SPECT/CT imaging: quantifying 99mTc-MDP concentration in the spine and pelvis.

OBJECTIVE: This study aimed to identify a relatively robust SUV for guiding clinical practice through quantitative measurement and comparison of various normalization methods based on the SUV of 99mTc-MDP in the normal spine and pelvis using an integrated SPECT/CT scanner. METHODS: Between June 2017 and September 2019, a total of 500 oncology patients (mean age, 60.9; men, 66.0%) who underwent bone SPECT/CT scans with 99mTc-MDP were enrolled in this retrospective study. The mean SUV (SUVmean) of 4962 spinal and pelvic bones was calculated based on the patients' body weight (BW), lean body mass (LBM), bone mineral content (BMC), body surface area (BSA), and body mass index (BMI), defined as SUVbw, SUVlbm, SUVbmc, SUVbsa, and SUVbmi, respectively. The coefficients of variation (CoVs) of the aforementioned parameters were compared, and the correlation and multiple linear regression analyses were used to compare the extent to which these parameters were affected by sex, age, height, weight, BMI, and CT values. RESULTS: The average SUVs in the normal spine and pelvis displayed a relatively wide variability: 4.573 ± 1.972 for SUVbw, 3.555 ± 1.517 for SUVlbm, 0.163 ± 0.071 for SUVbmc, 0.124 ± 0.052 for SUVbsa, and 1.668 ± 0.732 for SUVbmi. In general, SUVbsa had relatively lowest CoV (42.1%) in all vertebrae and pelvis compared with other SUVs. For correlation analyses, all SUVs displayed weak but significant correlations with age and CT values. For regression analyses, SUVbsa was influenced only by age, BMI, and CT values independently. The effects of these variables on SUVbsa were all smaller than those on conventional SUVbw. CONCLUSIONS: The SUVs of 99mTc-MDP in normal bone derived from quantitative bone SPECT/CT could serve as a reference for evaluating tumor bone metastasis, but it should be assessed on a site-specific basis. SUVbsa exhibited superior robustness among all the SUV normalization variations, indicating potential clinical applications.

Lincoln Sign: A Rare Presentation of Medication-related Osteonecrosis of the Jaw.

A 52-year-old female patient with metastatic breast cancer receiving denosumab for 7 years presented with marked diffuse tracer uptake in the mandible on Tc-99m-methylene diphosphonate bone scintigraphy, resembling the Lincoln sign. A diagnosis of medication-related osteonecrosis of the jaw (MRONJ) was confirmed, leading to immediate discontinuation of denosumab. Conservative therapy, including limited debridement and oral rinses, was initiated. MRONJ, a potential complication of bone-modifying agents, is more prevalent in advanced malignancy cases. The Lincoln sign has not been previously reported in MRONJ, emphasizing its consideration in cancer patients undergoing bone-modifying agent treatment.

Metallosis: A Rare Complication to Common Procedure with Its Imaging Finding.

Metallosis is a medical condition that shows local and systemic clinical symptoms due to the deposition of heavy metal debris in soft tissues and bones due to metallic prostheses. The estimated incidence of Metallosis is around 5%. Clinical presentation and imaging findings can mimic tumor likely situation, However local reactions of Metallosis shows some peculiar features on cross-sectional imaging, and here we present two such cases of Metallosis with its imaging findings.

Incidental Bilateral Thighs Muscular Uptake of Technetium-99m MDP on Bone Scan in a Patient with Left Condylar Hyperplasia.

We present a case of a 22-year-old male patient who underwent a bone scan for evaluation of left condylar hyperplasia. Incidentally, the bone scan revealed bilateral thighs muscular uptake of technetium-99m methylene diphosphonate, which initially raised concerns for an underlying pathological process. However, further investigation revealed that the abnormal uptake was due to postexercise effects. This case report highlights the importance of considering benign causes of abnormal radiotracer uptake and the need for careful correlation with clinical history to avoid unnecessary diagnostic interventions.

Analysis of the depth of penetration of an epoxy resin-based sealer following a final rinse of irrigants and use of activation systems: An in vitro study.

