The role of Tc-99m (V) DMSA scintigraphy in the diagnosis and follow-up of lung cancer lesions

Objective To define the role of Tc-99m (V) dimercaptosuccinic acid (DMSA) scanning in the detection of lung cancer (LC) and its metastases, and monitoring the response of LC lesions (LCL) to chemo/radiotherapy (TH). Methods Tc-99m (V) DMSA whole-body scans, planar thorax views, and thorax Single-photon emission computed tomography (SPECT) images were obtained both 30 min (early) and 5 h (late) after Tc-99m (V) DMSA administration in 12 small/nonsmall cell LC patients (11 men, 1 woman; mean age 59 years). Five patients also had bone scans. The same scintigraphic protocol was performed in 7 of 12 patients, 3 weeks after first-line TH. TH response was evaluated visually in all LCL and semiquantitatively in primary tumors (PT) of six patients, by comparing the tumor uptake ratios (TUR) of pre-TH and post-TH Tc-99m (V) DMSA SPECT [TUR = mean counts of region of interests (ROI) in PT/mean counts in contralateral ROI]. In seven patients, a 6-month survival was determined. Results Tc-99m (V) DMSA accumulated in 34 LCL (11 PT, 19 bone metastases, 1 suprarenal mass, 1 axillary node, 2 supraclavicular nodes). A total of 11 patients displayed Tc-99m (V) DMSA uptake in LCL and one patient did not show uptake. In six patients, SPECT imaging showed deeply located PT in the lung parenchyma better than planar views. In five patients, both planar and SPECT views revealed peripherally located PT in the lungs. Early scans showed 18 LCL and late scans displayed all the LCL. Nine bone metastases on pre-TH Tc-99m (V) DMSA scans revealed matched areas of increased Tc-99m methylene diphosphonate (MDP) uptake on bone scans; six bone metastases were additionally detected on Tc-99m (V) DMSA scans when compared with bone scans, and four bone metastases on Tc-99m (V) DMSA scans could not be compared with bone scans because bone scan was not performed. In one patient, Tc-99m (V) DMSA scans became positive for bone metastases on post-TH later than the bone scans for some of the bone metastases. Neither planar nor SPECT imaging showed mediastinal lesions defined on thorax CT in nine patients. On TH monitoring, 17 LCL showed diminished Tc-99m (V) DMSA uptake, one disappeared, four were unchanged, three displayed increased uptake, and five new lesions were established. Of the six patients, TUR in PT increased in two (one survived), decreased in one (exitus), was unchanged in two (two exitus) on post-TH scans, and PT totally disappeared in one (survived) patient. Conclusions Tc-99m (V) DMSA scans are useful in detecting LCL, except for those around the blood pool regions, making it a promising modality to monitor TH response. Obtaining a single fifth hour late Tc-99m (V) DMSA scan is appropriate. SPECT should be applied to all patients for the detection of deeply located lesions.     

Dural metastasis demonstrated on Tc-99m MDP bone scintigraphy in staging workup for a patient with breast cancer

An 80-year-old woman with multifocal invasive lobular carcinoma of the right breast treated 6 years previously with mastectomy, locoregional radiotherapy, and tamoxifen was referred for a bone scan to investigate generalized arthralgias. The patient reported right-sided headaches, blurred vision, and dizziness in the previous 3 months. The bone scan revealed a large area of unusual and abnormal Tc-99m methylene diphosphonate (MDP) uptake in the right frontoparietal skull region. CT and MRI of the brain were performed to evaluate the possibility of cerebral metastases. The CT revealed extensive abnormal thickening and enhancement of the dura in the right frontoparietal region. No calcification of the dura or bony destruction of the overlying skull was evident on CT. MRI similarly revealed extensive thickening and irregularity of the dura. The usual causes of increased skull Tc-99m MDP uptake on bone scanning such as skull metastases and dural calcification were not evident on CT or MRI.     

Ectopic parathyroid carcinoma presenting with hypercalcemic crisis, ectopic uptake in bone scan and obstruction of superior vena cava

A 28-year-old Chinese man diagnosed with hypercalcemic crisis was referred for Tc-99m sestamibi parathyroid imaging, which revealed a massive sestamibi-avid lesion in right-site of upper mediastinum. Contrast-enhanced CT demonstrated the lesion encroached and obstructed bilateral innominate veins and superior vena cava. Tc-99m methylene diphosphonate (MDP) bone scan and SPECT displayed ectopic uptakes in the lungs and stomach. Preoperative suspicion of parathyroid carcinoma prompted an en bloc surgery, which was confirmed in histopathology. Our case showed that although ectopic parathyroid carcinoma causing hypercalcemic crisis, extraskeletal microcalcifications, and great vessel obstruction is rare, parathyroid imaging and bone scan can help solve these diagnostic challenges.     

Detection of cold bone metastasis by Tc-99m MIBI imaging

We present a case of renal cell carcinoma metastasis to the skull, appearing as a photopenic area on Tc-99m MDP bone scan and with focal uptake in the same region on Tc-99m MIBI imaging.     

