Tc-99m MDP Uptake Research Articles

Incidental thyroid uptake during 99mTc-methylene diphosphonate bone scintigraphy in oncologic patients

Introduction: Extraosseous accumulation of 99mTc – methylene diphosphonate (MDP) may be due to neoplastic, dystrophic, hormonal, inflammatory, ischemic, traumatic or excretory disorders. 99mTc-MDP incidental thyroid uptake is not frequent and is possibly caused by the presence of dystrophic or metastatic calcification, biopsy procedure and presence of benign or malignant thyroid nodules. To analyze the etiological factors leading to 99mTc-MDP uptake in the thyroid gland. Methods: Fifty patients (pts), 19 females (38%) and 31 males (62%), 62±12 years, with no pervious history of thyroid disease, were included in the study. In the period January 2016 – January 2018, all pts underwent MDP bone scintigraphy due to oncologic indication and incidental tracer uptake was noted in the region of the thyroid gland. Ultrasonography (US) was performed in all pts. Patients with detected nodules underwent 99mTc-pertechnetate scintigraphy and fine needle aspiration cytology (FNAC). Thyroid hormone and autoantibodies levels were also analyzed. SPECT/CT procedure was performed in all patients to precisely localize the MDP uptake. Results: Thirty-nine patients had calcifications in the thyroid gland (29 with microcalcifications and 10 with macrocalcifications). In 23 patients, thyroid nodules were detected. 99mTc-pertechnetate scintigraphy presented 15 cold nodules and 8 nodules with increased tracer uptake. FNAC in 3 patients presented nuclear anisocariosis, with Hurthle cell metaplasia, and surgery was advised. In 11 patients, thyroid cartilage calcifications were detected. Conclusion: Incidental findings of thyroid 99mTc-MDP accumulation during bone scintigraphy indicate presence of additional, previously unexpected, active disease processes.

The PI3K inhibitor buparlisib suppresses osteoclast formation and tumour cell growth in bone metastasis of lung cancer, as evidenced by multimodality molecular imaging.

Non-small cell lung cancer (NSCLC) metastasis commonly occurs in bone, which often results in pathological fractures. Sustained phosphoinositide-3-kinase (PI3K) signalling promotes the growth of PI3K-dependent NSCLC and elevates osteoclastogenic potential. The present study investigated the effects of a PI3K inhibitor on NSCLC growth in bone and osteoclast formation, and aimed to determine whether it could control symptoms associated with bone metastasis. A bone metastasis xenograft model was established by implanting NCI-H460-luc2 lung cancer cells, which contain a phosphatidylinositol- 4,5-bisphosphate 3-kinase catalytic subunit α mutation, into the right tibiae of mice. After 1 week, the tumours were challenged with a PI3K inhibitor (buparlisib) or blank control for 3 weeks. Tumour growth and burden were longitudinally assessed in vivo via reporter gene bioluminescence imaging (BLI), small animal positron emission tomography/computed tomography (CT) [18F-fluorodeoxyglucose (18F-FDG)] and single-photon emission computed tomography/CT [99mTc-methylene diphosphonate (99mTc-MDP)] imaging. Tibia sections of intraosseous NCI-H460 tumours were analysed by immunohistochemistry (IHC), western blotting and flow cytometry. Dynamic weight bearing (DWB) tests were further performed to examine the improvement of symptoms associated with bone metastasis during the entire study. Administration of buparlisib significantly inhibited the progression of bone metastasis of NSCLC, as evidenced by significantly reduced uptake of 18F-FDG, 99mTc-MDP and BLI signals in the treated lesions. In addition, buparlisib appeared to inhibit the expression of tartrate-resistant acid phosphatase and receptor activator of nuclear factor-κB ligand, as determined by IHC. Buparlisib also resulted in increased cell apoptosis, as determined by a higher percentage of Annexin V staining and increased caspase 3 expression. Furthermore, buparlisib significantly increased weight-bearing capacity, as revealed by DWB tests. The PI3K inhibitor, buparlisib, suppressed osteoclast formation in vivo, and exhibited antitumour activity, thus leading to increased weight-bearing ability in mice with bone metastasis of lung cancer. Therefore, targeting the PI3K pathway may be a potential therapeutic strategy that prevents the structural skeletal damage associated with bone metastasis of lung cancer.

