Technetium-99m-sestamibi scintigraphy: an alternative approach for diagnosis and follow-up of active myeloma lesions after high-dose chemotherapy and autologous stem cell transplantation

The prognostic value of F-18 fluorodeoxyglucose bone marrow uptake in patients with recent diagnosis of multiple myeloma: a comparative study with Tc-99m sestamibi

PURPOSE

We assessed the prognostic value of F-18 fluorodeoxyglucose (FDG) uptake in the bone marrow of patients with multiple myeloma (MM) in comparison with Tc-99m methoxy-isobutyl-isonitrile (MIBI).

METHODS

The extent and intensity of FDG and MIBI uptake in the bone marrow of 18 patients with a recent diagnosis of MM were assessed by visual score and by calculating the mean SUV (mSUV) for FDG and the femora/thigh ratio (TG/BKG, [Target/Background ratio]) for MIBI images. These parameters were correlated with clinical indexes of disease using hemoglobin and beta-2-microglobulin levels and plasma cell infiltrate (PCI) percentage. The mean values of the visual score, mSUV, and TG/BKG levels were compared in patients deceased after a relatively short follow-up (n = 9; group A) and in patients with a longer survival or were alive at the end of the study (n = 9; group B).

RESULTS

Significant correlations of mSUV and TG/BKG values with PCI percentages and beta-2-microglobulin were found (P < 0.05). The extent of FDG and MIBI bone marrow uptake was greater in patients of group A (P < 0.01). Higher values of mSUV (P < 0.01) and TG/BKG (P < 0.05) were also observed in patients of group A. These results were consistent with the differences (not statistically significant) in hemoglobin, albumin, beta-2-microglobulin levels, and PCI percentages observed in the 2 groups.

CONCLUSION

Our study demonstrates that an increase of FDG bone marrow uptake may predict a more aggressive disease, as much as MIBI uptake. Therefore, an additional analysis of FDG bone marrow images should be performed in patients undergoing PET studies during the initial staging of MM.

Detection of multiple myeloma by PET/CT in a patient with colon cancer

A 76-year-old man with previous sigmoid colon resection for adenocarcinoma had low back pain for 2 months. Whole-body bone scintigraphy showed multiple focal Tc-99m methylene diphosphonate (MDP)-avid lesions in both rib cages and 3 lumbar vertebrae, indicating metastases. F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) imaging was performed for further evaluation of this possible metastatic disease and demonstrated the lumbar and costal metastases and several hypermetabolic areas in the pelvic bones, multiple thoracic vertebrae, both shoulders, and the right femur. Histopathologic examination of the right-sided iliac crest, however, revealed multiple myeloma.

Technetium-99m sestamibi scintigraphy is sensitive and specific for the staging and the follow-up of patients with multiple myeloma: a multicentre study on 397 scans

We evaluated the additional benefit of Technetium(99)-sestamibi (99mTc-MIBI) scanning in comparison with standard X-ray techniques for multiple myeloma patients either at diagnosis or during follow-up. Between February 2001 and January 2005, 397 whole body scans were acquired. On 229 scans performed at diagnosis, 146 (64%) were positive and 81 cases have discordant X-ray results. The sensitivity of 99mTc-MIBI and X-ray were 77% and 45% respectively. As a result of 99mTc-MIBI, 40% of asymptomatic myeloma patients were up-staged. The positivity of 99mTc-MIBI correlated significantly with all of the most relevant clinical and biological parameters. Multivariate analysis selected only high reactive C protein (P = 0.0005), bone marrow infiltration (P = 0.02) and bone pain (P = 0.002) as factors affecting 99mTc-MIBI pattern. In 22 patients with solitary myeloma, 99mTc-MIBI was positive in 86% of cases and detected more disease sites than X-ray. Among 168 scans performed during follow-up, 99mTc-MIBI presented high specificity in patients showing a complete response (CR; 86%), and correlated with myeloma activity and with response to therapy. At multivariate analysis, a positive pattern correlated with bone marrow infiltration (P = 0.002) and disease status other than CR (P = 0.03). We conclude that 99mTc-MIBI scanning is an additional diagnostic tool with a high specificity for the staging and the follow-up of multiple myeloma patients.

