Clinical uses of bone scanning

The skeleton is a frequent site of metastatic disease. Radiographic examination is not sufficiently reliable in early detection since an abnormality is unlikely to be observed until more than 50% of the bone material has been lost. Therefore, skeletal scanning represents a viable technique for demonstration of dynamic response of bone to tumor invasion. This technique provides a more sensitive method for detection of early skeletal metastatic disease. Technetium 99m labeled methylenediphosphonate seems to be the best technetium 99m labeled agent for skeletal images, although ethyline hydroxydiphosphonate may be equally good. The toxicity of the compounds is low and repetitive studies can be done for continued clinical evaluation of the patient without significant risk.This paper was supported by PHS Research Grants No. 1-R10-CA 12252 and 5-R10-CA12478 from the National Cancer Institute, by PHS Center Grant No. 1-P01-CA 14043 from the National Cancer Institute, by the Friends of the Radiation Therapy Center, and by the Alperin Foundation     

Recent advances in bone marrow scanning

Interest in bone marrow scanning has been renewed as the result of the development of radiopharmaceuticals for evaluating specific aspects of bone marrow anatomy, physiology and pathology. This article provides a brief review of bone marrow structure, blood flow and function essential to the understanding of basic principles of bone marrow radionuclide imaging. The prospects and limitations of imaging haematopoietic bone marrow in man using indium 111 chloride, technetium-99m (99mTc)-labelled microcolloid or 99mTc-labelled monoclonal antigranulocytic and antimyelocytic antibodies are discussed in more detail. The technical aspects of bone marrow scintigraphy are presented. Results of more recent studies evaluating bone marrow scanning in circulatory, inflammatory and in systemic haematological disorders are summarized. Special attention is paid to the concept of bone marrow micrometastases and its implications for the follow-up of patients with malignant tumours. Recent results suggest that immunoscintigraphy of bone marrow may provide a novel and sensitive approach for establishing the presence and extent of bone marrow infiltration.     

Abnormal bone marrow distribution following unsuccessful hip replacement: a potential confusion on white cell scanning

A case is presented in which a grossly abnormal distribution of bone morrow following failed hip replacement would have led to the false diagnosis of osteomyelitis. The value of combining bone marrow scanning with indium white cell scanning in possible osteomyelitis is emphasised.     

A comparison of iodine-123 meta-iodobenzylguanidine scintigraphy and single bone marrow aspiration biopsy in the diagnosis and follow-up of 26 children with neuroblastoma

In staging neuroblastomas, the demonstration of tumoural invasion of the bone marrow is an important criterion with regard to the therapeutic prospects and the prognosis. Iliac crest aspiration sampling has been used routinely for the detection of bone marrow metastases in neuroblastoma. However, due to the limited character of the sampling, it sometimes leads to false-negative results. Another procedure which is used to determine the extent of neuroblastoma is metaiodobenzylguanidine (mIBG) scintigraphy. In order to establish the respective merits of both diagnostic techniques retrospectively, 148 iodine-123 mIBG scans of 26 children with neuroblastoma have been re-evaluated and compared with the results of routine bone marrow samples obtained within a 4-week period before or after scanning. Three types of mIBG uptake in the bone/bone marrow could be differentiated: (1) no visualization of the skeleton; (2) diffuse uptake in the skeleton with or without focally increased uptake, which indicates massive, diffuse bone marrow invasion by the tumour; and (3) focal tracer accumulation in one or several bones. No tracer uptake was observed in the skeleton in 91 scans. In 89 of the 91 the bone marrow biopsy was negative. Twenty-four scans showed diffuse skeletal uptake with or without foci. The bone marrow biopsies were negative for eight of those 24 scans. Hyperactive foci in one or more bones without diffuse tracer accumulation in the skeleton were detected in 33 scans. In only 7 of these 33 scans did bone marrow biopsy specimens from the iliac MDP crest contain neuroblastoma cells. Available technetium-99m methylene diphosphonate (MDP) whole-body scintigrams were also compared with the corresponding mIBG scans. Thirty-eight mIBG scans showed no visualization of the skeleton; ^99mTc-MDP scintigrams were also normal. Seven patients with diffuse mIBG uptake in the skeleton appeared as normal on the ^99mTc-MDP scans. Among 27 cases showing focal mIBG uptake in the skeleton with or without diffuse uptake, only I8 demonstrated a hot spot on the bone scintigram. The results of our study indicate that for the assessment of bone marrow infiltration by neuroblastoma, 1231-mIBG scintigraphy is more sensitive than the conventional cytological examination of bone marrow smears routinely obtained from the iliac crest, has a very high sensitivity in excluding bone marrow invasion, has a high specificity for detecting bone marrow invasion, appears to be able to detect early tumoural deposits in the bone marrow before osseous invasion occurs as shown on the MDP scans and is superior to ^99mTc-MDP bone scan in detecting bone/bone marrow metastases of neuroblastoma. In patients with a positive mIBG scan in the skeleton, bone marrow biopsy will not yield additional information. Correspondence to: K. Osmanagaoglu     