Prognostic value of focal scintigraphic findings in clinically suspected cases of tibial stress fracture.

ObjectiveTo investigate the correlation between tracer uptake on bone scintigraphy and recovery time in patients with tibial stress fracture.Materials and MethodsWe evaluated two groups of athletes: those with clinical suspicion and a radiological diagnosis of tibial stress fracture (TSF group, n = 21); and those with no symptoms or evidence of fracture (control group, n = 10). All subjects underwent bone scintigraphy and magnetic resonance imaging with a maximum interval of 7 days between the assessments.ResultsUsing the region of interest technique, we obtained a quantitative evaluation index, comparing affected and unaffected legs. The mean uptake of 99mTc-MDP was significantly higher in the TSF group than in the control group (2.54 ± 0.77 vs. 1.05 ± 0.11; p < 0.001).ConclusionIn our sample of athletes, determining the bone scintigraphy uptake indices provided an objective method to estimate the appropriate recovery time after a tibial stress fracture.

Relationship between tumor volume and quantitative values calculated using two-dimensional bone scan images

The bone scan index (BSI) is calculated from a whole-body bone scan image; it shows the tumor burden in bone as a percentage of total skeletal mass. It has been used to determine the prognosis and to assess treatment effects; however, little has been reported on whether the BSI calculated using a two-dimensional image can accurately evaluate the three-dimensional spread in tumor volume. We investigated the relationship between tumor volume and BSI using Monte Carlo simulation (MCS). We simulated a gamma camera and constructed a voxel phantom based on an anthropomorphic phantom computed tomography (CT) image and gamma rays emitted from each part according to technetium-99m-labeled methylene diphosphonate (99mTc-MDP) uptake (bone 1, soft tissue 0.2, tumor 2-32). We constructed bone scan images from the obtained counts and analyzed them using the BSI calculation software. The BSI increased with increased tumor uptake (two- to 32-fold). However, there was not always a significant difference between change in BSI and tumor uptake of eight times or greater than that of bone. When BSI was calculated with a tumor having an uptake of four-to-eight times higher than that of bone, the BSI was consistent with tumor volume, but decreased to about half the tumor volume when tumors were in the thoracic spine (Th-spine) segment. The BSI can be a good indicator of tumor volume in most segments, even though it is affected by the tumor's 99mTc-MDP uptake. Nevertheless, values calculated from the Th-spine should be interpreted carefully.

Incidental Tc-99m Methylene Diphosphonate Uptake in an Active Thyroid Nodule.

Tc-99m-methylene diphosphonate (MDP) whole body scintigraphy is the method of choice for detection of metastatic bone diseases. It is primarily used to help diagnose various bone-related conditions such as primary or metastatic cancer of the bone, location of bone inflammation, and fractures that may not be visible on traditional X-ray images, as well as detection of bone damage due to infections and other conditions. In addition, bone scanning is often used for the follow-up or evaluation of response to treatment in some malignancies like prostate and breast cancers. Pathologies of other systems can also be incidentally detected on whole body bone scan. Herein we present an interesting image of an active thyroid nodule that showed Tc-99m MDP uptake in a prostate cancer patient.

Tc-99m MDP uptake in soft tissue calcification in systemic scleroderma (crest syndrome)