Guidelines for the use of imaging in the management of myeloma

In 2001, reference to the use of imaging in the British Committee for Standards in Haematology guidelines for the diagnosis and management of myeloma was confined to the standard use of plain X-rays in the diagnostic skeletal survey and emergency use of computed tomography (CT) and magnetic resonance (MR) imaging in the setting of cord compression. Since then, there has been a steady rise in interest in the use of various imaging techniques in the management of myeloma. The purpose of imaging in the management of myeloma includes the assessment of the extent and severity of the disease at presentation, the identification and characterisation of complications, and the assessment of response to therapy. Plain radiography, CT, and MR imaging are generally established examination techniques in myeloma whilst positron emission tomography (PET) and (99)Technetium sestamibi (MIBI) imaging are promising newer scanning techniques under current evaluation. These stand-alone imaging guidelines discuss recommendations for the use of each modality of imaging at diagnosis and in the follow up of patients with myeloma.

Sestamibi and FDG-PET scans to support diagnosis of jaw osteonecrosis

Osteonecrosis of the maxillary or mandibular bone is an infrequent but often severe event occurring in patients who undergo prolonged treatment with bisphosphonates. Histology is in some cases mandatory to differentiate it from neoplastic osteolysis, but a biopsy can further contribute to bone damage. Functional imaging obtained by a tracer that shows oncotropic properties, such as Tc99m-sestamibi, in comparison to a non-tumor-specific substance such as FDG-PET, can support the differential diagnosis, thus avoiding invasive procedures. Four patients affected by multiple myeloma and jaw osteonecrosis were prospectively evaluated by sestamibi and FDG-PET scans. Local diagnosis was performed by clinical, radiological and, in some cases, histological evaluations. Each patient was studied by Tc99m-sestamibi, performed by planar anterior and posterior whole-body scans and SPECT of the head and neck, and by PET/CT. Two nuclear medicine physicians, unaware of the final diagnosis, reviewed the images. No sestamibi uptake was evident in the four patients with jaw osteonecrosis, while FDG-PET/CT showed focal uptake in all of them. Our study suggests that the combined use of sestamibi scintigraphy and FDG-PET/CT could support the clinical diagnosis of oral osteonecrosis avoiding the risks of a surgical biopsy. Studies on higher number of patients are necessary to validate these preliminary observations.

Focal MIBI uptake is a better indicator of active myeloma than diffuse uptake

PURPOSE

Technetium-99m 2-methoxyisobutylisonitrile (MIBI) imaging has been proposed as a front-line investigation to detect bone disease both before and after the treatment of myeloma. In this study, we have compared the pattern of MIBI uptake (focal and diffuse) between patients with proven myeloma and a cohort of patients without myeloma, in order to identify the uptake pattern that best correlates with disease activity.

METHODS

Nineteen scans were taken in 16 consecutive patients (nine males and seven females: aged 39-71 yr) with active myeloma. A further 20 scans (10 subjects having MIBI myocardial perfusion scintigraphy and 10 subjects having MIBI parathyroid adenoma localisation studies), comprised the control (non-myeloma) cohort. Scans were evaluated in a double-blinded fashion by two observers for any diffuse skeletal MIBI uptake (homogeneous uptake in spine, sternum and/or long bones), and/or abnormal focal uptake (patchy, focal or tubular uptake in the skeleton or soft tissues).

RESULTS

The pattern of MIBI uptake was significantly different in the myeloma-positive subjects and the control cohort. Focal uptake was highly discriminatory, being seen in 15 of 19 (79%) scans of the myeloma-positive group as opposed to one of 20 (5%) scans of the control group (P < 0.0001). In contrast, diffuse uptake was seen in 17 of 19 (89%) scans in patients with myeloma, and in 11 of 20 (55%) of the control cohort (P = 0.02). Using multiple logistic regression analysis, any focal uptake was significantly predictive for active myeloma (P = 0.0007) but diffuse uptake was not (P = 0.15). Diffuse uptake alone, without focal uptake, was found in four of 19 scans with myeloma and in 10 of 20 without active myeloma, but was not significantly associated with absence of active myeloma (P = 0.06). Using the criteria of Pace et al. for positivity (diffuse activity >50% myocardial activity), we demonstrated improved specificity from 45% to 100%, but significantly impaired sensitivity for presence of myeloma (79% vs. 37%, P = 0.02).

CONCLUSION

Our study thus illustrates that the presence of any focal uptake of MIBI is useful in indicating active myeloma whereas diffuse uptake is not.

