Interpretation Of Bone Scans Research Articles

Enhancing bone scan image quality: an improved self-supervised denoising approach.

Bone scans play an important role in skeletal lesion assessment, but gamma cameras exhibit challenges with low sensitivity and high noise levels. Deep learning (DL) has emerged as a promising solution to enhance image quality without increasing radiation exposure or scan time. However, existing self-supervised denoising methods, such as Noise2Noise (N2N), may introduce deviations from the clinical standard in bone scans. This study proposes an improved self-supervised denoising technique to minimize discrepancies between DL-based denoising and full scan images. 
Retrospective analysis of 351 whole-body bone scan data sets was conducted. In this study, we used N2N and Noise2FullCount (N2F) denoising models, along with an interpolated version of N2N (iN2N). Denoising networks were separately trained for each reduced scan time from 5 to 50%, and also trained for mixed training datasets, which include all shortened scans. We performed quantitative analysis and clinical evaluation by nuclear medicine experts.
The denoising networks effectively generated images resembling full scans, with N2F revealing distinctive patterns for different scan times, N2N producing smooth textures with slight blurring, and iN2N closely mirroring full scan patterns. Quantitative analysis showed that denoising improved with longer input times and mixed count training outperformed fixed count training. Traditional denoising methods lagged behind DL-based denoising. N2N demonstrated limitations in long-scan images. Clinical evaluation favored N2N and iN2N in resolution, noise, blurriness, and findings, showcasing their potential for enhanced diagnostic performance in quarter-time scans.
The improved self-supervised denoising technique presented in this study offers a viable solution to enhance bone scan image quality, minimizing deviations from clinical standards. The method's effectiveness was demonstrated quantitatively and clinically, showing promise for quarter-time scans without compromising diagnostic performance. This approach holds potential for improving bone scan interpretations, aiding in more accurate clinical diagnoses.

Can Medical Students Learn and Perform POCUS in the Pediatric Emergency Department? Implementation of a Short Curriculum.

Purpose: To determine medical student ability to accurately obtain and interpret POCUS exams of varying difficulty in the pediatric population after a short didactic and hands-on POCUS course. Methods: Five medical students were trained in four POCUS applications (bladder volume, long bone for fracture, limited cardiac for left ventricular function, & inferior vena cava collapsibility) and enrolled pediatric ED patients. Ultrasound-fellowship-trained emergency medicine physicians reviewed each scan for image quality and interpretation accuracy using the American College of Emergency Physicians' quality assessment scale. We report acceptable scan frequency and medical student vs. Ultrasound-fellowship-trained emergency medicine physician interpretation agreement with 95% confidence intervals (CI). Results: Ultrasound-fellowship-trained emergency medicine physicians graded 51/53 bladder volume scans as acceptable (96.2%; 95% CI 87.3-99.0%) and agreed with 50/53 bladder volume calculations (94.3%; 95% CI 88.1-100%). Ultrasound-fellowship-trained emergency medicine physicians graded 35/37 long bone scans as acceptable (94.6%; 95% CI 82.3-98.5%) and agreed with 32/37 medical student long bone scan interpretations (86.5%; 95% CI 72.0-94.1%). Ultrasound-fellowship-trained emergency medicine physicians graded 116/120 cardiac scans as acceptable (96.7%; 95% CI 91.7-98.7%) and agreed with 111/120 medical student left ventricular function interpretations (92.5%; 95% CI 86.4-96.0%). Ultrasound-fellowship-trained emergency medicine physicians graded 99/117 inferior vena cava scans as acceptable (84.6%; 95% CI 77.0-90.0%) and agreed with 101/117 medical student interpretations of inferior vena cava collapsibility (86.3%; 95% CI 78.9-91.4%). Conclusions: Medical students demonstrated satisfactory ability within a short period of time in a range of POCUS scans on pediatric patients after a novel curriculum. This supports the incorporation of a formal POCUS education into medical school curricula and suggests that novice POCUS learners can attain a measure of competency in multiple applications after a short training course.