23 yasindaki bayan hasta, sag gluteal bolgede ve uyluk lateralinde yer alan akintili yara sikayetleri uzerine, osteomyelit on tanisi ile tum vucut kemik sintigrafisi icinklinigimize gonderildi. Hasta bes yil once Skleroderma tanisi almisti. 20 mCi Tc-99m-MDP nin iv. Enjeksiyonu sonrasi yapilan uc fazli kemik sintigrafisinde; sag gluteal bolgede perfuzyon artisi ve hiperemi ile uyumlu bulgular izlendi. Tc-99m MDP Uc fazli kemik sintigrafisi 3. Saat gec goruntulerinde her iki diz bolgesi proksimalinde olmak uzere pelvik bolgeye uzanan yumusak dokuya uyan alanda artmis radyofarmasotik tutulumu izlenmistir. Hastanin direk radyografi goruntulerinde ayni alanlarda yumusak doku kalsifikasyonu ile uyumlu gorunum izlendi. Hastanin direk radyografi goruntuleri incelendiginde her iki diz bolgesinde yumusak doku kalsifikasyonu ile uyumlu gorunum izlendi. Bu vakayi sunmaktaki amacimiz, kemik sintigrafisinin sklerodermali hastalardaki kalsinozisi gostermede ve vucuttaki yayginliginin saptanmasindaki katkisini gostermektir.

The value of 99mTc-methylene diphosphonate single photon emission computed tomography/computed tomography in diagnosis of fibrous dysplasia

BackgroundFibrous dysplasia (FD) is a rare benign bone disorder in which the normal bone is replaced by immature fibro-osseous tissue. However, some case reports have reported that FD showed significantly increased 99mTc-methylene diphosphonate (99mTc-MDP) uptake on whole-body bone scintigraphy (WBS), which may mimic bone metastasis or skeletal involvement of the patients with known cancer. Thus, the purpose of present study is to observe the reliable characteristics and usefulness of single photon emission computed tomography/computed tomography (SPECT/CT) for the diagnosis of FD.MethodsThis was a retrospective review of 21 patients with FD (14 males and 7 females, mean age 51.2 ± 12.5 years) who were referred to have WBS to determine whether there was any osseous metastasis. WBS and SPECT/CT images were independently interpreted by two experienced nuclear medicine physician together with a diagnostic radiologist. In cases of discrepancy, consensus was obtained by a joint reading. The final diagnosis was based on biopsy proof and radiologic follow-up over at least 1 year.ResultsThe lesions of FD were most frequently found in craniofacial region (15/21). Eighteen of the 21 (85.7%) cases showed moderate and high metabolism on WBS (compared to sternum). On CT imaging, GGO and expansion were the most common finding, were noted in 90.5% and 85.7% of the patients. Lytic lesions were present in 61.9% of the patients, and sclerosis was present in 38.1% of the patients. Cortical disruption was not seen in any patient.ConclusionsFD has certain characteristic appearance on SPECT/CT. It should be enrolled in the differential diagnoses when lesions show elevated 99mTc-MDP uptake on WBS. For SPECT/CT, the CT features of GGO and expansion in the areas of abnormal radiotracer uptake are helpful for the diagnosis of FD.

Comparison of 99mTc-MDP SPECT qualitative vs quantitative results in patients with suspected condylar hyperplasia.

To compare qualitative vs quantitative results of Single Photon Emission Computerised Tomography (SPECT), calculated from percentage of 99mTc-MDP (methylene diphosphonate) uptake, in condyles of patients with a presumptive clinical diagnosis of condylar hyperplasia. A retrospective, descriptive study was conducted on the 99mTc-MDP SPECT bone scintigraphy reports from 51 patients, with clinical impression of facial asymmetry related to condylar hyperplasia referred by their specialist in orthodontics or maxillofacial surgery, to a nuclear medicine department in order to take this type of test. Quantitative data from 99mTc-MDP condylar uptake of each were obtained and compared with qualitative image interpretation reported by a nuclear medicine expert. The concordances between the 51 qualitative and quantitative reports results was established. The total sample included 32 women (63%) and 19 men (37%). The patient age range was 13-45 years (21±8 years). According to qualitative reports, 19 patients were positive for right side condylar hyperplasia, 12 for left side condylar hyperplasia, with 8 bilateral, and 12 negative. The quantitative reports diagnosed 16 positives for right side condylar hyperplasia, 10 for left side condylar hyperplasia, and 25 negatives. Nuclear medicine images are an important diagnostic tool, but the qualitative interpretation of the images is not as reliable as the quantitative calculation. The agreement between the two types of report is low (39.2%, Kappa=0.13; P>.2). The main limitation of quantitative reports is that they do not register bilateral condylar hyperplasia cases.