Role of technetium-99m planar bone scanning in the evaluation of low back pain

The records of 1018 patients with low back pain in a tertiary spine referral practice were reviewed. One hundred thirty-nine out of 1018 (13.6%) underwent technetium-99m planar bone scanning as part of their investigation. Seventy-three out of 139 scans (52%) showed increased uptake in some area, but only 27 out of 139 (19.4%) showed increased uptake specifically in the low back. Scans consistently yielded no findings with reference to the back when the prescan diagnosis was spinal stenosis, lumbar pain syndrome, herniated nucleus pulposus, or postlaminectomy syndrome. Some scans gave positive findings in patients with a diagnosis of degenerative disc disease, pseudarthrosis, spondylolisthesis, fracture, infection, metabolic disorder, or tumor. Positive scans were generally obtained early after presentation (within 3 months) and negative scans obtained later (after 6 months), suggesting that clinical suspicion is still the main indication for early scanning. Planar bone scanning was helpful in both diagnosis and therapeutic decisionmaking in many conditions.     

Usefulness of technetium-99m hydroxymethylene diphosphonate scans in localizing bone metastases of differentiated thyroid carcinoma

Iodine-131 is uniquely able to demonstrate iodine uptake of differentiated thyroid carcinoma (DTC), but precise localization may be difficult, especially in the thorax, due to the quality of image resolution with 1311 and the lack of anatomical landmarks. When bone metastases do not show radioiodine uptake, bone scintigraphy can be used to detect them. We studied two groups of patients. In group 1, 15 patients with known bone metastases of DTC were treated with 3.7 GBq ¹³¹I. After 4 or 5 days, technetium-99m hydroxymethylene diphosphonate (HMDP; 740 MBq) was injected and a whole-body scan with simultaneous acquisition of ¹³¹I and ^99mTc-HMDP images was carried out using a large field of view gamma camera fitted with a high-energy collimator. Technetium uptake was abnormal in 47 of 63 localizations, being increased in 29 foci, decreased in 7 and heterogeneous in 11. The superimposition of ¹³¹I and ^99mTc-HMDP scans permitted an accurate localization in 80% of spine metastases and in 46% of osseous thoracic localizations, even in the presence of lung metastases. In group 2, 9 patients, who had bone pain, neurological signs or elevated serum thyroglobulin, had DTC bone metastases without iodine uptake. They received a diagnostic dose of ^99mTc-HMDP 3h prior to scintigraphy with a large field of view gamma camera fitted with a low-energy collimator. Technetium uptake was abnormal in 37 of 38 localizations, being increased in 34 foci and decreased in 3. One false-negative was found in a skull metastasis. In both groups of patients, ^99mTc-HMDP scans were useful. The procedure allows accurate localization of bone metastases and can be used as a guide for subsequent radiological investigations.     

Omission of bone scanning according to staging guidelines leads to futile therapy in non-small cell lung cancer

The leading European and American professional societies recommend that bone scans (BS) should be performed in the staging of lung cancer only in those patients with bone pain. This prospective study investigated the sensitivity of conventional skeletal scintigraphy in detecting osseous metastases in patients with lung cancer and addressed the potential consequences of failure to use this method in the work-up of asymptomatic patients. Subsequent to initial diagnosis of non-small cell lung cancer, 100 patients were examined and questioned regarding skeletal complaints. Two specialists in internal medicine decided whether they would recommend a bone scan on the basis of the clinical evaluation. Skeletal scintigraphy was then performed blinded to the findings of history and physical examination. The combined results of magnetic resonance imaging (MRI) of the vertebral column, positron emission tomography (PET) of skeletal bone and the subsequent clinical course served as the gold standard for the identification of osseous metastases. Bone scintigraphy showed an 87% sensitivity in the detection of bone metastases. Failure to perform skeletal scintigraphy in asymptomatic patients reduced the sensitivity of the method, depending on the interpretation of the symptoms, to 19–39%. Without the findings of skeletal scintigraphy and the gold standard methods, 14–22% of patients would have undergone unnecessary surgery or neoadjuvant therapy. On this basis it is concluded that bone scans should not be omitted in asymptomatic patients.     

