Extensive soft-tissue involvement of dermatomyositis detected by whole-body scintigraphy with 99mTc-MDP and 201TL-chloride

Role of bone scan in the assessment of polymyositis/dermatomyositis

The aim of this study was to determine the significance of bone scan findings in Korean polymyositis/dermatomyositis (PM/DM) patients. The participants in this study were 26 PM/DM patients who fulfilled the proposed criteria for definite or probable PM/DM. All patients had been examined by bone scan. The results were analyzed visually and quantitatively using the uptake ratios. Correlations between the bone scan parameters of six proximal muscle groups (trapezius, deltoid, biceps, iliopsoas, quadriceps, and gluteus medius and maximus) and clinical parameters (laboratory values and manual muscle test) representing disease activities were assessed. Based on visual analyses of their bone scans, 10 of 14 (71.4 %) patients with active PM/DM had abnormal muscle uptake. Visual grading of the bone scans had a sensitivity and specificity of 74 and 90.9 %, respectively, for the assessment of muscle inflammation. Maximal proximal muscle uptake ratios, as determined on the bone scans, were significantly higher in patients with active PM/DM than in those with inactive disease (median 1.97 vs. 1.02, p = 0.046). Maximal proximal uptake ratios correlated significantly with creatine kinase (r = 0.394, p = 0.046), lactate dehydrogenase (LDH, r = 0.473, p = 0.015), aldolase (r = 0.428, p = 0.029), erythrocyte sedimentation rate (r = 0.412, p = 0.036), C-reactive protein (r = 0.454, p = 0.002), and manual muscle test results (r = -0.399, p = 0.044). Mean proximal muscle uptake ratios correlated significantly with LDH (r = 0.438, p = 0.025) and aldolase (r = 0.572, p = 0.002). Visually assessed proximal muscle uptake grades and maximal proximal muscle uptake ratios as determined by bone scan correlated significantly with the levels of known PM/DM disease activity markers. The findings of this study suggest that bone scan is a useful imaging technique for the evaluation of PM/DM patients.

Technetium-99m Diphosphonate Imaging of Psammocarcinoma of Probable Ovarian Origin

Technetium-99m methylene diphosphonate (Tc-99m MDP) bone scans have long been used by clinicians to diagnose osseous metastases in patients with cancer. However, in several benign and malignant diseases, notably those characterized by extensive soft tissue calcification, Tc-99m MDP may be taken up by the tumor itself. We present a case of a stage IIIC psammoma-rich low-grade serous carcinoma of the ovary, whose identity and extent of disease were first suggested by Tc-99m MDP scintigraphy. The literature concerning this form of cancer, and the use of Tc-99m MDP bone scans to image soft tissue lesions, are reviewed.

Tc-99m MDP bone scintigraphy of myositis as a manifestation of chronic graft-versus-host disease after non-myeloablative peripheral stem cell transplantation

A 27-year-old man developed polymyositis as a manifestation of chronic graft-versus-host disease (GVHD) after non-myeloablative peripheral blood stem cell transplantation (PBSCT). Bone scintigraphy showed intense, striped, and heterogeneous accumulation of Tc-99m methylene diphosphonate (MDP) in the soft-tissue of his lower limbs, while faint activities were seen in the right upper limb. Tc-99m MDP scintigraphy was very useful for accurate and objective evaluation of the severity of the muscle injury and the extent of polymyositis caused by chronic GVHD.

Localization of Tc-99m MDP in the rectus abdominis muscle without associated symptoms

Skeletal tracer localization in the rectus abdominis muscle of a 17-year-old girl whose training regimen included vigorous abdominal exercise but who had no abdominal soreness is described. The case illustrates that bone tracers may localize to skeletal muscle without associated symptoms. This is consistent with bone tracer localization in skeletal muscle reflecting subtle fiber abnormalities rather than necrosis.

Outcome assessment in the adult and juvenile idiopathic inflammatory myopathies

Through the recent efforts of multi-center collaborative study groups, a number of measures have been developed and partially validated to assess disease activity, disease damage, and health-related quality of life in adult and juvenile patients with IIM. Preliminary core set domains and core set measures of activity and damage have also been developed for adult and juvenile patients with myositis. Validated definitions of improvement and disability should be forthcoming in the next few years. These extraordinary developments will enable much-needed standardization in the assessment of the IIM, particularly in therapeutic and other clinical research studies. Despite this substantial progress, there is a need to develop more sensitive measures to assess IIM disease activity and damage, to further validate the existing tools, to define their performance characteristics in various IIM subgroups, to develop improved imaging techniques that are also quantitative, and to validate activation markers as surrogate measures. The ongoing cooperation of multiple specialists with expertise in these disorders, combined with emerging novel technologies, should continue to enhance the assessment of myositis. Improved clinical care and more rapid development of new therapies for patients with myositis will be the ultimate gains realized from these efforts.

Scintigraphic evaluation of calcinosis in juvenile dermatomyositis with Tc-99m MDP

Two children with juvenile dermatomyositis and extensive, debilitating soft tissue calcifications are described. Whole-body bone scans with Tc-99m MDP were performed in both cases before and during specific treatment for the calcinosis. Baseline studies showed marked tracer localization in the soft tissues and provided an objective baseline assessment of the extent of the soft tissue calcifications. Follow-up studies showed gradual clearance of the extraskeletal uptake and were useful in monitoring the therapeutic response. These cases show that skeletal scintigraphy can function as a useful auxiliary tool to evaluate calcinosis in children with juvenile dermatomyositis.