CT in the detection of bone metastases.

18F-NaF PET/CT.

18F-NaF PET/CT is indicated for diagnostic imaging of bone to define altered osteogenic areas of activity. It provides high-resolution, high-contrast images of the skeletal tissue and has higher sensitivity, specificity, and accuracy than conventional nuclear bone scintigraphy. The low-dose CT

A prospective phase 2/3 study of PSMA-targeted 18F-DCFPyL-PET/CT in patients (pts) with prostate cancer (PCa) (OSPREY): A sub-analysis of disease staging changes in PCa pts with recurrence or metastases on conventional imaging.

e17003 Background: Conventional imaging and bone scintigraphy are suboptimal modalities for identifying PCa. PSMA-based imaging is highly promising for PCa detection. 18F-DCFPyL is a novel PSMA-targeted radiopharmaceutical for positron emission tomography (PET) that may be useful in staging of PCa. The diagnostic performance, detection rate, and potential impact of 18F-DCFPyL on staging of pts with high-risk PCa have been previously reported. Here we report on the impact of 18F-DCFPyL on staging of pts with PCa recurrence or metastases on conventional imaging. Methods: 18F-DCFPyL-PET/CT was evaluated in 117 men with radiologic evidence of local recurrence or metastatic disease on baseline anatomical imaging (CT, MRI) or whole-body bone scintigraphy and in whom at least one lesion was deemed amenable to biopsy. A single dose of 9 mCi (333 MBq) of 18F-DCFPyL was administered via intravenous injection, followed by PET/CT acquisition 1 to 2 hours thereafter. Based on TNM staging: prostatic (T), pelvic LN (N), extra-pelvic LN (M1a), bone (M1b) and other visceral organs/soft tissue (M1c), 18F-DCFPyL-PET/CT detection rates including lesion counts were systematically analyzed. Three central, blinded, and independent readers evaluated the 18F-DCFPyL scans. Results: In this study, 82 (70%) patients had baseline radiographic M1 stage disease (14 patients with M1a, 50 patients with M1b, 18 patients with M1c) and 33 (28%) patients were M0 stage at baseline by central conventional imaging review; two patients were unevaluable. 18F-DCFPyL-PET/CT up-staged 58% (19/33) of pts from M0 to M1, of whom 91% (10/11) who underwent an extra-pelvic biopsy were confirmed to have M1 disease by pathology, including 9 patients with M1b and 1 patient with M1a. Of the patients who were staged M1 at baseline, 18F-DCFPyL-PET/CT upstaged 16% (10/64; M1a to M1b or M1c: n = 4; M1b to M1c: n = 6) of pts to a higher M1 sub-stage and down-staged 22% (18/82) to M0. Conclusions: 18F-DCFPyL-PET/CT identified M1 disease in the majority of patients examined who otherwise had locoregional disease. These data suggest that 18F-DCFPyL-PET/CT may be a useful tool in properly staging men with both metastatic and nonmetastatic relapsed disease, which could lead to superior treatment paradigms than currently exist using conventional imaging. Clinical trial information: NCT02981368.

A prospective phase II/III study of PSMA-targeted 18F-DCFPyL-PET/CT in patients (pts) with prostate cancer (PCa) (OSPREY): A subanalysis of disease staging changes in PCa pts with recurrence or metastases on conventional imaging.