Radioimmunoscintigraphy with technetium-99m-labelled monoclonal antibody,SM3, in gynaecological cancer

Radioimmunoscintigraphy (RIS) with technetium-99m labelled SM3, a monoclonal antibody reacting with a polymorphic epithelial mucin glycoprotein core antigen, is evaluated. No adverse effects or thyroid uptake were observed. Studies in 45 patients (one twice) had a sensitivity for gynaecological malignancy of 100% (35/35) and a specificity of 73% (8/11), giving an overall accuracy of 93% (43/46). These results have led to the routine adoption of ^99mTc RIS in the management of patients suspected of or having primary or recurrent gynaecological cancer. Correspondence to: M. Granowska     

Reduced technetium 99m labelled NCA-95/CEA-antibody uptake in liver due to gentle antibody reconstitution

The influence of reconstituting a murine monoclonal IgG₁ antibody kit with pertechnetate technetium 99m on antibody distribution in the liver, spleen and sternal bone marrow of patients was examined. The^99mTc-labelled antibody used is directed against nonspecific cross-reacting antigen (NCA-95) and carcinoembryonic antigen (CEA) and has been successfully applied for imaging tissue inflammation and bone marrow scanning. Radioactivity uptake was determined in the liver, spleen, bone marrow and a precordial background region in a consecutive series of 25 patients, examined with an antibody preparation, routinely radiolabelled according to the manufacturer's recommendations and in 14 patients, in whom the antibody was reconstituted with special care, avoiding bubble formation and dropping of buffer into the antibody-containing vial. Gentle compared with routine antibody reconstitution caused a highly significant reduction of the antibody uptake in the liver, as determined by count densities, normalized to injected dose and acquisition time (13.2 ± 5.5 vs 20.1 ± 6.0 cpm per pixel, x±SID,P=0.008). The liver to background ratio was reduced from 3.4 ± 1.4 to 1.9 ±0.5 (P < 0.001). Spleen, sternal bone marrow and precordial background count rates were not significantly affected. These results clearly demonstrate that gentle antibody reconstitution can decrease non-specific antibody uptake in the liver by 34% ± 6.4% (x ± SEM). Thus, scan quality is improved, and the potential deleterious camouflage of underlying structures is avoided.     

Predictive value of bone marrow accumulation of Tc-99m tetrofosmin for subsequent development of distant metastases in breast cancer

OBJECTIVE: We evaluated the predictive value of bone marrow accumulation of technetium (Tc)-99m tetrofosmin in patients with breast cancer for distant metastases in comparison with conventional prognostic factors such as clinical stage, tumor size, axillary lymph node (Node) status, and estrogen receptor (ER) status. METHODS: Bone marrow scans with Tc-99m tetrofosmin were performed on 64 patients with breast cancer who had no clinical evidence of distant metastases. Accumulation in the femoral marrow was classified into four patterns, no detectable, lower, higher, and intensively higher. Higher or intensively higher pattern was interpreted as abnormal. Thirty-six patients with abnormal accumulation (marrow-positive group) and 28 patients without abnormal accumulation (marrow-negative group) were enrolled in the follow-up study. The mean length of observation after scans was approximately 3 years. The predictive value of femoral marrow status and conventional prognostic factors for distant metastases was evaluated by statistical analysis. RESULTS: Univariate analysis showed a significantly higher incidence of subsequent bone metastases (36%>4%; P<0.005), and distant metastases (69%>18%; P<0.001) in the marrow-positive group when compared with the marrow-negative group. Conventional prognostic factors except tumor size were also significantly associated with the development of distant metastases; 77% in clinical stage 3>39% in clinical stages 1, 2, P<0.05; 64% in Node-positive>29% in Node-negative, P<0.01; and 70% in ER negative>27% in ER positive, P<0.005. These conventional factors were not significantly associated with bone metastases. The Cox proportional hazard ratio for bone metastases was markedly higher in femoral marrow status (hazard ratio=11.07). The distant metastases-free survival was significantly reduced in ER negative (P<0.0005), Node-positive (P=0.0215), and clinical stage 3 patients (P=0.0163). On the other hand, a more marked difference was observed in the femoral marrow status (P<0.0001). The hazard ratio for distant metastases was 2.44 in clinical stage, 2.74 in tumor size, 2.74 in Node, and 3.68 in ER, which were each independent prognostic factors associated with distant metastases. However, femoral marrow status was markedly associated with distant metastases (hazard ratio=5.27). CONCLUSIONS: Bone marrow accumulation of Tc-99m tetrofosmin can be a promising prognostic factor independent of conventional prognostic factors for predicting development of not only bone metastases but also distant metastases in breast cancer.     

