Erratum: A novel approach for fibrous dysplasia assessment using combined planar and quantitative SPECT/CT analysis of Tc-99m-diphosphonate bone scan in correlation with biological bone turnover markers of disease activity

[This corrects the article DOI: 10.3389/fmed.2022.1050854.].

Safely omitting bone isotope scans in a cohort of grade group 2 prostate cancer

OBJECTIVE

A retrospective review conducted in our urology unit to assess the efficiency for requesting bone scans for newly diagnosed prostate cancer patients, aiming to minimize radiation exposure and avoiding unnecessary investigations as cost effective measure.

METHODS

A retrospective observational study included 360 patients with newly diagnosed prostate cancer within urology department at Calderdale and Huddersfield NHS Trust from April 2016 to March 2018. Parameters observed were: the prostatic specific antigen (PSA) on diagnosis, Gleason score, staging magnetic resonance imaging, and bone scans. We analyzed the possible correlation of the Gleason score and PSA to determine the risk of bony metastasis. Regarding PSA: Patients were categorized as with PSA <15, PSA ≥15. Regarding Gleason score: Patients were categorized as patients with grade group 1 or 2 and patients with grade group 3 and above. Data recorded was then analyzed using χ²  analysis to determine if results were deemed significant or not.

RESULTS

A total of 360 patients: 91 patients (25%) had positive bony metastasis. While 269 patients (75%) had a clear bone scan. Among patients with grade group 3 or above or having PSA ≥15, 90 patients out of 324 patients had bony metastasis (38%). Among patients with grade group 1 or 2 and PSA <15, only 1 patient out of 36 had bony metastasis (2.7%). Negative predictive value of grade group 1 or 2 and PSA <15 for bony metastasis was 97.22%.

CONCLUSION

Using a cutoff level of PSA <15 in grade group 1 and 2 seems to be a safe and efficient tool to exclude newly diagnosed prostate cancer patients from having an isotope bone scan for staging purpose.

Comparison of PSMA-based 18F-DCFPyL PET/CT and Tc-99m MDP bone scan in detection of bone metastasis in prostate cancer

While Tc-99m MDP bone scan (BS) remains the conventional standard for detection of bone metastasis in prostate cancer, newly FDA-approved imaging with PSMA-based ¹⁸F-DCFPyL PET/CT has shown promise for early detection of metastatic disease. However, a paucity of data remains in the diagnostic accuracy of PSMA PET/CT in detecting bone metastasis compared to BS. This retrospective study included 91 patients who received both BS and PSMA PET/CT within a 3-month interval from August 2021 to February 2022. Separate concurrent primary cancer, interval PSA levels greater than a 2-fold difference (or absolute difference >1 ng/ml) between the two studies were excluded. All abnormal bone lesions on either scan were compared. The findings were verified by pathological findings and/or 6-month clinical follow-up. High concordance (78%) was found between modalities with discordant findings (20/91, 22%) demonstrating more false positives (4/20, 20%) and false negatives (3/20, 15%) on BS compared to PET/CT. Additionally, more bone metastases were detected on PSMA PET/CT (13/20, 65%) with all true positive BS lesions also detected PET/CT. The sensitivity, specificity, PPV and NPV for BS were 89%, 91%, 80%, and 95% respectively; and 100%, 97%, 93%, and 100% for ¹⁸F-DCFPyL PET/CT respectively. Our results demonstrate that ¹⁸F-DCFPyL PET/CT identified more bone metastases while also identifying all bone metastases identified on BS. With the added diagnostic value of detecting primary tumor and soft tissue metastasis, ¹⁸F-DCFPyL PET/CT may render BS unnecessary to investigate bone metastases in patients with prostate cancer.

Prostatic bed calcification with MDP uptake: Easy to miss on planar images

A 65 years old man with high-risk prostate adenocarcinoma underwent bone scintigraphy with 99mTc-methylene diphosphate (99mTc-MDP). The scan revealed a focus of radiotracer uptake in the left pubic region, which was suspicious for metastatic involvement. Additional imaging with single photon emission computed tomography (SPECT/CT) confined the uptake to be extra-osseous and contributed to the calcified zone in the prostate bed. Prostatic bed calcification with 99mTc-MDP uptake mimics metastasis and can be easily missed on planar images.