32 Background: Conventional imaging and bone scintigraphy are suboptimal modalities for identifying PCa. PSMA-based imaging is highly promising for PCa detection. 18F-DCFPyL is a novel PSMA-targeted radiopharmaceutical for positron emission tomography (PET) that may be useful in staging of PCa. The diagnostic performance, detection rate, and potential impact of 18F-DCFPyL on staging of pts with high- risk PCa have been previously reported. Here we report on the impact of 18F-DCFPyL on staging of pts with PCa recurrence or metastases on conventional imaging. Methods: 18F-DCFPyL-PET/CT was evaluated in 117 men with radiologic evidence of local recurrence or metastatic disease on baseline anatomical imaging (CT, MRI) or whole-body bone scintigraphy and in whom at least one lesion was deemed amenable to biopsy. A single dose of 9 mCi (333 MBq) of 18F-DCFPyL was administered via intravenous injection, followed by PET/CT acquisition 1 to 2 hours thereafter. Based on TNM staging: prostatic (T), pelvic LN (N), extra-pelvic LN (M1a), bone (M1b) and other visceral organs/soft tissue (M1c), 18F-DCFPyL-PET/CT detection rates including lesion counts were systematically analyzed. Three central, blinded, and independent readers evaluated the 18F-DCFPyL scans. Results: In this study, 82 (70%) patients had baseline radiographic M1 stage disease (14 patients with M1a, 50 patients with M1b, 18 patients with M1c) and 33 (28%) patients were M0 stage at baseline by central conventional imaging review; two patients were unevaluable. 18F-DCFPyL-PET/CT up-staged 58% (19/33) of pts from M0 to M1, of whom 91% (10/11) who underwent an extra-pelvic biopsy were confirmed to have M1 disease by pathology, including 9 patients with M1b and 1 patient with M1a. Of the patients who were staged M1 at baseline, 18F-DCFPyL-PET/CT upstaged 16% (10/64; M1a to M1b or M1c: n = 4; M1b to M1c: n = 6) of pts to a higher M1 sub-stage and down-staged 22% (18/82) to M0. Conclusions: 18F-DCFPyL-PET/CT identified M1 disease in the majority of patients examined who otherwise had locoregional disease. These data suggest that 18F-DCFPyL-PET/CT may be a useful tool in properly staging men with both metastatic and nonmetastatic relapsed disease, which could lead to superior treatment paradigms than currently exist using conventional imaging. Clinical trial information: NCT02981368.

PET/CT imaging of prostate cancer in the era of small molecule prostate specific membrane antigen targeted tracers.

Staging and restaging of prostate cancer is crucial for treatment planning and prognosis. Accurate localization is of high relevance for a tailor-made therapy and an early detection of unknown metastatic spread can lead to a survival benefit. Evidence based guidelines that are currently in use were established using data from conventional imaging (such as magnetic resonance imaging (MRI), computed tomography (CT) and bone scintigraphy). Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) is rapidly evolving with promising results. However, up to now there is little consensus about the usefulness of this method, especially since different guidelines are "biased" depending on the association that shapes them. Firstly, little data exists on the staging of low risk tumors and probably PSMA PET/CT should be avoided in this setup for most patients. On the other hand, it has been recently proven that PSMA PET/CT can replace CT and bone scintigraphy (combined) in staging of advanced prostate cancer. Furthermore, the examination gained general acceptance through its excellent performance in biochemical recurrence, both for castration naïve and castration resistant tumors, and should be implemented where available. It is undisputed that PSMA PET/CT provides a more accurate picture of prostate cancer patients and can lead to both upstaging and downstaging, thus affecting therapeutic management. Though it is not clear yet if the more accurate staging will lead to better therapeutic decisions and improve patient outcomes, PSMA PET/CT appears as the next imaging standard for prostate cancer for the years to come.

Value of SPECT/CT in the assessment of necrotic bone fragments in patients with delayed bone healing or non-union after traumatic fractures.

To evaluate the value of single-photon emission computed tomography / computed tomography (SPECT/CT) compared with planar bone scintigraphy (BS) in the assessment of necrotic bone fragments in patients with delayed bone healing or non-union after traumatic fractures. Retrospective evaluation of patients with traumatic fractures and suspected delayed healing or non-union and/or persistent pain or suspected infection who had undergone planar late phase BS and SPECT/CT between 2011 and 2018. On the BS and SPECT/CT images, a necrotic fragment was considered if there was an area of absent radiotracer uptake (photopenia) related to bone at the fracture site. Histology served as a reference standard (presence or absence of necrotic bone fragments). If histology was not available, intraoperative findings and combined clinical and imaging follow-up served as reference standards. In 37 consecutive patients with traumatic fractures (femur (n = 18), tibia (11), humerus (6), radius (1), jaw (1)), necrotic bone fragments were suspected in 11 fractures (29.7%) on BS and in 16 fractures (43.2%) on SPECT/CT. 35 fractures (94.6%) had metallic implants. Histology showed necrotic fragments in 10/11 (90.9%) patients. For the detection of necrotic bone fragments, SPECT/CT showed sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 95%, 94%, 100%, and 97%, respectively, and BS 67%, 95%, 91%, 81%, and 83%, respectively. SPECT/CT significantly outperformed BS with better area under curve (AUC) for SPECT/CT (0.9773) compared to planar imaging (0.8106) (p-value < 0.01). SPECT/CT is an accurate tool in the assessment of necrotic bone fragments in patients with delayed bone healing or non-union after traumatic bone fractures and is superior to conventional planar BS. SPECT/CT is accurate and superior to planar BS in identification of necrotic bone fragments, responsible for delayed bone healing/non-union after fractures.