Species and immunoglobulin preparation related effects on the biodistribution of technetium-99m-labelled immunoglobulin G in a baboon model

Technetium-99m-labelled immunoglobulin G (^99mTc-IgG) is a convenient and useful radio-pharmaceutical for the scintigraphic detection of inflammatory foci. However, unfavourable physiological biodistribution patterns such as high activities in the liver and especially in the kidneys impede the efficacy of this agent. This report describes biodistribution studies in the baboon model of various thiol reduction-mediated ^99mTc-labelled immunoglobulins, including human IgG preparations (Sandoglobulin and Sigma: -globulins prepared from Cohn fractions II and III) as well as baboon IgG preparations (Sigma: -globulins prepared from Cohn fractions II and III and IgG isolated from the serum obtained from specific animals). The biodistribution studies demonstrated differences in kidney concentration, i.e. human IgG (Sandoglobulin) > baboon IgG (cross-over animal experiments with IgG isolated from the serum of the different animals) > human IgG (Sigma) baboon IgG (Sigma)baboon IgG (own IgG isolated from the serum of a specific animal, labelled with ^99mTc and reinjected). Differences in liver concentration were also observed: human IgG (Sandoglobulin)<human IgG(Sigma)baboon IgG (Sigma)baboon IgG (own IgG)IgG (cross-over). Characteristic were the relatively high activities in the liver and kidneys compared to those in other organs with high blood supply, and a relatively high retention in the blood pool. The results indicate that the effect of the heterologous antibody system is insignificant. These studies also demonstrate the suitability of the baboon model for evaluation of ^99mTc-IgG preparations for scintigraphic purposes and suggest that damage to the Fc portion of the IgG molecule during Sandoglobulin preparation may be the cause of the high kidney accumulation of ^99mTc-Sandoglobulin.     

Bone scanning in the child and young adult

Radionuclide bone scanning will identify readily areas of the skeleton where vascularity or osteogenesis is disturbed. Frequently, this will be achieved with a greater sensitivity than orthodox radiology by reflecting altered local physiology of bone. This procedure is, therefore, valuable not only for identifying metastatic disease, but also in benign skeletal disorders characterised by altered blood flow or osteoblastic reaction. These changes occur in many diseases involving bone which are more common in children and young adults. Special attention to the performance of the study and to its interpretation is, however, required in these age groups. The bone scan is invaluable in detecting metastatic disease related to either primary bone tumours or other neoplasia, both in the initial investigation and in the evaluation of therapy. Extra-osseous uptake may also occur, providing useful information relevant to the care of these patients.Part II of this article will appear in the next number of Skeletal Radiology     

Bone mineral density and bone scintigraphy in children and adolescents with osteomalacia

In order to demonstrate the role of bone mineral density (BMD) measurement and bone scans in the management of patients with osteomalacia, radioisotope bone scintigraphy using technetium-99m methylene diphosphonate (MDP) and BMD measurements of the lumbar spine and femur by means of dual X-ray absorptiometry (DXA) were performed at the time of diagnosis and 6 months after therapy in 26 Saudi patients (17 females and nine males). Their mean age was 13.5 years (range, 5–16). BMD measurements were compared with those of normal Saudi subjects matched for age and sex. Bone scan showed an increase in tracer uptake throughout the skeleton (“superscan”) in all children and demonstrated multiple stress fractures in eight. The mean BMD for the lumbar spine was 0.53 g/cm² (Z-score, −3.1) and for the femoral neck 0.55 g/cm² (Z-score, −2.8). Repeated bone scan and BMD after 5 months of therapy with oral vitamin D, calcium and proper sun exposure demonstrated a significant increase (P<0.001) in BMD and healing of pseudofractures. In conclusion, as a non-invasive method with minimal radiation exposure, measurements of BMD in children with osteomalacia are to be recommended in the initial assessment of the severity of osteopenia and in the follow-up to monitor the response to therapy. Bone scintigraphy is valuable in demonstrating the site and severity of stress fractures.     

