False-positive Bone Scans Research Articles

Downstream Studies Following the Use of Bone Scan in the Staging of Muscle-invasive Bladder Cancer

ObjectiveTo quantify the use of downstream studies following staging bone scans in patients with muscle-invasive bladder cancer. Bone scans may be obtained in high-risk bladder cancer patients prior to radical cystectomy to exclude bone metastases. However, false-positive bone scans can occur, resulting in the need for additional studies. Patients and MethodsUsing Surveillance, Epidemiology, and End Results (SEER)-Medicare data, we identified 4404 patients diagnosed with muscle-invasive bladder cancer from 2004 to 2011. We further identified those who underwent a bone scan prior to treatment within 6 months of diagnosis and prior to any treatment with cystectomy, radiotherapy, or chemotherapy. We determined the proportion of patients who underwent a subsequent study (bone X-ray, bone CT, bone MRI, and/or bone biopsy) within 3 months of the bone scan and prior to treatment. ResultsAmong patients diagnosed with muscle-invasive bladder cancer, 1373 (31%) had a staging bone scan of whom 26% received a downstream study (n = 213). Overall, 61 patients (7%) received downstream bone-specific X-rays, more than 141 patients (>17%) received bone-specific CTs, and 28 patients (3%) received bone-specific MRIs. The use of bone biopsy was rare (n < 11; <1%). The total cost of all downstream studies was $103,468. Furthermore, there was a one-month delay in treatment for those who received a downstream study compared to those who did not (P < 0.001). ConclusionUse of bone scan in the staging of muscle-invasive bladder cancer often results in the need for additional downstream studies. The delay in treatment and cost burden of downstream studies highlights a potential disadvantage of the routine use of this staging modality.

PD32-09 DOWNSTREAM PROCEDURES FOLLOWING THE USE OF BONE SCAN IN THE STAGING OF MUSCLE-INVASIVE BLADDER CANCER

You have accessJournal of UrologyGeneral & Epidemiological Trends & Socioeconomics: Value of Care: Cost and Outcomes Measures III1 Apr 2017PD32-09 DOWNSTREAM PROCEDURES FOLLOWING THE USE OF BONE SCAN IN THE STAGING OF MUSCLE-INVASIVE BLADDER CANCER Robert Turner II, Jonathan Yabes, Benjamin Davies, Dwight Heron, and Bruce Jacobs Robert Turner IIRobert Turner II More articles by this author , Jonathan YabesJonathan Yabes More articles by this author , Benjamin DaviesBenjamin Davies More articles by this author , Dwight HeronDwight Heron More articles by this author , and Bruce JacobsBruce Jacobs More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1400AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES A bone scan may be considered prior to radical cystectomy to exclude bone metastases in high-risk patients. However, false positive bone scans can occur due to tracer uptake in benign bone lesions with reactive osteoblastic change, resulting in the need for additional procedures such as x-ray, computed tomography (CT), magnetic resonance imaging (MRI), and bone biopsy to further evaluate bone scan findings. The current burden of these downstream procedures is unknown. We aim to quantify the use of downstream procedures following staging bone scans in patients with muscle-invasive bladder cancer. METHODS Using Surveillance, Epidemiology, and End Results (SEER)- Medicare data, we identified 4404 patients diagnosed with muscle-invasive bladder cancer from 2004-2011. We further identified those who underwent a bone scan prior to treatment within 6 months of diagnosis. Using outpatient and carrier claims files, we determined the proportion of patients who underwent a subsequent x-ray, CT, MRI, and/or bone biopsy within 3 months of the bone scan and prior to treatment. RESULTS Among patients diagnosed with muscle-invasive bladder cancer during the study period, 1373 (31%) were identified as having completed a staging bone scan. Overall, 231 patients (17%) received downstream bone-specific x-rays, 340 patients (25%) received bone-specific CTs, and 103 patients (8%) received bone-specific MRIs. The use of bone biopsy was rare (n = 17; 1%). CONCLUSIONS Use of bone scan in the staging of muscle-invasive bladder cancer often results in the need for additional downstream imaging. The cost burden of this downstream imaging highlights a potential disadvantage of the routine use of this staging modality. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e591-e592 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Robert Turner II More articles by this author Jonathan Yabes More articles by this author Benjamin Davies More articles by this author Dwight Heron More articles by this author Bruce Jacobs More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Pitfalls in the diagnosis of paediatric tumours