Survival in Breast Cancer Patients with Bone Metastasis: A Multicenter Real-World Study on the Prognostic Impact of Intensive Postoperative Bone Scan after Initial Diagnosis of Breast Cancer (CSBrS-023)

The prognostic value of intensive postoperative bone scan (BS) screening, which is performed in asymptomatic patients with breast cancer (BC) after surgery, remained unclear. Patients diagnosed with BC with bone metastasis (BM) from five medical centers in China during the years 2005−2013 were retrospectively collected. Propensity score matching (PSM) was performed to balance the baseline characteristics. The survival outcomes were overall survival (OS) and overall survival after BM (OSABM). Among 1059 eligible patients, 304 underwent intensive postoperative BS while 755 did not. During a median follow-up of 6.67 years (95%CI 6.45, 7.21), intensive postoperative BS prolonged the median OS by 1.63 years (Log-Rank p = 0.006) and OSABM by 0.66 years (Log-Rank p = 0.002). Intensive postoperative BS was an independent prognostic factor for both OS (adjusted HR 0.77, 95%CI 0.64, 0.93, adjusted p = 0.006) and OSABM (adjusted HR 0.71, 95%CI 0.60, 0.86, adjusted p < 0.001). The prognostic value of intensive postoperative BS was consistently favorable for OS among clinical high-risk patients, including those with ages younger than 50, stage II, histology grade G3 and ER-Her2- subtype. This multicenter real-world study showed that intensive postoperative BS screening improved survival for BC patients with BM and should probably be recommended for postoperative surveillance, especially for patients at clinical high-risk.

The effect of extracorporeal shock wave therapy on large neurogenic heterotopic ossification in a patient with pontine hemorrhage: A case report and literature review

RATIONALE

Heterotopic ossification (HO), an ectopic bone formation in soft tissue around the joint, is a complication observed in stroke patients. HO around the hip joint causes a reduction in the functional ability of patients by generating pain and limiting range of motion (ROM). In addition, it results in impaired mobility, ultimately affecting quality of life and increasing the mortality of patients. Extracorporeal shock wave therapy (ESWT) has demonstrated efficacy in treating soft tissue inflammation and has been used to reduce patients' pain in HO. However, almost none of the studies reported degradation in the size of HO on images obtained before and after ESWT application.

PATIENT CONCERNS AND DIAGNOSIS

We report a case of a 36-year-old man who developed HO around both hip joints 3 months after bilateral pontine hemorrhage.

INTERVENTIONS

Seven months after HO development, ESWT was administered to the area of HO every other day for a total of 10 sessions.

OUTCOMES

Immediately following treatment, the ROM of both hip joints increased. Thus the patient was able to maintain a sitting posture without having to be bound to the wheelchair. In addition, the tolerable sitting time before groaning increased from less than ten minutes to almost 60 minutes by the end of all ESWT sessions. Unlike other previous reports, a diminished HO size was confirmed by comparing plain X-rays and bone scans obtained before and after treatment sessions.

LESSONS

In this case, we report an objective size reduction in HO in radiologic findings after applying ESWT to both hips. ESWT is a safe, easy-to-apply, and noninvasive modality. We would like to emphasize the use of ESWT as a treatment option for HO to decrease the extent of HO, as well as to improve pain, spasticity and function in patients with stroke.

A Case of Extracranial Metastasis of Glioblastoma Multiforme Seen on Bone Scintigraphy

Glioblastoma multiforme (GBM) is the most common primary malignant tumor of the central nervous system in adults. It is known for its devastating intracranial progress thus attributing to its very short survival. Here, we report a case of 37-year-old female with GBM post surgery, chemotherapy and radiotherapy who presented with pain in right hip region. She was referred to our department for evaluation of skeletal metastasis. Tc-99m methylene diphosphonate bone scan revealed an expansile lesion involving the right iliac blade along with extensive lytic bony lesions throughout the axial skeleton.

Rates of metastatic prostate cancer in newly diagnosed patients: Numbers needed to image according to risk level

BACKGROUND

The numbers needed to image to identify pelvic lymph node and/or distant metastases in newly diagnosed prostate cancer (PCa) patients according to risk level are unknown.