Comparison of 99mTc-MDP SPECT qualitative vs quantitative results in patients with suspected condylar hyperplasia

ObjectiveTo compare qualitative vs quantitative results of Single Photon Emission Computerised Tomography (SPECT), calculated from percentage of 99mTc-MDP (methylene diphosphonate) uptake, in condyles of patients with a possible clinical diagnosis of condylar hyperplasia. Materials and methodA retrospective, descriptive study was conducted on the 99mTc-MDP SPECT bone scintigraphy reports from 51 patients, with clinical impression of facial asymmetry related to condylar hyperplasia referred by their specialist in orthodontics or maxillofacial surgery, to a nuclear medicine department in order to take this type of test. Quantitative data from 99mTc-MDP condylar uptake of each were obtained and compared with qualitative image interpretation reported by a nuclear medicine expert. ResultsThe concordances between the 51 qualitative and quantitative reports results was established. The total sample included 32 women (63%) and 19 men (37%). The patient age range was 13–45 years (21±8 years). According to qualitative reports, 19 patients were positive for right side condylar hyperplasia, 12 for left side condylar hyperplasia, with 8 bilateral, and 12 negative. The quantitative reports diagnosed 16 positives for right side condylar hyperplasia, 10 for left side condylar hyperplasia, and 25 negatives. ConclusionsNuclear medicine images are an important diagnostic tool, but the qualitative interpretation of the images is not as reliable as the quantitative calculation. The agreement between the two types of report is low (39.2%, Kappa=0.13; p>0.2).The main limitation of quantitative reports is that they do not register bilateral condylar hyperplasia cases.

Novel treatment of 99Tc-MDP improves clinical and radiographic results for patients with osteochondral lesions of the talus.

Management of osteochondral lesions of talus (OLT) remains controversial. 99Tc-MDP, a decay product of 99mTc-MDP which is widely used for bone scan, is effective in the clinical treatment of rheumatoid arthritis. The purpose of the study is to investigate the effects of 99Tc-MDP treatment on OLT. In the clinical evaluation, 66 patients with a total of 83 lesions of OLT who failed appropriate non-operative treatment and surgery were retrospectively included and treated with intravenous injection of 99Tc-MDP and Chinese herbal fumigation (CHF). The effects of 99Tc-MDP and CHF on OLT were evaluated by the American Orthopedic Foot and Ankle Society Ankle-Hindfoot Score (AOFAS), Visual Analog Scale (VAS), activities of daily living (Barthel Index), and MRI, 99mTc-MDP SPECT/CT and CT. Radiographic changes were also assessed by the transverse long diameter of the cyst on CT. At the last follow-up, AOFAS, VAS and Barthel Index improved significantly from 68.66±9.76, 3.05±0.34 and 85±8.31 to 85.4±8.31, 1.85±0.36 and 94.7±4.99 (P<0.01), respectively after one course treatment in 66 patients with OLT. Thirty one (31/66) patients had a second treatment course. Their AOFAS, VAS and Barthel Index also improved significantly after the mean follow-up of 7±2 (6-15) months. And the average diameter of the cysts decreased from 8.01±3.35 mm to 4.74±2.83 mm (P<0.01) in the 31 patients. The retrospective study indicates that a combination treatment of 99Tc-MDP and CHF is effective in pain relief and return of function in a short term of follow-up for patients with OLT. Our results suggest that the small cystic lesions with increased uptake of 99mTc-MDP on SPECT/CT can be well treated by 99Tc-MDP and CHF. This novel technique holds the potential to emerge as an effective conservative treatment for OLT without adverse effects. The level of evidence for 99Tc-MDP is medium for the number of patients and retrospective study.

99mTc-MDP uptake in SPECT/CT by a bladder hernia simulating inguinal metastasis: A case report.