Objective: The objective of the study was to compare and evaluate the depth of penetration of an epoxy resin-based sealer following a final rinse of 17% ethylenediaminetetraacetic acid (EDTA) and 18% 1-hydroxyethylidene 1, 1-diphosphonate (HEDP), with diode laser and passive ultrasonic activation (PUI): an in vitro confocal laser scanning microscopy study. Materials and Methods: Fifty-two extracted human mandibular premolar teeth with single root and single canal were selected. They were disinfected in 0.1% thymol solution, cleaned of calculus and soft tissues, and stored in 0.1% thymol solution till use. All teeth were radiographed and selected as per the inclusion and exclusion criteria. The teeth were decoronated using a diamond disk under copious water spray to acquire a standardized root length of 14 mm. Working length was established by inserting a size 10-K file into each root canal until it is visible at the apical foramen and by subtracting 1 mm from the recorded length. Instrumentation of the root canal was done till master apical file size of F3 using ProTaper universal, rotary instruments. The canals were irrigated with 2 mL of 3% sodium hypochlorite between successive files. Teeth were randomly divided into four subgroups n = 12 according to the intervention. Passive ultrasonic irrigation and diode laser were used to activate the irrigants. Final irrigation was performed with distilled water. These specimens were examined using confocal laser scanning microscope (OLYMPUS FLUOVIEW FV 3000) for dentinal tubule penetration of the sealer. Two-way ANOVA test and Tukey's multiple post hoc test were used for statistical analysis. Results: Highly significant difference was seen between the groups with EDTA and HEDP, with HEDP demonstrating the highest penetration. Among the activation techniques used in this study, PUI showed the highest penetration of the sealer. The least penetration was seen with diode laser activation and EDTA. Conclusions: The irrigation activation techniques significantly influence the penetration of sealer into root dentinal tubules. When penetration of sealer with different irrigation techniques and irrigants was evaluated, significant greater level of sealer penetration was attained with PUI activation of HEDP.

Assessment of unilateral condylar hyperplasia with quantitative SPECT/CT.

Purpose: The current study aimedto assess condylar activityin patients with unilateral condylar hyperplasia (UCH) with quantitative SPECT/CT. Patients and methods: This retrospective study included patients with UCH who underwent quantitative SPECT/CT. SPECT analysis and quantification of SPECT/CT were performed, and the maximum count per pixel and SUVmax of either side of the condyles were calculated. Results: 39 patients were included in the analysisand classified into three subgroups according to the percentile differential right-left ratio: inactive group, left active (LA) group, and right active (RA) group. Totally, the SUVmax of the affected side is significantly higher than the unaffected side (active:5.93 ± 2.43 vs inactive:3.62 ± 1.76, P < 0.001), SUVmax-based ratios correlated well with the ratios based on maximum count (R = 0.944, P < 0.001). ROC analysis showed poorSUVmaxperformance in differentiation between theactive condyles and the inactive condyles due to the lower area under the curve (AUC) (0.588). In subgroup analysis, the affected side is significantly higher than the unaffected side in active groups with SUVmax, no significant difference was found between the active sides or the inactive sides of active groups. Interestingly, the SUVmax of the left side was statistically higher than that of the right sidein the inactive group (P = 0.01),while the left side of the right active group has significantlylower activitythan that in the inactive group, meanwhile,the right side showed no significant difference. Furthermore, each side showed no significant difference between the left active group and the inactive group. Conclusions: SUVmax is not an optimal measurement effectively used to evaluate active condyles. However, SUV ratios correlated well with the count ratios, and the left side of condyles showed a peculiar feature in condyle growth status reflected in radioactivity quantified with SPECT/CT, which needs further study to determine the role in the development of the UCH.

Tc-99m MDP Scan with Unusual and Isolated Skeletal Metastasis in Skull Bone in a Case of Testicular Seminoma.

Seminomas are common germ cell tumors (GCT) that may arise in the testes as well as in extra testicular locations such as mediastinum with/without testicular tumor. Testicular tumors are usually detected early due to their location and presentation as testicular mass. The overall prognosis of the seminomatous GCTs is good with surgery as the mainstay of treatment in localized disease. Bone metastases, especially when present in isolation are exceedingly rare in seminoma. Here, we present a rare case of skull bone metastasis in a case of testicular seminoma which was detected on technetium-99m labeled methylene diphosphonate bone scintigraphy with single-photon emission computed tomography with computed tomography.

99mTechnetium-Ubiquicidin Scan with Single-Photon Emission Computed Tomography/Computed Tomography in Skull Base Osteomyelitis.