Molecular Imaging of Bone Metastases and Their Response to Therapy.

Bone metastases are common, especially in more prevalent malignancies such as breast and prostate cancer. They cause significant morbidity and draw on health-care resources. Molecular and hybrid imaging techniques, including SPECT/CT, PET/CT, and whole-body MRI with diffusion-weighted imaging, have improved diagnostic accuracy in staging the skeleton compared with previous standard imaging methods, allowing earlier tailored treatment. With the introduction of several effective treatment options, it is now even more important to detect and monitor response in bone metastases accurately. Conventional imaging, including radiographs, CT, MRI, and bone scintigraphy, are recognized as being insensitive and nonspecific for response monitoring in a clinically relevant time frame. Early reports of molecular and hybrid imaging techniques, as well as whole-body MRI, promise an earlier and more accurate prediction of response versus nonresponse but have yet to be adopted routinely in clinical practice. We summarize the role of new molecular and hybrid imaging methods, including SPECT/CT, PET/CT, and whole-body MRI. These modalities are associated with improvements in diagnostic accuracy for the staging and response assessment of skeletal metastases over standard imaging methods, being able to quantify biologic processes related to the bone microenvironment as well as tumor cells. The described improvements in the imaging of bone metastases and their response to therapy have led to adoption of some of these methods into routine clinical practice in some centers. These methods also provide a better way to assess the treatment response of bone metastases in clinical trials.

Prostate-specific membrane antigen positron emission tomography in the management of recurrent prostate cancer.

There is an unmet clinical need for early, accurate imaging of recurrent prostate cancer to improve patient outcomes. Staging, by conventional bone scintigraphy and CT have become outdated. 68Ga-PSMA PET/CT imaging in this setting has developed rapidly, with widespread International adoption in line with evidence-based guidelines in this group of patients. A PubMed search of English language articles was performed using following keywords: PSMA, PET/CT, biochemical recurrence, prostate cancer. The search revealed 85 articles, of which 75 were original; 70 of these involved use of the most widely available type of PSMA tracer (HBED). The review also relied on the clinical experience of reporting over 1000 PSMA PET/CT studies at a major tertiary referral centre for uro-oncology, with the majority of cases having been performed in the biochemical recurrence setting from 2015 to 2018. 68Ga-PSMA PET is a game changer and superior to choline PET and other established tracers which have been used in prostate cancer evaluation. Detection of recurrence at the prostate bed remains challenging due to bladder and urethral tracer accumulation. The main strength of PSMA PET/CT is its ability to identify small (<8 mm) pathological lymph nodes, upstaging nodal status in up to two-thirds of cases. Additionally, PSMA PET/CT, detects bone and bone marrow metastases missed by conventional bone and CT imaging. Thus, PSMA PET/CT has major impact on patient management, with studies reporting overall changes in 39-76% of cases. Controversy exists regarding patient access and NHS affordability of PSMA PET/CT imaging. Currently, no reimbursement is available under the NHS tariff system. The cost outlay for tertiary hospital linked PET centres ranges from £150-170 K. Large referral volumes, and technical advances in manufacturing process will make this tracer cost neutral and similar to the current funded, but less sensitive, choline PET. Current NICE guidelines for prostate cancer management do not include a recommendation on when PSMA PET/CT should be used and this is likely to remain the case in the next revision, due in 2019. Although PSMA PET/CT imaging results in significant management change, there is a need for high quality economic evaluation and cost analysis for this modality. Lack of this data will result in poor adoption of this technique and thus limit patient access. Furthermore, it is hoped that future tracers will become even more sensitive and identify disease at earlier thresholds. Well-designed clinical trials with consideration of the health economic benefit of using PSMA PET/CT will be essential to provide a basis for entry into guidelines such as NICE and to provide a rationale for reimbursement.