Bone Scintigraphy in Common Tumors With Osteolytic Components

Osteolytic lesions are frequently encountered in clinical practice. Radionuclide bone scans with technetium-99m-labeled diphosphonates are often performed in the evaluation of both solitary and multiple osteolytic lesions. In this pictorial review, we critically evaluate the current role of bone scan in common osteolytic tumors including aneurysmal bone cyst, simple bone cyst, fibrous dysplasia, nonossifying fibroma, giant cell tumor, eosinophilic granuloma, enchondroma, chondrosarcoma, osteosarcoma, Ewing sarcoma, myeloma, and metastases. The merits and limitations of bone scanning are emphasized.

Tc99m-sestaMIBI uptake in nonsecretory multiple myeloma

Staging and monitoring of multiple myeloma (MM) is mainly based on monoclonal component quantification; the absence of such a parameter renders difficult follow up of patients with nonsecretory MM (nsMM). In this study our aims were to determine the specificity and sensitivity of Tc99m-sestaMIBI scintigraphy at diagnosis and during follow up of nsMM patients. Nine nsMM patients were prospectively studied at diagnosis and during treatment for a mean time of 33 months (range: 12-65+). Tc99m-sestaMIBI (MIBI) scintigraphy was compared to conventional imaging (CI: X ray with CAT or NMR details) at diagnosis and during follow up. At diagnosis, CI and MIBI were concordant in three patients; CI showed more focal lesions than MIBI in four patients, while MIBI revealed more focal lesions than CI in two patients. During the follow up, MIBI uptake was normal in the four patients who achieved remission. Five patients did not achieve remission: CI and MIBI were concordant in three, while MIBI was falsely negative in two patients. In conclusion, Tc99m-sestaMIBI scintigraphy has high sensitivity (no false positive cases) and 78% specificity (2/9 false negative cases) in tracing active nsMM lesions; it should be considered complementary to CI for monitoring this rare disease.

A comparison of fluorine-18 fluoro-deoxyglucose PET and technetium-99m sestamibi in assessing patients with multiple myeloma

OBJECTIVE

The extent of disease in patients with multiple myeloma or related conditions may be difficult to assess. In previous small studies, both FDG-PET (PET) and Tc-99m sestamibi scans (MIBI) have identified sites of occult disease in myeloma.

METHODS

We reviewed the results for patients at our institution who have undergone PET and/or MIBI scans to assess myeloma. Concordance between the scans, ability to identify otherwise occult disease and impact on patient management was assessed.

RESULTS

Thirty-six patients had > or =1 PET scan, 56 had > or =1 MIBI scan and 23 had concurrent PET and MIBI scans. MIBI detected additional sites to skeletal survey in 38 of 56 (68%) cases. PET detected additional sites to skeletal survey in 18 of 36 (50%) cases. MIBI generally detected more disease sites than PET. PET and MIBI were concordant in eight of 23 (35%) cases. The percentage plasma cell infiltrate within the marrow correlated with the number of sites detected by MIBI, but not by PET. In 23 of 69 cases (33%), scan results impacted on management, particularly by upstaging disease at diagnosis and by recognising subsequent disease progression. The results were also helpful for evaluating the presence of ongoing disease activity in previously irradiated sites remaining abnormal on skeletal survey following treatment.

CONCLUSIONS

MIBI and PET are useful additional diagnostic tools for detecting otherwise occult sites of myeloma. The use of MIBI PET should particularly be considered in the evaluation of a patient with an early-stage plasma cell dyscrasia to exclude the presence of more extensive disease.

Urinary N-telopeptide levels in multiple myeloma patients, correlation with Tc-99m-sestaMIBI scintigraphy and other biochemical markers of disease activity

Urinary cross-linked N-telopeptide of type I collagen (NTx) has been reported to be a sensitive and specific marker of bone resorption in multiple myeloma (MM). In this study, we measured the levels of NTx in 30 newly diagnosed MM patients and 25 controls. We examined its association with the overall score of skeletal involvement measured by Tc-99m-MIBI scintigraphy and other biochemical markers of bone disease (tumour necrosis factor a (TNF-a), serum calcium and creatinine). We further studied the correlation of NTx with the stage of disease (according to Durie-Salmon criteria) and bone marrow infiltration by plasma cells. High levels of NTx, bone marrow infiltration, TNF-alpha, calcium and creatinine were noted at advanced stages of disease (p < 0.05). NTx and TNF-a were found at significantly higher concentrations in patients with a high overall score (3 and 4) in Tc-99m-sestaMIBI in comparison to a low score (0, 1 and 2; p < 0.05). Positive correlations were found between NTx and TNF-a, as well as between bone infiltration and TNF-a or calcium. In conclusion, NTx is a useful marker for the monitoring of bone resorption in MM and correlates with imaging findings on Tc-99m-sestaMIBI and other biochemical markers of disease activity.