Diagnostic software proposal for bone scan follow-up using false color based on the gammagrams analysis from gray tone histograms

In this work we introduce a technique to speed up the interpretation of bone scans with the aim of determining the presence or absence of metastatic disease. We use gray tone histograms, resembling the use of band-pass filters, in order to ensure a reliable interpretation of the bone scan, therefore providing an accurate diagnosis. We draw particular attention to three cases. The first case corresponds to shifted histograms. If the histogram is shifted toward the origin, the bone scan is free of metastasis. If it is shifted to the right and slightly broadened, this indicates the presence of a bone scan anomaly other than metastasis. On the other hand, if the histogram is broadened and shifted to the left, this suggests the presence of metastatic disease. The second case corresponds to a histogram with noticeable fluctuations, indicating the presence of metastasis. Such fluctuations could become local maxima peaks, indicating the advance of the metastasis. The third case corresponds to the false color results, displayed in terms of the gray tones, observed in the histogram. Such false color is assigned from the construction of a 7-color palette and is selected in terms of the gray tones range. This eases the ad hoc false color assignation for visualization purposes. The final diagnosis is carried out in terms of the color, geometry, extension, and location of the region of interest in the images. Our proposed technique has the potential to be used in high-demand oncology centers due to its simplicity and diagnostic efficiency, confirmed and tested by specialists in the Centro Medico Siglo XXI (XXI Century Medical Center), CDMX-México.

75P - A parallel deep learning network framework for whole-body bone scan image analysis

BackgroundA parallel deep learning network framework for whole-body bone scan image analysis Whole-body bone scan image analysis in nuclear medicine is a common method assisting physicians in bone metastases detection of cancer. As the increasing need for diagnostic examinations in the huge and elderly population in China, physicians are facing a significant growth of workload but must still manage to read the diagnostic images carefully and avoid errors in interpretation. It is crucial to develop a clinical decision support tool in assisting physicians in their clinical routine. MethodsIn this study, we proposed a parallel deep learning network framework for bone-scan interpretations of the presence or absence of bone metastases. The whole-body bone scans (anterior and posterior views) of 707 patients who are suspected bone metastatic disease were studied. The physicians were asked to classify each case for the presence or absence of bone metastasis manually. Each bone scan image was automatically segmented into 26 different anatomical regions of homogeneous bones based on the skeletal frame. The corresponding 26 deep learning networks made a diagnosis by inspecting each region and searching for abnormal lesion activity simultaneously. To estimate the performance of each anatomical sub-region identification models, a ten-fold cross testing scheme was applied where the data set was divided into ten parts of equal size randomly. ResultsThe sensitivity, specificity and the mean number of false lesions detected were adopted as performance indices to evaluate the proposed model. The best sensitivity and specificity of an individual network corresponding to each sub-region are 99.9 % and 97.3% respectively. The overall mean sensitivity and specificity of the parallel model are 99.2% and 71.8% respectively, as well as 2.0 false detections per patient scan image within millisecond. ConclusionsWith an extremely high sensitivity, specificity and a low false lesions detection rate, this proposed parallel deep learning network model is demonstrated as useful for detecting metastases in bone scans. Our proposed framework appears to have significant potential as a clinical decision support tool in assisting physicians in their clinical routine. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureX. Pu: Full / Part-time employment: University of Electronic Science and Technology of China; Full / Part-time employment: University of Electronic Science and Technology of China; Full / Part-time employment: University of Electronic Science and Technology of China. G. Tang: Full / Part-time employment: West China University Hospital, Sichuan University. K. Cai: Research grant / Funding (institution): School of Computer Science and Engineering, University of Electronic Science and Technology of China. Y. Huang: Research grant / Funding (institution): College of Computer Science, Sichuan University. M. Ping: Research grant / Funding (institution): School of Computer Science and Engineering, University of Electronic Science and Technology of China. Z. Peng: Research grant / Funding (institution): Big Data Research Center, University of Electronic Science and Technology of China. H. Qiu: Full / Part-time employment: School of Computer Science and Engineering, University of Electronic Science and Technology of China.