METHODS

Relying on Surveillance, Epidemiology, and End Results (2010-2016), we tabulated rates and proportions of patients with (a) lymph node or (b) distant metastases according to National Comprehensive Cancer Network (NCCN) risk level and calculated the number needed to image (NNI) for both endpoints. Multivariable logistic regression analyses were performed.

RESULTS

Of 145,939 newly diagnosed PCa patients assessable for analyses of pelvic lymph node metastases (cN1), 4559 (3.1%) harbored cN1 stage: 13 (0.02%), 18 (0.08%), 63 (0.3%), 512 (2.8%), and 3954 (14.9%) in low, intermediate favorable, intermediate unfavorable, high, and very high-risk levels. These resulted in NNI of 4619, 1182, 319, 35, and 7, respectively. Of 181,109 newly diagnosed PCa patients assessable for analyses of distant metastases (M1_a-c ), 8920 (4.9%) harbored M1_a-c stage: 50 (0.07%), 45 (0.1%), 161 (0.5%), 1290 (5.1%), and 7374 (22.0%) in low, intermediate favorable, intermediate unfavorable, high, and very high-risk. These resulted in NNI of 1347, 602, 174, 20, and 5, respectively.

CONCLUSIONS

Our observations perfectly validated the NCCN recommendations for imaging in newly diagnosed high and very high-risk PCa patients. However, in unfavorable intermediate-risk PCa patients, in whom bone and soft tissue imaging is recommended, the NNI might be somewhat elevated to support routine imaging in clinical practice.

Equine skeletal scintigraphy: Comparing normal bone-to-soft tissue ratio 2 and 4 hours after injection with either hydroxymethylene diphosphonate or methylene diphosphonate

BACKGROUND

In equine skeletal scintigraphy, there is no information about the possible influence of different phosphonate compounds on image quality.

METHODS

This prospective randomised study determined bone uptake changes and image quality for hydroxymethylene diphosphonate (HDP) and methylene diphosphonate (MDP) in equine patients at different time points. Scintigraphic images of the radius and the tibia of 20 horses were acquired at 2 and 4 hours after injection of either technetium-labelled HDP or MDP. Three regions of interest were identified-in the bone diaphysis, adjacent soft tissue and background area-to determine the normal bone-to-soft tissue ratio (BSR). Qualitative analysis was performed using a modified scoring system.

RESULTS

In terms of BSR and count rates, HDP showed a slightly better incorporation into bone compared to MDP, but significant differences were only detected for count rates at 4 hours after injection (p = 0.048). The radiopharmaceutical used did not influence qualitative image scoring, which was correlated with the BSR (ρ = 0.49; p ≤ 0.001).

CONCLUSION

The choice of HDP or MDP for equine skeletal scintigraphy does not seem to substantially affect BSR and qualitative image scoring. Further studies with a larger sample size, including the evaluation of lesion detection ability for both bone-seeking agents, are needed.

Bone Scan With SPECT/CT Demonstrated C1 to C2 Involvement in Rheumatic Arthritis

ABSTRACT

An 80-year-old man was treated with rituximab for active rheumatoid arthritis until 2019, now controlled with Salazopyrin, prednisolone, methotrexate, and folic acid. However, laboratory data showed elevated C-reactive protein and erythrocyte sedimentation rate. Whole-body bone scan showed bony and joint destruction to the upper cervical vertebra (C spine), bilateral shoulders, wrists, finger joints, ankles, and left knee. SPECT/CT localized the upper C spine uptake to the C1/C2 joint and adjacent C1 and C2 with C1/C2 subluxation. C spine CT showed vertical atlantoaxial subluxation and bony erosions.

Metabolic Activity of Neurogenic Heterotopic Ossification on 18F-FDG PET/CT Matching with Ongoing Osteoblastic Activity on Bone Scan

A 54-year-old man, with previous history of neurogenic heterotopic ossification (HO) in muscles around the left hip following a spinal cord injury ten months earlier, was referred to our nuclear medicine center for an ¹⁸fluorine-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) to rule out a spondylodiscitis. No sign of spondylodiscitis was found on ¹⁸F-FDG PET/CT, but images revealed an increased ¹⁸F-FDG uptake in HO areas, matching with ongoing osteoblastic activity on a following bone scan.