Technical feasibility, radiation dosimetry and clinical use of 18F-sodium fluoride (NaF) in evaluation of metastatic bone disease in pediatric population.

The role of 18F-fluoride (18F-NaF) PET-CT for the detection of bone metastases in adults is well established and is considered superior to conventional bone scintigraphy. However, data pertaining use of 18F-NaF PET-CT in pediatric oncology is relatively sparse. The aim of the present study is to retrospectively analyze and share a single-center experience of 18F-NaF PET-CT in pediatric population and to provide preliminary information regarding imaging technique, feasibility of this modality in young patients and radiation dosimetry measurements in pediatric oncology cases. Twenty-four pediatric patients (mean age 8.0 ± 3.9) were included in the study for retrospective analysis. All patients were referred for primary staging or restaging for potential osseous metastatic disease and PET-CT scan was performed by injecting 2.2MBq/kg (0.06mCi/kg) of 18F-NaF. Nine patients were imaged for primary staging and in all cases increase osteoblastic activity was seen in the primary tumor and of these, metastatic bone disease was identified in 2/9 patients. In the restaging group comprising 15/24 patients, metastatic deposits were identified in 3/15 whilst no disease was seen in the remaining 12 patients. Patients were injected a mean dose of 90.35 ± 22.9MBq with an estimated mean effective absorbed doses of 2.98 ± 0.75mSv for 18F-NaF and 3.37 ± 2.4mSv for CT alone. Mean cumulative effective dose of 18F-NaF PET-CT scan was 5.11 ± 2.7mSv. 18F-NaF PET-CT may be a feasible alternative to 99mTc MDP for radionuclide bone scintigraphy in the evaluation of pediatric bone pathology. Due to its better pharmacokinetics, there is potential that osseous staging can be achieved with relatively low doses and with a similar radiation burden as with 99mTc-MDP imaging.

Evaluation of Skeletal Hot Spots in Carcinoma Prostate Patients by Scintimetric Method

&lt;p&gt;Skeletal scintigraphy is a highly sensitive tool in the detection of metastatic disease from prostate cancer, but its specificity is relatively low. Various quantitative parameters have been introduced to improve the bone scan specificity. Scintimetric method based Dr. V. Siva’s retention ratio is one such parameter proposed to help in predicting malignant or metastatic nature of the skeletal hot spots in a bone scan non-invasively. This study was performed to evaluate the V. Siva’s ratio in a small sample of prostate cancer patients in Bangladeshi population. This prospective observational study was carried out at the National Institute of Nuclear Medicine and Allied Sciences (NINMAS) from July 2015 to June 2016. A total of 32 patients with diagnosed prostate cancer were enrolled. Each patient underwent two bone scans at 4 hours and 24 hours respectively after radiopharmaceutical injection. Focal hot spots reported by expert Nuclear Medicine specialists were identified in both scans and maximum counts were taken by drawing region of interest over the spots. Dr. V. Siva’s retention ratio was calculated by dividing the 4-hour count with 24-hour count. Finally statistical analysis was done. The mean V. Siva's ratio of metastatic group was 9.3 ± 2.2 (95% CI 8.5-10.1) and that of degenerative group was 8.2 ± 2.0 (95% CI 7.5-8.9). Statistically significant difference was observed between the two groups. So it can be said that V. Siva’s retention ratio might be useful as a quantitative parameter in adjunct to conventional bone scintigraphy for the skeletal survey of carcinoma prostate patients.&lt;/p&gt;&lt;p&gt;Bangladesh J. Nuclear Med. 20(1): 9-13, January 2017&lt;/p&gt;