The Association between Degenerative Spine Disease and Obesity in Cancer Patients: An Evaluation by Bone Scintigraphy

Introduction: Degenerative changes of the spine are common in obese cancer patients and are frequently confusing duringthe interpretation of bone scan of those patients. Aim: To investigate the influence of body weight on the frequency of degenerative spine disease in a cohort of cancer patients using technetium-99m methylene diphosphonate (Tc-99m MDP) bone scan. Methods: A prospective study of 100 cancer patients with or without back pain referred for bone scanning. Their mean age was 58.5±10.2 years and 46% were males. Tc-99m MDP bone scan was done followed by spinal magneticresonance imaging (MRI) examination. Patients were divided into two groups according to the body mass index (BMI) intogroup 1 including 60 overweight and obese (BMI ≥ 25) patients and group 2 including 40 non-obese (BMI < 25) patientsserving as a control group. Any spot of enhanced radiotracer uptake at any part of the vertebrae was considered abnormaland correlated with MRI findings. Results: A total of 168 vertebral lesions were detected by bone scan (150 in group 1 and 18 in group 2) with significant difference between both groups and between different grades of obesity in group 1. All lesions were accurately localized and proved to be of degenerative nature by MRI. The percentage of patients with back pain in group 1 was significantly higher than in group 2 (65% vs. 35%, respectively). Conclusion: Bone scintigraphy is a good technique to detect degenerative spinal disease in obese cancer patients.

Expert System for Bone Scan Interpretation Improves Progression Assessment in Bone Metastatic Prostate Cancer.

The bone scan index (BSI) was introduced as a quantitative tool for tumor involvement in bone of patients with metastatic prostate cancer (mPCa). The computer-aided diagnosis device for BSI analysis EXINIboneBSI seems to represent technical progress for the quantitative assessment of bone involvement. But it is not yet clear if the automated BSI (aBSI) could contribute to improved evaluation of progression in patients under antiandrogens or chemotherapy in contrast to the visual interpretation and/or conventional biomarkers such as the prostate-specific antigen (PSA). In 49 mPCa patients, bone scans were performed initially and during different therapy courses. Scans were evaluated visually and by the artificial-neural-network-based expert system EXINIboneBSI. Progression of metastatic bone involvement was defined according to the Prostate Cancer Clinical Trials Working Group 2 (PCWG2) criteria in the visual interpretation. The computer-assisted interpretation was based on different cutoff values in relative changes of the aBSI. Additionally, assessments according to bone scanning were compared to changes in the PSA value as a potential surrogate for treatment response. Using a sensitive cutoff value (5% or 10%) for the relative aBSI increase led to significantly increased progression determination compared to the visual interpretation of bone scans (49% and 43% vs. 27%, p<0.001). In 63% of the cases PSA and BSI changes matched, whereas in 18% progression was only indicated by the aBSI. A relative cutoff of 5% for the aBSI decrease could reclassify 47 serial scan pairs which were visually interpreted as stable into 22 progressive and 25 remissive scans. Distinct thresholds of the relative aBSI could help to better assess disease progression in mPCa patients. Manual corrections of the BSI values are not required in most cases. The aBSI could serve as a useful additional parameter for therapy monitoring in mPCa patients in the future.

Three phase bone scan interpretation based upon vascular endothelial response.

Objectives:A new method of interpretation of Three Phase Bone Scan (TPBS) scan based upon the normal physiological vascular endothelial related response.Materials and Methods:Fifty cases of TPBS were evaluated. Thirteen were normal. In remaining 37 positive studies, 20 showed localized hyperemic response. All localized hyperemic responses except one with vascular endothelial dysfunction were without infection (95.0%). Infection could be ruled out in absence of generalized massive flow and pool response. All 17 cases with generalized massive hyperemic response had infection, consistent with infection or CRPS/RSD. Micro-bacterial or histological confirmation of infection was obtained in 11 cases. All 11 cases with confirmed infection showed generalized massive hyperemic response (100.0%). Two were CRPS/RSD and 2 cases were of cellulitis (100.0%). Among remaining 2, one refused surgery and other was lost to follow-up. Additionally, 20 published cases in the literature of osteomyelitis were also analyzed. Nineteen cases of bone and joint infection, (osteomyelitis/arthritis/cellulitis) except one with endothelial dysfunction showed generalized massive increased flow and pool response (95.0%). All published cases of osteomyelitis in the literature showed generalized massive hyperemic response (100.0%).Results:The data clearly indicated that 100% of the cases of bone infection (osteomyelitis/arthritis/cellulitis) and cases of CRPS/RSD showed generalized massive flow and pool pattern. Infection could be ruled out in absence of generalized massive flow and pool response. All 100% published cases of osteomyelitis in the literature showed positive vascular endothelial response.Conclusion:By incorporating the concept of vascular endothelial related response causing massive vasodilatation in infection, the interpretation of the TPBS can be more précised as it is based upon the normal physiology. Larger studies are recommended.