Segmented linear correlations between bone scan index and prostate cancer biomarkers, alkaline phosphatase, and prostate specific antigen in patients with a Gleason score ≥7

Technetium-99m methyl diphosphonate bone scintigraphy is relatively easily accessible for detecting bone metastases in prostate cancer patients. However, it is subjective and can be challenging to compare images taken at different time points. The bone scan index (BSI) is a more objective evaluation and allows for better comparison of images. Its correlation with other biomarkers of prostate cancer metastases such as prostate specific antigen (PSA) and alkaline phosphatase (ALP) is not clearly understood. This study thus aimed to compare the BSI correlation to PSA against that of BSI to ALP levels in patients with a Gleason score ≥7.A retrospective analysis of the medical records of 50 prostate cancer patients with a Gleason score of ≥7 referred for a bone scan between January 1, 2015 and December 31, 2018 was undertaken. Bone scans were interpreted visually, and using a semi-automated computer programme to quantify the BSI and its relation to PSA and ALP measurements.For the metastasis positive measurements, there was a statistically significant moderate positive overall linear correlation between BSI and PSA. For ALP and BSI, there were 2 segmented strong positive linear relationships between them. The first segment consisted of ALP < 375 IU/L and BSI >10%, where ALP and BSI were strongly and positively correlated. The other segment tended to have generally low BSI measurements (<10%) and also had a strong and positive correlation.The BSI was found to be better linearly correlated with ALP than PSA.

Application of 68Ga-citrate PET/CT for differentiating periprosthetic joint infection from aseptic loosening after joint replacement surgery

AIMS

We aimed to evaluate the utility of ⁶⁸Ga-citrate positron emission tomography (PET)/CT in the differentiation of periprosthetic joint infection (PJI) and aseptic loosening (AL), and compare it with ^99mTc-methylene bisphosphonates (^99mTc-MDP) bone scan.

METHODS

We studied 39 patients with suspected PJI or AL. These patients underwent ⁶⁸Ga-citrate PET/CT, ^99mTc-MDP three-phase bone scan and single-photon emission CT (SPECT)/CT. PET/CT was performed at ten minutes and 60 minutes after injection, respectively. Images were evaluated by three nuclear medicine doctors based on: 1) visual analysis of the three methods based on tracer uptake model, and PET images attenuation-corrected with CT and those not attenuation-corrected with CT were analyzed, respectively; and 2) semi-quantitative analysis of PET/CT: maximum standardized uptake value (SUVmax) of lesions, SUVmax of the lesion/SUVmean of the normal bone, and SUVmax of the lesion/SUVmean of the normal muscle. The final diagnosis was based on the clinical and intraoperative findings, and histopathological and microbiological examinations.

RESULTS

Overall, 23 and 16 patients were diagnosed with PJI and AL, respectively. The sensitivity and specificity of three-phase bone scan and SPECT/CT were 100% and 62.5%, 82.6%, and 100%, respectively. Attenuation correction (AC) at 60 minutes and non-AC at 60 minutes of PET/CT had the same highest sensitivity and specificity (91.3% and 100%), and AC at 60 minutes combined with SPECT/CT could improve the diagnostic efficiency (sensitivity = 95.7%). Diagnostic efficacy of the SUVmax was low (area under the curve (AUC) of ten minutes and 60 minutes was 0.814 and 0.806, respectively), and SUVmax of the lesion/SUVmean of the normal bone at 60 minutes was the best semi-quantitative parameter (AUC = 0.969).

CONCLUSION

⁶⁸Ga-citrate showed the potential to differentiate PJI from AL, and visual analysis based on uptake pattern of tracer was reliable. The visual analysis method of AC at 60 minutes, combined with ^99mTc-MDP SPECT/CT, could improve the sensitivity from 91.3% to 95.7%. In addition, a major limitation of our study was that it had a limited sample size, and more detailed studies with a larger sample size are warranted. Cite this article: Bone Joint Res 2022;11(6):398-408.