A 72-year-old male with a history of prostate cancer and high prostate specific antigen levels underwent 99mtechnetium-methylene diphosphonate (99mTc-MDP) single-photon emission computed tomography/computed tomography (SPECT/CT), to identify bone metastasis. The patient possessed no previous history of serious illnesses or surgical procedures and no family history of malignancies. A whole-body CT scan revealed an intense MDP uptake in the right inguinal region on the anterior view, but not in the posterior view, which was suspected to be a metastatic lesion. However, there was no evidence of bone metastasis on the CT scan. In addition, an increased 99mTc-MDP uptake was indicated on the SPECT images in the right inguinal region, which appeared to be separate from the main bladder activity. CT images of the pelvis revealed an inferior tongue-like extension of the bladder into the right inguinal region. Fused SPECT/CT axial images indicated the circular accumulation of the 99mTc-MDP in the medial right groin, with well-defined walls that connected the accumulation to the bladder. The final diagnosis was a bladder hernia (T2N0M0), which may have been responsible for the misdiagnosis of bone metastasis due to the use of radiopharmaceuticals (99mTc-MDP) that were mainly excreted through urination. Considering the comprehensive situation of the patient, radical prostatectomy was performed. The bladder hernia was subsequently monitored by follow-up examination every 3 months, and remains alive and under follow-up to date.

SPECT/CT imaging characteristic of osteolytic lesions with increased bone metabolism and its correlation with CT manifestation

Objective To explore the characteristic of SPECT/CT imaging of osteolytic lesions with increased bone metabolism and its correlation with CT manifestation. Methods Twenty-one cancer patients with bone metastases underwent 99Tcm-MDP SPECT/CT imaging (13 males, 8 females; age: (60.52±6.85) years) were retrospectively studied. The imaging characteristic of the lesion with high uptake of 99Tcm-MDP was observed and the correlation between the lesion/background (L/B) ratio and CT manifestation were analyzed. One-way analysis of variance, two-sample t test and linear correlation analysis were used. Results A total of 111 lesions were found in 21 patients by 99Tcm-MDP whole-body bone scan, and 125 lesions were found by SPECT/CT imaging, including 111 lesions with increased bone metabolism and abnormal CT manifestation and 14 osteolytic lesions with decreased bone metabolism. In 111 lesions with increased bone metabolism, there were 23(20.72%) osteolytic lesions, 54 (48.65%) osteoblastic lesions and 34 (30.63%) mixed lesions. The L/B ratio of osteolytic lesions with increased bone metabolism (11.82±6.61) was lower than that of osteoblastic lesions (20.03±13.24) and that of mixed lesions (25.42±19.51; F=6.00, P<0.05). The CT value of osteolytic lesions with increased bone metabolism was higher than that of osteolytic lesions with decreased bone metabolism: (167.53±79.21) HU vs (88.63±49.16) HU; t=3.345, P<0.05. The L/B ratio of lesions with increased bone metabolism was positively correlated to CT value(r=0.404, P<0.05). Conclusions A part of lesions with increased bone metabolism on SPECT/CT images are osteolytic lesions. The L/B ratio of them is positively correlated to CT value. SPECT/CT imaging can reduce missed diagnosis and misdiagnosis. Key words: Neoplasm metastasis; Skeleton; Radionuclide imaging; Tomography, emission-computed, single-photon; Tomography, X-ray computed; MDP

The Value of SPECT/CT in Monitoring Prefabricated Tissue-Engineered Bone and Orthotopic rhBMP-2 Implants for Mandibular Reconstruction.

Bone tissue engineering shows good prospects for mandibular reconstruction. In recent studies, prefabricated tissue-engineered bone (PTEB) by recombinant human bone morphogenetic proteins (rhBMPs) applied in vivo has found to be an effective alternative for autologous bone grafts. However, the optimal time to transfer PTEB for mandibular reconstruction is still not elucidated. Thus, here in an animal experiment of rhesus monkey, the suitable transferring time for PTEB to reconstruct mandibular defects was evaluated by 99mTc-MDP SPECT/CT, and its value in monitoring orthotopic rhBMP-2 implants for mandibular reconstruction was also evaluated. The result of SPECT/CT showed higher 99mTc-MDP uptake, indicating osteoinductivity, in rhBMP-2 incorporated demineralized freeze-dried bone allograft (DFDBA) and coralline hydroxyapatite (CHA) implants than those without BMP stimulation. 99mTc-MDP uptake of rhBMP-2 implant peaked at 8 weeks following implantation while CT showed the density of these implants increased after 13 weeks’ prefabrication. Histology confirmed that mandibular defects were repaired successfully with PTEB or orthotopically rhBMP-2 incorporated CHA implants, in accordance with SPECT/CT findings. Collectively, data shows 99mTc-MDP SPECT/CT is a sensitive and noninvasive tool to monitor osteoinductivity and bone regeneration of PTEB and orthotopic implants. The PTEB achieved peak osteoinductivity and bone density at 8 to 13 weeks following ectopic implantation, which would serve as a recommendable time frame for its transfer to mandibular reconstruction.