Tc-99m methoxyisobutylisonitrile bone marrow imaging for predicting the levels of myeloma cells in bone marrow in multiple myeloma: correlation with CD38/CD138 expressing myeloma cells

The percentage of myeloma cells in bone marrow is subsequently an important index of disease in patients with multiple myeloma (MM). Bone marrow myeloma cells can be detected by strong CD38/CD138 positivity and light scatter characteristics using flow cytometry. The aim of the study was to evaluate the relationship between the degree of Tc-99m methoxyisobutylisonitrile (MIBI) uptake and the percentage of CD38/CD138 expressing myeloma cells in the bone marrow of patients with MM. A total of 15 patients with MM (mean age: 61.7+/-2.4 years; 7 F and 8 M) were included in the study. Tc-99m MIBI imaging was obtained 20 min after injection of 740 MBq Tc-99m MIBI. Planar spot images of the pelvis and thorax were acquired. The uptake of Tc-99m MIBI in the bone marrow was evaluated using a qualitative and also a semiquantitative scoring system for the bone marrow in areas that included the proximal femurs, anterior iliac crest, and sternum. In all patients, flow cytometry was performed for assessing the percentage of CD38/CD138 expressing myeloma cells in the bone marrow samples. There was a statistically significant positive correlation between the percentage of CD38/CD138 expressing plasma cells in bone marrow and both mean qualitative (r=0.689, p=0.005) and semiquantitative (r=0.669, p=0.006) results of Tc-99m MIBI uptake. In conclusion, our results indicate that increased Tc-99m MIBI uptake of bone marrow is related to the percentage of plasma cell infiltration of bone marrow. Tc-99m MIBI bone marrow imaging may be a useful tool for predicting the levels of myeloma cells in bone marrow of patients with MM.

Gallium-67 demonstration of extensive soft-tissue involvement of multiple myeloma

A 46-year-old woman with multiple myeloma presented with neurological symptoms in the right upper extremity. After MR imaging of the cervical spine failed to show the cause of her symptoms, Ga-67 scintigraphy demonstrated increased uptake in multiple areas including the right supraclavicular region and bilateral lower extremities. Histology of the specimen obtained from the left thigh proved soft-tissue involvement of myeloma, and extensive extramedullary involvement was diagnosed. Radiotherapy to the right supraclavicular mass relieved her symptoms. Although Ga-67 scintigraphy is generally considered of limited value in multiple myeloma, this modality contributed to the development of an appropriate strategy in this patient with extensive extramedullary involvement.

Correlation between the uptake of Tc-99m-sestaMIBI and prognostic factors in patients with multiple myeloma

Technetium 99m-2-methoxyisobutil-isonitrile (Tc-99m-MIBI), also called sestaMIBI, has been used successfully to detect malignant tumours at diagnosis. Recently, it has been proposed as a safe and effective tracer in patients with multiple myeloma (MM). The purpose of this study was to demonstrate the value of the Tc-99m-MIBI uptake in disease detection and to assess the correlation between the uptake of this scintigraphy agent and prognostic factors in newly diagnosed MM patients. Thirty-five untreated patients were enrolled in the study. Tc-99m-MIBI scanning was performed in 33 patients after intravenous injection of 7.4 MBq/kg. Whole-body anterior and posterior scans were obtained after 30 min, 60 min, 2 and 4 h. The correlation between known prognostic factors of MM and the intensity of Tc-99m-MIBI uptake was assessed. Our results showed seven patients with an intensity score of I0, 12 patients with I1, eight patients with I2 and six patients with a score of I3. There was a positive correlation between Tc-99m-MIBI intensity and C-reactive protein (CRP; r=0.506, P < 0.01), erythrocyte sedimentation rate (ESR; r=0.368, P < 0.05), beta2- microglobulin (beta2M; r=0.749, P < 0.001), interleukin-6 (IL-6; r=0.823, P < 0.001), soluble Interleukin-6 receptor (sIL-6r; r=0.806, P < 0.001), serum calcium (r=0.578, P < 0.001) and bone alkaline phosphatase (BAP; r=0.472, P < 0.01). An inverse correlation was found between Tc-99m-MIBI intensity and osteocalcin (OC) and type I procollagen carboxyterminal propeptide (PICP). In conclusion, the results of this study suggest that more extensive disease activity, as determined by high levels of CRP, beta2M, IL-6 and sIL-6r correlated with a higher uptake of the radiotracer.