Seeing the Invisible: The Value of Bone Scan to Distinguish Chondroblastic Osteosarcoma From Prosthesis Loosening

ABSTRACT

A 76-year-old woman with uterine cervical cancer 20 years ago received right total hip replacement 3 months ago for right hip avascular necrosis without specific intraoperative finding. She reported persistent right hip pain after falling from bed. Pelvic x-ray showed right pubic ramus fracture. To evaluate prosthesis loosening, 99mTc-MDP 3-phase bone scan was arranged, showing diffusely and heterogeneously increased vascularity and tracer perfusion over the right hip, with intensely and heterogeneously increased metabolism in the right iliac bone and hip. SPECT/CT showed nearby swelling of calcified muscles. After debridement and synovectomy, the pathologic report showed chondroblastic osteosarcoma.

Systematic review & meta-analysis of positron emission tomography/computed tomography and bone scan in the diagnosis of prostate lesions

Background

To date, the results of studies into the effectiveness of positron emission tomography (PET) combined with computed tomography (CT) and bone scan (BS) in the diagnosis of malignant prostate lesions have been inconsistent, and the advantages and disadvantages of the two methods cannot be accurately judged.

Methods

Articles were retrieved from the China National Knowledge Infrastructure (CNKI) database, Wan Fang Medical Network, PubMed, Excerpta Medica data BASE (EMBASE), Medline, and Cochrane database. The keywords used in the search were: ⁶⁸Ga-prostate specific membrane antibody (⁶⁸Ga-PSMA), PET/CT, prostate lesions, prostate adenocarcinoma, bone metastasis, and BS.

Results

Ultimately, 3 publications were selected for inclusion in the meta-analysis. A total of 215 patients were considered in the 3 articles that met the inclusion criteria. All of the included articles were small sample studies, with sample sizes ranging from 28 to 113 cases. In this study, from the 3 randomized controlled trials, only 2 (66.67%) randomized controls described the correct randomized allocation method, and only 1 (33.33%) described the hidden allocation scheme in detail. The highest sensitivity for ⁶⁸Ga-PSMA PET/CT was 0.96, with 95% CI: 0.87, 1.00, and the highest specificity was 1.00, with 95% CI: 0.96, 1.00. The highest sensitivity and specificity of BS were 0.92 with 95% CI: 0.81, 0.98 and 0.96 with 95% CI: 0.78, 1.00, respectively. The results of meta-analysis of ⁶⁸Ga-PSMA PET/CT diagnosis with confirmation by surgical and histopathological examination showed that the area under the summary receiver operating characteristics (SROC) curve (AUC) =0.826 and standard error (SE) (AUC) =0.0425. The results of meta-analysis of BS diagnosis with confirmation by surgical and histopathological examination showed that the area under the SROC curve (AUC) =0.714 and SE (AUC) =0.0034.

Discussion

The meta-analysis showed that ⁶⁸Ga-PSMA PET/CT has clear advantages over BS in the diagnosis of bone metastases of malignant prostate tumors, and could improve the diagnostic accuracy of bone metastases.

A novel approach for fibrous dysplasia assessment using combined planar and quantitative SPECT/CT analysis of Tc-99m-diphosphonate bone scan in correlation with biological bone turnover markers of disease activity

Purpose

To investigate the emerging role of Tc-99m-labeled diphosphonate (Tc-99m-DPD) uptake quantification by SPECT/CT in fibrous dysplasia (FD) bone lesions and its correlation with biological bone turnover markers (BTMs) of disease activity.

Materials and methods

Seven patients (49 ± 16 years) with a confirmed diagnosis of FD were included in this retrospective study. Bone scans with Tc-99m-DPD and quantitative SPECT/CT (xSPECT/CT) were performed. SUV_max (maximum standard unit value) and SUV_mean (mean standard unit value) were measured in all FD bone lesions. The skeletal burden score (SBS) was assessed on planar scintigraphy and multiplied by mean SUV _max and SUV_mean to generate two new parameters, SBS_SUV_max and SBS_SUV_mean, respectively. Planar and xSPECT/CT quantitative measures were correlated with biological BTMs of disease activity, including fibroblast growth factor 23 (FGF-23), alkaline phosphatase (ALP), procollagen 1 intact N-terminal propeptide (P1NP) and C-terminal telopeptide (CTX), as well as scoliosis angle measured on radiographs. Statistical significance was evaluated with Spearman's correlations.