99mTc-Oxidronate Uptake Within Urothelial Carcinoma Confirmed With SPECT/CT Imaging

A 63-year-old woman with recurrent urothelial carcinoma was referred for skeletal scintigraphy to evaluate for osseous metastatic disease. The bone scan showed no osseous metastatic disease, but did show intense focal radiotracer accumulation along the left aspect of the urinary bladder. SPECT/CT images localized this uptake to a calcified bladder wall mass corresponding with the biopsy-proven (via cystoscopy) recurrent tumor. This case demonstrates that (a) some tumors may accumulate radionuclide bone tracer, emphasizing the need for careful evaluation of nonosseous structures during bone scan interpretation; (b) SPECT/CT is useful for clarifying potentially confusing findings and preventing misdiagnosis.

Monitoring the Clinical Outcomes in Advanced Prostate Cancer: What Imaging Modalities and Other Markers Are Reliable?

Effective patient care and efficient drug development require accurate tools to assess treatment effects. For metastatic castration-resistant prostate cancer (mCRPC), response biomarkers have historically been poorly reproducible, inaccurate, inconsistently applied, or only loosely associated with tangible clinical benefits such as survival. However, the field of response assessments for prostate cancer is maturing, in compliance with a rigorous process defined by analytic validation, clinical validation, and clinical qualification. For example, bone imaging with technetium-99m scintigraphy has historically been poorly used in prostate cancer clinical trials and routine patient care, and frequently has led to poor decision-making. However, contemporary clinical trial consensus criteria (Prostate Cancer Working Group 2 [PCWG2]) have standardized the definition of progression on bone scintigraphy and the clinical trials endpoint of radiographic progression-free survival (rPFS). A validated bone scan interpretation form captures the relevant data elements. rPFS and the forms have been undergoing prospective testing in multiple phase III studies. The first of these trials demonstrated a high degree of reproducibility and correlation with overall survival, and rPFS was used by the US Food and Drug Administration (FDA) for approval of abiraterone in chemotherapy-naïve mCRPC. Circulating tumor cells (CTC) are another class of assays with significant promise as response-indicator biomarkers. CTC enumeration has undergone analytic validation and has been FDA-cleared for monitoring patients with prostate cancer in conjunction with other clinical methods. It is not yet a surrogate for survival. Patient-reported outcomes (PROs) are direct indicators of patient benefit. The assays to measure PROs must undergo each of the steps of biomarker development, and are increasingly being standardized and used as clinical trial endpoints. In this review, we critically assess each of these classes of novel biomarkers--imaging, CTC, and PROs--in regard to the quality of data supporting their use to monitor clinical outcomes in advanced prostate cancer.

A comparison of the diagnostic performance of half-time SPECT and multiplanar pelvic bone scan in patients with significant bladder artifacts

The objective of this study was to evaluate the diagnostic performance of half-time single-photon emission computed tomography (SPECT) in the interpretation of bone scans in patients with bladder artifacts in comparison with multiplanar imaging. We also investigated whether SPECT could reduce the radiation dose to nuclear medicine personnel and shorten the acquisition time. Data from 29 patients with significant bladder artifacts were assessed by two nuclear medicine physicians. The presence or absence of pelvic bone lesions was individually interpreted with both techniques, multiplanar imaging and half-time SPECT, using a three-point pelvic score as follows: 0=definitely no lesion, 1=indeterminate, 2=definite positive lesion. A comparison of the diagnostic performances between the two techniques was made. The radiation dose to personnel and acquisition time were also investigated. Using half-time SPECT, the incidence of studies interpreted without interference from bladder artifacts (artifact-free image) was 100% on both patient-based and lesion-based analyses of 29 patients, whereas multiplanar imaging revealed incidences of 52 and 90% on patient-based and lesion-based analyses, respectively. Ninety percent of technologists and 58% of assistants received 1 µSv/case radiation dose while performing multiplanar imaging. Only 10% of technologists received 1 µSv/case and none of the assistants received a detectable radiation dose from SPECT. The SPECT technique could also reduce the examination time, particularly when positioning time was included. Half-time SPECT can significantly improve the diagnostic confidence of interpreting equivocal pelvic lesions in patients with bladder artifacts, compared with multiplanar imaging. This technique also provides lower radiation dose to nuclear medicine staff and requires shorter examination time.