Effects of magnetic resonance-guided high-intensity focused ultrasound ablation on bone mechanical properties and modeling.

BackgroundMagnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) is a promising technique for palliative treatment of bone pain. In this study, the effects of MR-HIFU ablation on bone mechanics and modeling were investigated.MethodsA total of 12 healthy rat femurs were ablated using 10 W for 46 ± 4 s per sonication with 4 sonications for each femur. At 7 days after treatments, all animals underwent MR and single photon emission computed tomography/computed tomography (SPECT/CT) imaging. Then, six animals were euthanized. At 1 month following ablations, the remaining six animals were scanned again with MR and SPECT/CT prior to euthanization. Thereafter, both the HIFU-treated and contralateral control bones of three animals from each time interval were processed for histology, whereas the remaining bones were subjected to micro-CT (μCT), three-point bending tests, and micro-finite element (micro-FE) analyses.ResultsAt 7 days after HIFU ablations, edema formation around the treated bones coupled with bone marrow and cortical bone necrosis was observed on MRI and histological images. SPECT/CT and μCT images revealed presence of bone modeling through an increased uptake of 99mTc-MDP and formation of woven bone, respectively. At 31 days after ablations, as illustrated by imaging and histology, healing of the treated bone and the surrounding soft tissue was noted, marked by decreased in amount of tissue damage, formation of scar tissue, and sub-periosteal reaction. The results of three-point bending tests showed no significant differences in elastic stiffness, ultimate load, and yield load between the HIFU-treated and contralateral control bones at 7 days and 1 month after treatments. Similarly, the elastic stiffness and Young’s moduli determined by micro-FE analyses at both time intervals were not statistically different.ConclusionsMultimodality imaging and histological data illustrated the presence of HIFU-induced bone damage at the cellular level, which activated the bone repair mechanisms. Despite that, these changes did not have a mechanical impact on the bone.

(99m)TC-Methylene diphosphonate uptake at injury site correlates with osteoblast differentiation and mineralization during bone healing in mice.

99mTc-Methylene diphosphonate (99mTc-MDP) is widely used in clinical settings to detect bone abnormalities. However, the mechanism of 99mTc-MDP uptake in bone is not well elucidated. In this study, we utilized a mouse tibia injury model, single-photon emission computed tomography (gamma scintigraphy or SPECT), ex vivo micro-computed tomography, and histology to monitor 99mTc-MDP uptake in injury sites during skeletal healing. In an ex vivo culture system, calvarial cells were differentiated into osteoblasts with osteogenic medium, pulsed with 99mTc-MDP at different time points, and quantitated for 99mTc-MDP uptake with a gamma counter. We demonstrated that 99mTc-MDP uptake in the injury sites corresponded to osteoblast generation in those sites throughout the healing process. The 99mTc-MDP uptake within the injury sites peaked on day 7 post-injury, while the injury sites were occupied by mature osteoblasts also starting from day 7. 99mTc-MDP uptake started to decrease 14 days post-surgery, when we observed the highest level of bony tissue in the injury sites. We also found that 99mTc-MDP uptake was associated with osteoblast maturation and mineralization in vitro. This study provides direct and biological evidence for 99mTc-MDP uptake in osteoblasts during bone healing in vivo and in vitro.

The effect of MRI contrast agents on hepatic and splenic uptake in the rabbit during (99m) Tc-MDP bone scintigraphy.