Results

A total of 76 FD bone lesions were analyzed, showing an average SUV_max and SUV_mean (g/mL) of 13 ± 7.3 and 8 ± 4.5, respectively. SBS, SBS_SUV_max and SBS_SUV_mean values were 30.8 ± 25.6, 358 ± 267 and 220.1 ± 164.5, respectively. Mean measured values of FGF-23 (pg/mL), ALP (U/L), P1NP (μg/L) and CTX (pg/mL) were 98.4 (22-175), 283.5 (46-735), 283.1 (31-1,161) and 494 (360-609), respectively. Mean scoliosis angle was 15.7 (7-22) degrees. We found a very strong positive correlation between planar-derived SBS and CTX (r = 0.96, p = 0.010), but no significant correlation between SUV_max or SUV_mean and biological BTMs. SBS_SUV_max showed a strong to very strong positive correlation with CTX (ρ = 0.99, p = 0.002), FGF-23 (ρ = 0.91, p = 0.010), ALP (ρ = 0.82, p = 0.020), and P1NP (ρ = 0.78, p = 0.039), respectively.

Conclusion

This study showed that biological BTMs are significantly correlated with diphosphonate uptake on bone scan, quantified by a new parameter combining information from both planar and quantitative SPECT/CT. Further analysis of bone scan quantitative SPECT/CT data in a larger patient population might help better characterize the skeletal disease burden in FD, and guide treatment and follow-up.

An optimized imaging protocol for [99mTc]Tc-DPD scintigraphy and SPECT/CT quantification in cardiac transthyretin (ATTR) amyloidosis

BACKGROUND

In [99mTc]Tc-DPD scintigraphy for myocardial ATTR amyloidosis, planar images 3 hour p.i. and SPECT/CT acquisition in L-mode are recommended. This study investigated if earlier planar images (1 hour p.i.) are beneficial and if SPECT/CT acquisition should be preferred in H-mode (180° detector angle) or L-mode (90°).

METHODS

In SPECT/CT phantom measurements (NaI cameras, N = 2; CZT, N = 1), peak contrast recovery (CRpeak) was derived from sphere inserts or myocardial insert (cardiac phantom; signal-to-background ratio [SBR], 10:1 or 5:1). In 25 positive and 38 negative patients (reference: endomyocardial biopsy or clinical diagnosis), Perugini scores and heart-to-contralateral (H/CL) count ratios were derived from planar images 1 hour and 3 hour p.i.

RESULTS

In phantom measurements, accuracy of myocardial CRpeak at SBR 10:1 (H-mode, 0.95-0.99) and reproducibility at 5:1 (H-mode, 1.02-1.14) was comparable for H-mode and L-mode. However, L-mode showed higher variability of background counts and sphere CRpeak throughout the field of view than H-mode. In patients, sensitivity/specificity were ≥ 95% for H/CL ratios at both time points and visual scoring 3 hour. At 1 hour, visual scores showed specificity of 89% and reduced reader's confidence.

CONCLUSIONS

Early DPD images provided no additional value for visual scoring or H/CL ratios. In SPECT/CT, H-mode is preferred over L-mode, especially if quantification is applied apart from the myocardium.

Detection of Bone Metastases on Bone Scans through Image Classification with Contrastive Learning

Patients with bone metastases have poor prognoses. A bone scan is a commonly applied diagnostic tool for this condition. However, its accuracy is limited by the nonspecific character of radiopharmaceutical accumulation, which indicates all-cause bone remodeling. The current study evaluated deep learning techniques to improve the efficacy of bone metastasis detection on bone scans, retrospectively examining 19,041 patients aged 22 to 92 years who underwent bone scans between May 2011 and December 2019. We developed several functional imaging binary classification deep learning algorithms suitable for bone scans. The presence or absence of bone metastases as a reference standard was determined through a review of image reports by nuclear medicine physicians. Classification was conducted with convolutional neural network-based (CNN-based), residual neural network (ResNet), and densely connected convolutional networks (DenseNet) models, with and without contrastive learning. Each set of bone scans contained anterior and posterior images with resolutions of 1024 × 256 pixels. A total of 37,427 image sets were analyzed. The overall performance of all models improved with contrastive learning. The accuracy, precision, recall, F1 score, area under the receiver operating characteristic curve, and negative predictive value (NPV) for the optimal model were 0.961, 0.878, 0.599, 0.712, 0.92 and 0.965, respectively. In particular, the high NPV may help physicians safely exclude bone metastases, decreasing physician workload, and improving patient care.