The most important factor in terms of differential diagnosis of a new mass lesion in children is the child’s age. In infancy, for example, congenital masses and many benign tumours are relatively common. As children grow older, the likely tumours vary with time. Some tumours, such as rhabdomyosarcomas, occur throughout childhood but most malignancies have relatively specific ages when their frequency is greatest. Those masses that manifest as a lump anywhere in the body, including the skull, should be evaluated first with ultrasound. Although benign lesions are often soft to palpation and malignant lesions firm, this is an unreliable clinical sign. Many lymphatic malformations come to attention as a result of an intra-lesional bleed which makes the mass tense and firm initially. Ultrasound can identify the cystic or solid nature of a mass lesion with relative ease. Vascularity can also be easily assessed, an important factor in evaluating proliferating haemangiomas, which manifest typically as fast-growing lumps in the first year of life. More complex mass lesions, or lesions with a deep extension, merit further cross-sectional imaging ideally with magnetic resonance (MR) imaging. If computed tomography (CT) is used, then only post contrast enhanced images are necessary as non-contrast images are usually uninterpretable (because of a lack of retroperitoneal or mediastinal fat in the abdomen and chest, respectively). Post contrast enhanced MR images are useful too in general, because enhanced sequences are necessary to fully evaluate lymphatic and vascular malformations, both of which can mimic malignant solid masses. Most solid tumours ultimately need biopsy confirmation, which is usually possible under ultrasound guidance. All tumours, with the exception of neuroblastoma, require chest CT for staging purposes. Sarcomas currently are also staged with radionuclide bone scans although there is a trend towards using more positron emission tomography (PET)/CT in patients with sarcomatous tumours. Neuroblastoma is staged via a combination of a meta-iodo-benzyl-guanidine scan plus bone marrow aspirates and trephine biopsies. Some imaging pitfalls such as foot vein contrast medium injection mimicking inferior vena cava thrombus, false-positive bone scans after bone biopsy, heavily calcified lesions mitigating against adequate ultrasound evaluation, and other examples will be illustrated via individual case presentations.

Bone Scan in Nasopharyngeal Carcinoma in a Malaysian Hospital

In Sarawak Malaysia, nasopharyngeal carcinoma is a very common male malignancy often presenting in advanced stages with distal metastasis. The great majority of these NPC patients are treated by radiotherapy in Sarawak General Hospital. Bone scans using Tc were done on 41 of these patients over the period of nine months from July 2003 to March 2004. A Very low true positive rate of 9.8 % and relatively high false positive rate of 44% were found and this is mainly due to large numbers of benign diseases such as degenerative spines. The radiologists' correct report rate in true positive bone scans is 75% but their high uncertain report rates of 72% in false positive bone scans are also high, probably suggesting their caution in patients with benign diseases showing positive bone scans. Positive bone scans were found in 51.7 % (15/29) of the newly diagnosed patients, and 58 % (7/12 of the treated patients, suggesting that bone scans are sensitive for screening so as to help target the sites for XR imaging for confirmation of presence of metastasis. Based on 18 cases of false positive scans and 2 cases of true negative scans the specificity of bone scans in NPC is 10% which is low. As there were no cases of false negative scans found, the sensitivity of the bone scan could not be calculated. Moreover, this series compares well with the past reported series in terms of the positive and true positive bone scan rates.

Evidence for selective use of bone scans in early stage breast cancer.

To determine the usefulness of bone scans in detecting metastatic disease in women with early stage breast cancer, records of 193 patients who had bone scans preformed and underwent breast conservation therapy at a single institution were reviewed. Patients with invasive T1 or T2 breast carcinomas were eligible for this study; patients with a true positive bone scan were excluded from conservation therapy and, thus, were excluded from this study. The incidence of false positive bone scans in this study population was 32.6% (63/193 patients). Patients over 50 years of age had a significantly greater incidence of false positive bone scans (p<0. 05). In the 63 patients with false positive bone scans, 101 radiographs were performed to exclude metastatic disease in areas of increased uptake identified on bone scan. No significant difference in the rate of false positive bone scans was seen in relation to tumor size, pathologic or clinical nodal status or hormone receptor activity of the primary tumor. Thus, selective use of bone scans is advocated in patients with early stage (T1 or T2) breast cancer.