The objective of this study was to investigate the effects of Omniscan® and Magnevist® on (99m) Tc-MDP uptake in rabbits during (99m) Tc-MDP bone scintigraphy. In Experiment Group 1, 30 healthy adult rabbits were randomized into six subgroups (n = 5); each subgroup experienced a different time interval between injections (30 min, 60 min, 120 min, 240 min, 360 min, 24 h). All six subgroups were injected first with Omniscan®, then with (99m) Tc-MDP. After 7 days, the same six subgroups were injected with normal saline followed by (99m) Tc-MDP at the same time intervals. In Experiment Group 2, 20 healthy adult rabbits were allocated randomly to four subgroups (n = 5); each subgroup experienced a different time interval between injections (30 min, 60 min, 120 min, 240 min). All four subgroups were injected first with Magnevist®, then with (99m) Tc-MDP. After 7 days, the same four subgroups were injected with normal saline followed by (99m) Tc-MDP. In all experiments, whole-body skeletal imaging was performed. Liver, spleen, and background were delineated to determine the target-to-background (T/B) ratio. Diffusely increased intake of the imaging agent was seen in the liver and spleen when the injection-time interval between Omniscan® and (99m) Tc-MDP varied from 30 min to 240 min and when the time interval between Magnevist® and (99m) Tc-MDP was 30 min-60 min. The imaging findings are consistent with the results of L/B and S/B ratios in each experiment group. Both Omniscan® and Magnevist® have an effect on (99m) Tc-MDP uptake during bone scanning; the main effect is diffusely increased hepatic and splenic activity.

Quantification of radionuclide uptake levels for primary bone tumors

The purpose of the study is to quantify the level of uptake of administered radionuclide in primary bone tumors for patients undergoing bone scintigraphy. Retrospective study on 48 patient's scintigrams to quantify the uptake levels of administered radiopharmaceuticals was performed in a nuclear medicine unit in Ghana. Patients were administered with activity ranging between 0.555 and 1.110 MBq (15–30 mCi), and scanned on Siemens e.cam SPECT system. Analyses on scintigrams were performed with Image J software by drawing regions of interest (ROIs) over identified hot spots (pathologic sites). Nine skeletal parts namely cranium, neck, shoulder, sacrum, sternum, vertebra, femur, ribcage, and knee were considered in the study, which involved 96 identified primary tumors. Radionuclide uptakes were quantified in terms of the estimated counts of activity per patient for identified tumor sites. Average normalized counts of activity (nGMC) per patient ranged from 5.2759 ± 0.6590 cts/mm2/MBq in the case of cranium tumors to 72.7569 ± 17.8786 cts/mm2/MBq in the case of ribcage tumors. The differences in uptake levels could be attributed to different mechanisms of Tc-99m MDP uptake in different types of bones, which is directly related to blood flow and degree of osteoblastic activity. The overall normalized count of activity for the 96 identified tumors was estimated to be 23.0350 ± 19.5424 cts/mm2/MBq. The study revealed highest uptake of activity in ribcage and least uptake in cranium. Quantification of radionuclide uptakes in tumors is important and recommended in assessing patient's response to therapy, doses to critical organs and in diagnosing tumors.

Introduction of a metabolic joint asymmetry score derived from conventional bone scintigraphy. A new tool to differentiate psoriatic from rheumatoid arthritis.