Effectiveness of bone scans in the diagnosis of osteoarthritis of the temporomandibular joint

In reference to the article by Kim et al,1 we would like to congratulate the authors on publishing an informative study. However, there are few concerns regarding this study that we would like to share with the authors. First, the authors did not mention whether ethical clearance or informed consent were obtained for this study. These considerations are important while conducting a study, especially one involving radiation exposures. We feel that a mention of the exact number of patients included in the study along with their clinical and radiographical diagnoses (i.e. unilateral/ bilateral involvement, internal derangement/osteoarthritis) in the materials and methods section would have enabled readers to make a clearer interpretation of the results. Even though it is appreciable that the interobserver reliability was calculated for the interpretation of panoramic radiographs in this study, we fail to understand why it was not checked for interpretation of the bone scan images. Also, it is known that while interpreting planar nuclear images nuclear activity from adjacent structures may be superimposed on the area of interest.2 Such a factor should also be considered while interpreting the results. Another appreciable factor in this study is that both qualitative and quantitative methods were used to analyse the bone scan images. However, no comparison was made between these two methodologies in the results section of the study. We would like to know the authors' experience in this regard. Finally, we would like to bring to notice an error in the first paragraph of the results, in which the authors have mentioned number of patients, instead of number of joints. This study has attempted to quantify the interpretation of bone scan for the diagnosis of osteoarthritis of the temporomandibular joint and we would like to highlight our appreciation for the efforts taken by the authors in conducting this study.

Extraosseous accumulation of bone scan tracer 99m Tc-methylene diphosphonate in a phlebolith

Uptake in non-osseous, non-urologic tissues is occasionally found in the performance of bone scintigraphy. These uptakes reflect an atypical interaction between the radiopharmaceutical and the patient. Knowledge of the rare extraskeletal uptakes and their clinical relevance helps in better interpretation of bone scans. We report an unusual occurrence of extraosseous accumulation of 99mTc-methylene diphosphonate in a phlebolith in bone scan, confirmed with the aid of photon emission computed tomography and computed tomography.

Abstract B114: Cabozantinib effects on bone metastasis: Computer-aided quantitative bone scan assessment of prostate cancer treatment response.