HYBRID BONE SCINTIGRAPHY IN GASTROINTESTINAL MALIGNANCIES – INSTITUTIONAL EXPERIENCE

Objective: Bone metastases in gastrointestinal (GI) malignancies are uncommon and known to be predominantly lytic thus rendering a limited role for conventional bone scintigraphy. The aim of the study is to review Tc99m MDP bone scans performed in patients with known GI malignancy and the utility of Single-photon emission computed tomography (SPECT)/CT in characterization of bone lesions.Methods: Retrospective review of bone scans was done from June 2014 to December 2016 in patients with known GI malignancy, using electronic Hospital Information System.Results: A total of 110 patients (60 males, 50 females; Age range: 22–84 years, Mean Age 51.4 years with SD of 14.8) had bone scan over a period of 30 months. The commonest indications for referral were suspected bone metastasis on other imaging modalities including [CT (n = 56), Magnetic resonance imaging (n = 10), Positron emission tomography/CT (n = 6)], musculoskeletal pain (n = 37), pathological fracture (n = 1), neurological symptoms (n = 1), hypercalcemia (n = 1) and others (n =14) including restaging workup etc. Metastatic lesions were identified in 32 (29%) patients whereas 78 (71%) patients had benign non-aggressive lesions leading to normal bone scans. Among 32 patients with osseous metastasis, 8 (25%) patients had unifocal lesion; axial skeleton (n = 2) appendicular skeleton (n = 6), 24 (75%) patients had multifocal lesions; axial skeleton (n = 6), appendicular skeleton (n = 6) and both axial + appendicular (n = 12). Four (12%) patients had concurrent visceral metastases. In our cohort, based on the location of primary tumour, the frequencies of osseous metastasis were; esophagus = 15 out of 43 (35%), gastric = 7 out of 18 (39 %), gastro-esophageal junction = 1 out of 8 (1.5%) and colorectal = 9 out of 40 (22.5). SPECT/CT was acquired in 29 out of 110 patients, which characterized metastatic lesions (n = 12) and benign looking non-aggressive entities (n =17). Overall, bone scan upstaged disease in 31% and down staged 15% patients.Conclusion: Bone metastases in GI malignancies, though uncommon, show an aggressive pattern, with axial and appendicular involvement, and can be readily identified with hybrid bone scintigraphy in symptomatic patients. Key words: Hybrid imaging, Tc99m MDP, bone metastases, gastrointestinal malignancies

A proof-of-concept study analyzing the clinical utility of fluorine-18-sodium fluoride PET-CT in skeletal staging of oncology patients with end-stage renal disease on dialysis.

The quality of conventional bone scintigraphy can be poor in patients with end-stage renal disease (ESRD). Fluorine-18-sodium fluoride (F-NaF) PET-computed tomography (CT) has rapid single-pass extraction, fast clearance from the soft tissues and a better target to background ratio. The aim of the present study is to preliminarily assess the superior tracer kinetics of F-NaF in ESRD patients. A cohort comprising of 13 patients with ESRD (mean age 65.5 years; median age 68.5 years; six men and seven women) and a control group of 20 patients with normal renal function (mean age 64±7.7 years, nine men and 11 women) were analyzed qualitatively and quantitatively. Both sets of patients were referred for osseous staging of malignancy. All patients underwent a PET-CT scan after an injection of 0.06 mCi/kg of F-NaF. Qualitative analysis of the ESRD and the control group did not show a significant difference. The signal to noise ratio in the ESRD group (26.24±10.5) and the control group was similar (22.06±10.9), P=0.35. The extraction of radiotracer in bone was higher in ESRD with a bone to soft tissue index of 4.03±2.2 versus 2.48±1.0 in control patients (P=0.01). F-NaF PET-CT was positive for bone metastases in three patients and negative in 10 patients. Of the 48 total lesions, 34 (71%) were classified as benign on F-NaF PET-CT, whereas 10 (21%) were classified as malignant and four (8%) were classified as equivocal. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of F-NaF PET-CT were 91, 89.5, 90, 71.4, and 89.7%, respectively (P<0.001). The image quality of F-NaF PET-CT in patients with ESRD was comparable to imaging in patients with normal renal function. This can potentially translate into better diagnostic performance in patients with ESRD.