Malignant otitis externa (MOE) with skull base osteomyelitis (SBO) is an aggressive infection that predominantly affects elderly, diabetic, or immunocompromised patients, and is associated with high disease-specific mortality. Pseudomonas aeruginosa is the most isolated microorganism. External otitis associated with granulation tissue and pain is the most common presenting feature; a biopsy is obtained to rule out malignancy. A proper consensus is lacking regarding the best imaging modality for early initial diagnosis and follow-up. 99mTechnetium (99mTc)-labeled ubiquicidin (UBI) 29-41 is a bacterial attaching peptide that does not bind to activated leukocytes. We report a case of SBO initially misdiagnosed as a chronic otitis media, but later proved to be a case of MOE. 99mTc methylene diphosphonate bone scan and 99mTc-UBI 29-41 scan with single-photon emission computed tomography/computed tomography scans were performed to corroborate the clinical diagnosis. SBO remains a great challenge due to its increasing prevalence and high morbidity are difficult to diagnose and are often confused with cholesteatoma and neoplastic process. The UBI scan could be an auxiliary noninvasive diagnostic alternative in early diagnosis.

The diagnostic value of quantitative bone SPECT/CT in solitary undetermined bone lesions.

Objective: To investigate the diagnostic value of the maximum standard uptake value (SUVmax) of quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) in solitary undetermined bone lesions. Methods: In Part I, retrospective study, 167 untreated patients with extra-skeletal malignant tumors by pathology were consecutively enrolled for staging with Tc-99m methyl-diphosphonate (99mTc-MDP) whole-body bone scan (WBS) and quantitative SPECT/CT, and a total of 396 bone lesions with abnormal radioactivity concentration in 167 patients were included from April 2019 to September 2020. The differences in SUVmax among the benign bone lesions, malignant bone lesions, and normal vertebrae were analyzed. The receiver operating characteristic (ROC) curve and cutoff value of SUVmax were obtained. Part II, prospective study, 49 solitary undetermined bone lesions in SPECT/CT in 49 untreated patients with extra-skeletal malignant tumors were enrolled from October 2020 to August 2022. The diagnostic efficacy of SUVmax in solitary undetermined bone lesions was assessed. The final diagnosis was based on follow-up imaging (CT, MRI, or 2-deoxy-2-[18F]fluoro-D-glucose-positron emission tomography/computed tomography) for at least 12 months. Results: In Part I, a total of 156 malignant and 240 benign bone lesions was determined; the SUVmax of malignant lesions (26.49 ± 12.63) was significantly higher than those of benign lesions (13.92 ± 7.16) and normal vertebrae (6.97 ± 1.52) (P = 0.00). The diagnostic efficiency of the SUVmax of quantitative SPECT/CT revealed a sensitivity of 75.00% and a specificity of 81.70% at a cutoff value of 18.07. In Part II, 17 malignant and 32 benign lesions were determined. Using SUVmax ≥18.07 as a diagnostic criterion of malignancy, it has a sensitivity of 82.35%, a specificity of 93.75%, and an accuracy of 89.80%. Conclusion: The SUVmax of quantitative SPECT/CT is valuable in evaluating solitary undetermined bone lesions. Using a cutoff SUVmax value of 18.07, quantitative SPECT/CT demonstrated high sensitivity, specificity, and accuracy in differentiating malignant from benign bone lesions.

A rapid and sensitive method for determination of methylene-diphosphonate in rat bone using liquid chromatography-mass spectrometry.

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of methylene-diphosphonate (MDP) in rat bone. This method employed derivatization of MDP and allowed rapid and sensitive quantification of MDP in rat shin bone. The analyte was extracted from the bone tissues with phosphoric acid and derivatized to MDP tetramethyl phosphonate using trimethylsilyl diazomethane (TMS-DAM). MDP tetramethyl phosphonate was then quantified by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), with high selectivity, accuracy, and precision. The total run time was 6.5 min. The lower limit of quantification was 2.00 ng/mL. The intra- and inter-assay precision (in RSD) calculated from quality control samples was less than 15%, and the accuracy was between 98.1% and 100.2%. The analytical process for the determination of MDP in rat bone is fully described, which is a pivotal step for further biomedical research on MDP.