Imaging of bone infection with labelled white blood cells role of contemporaneous bone marrow imaging

The uptake of white blood cells (WBC) into normal bone marrow may lead to difficulty in detecting bone infection. Twenty-one patients in whom the WBC scan was equivocal or positive underwent a technetium 99m colloid scan to show the distribution of bone marrow. Six patients had a positive WBC scan, and in five of them a discordant colloid scan confirmed infection. However, in one the colloid scan was concordant, indicating that the WBC activity was not due to infection but the result of normal bone marrow uptake. Fifteen patients had an equivocal WBC scan. In 14, infection was excluded by a concordant scan, and 1 patient with a discordant scan was lost to follow-up. We conclude that the combination of a WBC scan and a colloid scan is an effective method to distinguish infection from normal bone marrow activity and, in particular, reduces the number of incorrect diagnoses of infection.     

How does iliac crest bone marrow biopsy compare with imaging in the detection of bone metastases in small cell lung cancer?

Iliac crest bone marrow biopsy (BMB) has often been used as the gold standard for the detection of bone marrow metastases in small cell lung cancer (SCLC). However, it is likely to lead to numerous false-negative results. For this reason, we compared the results of bone scintigraphy (BS), magnetic resonance imaging (MRI), and BMB in 48 sequential patients affected with pathologically confirmed SCLC (47 were evaluable; mean age, 58.4 years). The three procedures were carried out within 1 week, no treatment being performed during this period. Whole-body scans and spot views were obtained in the anterior and posterior projections. For MRI, only the thoracolumbar spine, the sternum and the pelvis were scanned, using spin-echo T1-weighted sequences, resulting in an acquisition time of less than 45 min. Only five BMBs were rated as positive. In these cases, both BS and MRI were also positive. The other 42 biopsies were negative. Among them, in ten cases both BS and MRI were positive. In 21 cases, both BS and MRI were negative. In five cases MRI was positive while BS was negative. Finally, in six cases MRI was negative whilst BS was positive. In most cases in which either BS or MRI was positive, follow-up scans confirmed the initial findings. This study suggests that BMB is more invasive and less sensitive than BS or MRI in detecting bone metastases. MRI seems to be more sensitive than BS in detecting small spinal or pelvic metastases. Whole-body bone scintigraphy is more sensitive in detecting skull, costal or peripheral metastases. BS and MRI should be used in combination and may replace BMB in the detection of bone metastases in SCLC. Correspondence to: I. Perrin-Resche     

Technetium-99m hexamethylpropylene amine oxime leucocyte scintigraphy for the diagnosis of bone and joint infections: a retrospective study in 116 patients

The aim of this study was to evaluate the diagnostic value of technetium-99m hexamethylpropylene amine oxime leucocyte scintigraphy (HMPAO-LS) by means of a retrospective review of 116 patients divided into three groups of bone and joint infection. One hundred and thirty-one LS examinations were performed, and 143 sites analysed. The final diagnosis of infection was based on surgical, histological and bacteriological data and follow-up. Ninety-four suspected localizations were examined in group 1, which included 74 patients with an infection suspected to involve orthopaedic implants. In this group, there were 38 true-positives, 1 false-negative, 49 true-negatives and 6 false-positives. Surgical confirmation was obtained in 34 cases. In group 2 (24 patients with suspected osteomyelitis), there were 27 localizations of which 14 were true-positives and 13 were true-negatives (including seven surgical confirmations). In group 3 (18 patients suspected of septic arthritis) there were eight true-positives, two false-negatives, ten true-negatives and two false-positives. Overall sensitivity of^99mTc-HMPAO-LS for the detection of bone and joint infection was 95%, with a specificity of 90% (group 1: sensitivity 97%, specificity 89%; group 2: 100% and 100%; group 3: 80% and 83%). It may be concluded that HMPAO-LS is an effective tool for the diagnosis of both bone infection involving implants and chronic osteomyelitis.     