Potential False-Positive Bone Scan Secondary to a Calcified Venous Thrombus

The authors report a rare case of uptake in a calcified venous thrombus on bone scintigraphy that simulated a pelvic fracture in a patient with a history of trauma. The absence of any findings on the posterior image suggested that the abnormal focus was located in the anterior pelvic soft tissues. A CT scan revealed a calcified venous thrombus overlying the left acetabulum, and a venous doppler study confirmed the presence of a thrombus in the left femoral vein.

Efficacy of metaiodobenzylguanidine as a scintigraphic agent for the detection of neuroblastoma.

Metaiodobenzylguanidine (MIBG) has been shown to be both sensitive and highly specific for the detection of neuroblastoma. However, controversy surrounds its sensitivity in detecting neuroblastoma when compared with radionuclide (technetium 99m-methylene diphosphonate [99mTc]-MDP) bone scans. Because a diagnostic test ideally should be easy to interpret in addition to being sensitive and specific, this study aims to determine the most efficacious scintigraphic agent for diagnostic use in neuroblastoma. Twenty patients with neuroblastoma had a total of 26 paired MIBG and 99mTc-MDP bone scans obtained less than 4 weeks apart. Each study was evaluated independently of its counterpart by six separate observers (3 experienced and 3 inexperienced in MIBG scintigraphy) to determine the presence or absence of disease and the tumor burden. Inexperienced observers reported more confidence in their interpretations of 99mTc-MDP bone scans; however, seven false-positive bone scans were reported. Using MIBG, all true-positive and true-negative scans, as well as significantly more sites of both primary and metastatic disease, were identified by all observers. This study suggests that MIBG is the more efficacious agent for the scintigraphic evaluation of neuroblastoma.

Diagnosis of Pedal Osteomyelitis in Diabetic Patients Using Current Scintigraphic Techniques

Seventy-seven diabetic patients with suspected osteomyelitis of the foot were evaluated by three-phase bone scintigraphy (TPBS), indium 111-labeled white blood cell scintigraphy (WBCS), roentgenography, or some combination thereof. Retrospective analysis after clinical and pathologic follow-up indicated that the sensitivity of TPBS alone in the diagnosis of osteomyelitis was 100%, with a specificity of only 38% and an accuracy of 63%; the sensitivity of WBCS alone was 100%, with a specificity of 78% and an accuracy of 87%; and the combination of TPBS and WBCS yielded a sensitivity of 100%, with a specificity of 79% and an accuracy of 87%. Roentgenography yielded a sensitivity of 69%, with a specificity of 82% and an accuracy of 76%. The results of this study demonstrate that WBCS is superior to TPBS in the diagnosis of osteomyelitis in the diabetic foot, and TPBS adds little when viewed in conjunction with WBCS. Based on our observations and because of the high prevalence of neuropathic joint disease and other causes of false-positive bone scans, we believe that WBCS alone is adequate for evaluation of suspected pedal osteomyelitis in diabetic patients, particularly when the suspected lesion is located in the tarsometatarsal region in contrast to the toe region (7% vs 44% specificity and 28% vs 69% accuracy, respectively, for TPBS in these two regions, compared with 100% vs 68% specificity and 100% vs 80% accuracy, respectively, for WBCS in the same two regions).

Bone Scintigraphy in the Evaluation of Children With Obscure Skeletal Pain

A retrospective analysis of bone scans of 381 children with unexplained skeletal pain was made. Of these, findings are reported on 358 for whom there were sufficient clinical data. The bone scan results suggested trauma as the cause of pain in 43 patients, inflammatory disease in 73 patients, and neoplasia in ten patients. There was only one false-positive bone scan. Normal findings were obtained from 227 patients, in whom no significant skeletal disease was detected on follow-up, except for juvenile rheumatoid arthritis in 23 patients. Bone scintigraphy is, therefore, an important, noninvasive diagnostic test for evaluating children with obscure bone or joint pain. We recommend that this test be performed early in the evaluation of these children to arrive at the diagnosis expeditiously and with minimal patient discomfort and morbidity.

Negative bone scans of joints after aspiration or arthrography: experimental studies.