Use of intraoperative bone scintigraphy for resection of spinal osteoid osteoma.

BACKGROUND: The location and proximity to the spinal cord in spinal osteoid osteoma can increase the likelihood of an incomplete resection. Intraoperative bone scintigraphy (IOBS) can be used to verify location and complete surgical resection. OBJECTIVE: To review our experience using IOBS for resection of intraspinal osteoid osteoma. METHODS: IRB approved, retrospective review of IOBS-guided resection over 10 years. Patients underwent injection of 200 uCi/kg (1-20 mCi) 99mTc-MDP 3-4 h prior surgery. Portable single-headed gamma camera equipped with a pinhole collimator (3- or 4-mm aperture) was used. Images were obtained pre-operatively, at the start of the procedure, and intraoperatively. Operative notes were reviewed. Evaluation of recurrence and clinical follow-up was performed. RESULTS: Twenty IOBS-guided resections were performed in 18 patients (median age 13.5 years, 6-22 years, 12 males). Size ranged 5-16 mm, with 38.9% (7/18) cervical, 22.2% (4/18) thoracic, 22.2% (4/18) lumbar, and 16.7% (3/18) sacral. In all cases, IOBS was able to localize the lesion. After suspected total excision, IOBS altered the surgical plan in 75% of cases (15/20), showing residual activity prompting further resection. Median length of follow-up was 6 months (range 1-156 months) with 90% (18/20) showing complete resection without recurrence. Two patients had osteoid osteoma recurrence at 7 and 10 months following the original resection, requiring re-intervention. CONCLUSIONS: IOBS is a useful tool for real-time localization and assessment of spinal osteoid osteoma resection. In all cases, IOBS was able to localize the lesion and changed surgical planning in 75% of cases. Ninety percent of patients achieved complete resection and remain recurrence free.

A rare case of asymptomatic Paget's disease of the skull in a 60-year-old Asian female.

Background and Aim: Paget's disease of the bone refers to a chronic cumulative disorder characterized by enhanced osteoclastic function followed by a secondary surge in osteoblastic activity. The condition can manifest as a polyostotic or monostotic bone disease with most patients having an asymptomatic presentation, although some may complain of pain localized to the affected bone while others express symptoms of nerve compression. A pagetic bone is predisposed to develop pathological fractures, bony deformities, and a rare yet detrimental transformation into osteosarcoma. Detection is often accidental when performing radiographic tests for other indications or when elevated blood levels of alkaline phosphatase (ALP) are detected. Treatment with third-generation bisphosphonates is helpful in preventing further bone resorption and, additionally, reduces bony pains that are believed to be caused by excessive metabolic activity. Here, we present a case of a middle-aged asymptomatic female with elevated serum ALP levels up to 1537 IU/L (reference range 40-150 U/L) during her pre-operative evaluation for elective cholecystectomy.99m Tc-methylene diphosphonate bone scintigraphy revealed diffuse uptake in the skull and, hence, was diagnosed as a case of isolated Paget's disease of the skull. Relevance for Patients: The rarity of this disease in Southeast-Asians, its uncontrived detection, and the isolated skull involvement, imparts high clinical relevance on this case. Early detection and management of this disease can help prevent the development of life-threatening complications in affected patients, hence decreasing the morbidity.

Brain meningioma incidentally detected on a bone scan: A Case report.

Incidental meningioma is defined as a mass diagnosed radiologically on MRI and CT scans without histopathological confirmation. In occasional cases, meningiomas can be diagnosed incidentally by bone scintigraphy. This article presents an interesting case where a 44-year-old lady with known breast cancer was found to have a brain meningioma, incidentally, detected on a bone scan, which was initially suspected to be metastatic brain changes. The follow-up MRI and histopathological studies confirmed the diagnosis of meningioma.

Skeletal standardized uptake values obtained using quantitative SPECT/CT for the detection of bone metastases in patients with lung adenocarcinoma.