Abstract Background: Cabozantinib is an oral inhibitor of MET and VEGFR2 and at a dose of 100 mg qd has demonstrated high rates of partial or complete bone scan resolution in CRPC patients with bone metastases, as assessed by manual visual reads. No accepted approach exists for the assessment of bone scan response in prostate cancer patients. An FDA 510(k) approved image analysis package has been developed that includes a computer-aided detection (CAD) system to detect pixels associated with bone lesions on bone scan with high accuracy, thus facilitating quantitative assessment of tumor burden with advantages of objectivity and consistency over manual approaches. A change in total Bone Scan Lesion Area of 30% or greater has been previously established as a cutoff point to distinguish responders from non-responders [1]. Methods: Original Digital Imaging and Communications in Medicine (DICOM) format images of baseline and week 6 bone scan assessments were collected and analyzed by the automated CAD system then reviewed by a physician experienced with bone scan interpretation as part of an ongoing clinical study of single agent cabozantinib at a lower starting dose of 40 mg qd in CRPC subjects with evidence of bone metastases. All subjects had undergone standard of care whole body scintigraphy, 2–4 hours post-injection of 20–25 mCi of Tc MDP. All images underwent intensity normalization to a bone scan reference to account for differences in radiotracer dosing levels and scan timing to improve reproducibility. Lesions consistent with metastatic foci of disease were automatically segmented based on anatomic region-specific intensity thresholds. Each segmented image was reviewed by a nuclear medicine physician for removal of any remaining false positive regions (e.g. areas of degenerative joint disease). Quantitative assessment of lesion burden was then determined. Results: 10 CRPC subjects showing evidence of bone metastasis were treated in an ongoing dose-ranging study with cabozantinib and were evaluable for bone scan response assessment at week 6. Reductions in the following parameters (median and range) were observed at week 6 relative to baseline: total Bone Scan Lesion Area (168.5 cm2 [20, 864] to 54 cm2 [0, 431]; 68% reduction), Bone Scan Lesion Count (34 [3, 74] to 3 [0, 64]; 91% reduction), and mean normalized Bone Scan Lesion Intensity (92.2 [56.5, 155.0] to 57.0 [0, 90.5]; 38% reduction). All 10 subjects had a reduction in Bone Scan Lesion Area, with 9 achieving a bone scan response at the week 6 timepoint as assessed by both the CAD system and visual review by the investigator. Conclusion: A significant reduction in apparent bone scan abnormality was demonstrated by the automated CAD system. The results demonstrate the potential for objective measurement of cabozantinib treatment effects in bone, laying the foundation for further validation against other clinically relevant outcome measures such as pain and overall survival. Reference: 1. G. H. Chu, M. S. Brown, H. J. Kim, M. Auerbach, C. Poon, B. Ramakrishna, A. Vidovic, D. W. Gjertson, M. J. Morris, S. M. Larson, J. G. Goldin, H. I. Scher. Initial analytic validation of automated bone scan measures for treatment response assessment in patients with metastatic castration-resistant prostate cancer (CRPC). J Clin Oncol 29: 2011 (suppl; abstr e15174). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B114.

719 SERUM CONCENTRATION OF TESTOSTERONE MEASURED BY ISOTOPE DILUTION-LIQUID CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY (ID-LC-MS/MS) IN MEN AFTER BILATERAL ORCHIECTOMY OR LUTEINIZING HORMONE RELEASING HORMONE (LHRH) AGONIST THERAPY

P in chemotherapy-naive patients (pts) with mCRPC, and to assess the frequency of interpretation of bone scans that is discordant with PSA and clinical response. METHODS: COU-AA-002 was a single-arm, open-label, multicenter, phase II study of 1000 mg AA with 5 mg po P BID in continuous 28-day cycles. Primary end point: pts achieving a 50% PSA decline by Week 12. Secondary end points: objective radiographic response (RECIST), time to PSA progression (TTPP), overall survival and clinical benefit of disease stabilization, change in ECOG status and safety. Bone scan flare was evaluated for all pts who had scans available at baseline, 4, and 7 months. RESULTS: Between October 2007 and May 2008, 33 pts with mCRPC were enrolled. A 50% PSA decline at Week 12 was seen in 22 pts (67%). Maximal PSA declines of 50% and 90% were seen in 26 (79%) and 15 (46%) pts, respectively, with undetectable PSA levels ( 0.1 ng/mL) in 2 pts. Overall, an objective tumor response occurred in 9/33 (27%) as partial responses; 2 had stable disease. The median time on therapy was 63 weeks (range, 8 –104 weeks), with 15 (46%) pts still on treatment. Median TTPP was 71 weeks (95% CI; 40 weeks, not estimable). ECOG-PS improved from 1 to 0 in 8 (24%) pts. Bone scan flare was observed in 30% overall and in 10/23 (43.5%) of those who experienced a decline in PSA. Adverse events were mainly grade 1 to 2, with the most common being fatigue (46%), hot flush (30%), bone pain (24%), peripheral edema (24%), arthralgia (21%), dizziness (21%), and hypokalemia (21%). CONCLUSIONS: Clinical response to AA P was frequent and durable in chemotherapy-naive pts with mCRPC, with over 50% on therapy for 1 year. The high rate of bone scan flare indicates that further investigation is needed to clarify the clinical meaning of this phenomenon. AA P was well tolerated. Maturing data from the COU-AA-302 phase 3 study comparing AA/P to placebo/P will further clarify the effects of abiraterone in chemotherapy-naive mCRPC.