Metastatic Pulmonary Calcification Detected on 18F-FDG PET/CT and 99mTc-MDP Bone Scan

Metastatic calcification relates to abnormal calcification resulting from hypercalcemia and can affect soft tissues, skeletal muscle, myocardium, lungs, stomach, kidneys, and blood vessels. We describe a case of metastatic pulmonary calcification in a 71-year-old male, images with ¹⁸F-fluorodeoxyglucose (FDG) PET/CT and ^99mTc- methylene diphosphonate (MDP) bone scan.

Bone Scanning Findings in a Patient with Heat Stroke-Induced Rhabdomyolysis

We present a case that caused a diagnostic dilemma on a bone scan. We also review the broad spectrum of nonmalignant findings that can impact the interpretation of a bone scan and the value of correlative imaging using SPECT/CT for exact localization and characterization of lesions. The imaging features of important benign pathologies-that is, metastatic mimics-are elaborated so that the reader can avoid misinterpretations when reporting them. We elucidate 4 uncommon benign findings on a bone scan. Rhabdomyolysis is a result of lysis of skeletal muscle with release of cell contents, such as myoglobin and muscle enzymes, and is diagnosed mostly through a combination of clinical appearance and laboratory values. Myositis ossificans is the most common form of heterotopic ossification, usually occurring within large muscles. Its importance stems largely from its ability to mimic more aggressive pathologic processes. Myositis ossificans is one of the skeletal "do not touch" lesions. Such bone lesions are defined by characteristic imaging features, the identification of which precludes the need for additional diagnostic tests or biopsies, thereby avoiding unnecessary interventions. Acute tubular necrosis is kidney injury caused by damage to the kidney tubule cells (kidney cells that reabsorb fluid and minerals from urine as it forms). Common causes are low blood flow to the kidneys, drugs that damage the kidneys, or a severe underlying infection.

Can the Diagnostic Accuracy of Bone Scintigraphy be Maintained with Half the Scanning Time?

Purpose: We aim to show that the acquisition time of a conventional bone scan can be reduced by one-half without loss of the diagnostic value of the scan. Materials and Methods: Fifty adult patients (37 male and 13 female, mean age 62.5, SD 8.7 years) were enrolled. Patients were injected with 25-30 mCi (925-1110 MBq) ^99mTc MDP IV. The Standard Protocol whole body planar images were acquired first [scan speed = 10 cm/min, acquisition time around 20 minutes] and were followed immediately by the Half-Time Protocol whole body planar images [scan speed = 20 cm/min; acquisition time around 10 minutes]. Both images were interpreted by two nuclear medicine physicians. Each reviewer, when reviewing the Standard Protocol images, was "self-blinded" to the result they had obtained when reviewing the Half-Time images, and vice-versa. This self-blinding was accomplished by allowing a minimum of two weeks to elapse between the two interpretations. We used the κ-coefficient to compare the agreement between the Standard-Protocol results and the Half-Time results. Results: There was no difference in clinically significant diagnostic information for Half -Time and Standard Protocol. The diagnostic quality of Half-Time and the Standard Protocol images were not significantly different (0.86 < κ < 1.0). Conclusion: Our data suggest that if we reduce the ^99mTc MDP dose by half and keep the acquisition time at its standard value we gain the benefits of reduced dose without loss of diagnostic value of the scan.