Intérêt de la médecine nucléaire dans la maladie d’Erdheim-Chester : une expérience lilloise

IntroductionErdheim-Chester disease is a rare form of non-langerhans histiocytosis and its etiology is still not well established. The aims of the study were to assess the value of the bone scintigraphy and the 18F-FDG PET/CT for the diagnostic and for the latter in the therapeutic evaluation. MethodsWe retrospectively reviewed 49 patients suspected of Erdheim-Chester disease between 2004 and 2016. Bone scintigraphy was compared with histopathology and PET-CT to conventional morphological examinations and bone scintigraphy. For therapeutic evaluation, thresholds similar to PERCIST 1.0 were used. ResultsForty-nine bone scintigraphy were evaluated with a sensitivity of 100%, a specificity 97%, a positive predictive value 90% and a negative predictive value of 100%. Eight patients had at least an initial PET-CT. The sensitivity compared to conventional morphological examinations differed from the location but was excellent for orbital, bone and vascular involvements. Specificity was comparable between the different examinations. Six patients treated with interferon® and three with vemurafenib® were followed by PET-CT. PET-CT, in agreement to clinicobiological data, identified 4 partial responses and one complete response with interferon® et two partial responses and one complete response with vemurafenib®. ConclusionOur retrospective study suggests that bone scintigraphy and 18F-FDG PET/CT could be useful in the initial assessment of Erdheim-Chester disease but also for the latter in the therapeutic evaluation.

Abnormal Focal Jaw Uptake of 153 Sm-Ethylene-Diamine-Tetra- Methylene-Phosphonate (EDTMP) – What is the Reason?

Abnormal focal tracer uptake in the jaw during conventional bone scintigraphy is a quite frequent finding usually not related to malignant disease. In patients undergoing radionuclide therapy with lanthanoids or rhenium, the appearance is also quite frequent. ItAS¼s origin so far has not been studied in a large number of patients. Objective, to evaluate the underlying reason of abnormal focal tracer uptake in the jaw in patients who underwent 153Sm-EDTMP therapy for painful metastatic lesions. Methods, out of 138 patients, 82 revealed a positive result, 60 males and 22 females (mean age: 63.9 ± 13.9years; range 19-90 years), with metastatic bone pain were examined. Their lesions were judged by a dentist clinically and radiologically. Results, the most frequent reason of increased focal uptake in the group of mainly prostate and breast cancer patients was inflammation in 13 (24.5%) and 9 (41%) patients, respectively. In the patients below 70 years of age, inflammation was the most frequent reason with (32.7%) while in the older ones of 70 years, it was mechanically irritated by a prosthesis with (50%). In 4 of the patients, the increased uptake of 153Sm-EDTMP was due to metastatic disease as shown by PET/CT and/or MRI. Conclusion, although the number of secondary lesions in the jaw is small (4.8%), the underlying reason in conventional bone scintigraphy as well as in post-therapeutic scintigraphy should be always evaluated.

Assessment of Bone Pain Response in Cancer Patients Receiving Single Dose of Sm-153 EDTMP Therapy

Background: Painful metastatic bone dissemination is a common complication of solid malignant tumors that can lead to severe morbidity. There are different treatment strategies currently available for pain relief. Among those, we obtained clinical experience with Sm-153 EDTMP.Objective: It was to evaluate the overall therapeutic response in 110 patients who underwent a single dose of Sm-153 EDTMP therapy and report if there is a significant correlation of metastatic bone pain response with gender, pathology of primary cancer, patient’s age, extent of the metastatic bone dissemination.Patients and methods: 110 cancer patients were included in this retrospective analysis, 63 (57.2%) males (age range; 52-89 years) and 47 (42.7%) females (age range: 35-84 y), their diagnosis were prostate and breast cancer, respectively. all patients performed conventional bone scintigraphy to prove the evidence of metastatic bone dissemination. Pain severity was assessed clinically and according to WHO Analgesia Scale.Results: Out of 110 cancer patients received a therapeutic dose of 153 Sm- EDTMP for palliation of painful metastatic bone lesions, 93.6% (103/110) showed overall therapeutic response and 6.4% (7/110) showed no response at all. 61% (67/110) of patients were completely pain-free, 32.6% (36/110) were partially responded to therapy, that response shows insignificant relations with the patients gender, pathology of primary tumor, patients age as well as the extent of metastatic bone dissemination.Conclusion: The results of this study showed that a single dose of Sm-153 EDTMP offers an effective treatment option in patients with painful metastatic bone disseminations irrespective to their gender, age, tumor pathology as well as to the bone lesions extent.

The Role of 18F-Sodium Fluoride PET/CT Bone Scans in the Diagnosis of Metastatic Bone Disease from Breast and Prostate Cancer.