Complimentary role of FDG-PET imaging and skeletal scintigraphy in the evaluation of patients of prostate carcinoma

Prostate cancer is one of the most common malignancies of elderly males. Management depends on the accurate estimation of disease both at initial diagnosis and in its subsequent course. In the present study, we evaluated the diagnostic utility of positron emission tomography with 18 F-fluorodeoxyglucose (FDG-PET) in patients having prostate cancer. The findings were compared with the results of bone scan (BS) for the detection of bone metastases. Sixteen patients (age range, 55-83 years) with confirmed diagnosis of prostate cancer were included in the prospective study. Three patients had undergone bilateral orchidectomy, 1 had hormonal therapy, 9 had undergone both, and 3 had no therapy. All the patients underwent wholebody BS and FDG-PET within 1 week. Interpretation of BS and FDG-PET were performed qualitatively. Osseous abnormalities detected by both methods were compared. Involvement of the disease in other sites as seen on FDG-PET was also noted. BS detected 197 osseous lesions, whereas FDG-PET could detect 97 (49%) bone lesions. However, in 3 patients without any prior therapeutic intervention, FDG-PET results were superior or equivalent to that of BS. FDG-PET also detected extensive involvement of the disease in the bone marrow in 4 patients, lymph node metastases at various sites in 8, liver metastases in 2, and lung metastases in 1 patient. FDG-PET could demonstrate less number of osseous metastases in comparison with BSs, but the results have to be interpreted in the background of prior treatment administered and the tumor biology of the lesion. It is evident that FDG-PET could detect the unknown soft tissue involvement of the disease with good sensitivity, which might play an important role in the management of prostate cancer. Overall, in the absence of novel PET tracers, both skeletal scintigraphy and FDG-PET imaging can play a complimentary role in the management of prostate cancer.

Guidelines for paediatric bone scanning with 99mTc-labelled radiopharmaceuticals and 18F-fluoride

The purpose of these guidelines is to offer nuclear medicine teams a framework that could prove helpful in daily practice. The guidelines include information related to the indications, acquisition, processing and interpretation of bone scans in children, focusing primarily on (99m)Tc-labelled diphosphonate scintigraphy, and also recommendations with regard to the emerging use of PET with (18)F-fluoride.

Complimentary role of FDG-PET imaging and skeletal scintigraphy in the evaluation of patients of prostate carcinoma

Prostate cancer is one of the most common malignancies of elderly males. Management depends on the accurate estimation of disease both at initial diagnosis and in its subsequent course. In the present study, we evaluated the diagnostic utility of positron emission tomography with 18 F-fluorodeoxyglucose (FDG-PET) in patients having prostate cancer. The findings were compared with the results of bone scan (BS) for the detection of bone metastases. Sixteen patients (age range, 55-83 years) with confirmed diagnosis of prostate cancer were included in the prospective study. Three patients had undergone bilateral orchidectomy, 1 had hormonal therapy, 9 had undergone both, and 3 had no therapy. All the patients underwent wholebody BS and FDG-PET within 1 week. Interpretation of BS and FDG-PET were performed qualitatively. Osseous abnormalities detected by both methods were compared. Involvement of the disease in other sites as seen on FDG-PET was also noted. BS detected 197 osseous lesions, whereas FDG-PET could detect 97 (49%) bone lesions. However, in 3 patients without any prior therapeutic intervention, FDG-PET results were superior or equivalent to that of BS. FDG-PET also detected extensive involvement of the disease in the bone marrow in 4 patients, lymph node metastases at various sites in 8, liver metastases in 2, and lung metastases in 1 patient. FDG-PET could demonstrate less number of osseous metastases in comparison with BSs, but the results have to be interpreted in the background of prior treatment administered and the tumor biology of the lesion. It is evident that FDG-PET could detect the unknown soft tissue involvement of the disease with good sensitivity, which might play an important role in the management of prostate cancer. Overall, in the absence of novel PET tracers, both skeletal scintigraphy and FDG-PET imaging can play a complimentary role in the management of prostate cancer.