Colorectal cancer with first known case of simultaneous bilateral tibial metastases

The most common osseous metastatic regions for colorectal cancer are the lumbar and sacral vertebrae and the pelvis. There are few reported cases of isolated solitary tibial metastasis, and simultaneous bilateral solitary tibial metastases in colorectal cancer are even rarer. A 62-year-old female patient was admitted to our inpatient clinic 3 years after receiving initial chemotherapy for a rectosigmoid adenocarcinoma with liver metastasis. The patient complained of left leg pain. Radiographs and magnetic resonance imaging revealed a 3- × 3-cm mass in the right proximal tibia and a 2- × 7-cm mass in the middle third of the left tibia; both were highly suggestive of bone metastases. Bilateral tibial metastases were confirmed after tumor excision and prophylactic open reduction and internal fixation. The postoperative course was relatively uneventful. Colorectal cancer with bone metastases is uncommon, and most metastases are found at a single site in an extremity. We believe this is the first published case of simultaneous bilateral tibial metastases in a patient with colorectal cancer.

A Radiological Scoring System for Differentiation between Enchondroma and Chondrosarcoma

Simple Summary

Background: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. Methods: To evaluate the diagnostic usefulness of radiological findings for differentiation between enchondromas and chondrosarcomas, correlations between various radiological findings and final diagnoses were investigated. Based on the correlations, a scoring system combining these findings was developed. Results: In a cohort of 81 patients, periosteal reaction on X-ray, endosteal scalloping and cortical defect on CT, extraskeletal mass, multilobular lesion, abnormal signal in adjacent tissue on MRI, and increased uptake in bone scan and thallium scan was significantly correlated with final diagnoses. Based on the correlations, a radiological scoring system combining radiological findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and chondrosarcomas were 88%, 89%, and 88%, respectively. Conclusion: Comprehensive assessment combining radiological findings is recommended to differentiate between enchondromas and ACTs/chondrosarcomas.

Abstract

Background: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. In this study, correlations between radiological findings and final diagnosis were investigated in patients with central cartilaginous tumors. Methods: To evaluate the diagnostic usefulness of radiological findings, correlations between various radiological findings and final diagnoses were investigated in a cohort of 81 patients. Furthermore, a new radiological scoring system was developed by combining radiological findings. Results: Periosteal reaction on X-ray (p = 0.025), endosteal scalloping (p = 0.010) and cortical defect (p = 0.002) on CT, extraskeletal mass (p < 0.001), multilobular lesion (p < 0.001), abnormal signal in adjacent tissue (p = 0.004) on MRI, and increased uptake in bone scan (p = 0.002) and thallium scan (p = 0.027) was significantly correlated with final diagnoses. Based on the correlations between each radiological finding and postoperative histological diagnosis, a radiological scoring system combining these findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and ACTs/chondrosarcomas were 88%, 89%, and 88%, respectively (p = 0.003). Conclusion: Radiological assessment with combined radiological findings is recommended to differentiate between enchondromas and ACT/chondrosarcomas.

Advantage of Hybrid 18F-Fluoride Positron Emission Tomography/Computed Tomography to Diagnose Malignant Rib Invasion by Pleural Metastasis in a Background of Reactive Periostitis

Diffuse osteoblastic activity in the ribs on bone scan is seen in association with pleural thickening. Irrespective of the pleural pathology, this represents benign finding caused by pleural hyperemia or reactive periostitis, with preserved cortical integrity. However, malignant involvement of the ribs can occur by local invasion of pleural malignancy causing cortical lysis. Herein, we describe the ¹⁸F-fluoride positron emission tomography/computed tomography findings of reactive periostitis of the ribs in pleural metastasis and emphasize the advantage of hybrid imaging in detecting local malignant tumor invasion superimposed in such condition.

Magnetic Resonance Imaging Signal Changes Mimicking Bone Metastasis in Patients Receiving Bisphosphonate Therapy

Bisphosphonates are inorganic pyrophosphate agents that reduce bone turnover. These agents reduce bone pain and delay skeletal complications, such as fractures in patients with metastatic lytic lesions, malignant-related hypercalcemia, multiple myeloma, Paget’s disease of bone, and osteoporosis. Osteonecrosis, developing in the jaw bones specifically, has been described as a complication associated with the use of bisphosphonates. In this report, we presented osteonecrosis-like magnetic resonance imaging findings that can be confused with bone metastasis in two patients who underwent long-term bisphosphonate treatment and the value of bone scan and ¹⁸flor-fluorodeoxyglucose positron emission tomography/computerized tomography in the differential diagnosis.