We describe the role of 18F-sodium fluoride (18F-NaF) PET/CT bone scanning in the staging of breast and prostate cancer. 18F-NaF PET was initially utilized as a bone scanning agent in the 1960s and early 1970s, however, its use was restricted by the then-available γ-cameras. The advent of hybrid PET/CT cameras in the late 1990s has shown a resurgence of interest in its use and role. After a brief introduction, this paper describes the radiopharmaceutical properties, dosimetry, pharmacokinetics, and mechanism of uptake of 18F-NaF. The performance of 18F-NaF PET/CT is then compared with that of conventional bone scintigraphy using current evidence from the literature. Strengths and weaknesses of 18F-NaF PET/CT imaging are highlighted. Clinical examples of improved accuracy of diagnosis and impact on patient management are illustrated. Limitations of 18F-NaF PET/CT imaging are outlined.

Inguinal Herniation of Urinary Bladder on F-18 Sodium Fluoride (NaF) PET-CT.

Inguinal herniation of urinary bladder is uncommon and usually an incidental finding in asymptomatic patients. In some of these patients, residual urine volume and consequently, urinary tracer activity can be higher in the herniated bladder than the native bladder, in which case interpretation can be challenging on conventional planar imaging. We describe an interesting case of physiological activity in a herniated bladder simulating a "tear-drop". This case serves an important reminder that whilst F-18 NaF PET-CT has a similar spectrum of urinary activity to conventional bone scintigraphy; morphological correlation on hybrid imaging is invaluable in ensuring the physiological nature of uptake.

Metastatic superscan in prostate carcinoma on gallium-68-prostate-specific membrane antigen positron emission tomography/computed tomography scan.

We describe the imaging features of a metastatic superscan on gallium-68 Glu-NH-CO-NH-Lys-(Ahx)-[Ga-68(HBED-CC)], abbreviated as gallium-68-prostate-specific membrane antigen (68Ga-PSMA) positron emission tomography/computed tomography (PET/CT) imaging. 68Ga-PSMA is novel radiotracer undergoing evaluation for PET/CT imaging of prostate carcinoma. This patient had a superscan of metastases on conventional bone scintigraphy and was referred for 68Ga-PSMA PET/CT to evaluate the feasibility of 177Lu-PSMA therapy.

Prospective study evaluating the relative sensitivity of 18F-NaF PET/CT for detecting skeletal metastases from renal cell carcinoma in comparison to multidetector CT and 99mTc-MDP bone scintigraphy, using an adaptive trial design

BackgroundThe detection of occult bone metastases is a key factor in determining the management of patients with renal cell carcinoma (RCC), especially when curative surgery is considered. This prospective study assessed the sensitivity of 18F-labelled sodium fluoride in conjunction with positron emission tomography/computed tomography (18F-NaF PET/CT) for detecting RCC bone metastases, compared with conventional imaging by bone scintigraphy or CT. Patients and methodsAn adaptive two-stage trial design was utilized, which was stopped after the first stage due to statistical efficacy. Ten patients with stage IV RCC and bone metastases were imaged with 18F-NaF PET/CT and 99mTc-labelled methylene diphosphonate (99mTc-MDP) bone scintigraphy including pelvic single photon emission computed tomography (SPECT). Images were reported independently by experienced radiologists and nuclear medicine physicians using a 5-point scoring system. ResultsSeventy-seven lesions were diagnosed as malignant: 100% were identified by 18F-NaF PET/CT, 46% by CT and 29% by bone scintigraphy/SPECT. Standard-of-care imaging with CT and bone scintigraphy identified 65% of the metastases reported by 18F-NaF PET/CT. On an individual patient basis, 18F-NaF PET/CT detected more RCC metastases than 99mTc-MDP bone scintigraphy/SPECT or CT alone (P = 0.007). The metabolic volumes, mean and maximum standardized uptake values (SUVmean and SUVmax) of the malignant lesions were significantly greater than those of the benign lesions (P < 0.001). Conclusions18F-NaF PET/CT is significantly more sensitive at detecting RCC skeletal metastases than conventional bone scintigraphy or CT. The detection of occult bone metastases could greatly alter patient management, particularly in the context when standard-of-care imaging is negative for skeletal metastases.