Role of bone scanning in the management of non-united fractures: a clinical study

Technetium-99m methylene diphosphonate (^99mTc-MDP) bone scintigraphy was performed in 45 patients (42 male and 3 female) with established non-united fractures to predict the healing response to pulsing electromagnetic field stimulation therapy. The bone scans revealed 3 different scintigraphic patterns. The most frequent pattern was an increased uniform uptake of the tracer at the non-union site (group 1). The second pattern was increased activity at the bone ends with a photon-deficient area between the fracture sites (group 2a) or a generalized decrease in the radionuclide concentration in the region of bone fragments (group 2b). When the scintigraphic pattern did not fit either of the two patterns or when the presence of the cold area between the bone fragments could not be judged with certainty, it was called indeterminate (group 3). All patients underwent pulsing electromagnetic field stimulation. The healing rate was 87.5% and 42.8% in group 1 and group 3 patients, respectively. None of the group 2 patients had any evidence of healing, and they all underwent surgical exploration, revealing complicated non-unions. We conclude that ^99mTc bone scintigraphy is a useful tool in determining complicated non-unions and selecting the proper therapy mode. Offprint requests to: B. Günalp     

Iron-oxide-enhanced MR imaging of bone marrow in patients with non-Hodgkin's lymphoma: differentiation between tumor infiltration and hypercellular bone marrow

The aim of this study was to differentiate normal, hypercellular, and neoplastic bone marrow based on its MR enhancement after intravenous administration of superparamagnetic iron oxides in patients with cancer of the hematopoietic system. Eighteen patients with cancer of the hematopoietic system underwent MRI of the spine before and after infusion of ferumoxides ( n=9) and ferumoxtran ( n=9) using T1- and T2-weighted turbo spin-echo (TSE) and short tau inversion recovery sequences (STIR). In all patients diffuse or multifocal bone marrow infiltration was suspected, based on iliac crest biopsy and imaging such as conventional radiographs, MRI, and positron emission tomography. In addition, all patients had a therapy-induced normocellular ( n=7) or hypercellular ( n=11) reconversion of the normal non-neoplastic bone marrow. The MRI data were analyzed by measuring pre- and post-contrast signal intensities (SI) of hematopoietic and neoplastic marrow and by calculating the enhancement as deltaSI(%) data and the tumor-to-bone-marrow contrast as contrast-to-noise ratios (CNR). Changes in bone marrow signal intensity after iron oxide administration were more pronounced on STIR images as compared with T1- and T2-weighted TSE images. The STIR images showed a strong signal decline of normal and hypercellular marrow 45-60 min after iron oxide infusion, but no or only a minor signal decline of neoplastic bone marrow lesions; thus, deltaSI% data were significantly higher in normal and hypercellular reconverted marrow compared with neoplastic bone marrow lesions ( p<0.05). Additionally, the contrast between focal or multifocal neoplastic bone marrow infiltration and normal bone marrow, quantified by CNR data, increased significantly on post-contrast STIR images compared with precontrast images ( p<0.05). Superparamagnetic iron oxides are taken up by normal and hypercellular reconverted bone marrow, but not by neoplastic bone marrow lesions, thereby providing significantly different enhancement patterns on T2-weighted MR images; thus, superparamagnetic iron oxides are useful to differentiate normal and neoplastic bone marrow and to increase the bone marrow-to-tumor contrast.     

放射性核素89Sr治疗骨转移癌的新进展

乳腺癌、前列腺癌和肺癌骨转移最常见的症状是骨疼痛。在广泛性骨转移癌出现严重骨疼痛时，那些通常使用的治疗手段即止痛药物、激素、化疗和外照射治疗都不够理想，且均可出现严重副作用或治疗失败。锶放射性同位素（^89Sr）治疗骨转移癌是一种新的治疗方法，也是一种安全有效的方法，较传统治疗方式而言，更能靶向定位于所有受累部位，包括骨扫描及X线片或CT，MRI难以发现的隐匿转移癌灶，选择性病灶摄取使正常组织仅受有限的辐射剂量而治疗效率增高，副作用较小。^89Sr治疗骨转移癌的总有效率大于80％，其对血细胞的抑制作用轻微且是一过性的，短期内能得到恢复。^89Sr加用外放疗或者化疗药物联合治疗，能够显著减轻骨疼痛、降低治疗的副作用，并可抑制病骨病灶继续发展而延长患者的生存期。