Purpose: To assess the utility of skeletal standardized uptake values (SUVs) obtained using quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) in differentiating bone metastases from benign lesions, particularly in patients with lung adenocarcinoma. Methods: Patients with lung adenocarcinoma who had undergone whole-body Tc-99m methyl-diphosphonate (99mTc-MDP) bone scans and received late phase SPECT/CT were retrospectively analyzed in this study. The maximum SUV (SUVmax); Hounsfield units (HUs); and volumes of osteoblastic, osteolytic, mixed, CT-negative metastatic and benign bone lesions, and normal vertebrae were compared. Receiver operating characteristic curves were used to determine the optimal cutoff SUVmax between metastatic and benign lesions as well as the cutoff SUVmax between CT-negative metastatic lesions and normal vertebrae. The linear correlation between SUVmax and HUs of metastatic lesions as well as that between SUVmax and the volume of all bone lesions were investigated. Results: A total of 252 bone metastatic lesions, 140 benign bone lesions, and 199 normal vertebrae from 115 patients with lung adenocarcinoma were studied (48 males, 67 females, median age: 59 years). Metastatic lesions had a significantly higher SUVmax (23.85 ± 14.34) than benign lesions (9.67 ± 7.47) and normal vertebrae (6.19 ± 1.46; P < 0.0001). The SPECT/CT hotspot of patients with bone metastases could be distinguished from benign lesions using a cutoff SUVmax of 11.10, with a sensitivity of 87.70% and a specificity of 80.71%. The SUVmax of osteoblastic (29.16 ± 16.63) and mixed (26.62 ± 14.97) lesions was significantly greater than that of osteolytic (15.79 ± 5.57) and CT-negative (16.51 ± 6.93) lesions (P < 0.0001, P = 0.0003, and 0.002). SUVmax at the cutoff value of 8.135 could distinguish CT-negative bone metastases from normal vertebrae, with a sensitivity of 100.00% and a specificity of 91.96%. SUVmax showed a weak positive linear correlation with HUs in all bone metastases and the volume of all bone lesions. Conclusion: SUVmax of quantitative SPECT/CT is a useful index for distinguishing benign bone lesions from bone metastases in patients with lung adenocarcinoma, particularly in the diagnosis of CT-negative bone metastases, but other factors that may affect SUVmax should be considered.

Optimum Value of Scale and Threshold for Compression of 99mTc-MDP Bone Scan Images using Haar Wavelet Transform.

Introduction: Wavelet transforms of an image result in set of wavelet coefficients. Thresholding eliminates insignificant coefficients while retaining the significant ones (resulting in matrix having few nonzero elements that need to be stored). The compressed image is reconstructed by applying inverse wavelet transform. The quality of compressed image deteriorates with increase in compression. Hence, finding optimum value of scale and threshold is a challenging task. The objective of the study was to find the optimum value of scale and threshold for compressing 99mTc-methylene diphosphonate (99 mTc-MDP) bone scan images using Haar wavelet transform. Materials and Methods: Haar wavelet transform at scale 1-8 was applied on 106 99 mTc-MDP whole-body bone scan images, and wavelet coefficients were threshold at 90, 95, 97, and 99 percentiles, followed by inverse wavelet transform to get 3392 compressed images. Nuclear medicine physician (NMP) compared compressed image with its corresponding input to label it as acceptable or unacceptable. The values of scale and threshold that resulted in majority of acceptable images were considered to be optimum. The quality of compressed image was also evaluated using perception image quality evaluator (PIQE) image quality metrics. Compression ratio was calculated by dividing the number of nonzero elements after thresholding wavelet coefficients by the number of nonzero elements in Haar decomposed matrix. Results: NMP found quality of compressed images (obtained at scale 2 and 90 percentile threshold) identical to the quality of the corresponding input images. As per PIQE score, quality of compressed images was perceptually better than that of the corresponding input images. Conclusions: The optimum values of scale and threshold were determined to be 2 and 90 percentiles, respectively.

Skeletal scintigraphy as an important complement for detecting bone metastasis from nasopharyngeal carcinoma.

Bone metastasis occurs frequently in patients with nasopharyngeal carcinoma (NPC). Although fluorine-18 fluorodeoxyglucose positron emission tomography with computed tomography (PET/CT) has been proven to be more sensitive at detecting bone metastases than Technetium-99m methylene diphosphonate skeletal scintigraphy in pretreatment patients with NPC in most clinical settings, there have been metastatic lesions that were positive on skeletal scintigraphy but negative on PET/CT scans. Herein, we report the case of a patient with stage IV NPC that manifested as multiple metabolically abnormal lesions on pretreatment skeletal scintigraphy and were considered malignant although they were negative on PET/CT examination. Follow-up evaluations with both skeletal scintigraphy and PET/CT scans as post-therapeutic imaging are also presented.