Improved Classifications of Planar Whole-Body Bone Scans Using a Computer-Assisted Diagnosis System: A Multicenter, Multiple-Reader, Multiple-Case Study

The aim of this multicenter study was to investigate whether a computer-assisted diagnosis (CAD) system could improve performance and reduce interobserver variation in bone-scan interpretations of the presence or absence of bone metastases. The whole-body bone scans (anterior and posterior views) of 59 patients with breast or prostate cancer who had undergone scintigraphy for suspected bone metastatic disease were studied. The patients were selected to reflect the spectrum of pathology found in everyday clinical work. Thirty-five physicians working at 18 of the 30 nuclear medicine departments in Sweden agreed to participate. The physicians were asked to classify each case for the presence or absence of bone metastasis, without (baseline) and with the aid of the CAD system (1 y later), using a 4-point scale. The final clinical assessments, based on follow-up scans and other clinical data including the results of laboratory tests and available diagnostic images (such as MRI, CT, and radiographs from a mean follow-up period of 4.8 y), were used as the gold standard. Each physician's classification was pairwise compared with the classifications made by all the other physicians, resulting in 595 pairs of comparisons, both at baseline and after using the CAD system. The physicians increased their sensitivity from 78% without to 88% with the aid of the CAD system (P < 0.001). The specificity did not change significantly with CAD. Percentage agreement and kappa-values between paired physicians on average increased from 64% to 70% and from 0.48 to 0.55, respectively, with the CAD system. A CAD system improved physicians' sensitivity in detecting metastases and reduced interobserver variation in planar whole-body bone scans. The CAD system appears to have significant potential in assisting physicians in their clinical routine.

Computer-Assisted Interpretation of Planar Whole-Body Bone Scans

The purpose of this study was to develop a computer-assisted diagnosis (CAD) system based on image-processing techniques and artificial neural networks for the interpretation of bone scans performed to determine the presence or absence of metastases. A training group of 810 consecutive patients who had undergone bone scintigraphy due to suspected metastatic disease were included in the study. Whole-body images, anterior and posterior views, were obtained after an injection of (99m)Tc-methylene diphosphonate. The image-processing techniques included algorithms for automatic segmentation of the skeleton and automatic detection and feature extraction of hot spots. Two sets of artificial neural networks were used to classify the images, 1 classifying each hot spot separately and the other classifying the whole bone scan. A test group of 59 patients with breast or prostate cancer was used to evaluate the CAD system. The patients in the test group were selected to reflect the spectrum of pathology found in everyday clinical work. As the gold standard for the test group, we used the final clinical assessment of each case. This assessment was based on follow-up scans and other clinical data, including the results of laboratory tests, and available diagnostic images, such as from MRI, CT, and radiography, from a mean follow-up period of 4.8 y. The CAD system correctly identified 19 of the 21 patients with metastases in the test group, showing a sensitivity of 90%. False-positive classification of metastases was made in 4 of the 38 patients not classified as having metastases by the gold standard, resulting in a specificity of 89%. A completely automated CAD system can be used to detect metastases in bone scans. Application of the method as a clinical decision support tool appears to have significant potential.

Quality of planar whole-body bone scan interpretations—a nationwide survey

The purpose of this study was to investigate, in a nationwide study, the inter-observer variation and performance in interpretations of bone scans regarding the presence or absence of bone metastases. Bone scan images from 59 patients with breast or prostate cancer, who had undergone scintigraphy due to suspected bone metastatic disease, were studied. The patients were selected to reflect the spectrum of pathology found in everyday clinical work. Whole body images, anterior and posterior views, were sent to all 30 hospitals in Sweden that perform bone scans. Thirty-seven observers from 18 hospitals agreed to participate in the study. They were asked to classify each of the patient studies regarding the presence of bone metastasis, using a four-point scale. Each observer's classifications were pairwise compared with the classifications made by all the other observers, resulting in 666 pairs of comparisons. The interpretations of the 37 observers were also compared with the final clinical assessment, which was based on follow-up scans and other clinical data. On average, two observers agreed on 64% of the bone scan classifications. Kappa values ranged between 0.16 and 0.82, with a mean of 0.48. Sensitivity and specificity for the observers compared with the final clinical assessment were 77% and 96%, respectively, for detecting bone metastases in planar whole-body bone scanning. Moderate inter-observer agreement was found when observers were compared pairwise. False-negative errors seem to be the major problem in the interpretations of bone scan images, whilst the specificities for the observers were high.