It has long been suspected anecdotally that needle aspiration or contrast arthrogram before bone scan may cause a false-positive bone scan. This dictum often directs the sequence of events in the clinical workup of joint disease, yet data to support or refute this are lacking. This study was undertaken to generate such data. Fifty-six joints in mature dogs were examined, including hips, knees, elbows, and shoulders. The joints were examined in pairs; one joint was injected with Conray 60 for an arthrogram, and the contralateral joint was injected with an equal volume of normal saline to simulate a joint aspiration. Confirmation of needle placement and injection into the joints was made with fluoroscopic and digital subtraction imaging. Numbers of attempts required for aspiration and quantity of contrast material extravasated were noted for each joint. Baseline 99mTc-HDP or 99mTc-MDP bone scans were done before the experimental joint aspirations, with follow-up scans at 24 and 96 hr. The scans showed no significant change from baseline after either needle aspiration or arthrogram. When the diagnostic workup suggests the need for such a procedure, it should be performed. In contradiction to popular belief, joint aspiration and/or arthrogram did not affect a subsequent bone scan.

Does aspiration of bones and joints affect results of later bone scanning?

To determine the effect, if any, of needle aspiration on 99mTc bone scanning, three different areas of 15 dogs were first aspirated and then imaged with technetium bone scintigraphy. The hip joint was aspirated, the distal femoral metaphysis was drilled and aspirated, and the tibial periosteum was scraped with an 18- or 20-gauge needle. Varying amounts of trauma were inflicted to simulate varying difficulties at aspiration. 99mTc bone scans were obtained from 5 h to 10 days later. There was no evidence of focal technetium uptake after any hip joint aspiration. This was consistent regardless of the amount of trauma inflicted or the time from aspiration to bone scanning. Metaphyseal cortical drilling and tibial periosteal scraping occasionally caused some focal uptake when scanning was delayed greater than 2 days. When osteomyelitis or pyarthrosis is clinically suspected, joint aspiration can be performed without fear of producing a false-positive bone scan.

False positive bone scan in bone tumors of the lower limb.

When examined using bone scanning agents, eight out of nine patients with lower limb malignancy, and neither of two affected in the upper limb showed a pathologic focus of isotope uptake in an area distal to the tumor. On pathologic examination the positive findings proved false. Such misleading results were found to be avoidable if a tumor-seeking agent instead of a bone scanning one is used.

Technetium-99M polyphosphate bone scanning in carcinoma of the prostate.

SummaryIn 100 consecutive patients with newly diagnosed carcinoma of the prostate examined by X‐ray, skeletal metastases were diagnosed in 18 patients. The additional use of bone scanning with 99mTc‐P.P. increased this figure to 34.Of the 16 patients with metastatic disease demonstrated on a bone scan but not apparent at the initial reading of the radiographs, confirmatory evidence has been forthcoming in 11.X‐ray examination, which need only be of limited scope, remains desirable. It is necessary to exclude false positive bone scans due to coincidental abnormalities such as Paget's disease of bone.We are indebted to Mrs Mary Laschowski both for assistance in carrying out this analysis, and for considerable secretarial help.The illustrations were kindly prepared by Mr Karl Leisner and the statistical analyses carried out by Dr Michael Grace.

85Sr bone scan in neoplastic disease

The skeleton is a frequent site of metastases from neoplasms that are primary elsewhere. Bone scanning was introduced in 1961 to detect enhanced localization of 85 Sr at the sites of skeletal abnormalities. After 10 yr of experience with the bone scan, certain conclusions can be proposed. The bone scan is not helpful in the evaluation of diseases that diffusely affect the skeleton, but it is a sensitive method for detecting diseases that elicit a localized reparative reaction of the skeleton. Approximately 10–40% of patients with skeletal metastases have a normal skeletal roentgenogram at a time when the bone scan is abnormal, whereas less than 5% of bone scans are normal at a time when the skeletal roentgenogram reveals localized abnormalities. False positive bone scans can be reduced to considerably less than 1% through a knowledge of the mechanisms of localization of 85 Sr. The bone scan is particularly useful in patients with lymphomatous diseases and carcinoma of the lung, prostate, breast, and oropharynx. The serum alkaline and acid phosphatases are not sensitive enough for the detection of skeletal metastases. The primary limitation of bone scanning has been, and to some extent remains, the length of time required to accomplish the technical portion of the procedure. However, improved instrumentation and short-lived radiopharmaceuticals promise to make bone scanning feasible as a survey procedure. A certain amount of caution is still in order before accepting short-lived radiopharmaceuticals as a replacement for 85 Sr.