Sclerotic lumbar chordoma: A case report.

Chordoma is a rare tumor, often occurring in the cervical spine and sacrococcygeal spine with a lytic appearance, but rarely in the thoracolumbar spine. Chordomas can occasionally be sclerotic and are included in the differential diagnosis for an ivory vertebra. We present a case of a sclerotic chordoma in an upper lumbar vertebral body with corresponding multimodality imaging. This case demonstrates that chordoma should be a concern for an older adult with a sclerotic vertebral lesion, particularly if it is a solitary lesion. Knowledge of the variable location and appearance of chordomas is critical so it is not mistaken for a metastasis.

The Rationale for Using Neridronate in Musculoskeletal Disorders: From Metabolic Bone Diseases to Musculoskeletal Pain.

Neridronate or ((6-amino-1-hydroxy-1-phosphonohexyl) phosphonic acid) is an amino-bisphosphonate (BP) synthetized in Italy in 1986. Bisphosphonates are molecules with a P-C-P bond in their structure that allows strong and selectively binding to hydroxyapatite (HAP) as well as osteoclasts inhibition through different mechanisms of action. Neridronate was initially used to treat Paget disease of the bone, demonstrating effectiveness in reducing bone turnover markers as well as pain. The interesting molecular properties of neridronate foster its wide use in several other conditions, such as osteogenesis imperfecta, and osteoporosis. Thanks to the unique safety and efficacy profile, neridronate has been used in secondary osteoporosis due to genetic, rheumatic, and oncological diseases, including in pediatric patients. In the last decade, this drug has also been studied in chronic musculoskeletal pain conditions, such as algodystrophy, demonstrating effectiveness in improving extraskeletal outcomes. This review highlights historical and clinical insights about the use of neridronate for metabolic bone disorders and musculoskeletal pain conditions.

Is it sufficient to evaluate metastatic bone involvement in breast cancer using SPECT/CT? A new approach of SPECT/CT-guided targeted bone marrow biopsy.

OBJECTIVE: To investigate the feasibility, safety, and clinical application value of single photon emission computed tomography/computed tomography (SPECT/CT)-guided bone marrow biopsy (BMB) in breast cancer (BC) patients with suspected bone metastases (BM) and compare its diagnostic performance for detection of BM with SPECT/CT. METHODS: The records of breast cancer patients referred for bone scintigraphy (BS), SPECT/CT and SPECT/CT-guided BMB from January of 2018 to June of 2021 in our hospital were retrospectively reviewed. 49 Patients were consecutively included in this study, all 49 specimens were analyzed by pathological and immunohistochemical studies.The biopsy success rate, total examination time, biopsy operation time, complications, CT radiation dose, and pathological and immunohistochemical results were recorded. The diagnostic performance based on SPECT/CT and SPECT/CT-guided BMB were compared with pathological, immunohistochemical examinations and the results of subsequent follow-up. RESULTS: Bone samples of the sites with high uptake were obtained in all 49 patients under BMB. No severe postoperative complications occurred. Among all 49 cases, 34 specimens were positive for metastatic breast cancer (69%, 34/49), and positive for benign tissue in 15 cases (31%, 15/49). 1 case of 15 cases was subsequently diagnosed as metastatic breast cancer according to the follow-up result. SPECT/CT-guided BMB demonstrated significantly higher negative predictive value (NPV) when compared to SPECT/CT (p = 0.021 < 0.05). Patients with differential expression of ER, PR, and HER-2 between primary lesions and metastatic lesions accounted for 12, 17, and 5 cases, respectively, and the changing rates were 35.2% (12/34), 50% (17/34), and 14.7% (5/34), respectively. Molecular subtype changes occurred in 7 patients, accounting for 47% (16/34) of metastatic patients. CONCLUSION: It is insufficient to evaluate BM in BC patients using SPECT/CT imaging. SPECT/CT-guided BMB provided significantly higher sensitivity and NPV than SPECT/CT for detection of BM in BC patients. Our research redefines a new approach which can confirm diagnosis and potential molecular subtype changes for suspected bone metastatic lesions in BC patients, which can offer important opportunities for precision treatment and improved quality of life of BC patients with BM.