Clinical differentiation of psoriatic arthritis (PsA) and rheumatoid arthritis (rA) based on the pattern of joint involvement can be difficult; the frequent form of PsA with polyarthritis of the peripheral joints may sometime resemble rA. We investigated a metabolic joint asymmetry score (MJAS), reflecting the overall asymmetric joint involvement on conventional bone scintigraphy, for differentiating PsA from rA in patients presenting with peripheral polyarthritis. 106 patients (n = 61, PsA; n = 45, rA) with peripheral polyarthritis (≥ 5 joints) as well as 26 control subjects with no history of chronic joint disorders were analyzed. The intensity of articular 99mTc-MDP uptake in 40 peripheral joint pairs was scored regarding the bilateral difference of each joint based on a scale of 0-2 (no significant, moderate, and marked asymmetry, respectively). The patient's MJAS was defined as the sum of uptake difference scores of all joint pairs. The association of MJAS with the underlying condition (Psoriasis criteria, Revised Criteria of the ACR) was examined. 5280 peripheral joint pairs were investigated. There was no significant difference in the total number of involved joints in PsA 15.0 ± 8.2 versus rA 17.5 ± 8.8 patients (p = 0.132), but significantly less involvement in the control group (6.7 ± 5.0, p < 0.001). MJAS was markedly higher in PsA (17.0 ± 9.6) than in rA (4.8 ± 3.9, p < 0.001), and correlated with the total number of involved joints in PsA (r= 0.516, p < 0.001), but not in rA (r = 0.078, p = 0.380). The MJAS disparity between PsA and rA persisted after exclusion of the DIP joints (14.4 ± 7.7 vs. 4.4 ± 3.3; p<0.001). The new reproducible semi-quantification method for the asymmetry of metabolic joint involvement permits differentiation of psoriatic from rheumatoid peripheral arthritis with MJAS being markedly higher in patients with PsA as compared to rA patients. The score may offer an effective complementary tool for characterizing patients with peripheral polyarthritis.

Asymmetric 99mTc-MDP Uptake in Mineralized Tendons Might Mimic Bone Lesions

A 55-year-old man was a hepatocellular carcinoma patient, diagnosed by sonography and a biopsy. Because of his musculoskeletal tenderness, a bone scan was performed to exclude skeletal metastasis. A subsequent F-FDG PET/CT scan revealed that the unilateral abnormal uptake seen on the bone scan was actually a mineralized tendon. A mineralized tendon is easily detectable using Tc-MDP; therefore, it is imperative to differentiate between bone lesions and mineralized tendons. In addition, few studies have reported F-FDG uptake in a calcified tendon.

Preclinical Evaluation of Imaging Biomarkers for Prostate Cancer Bone Metastasis and Response to Cabozantinib

Prostate cancer is incurable once it has metastasized to the bone. Appropriate preclinical models are lacking. The therapeutic efficacy of the multikinase inhibitor cabozantinib was assessed in an orthotopic xenograft model of castration-resistant prostate cancer (CRPC) bone metastasis using noninvasive, multimodality functional imaging. NOD/SCID mice were injected intratibially with luciferase-expressing ERG (v-ets avian erythroblastosis virus E26 oncogene homolog) rearranged VCaP human prostate carcinoma cells. The response of VCaP xenografts (n = 7 per group) to cabozantinib was investigated using bioluminescence imaging and anatomical and diffusion weighted magnetic resonance imaging. This enabled quantitation of tumor volume and apparent diffusion coefficient (ADC). Bone uptake of technetium-methylene diphosphonate ((99m)Tc-MDP) was assessed by single-photon emission computed tomography. Ex vivo micro computed tomography was used to quantify bone volume and correlated with appropriate histopathology. Statistical significance was determined using the two-sided Mann-Whitney test or Wilcoxon signed rank test. VCaP xenografts were predominantly osteosclerotic with some osteolytic activity. Fluorescent in situ hybridization analysis confirmed retention of ERG oncogene rearrangements. Cabozantinib induced a statistically significant 52% reduction in tumor luminance (P = .02) and stasis in tumor volume after 15 days of treatment. Tumor ADC statistically significantly increased with cabozantinib and was associated with extensive necrosis (after 10 days, mean tumor ADC ± SD = 556±43×10(-6) mm(2)/s vs pretreatment ADC = 485±43×10(-6) mm(2)/s; P = .02 ). Tumor-associated uptake of (99m)Tc-MDP was statistically significantly reduced after 3 days of treatment (P = .02), sustained over 15 days treatment, and associated with a statistically significant (P = .048) reduction in bone growth on the tibial cortex, yet a highly statistically significant (P = .001) increase in trabecular bone volume. The intratibial VCaP model faithfully emulates clinical disease. Cabozantinib exerts potent effects on both tumor and tumor-induced bone matrix remodeling, and quantitation of ADC provides a clinically translatable imaging biomarker for early, sensitive assessment of treatment response in CRPC bone metastasis.