Focal Increased Tc-99m MDP Uptake in the Nutrient Foramen of the Femoral Diaphysis on Bone SPECT/CT

We present images of an 83-year-old female with a history of osteoporosis and bilateral total knee replacement arthroplasty, referred for bone scintigraphy and single-photon emission computed tomography (SPECT)/computed tomography (CT), owing to left knee pain. No trauma to, or intense exercise of, the knee was reported. The bone scan and SPECT/CT revealed a focally increased Tc-99m methylene diphosphonate (MDP) uptake in the medial cortex of the left femoral diaphysis with matched linear radiolucency on CT images. This was misinterpreted as atypical femoral stress fracture; however, focal stress reaction injury to the nutrient foramen was confirmed on contrast-enhanced magnetic resonance imaging.     

Accumulation of Tc-99m methylene diphosphonate in calcified metastatic lesions of the liver from colonic carcinoma. Comparison with calcification on X-ray computed tomogram

Abnormal accumulation of Tc-99m MDP in two metastatic lesions of the liver was observed in a patient with resected colon carcinoma. Single-photon emission computed tomography (SPECT) revealed characteristic marginal accumulation of Tc-99m MDP in both of those metastatic lesions. X-ray CT showed the corresponding marginal calcification in one of the metastases, but no apparent calcification was observed in the other lesion. Two months later, however, the latter also became calcified on x-ray CT. These findings suggest that the accumulation of Tc-99m MDP in the present case is strongly related to the calcium deposition and that Tc-99m MDP may accumulate in a calcified metastatic lesion before the calcification appears on x-ray CT.     

Positive Tc-99m-MIBI scan in a patient with confirmed Paget's disease of bone

A 46-year-old man was referred to our department for a Tc-99m MDP bone scan after he was admitted to our hospital with diffuse bone pain and the subsequent finding of multiple mixed type (lytic-blastic) lesions on routine x-rays. The Tc-99m MDP scan was highly suspicious for malignancy and, therefore, a Tc-99m MIBI scan was performed, which also revealed abnormal uptake in all regions with increased osteoblastic activity. Clinical chemistry and further workup revealed a highly elevated serum alkaline phosphatase and increased excretion of hydroxyproline in the urine. The presumed diagnosis of Paget's disease of the bone was further confirmed by biopsy.     

Focal uptake of Tc-99m MDP in a gossypiboma

A 51-year-old Korean woman with a history of breast cancer underwent screening bone scintigraphy, which revealed minimal soft tissue uptake of Tc-99m methylene diphosphonate (MDP) in the right lower quadrant. CT and plain films confirmed that the uptake was due to a retained surgical sponge or gossypiboma. The incidence of gossypibomas has been reported at high as 1 in 1000 to 15,000 intra-abdominal operations. The natural progression of an aseptic gossypiboma is a foreign body reaction and granuloma formation. This inflammatory granulomatous reaction is the most likely cause of the extraosseous accumulation of Tc-99m MDP. This entity should be added to the already extensive list of etiologies of extraosseous MDP accumulation.     

Accumulation of a bone imaging agent in liver metastases from prostate carcinoma

A patient with adenocarcinoma of the prostate presented with right upper quadrant abdominal pain and weight loss. Liver biopsy revealed hepatic metastases from prostate carcinoma. A bone scan demonstrated marked uptake of Tc-99m MDP within the hepatic metastases.     

Ivory vertebra appearing photopenic on Tc-99m MDP bone scan: demonstration by SPECT/CT

We report the case of a 72-year-old man with prostate cancer, in whom Tc-99m MDP bone scintigraphy revealed a "superscan" pattern, except in a dorsal vertebra, which appeared photopenic. A low-dose SPECT/CT acquisition demonstrated that the lack of tracer uptake corresponded to a blastic lesion with no lytic component. Surprisingly, the cold vertebra appeared as an "ivory vertebra" on the CT part of the SPECT/CT acquisition. In the present case, the photopenic appearance is thought to be due to a concomitant blastic lesion and spine infarct.     

Incidental detection of gastrointestinal stromal tumor by Tc-99m MDP bone scan

This case demonstrates extraosseous 99m-technetium methylene diphosphonate (Tc-99m MDP) accumulation from a gastrointestinal stromal tumor. A 75-year-old woman underwent a temporal bone CT for conductive hearing loss that showed sclerosis in the right occipital condyle. Follow-up Tc-99m MDP bone scan for osseous metastases instead showed a mass-like extraosseous accumulation of Tc-99m MDP in the anterior left upper quadrant. Differential diagnoses included gastric cancer, lymphoma, metastatic melanoma, systemic hypercalcemia, or heterotopic mesenteric ossification. Contrast CT showed a well-circumscribed mass arising from the stomach, and subsequent pathology confirmed gastrointestinal stromal tumor. These tumors rarely can contain osteoclast-like giant cells and should be considered for extraosseous Tc-99m MDP accumulation.     

Concentration of Tc-99m MDP in ovarian carcinoma and its soft tissue metastases

A patient with ovarian carcinoma was evaluated for skeletal metastasis with a routine whole body bone scan. Although no bone metastases were visualized, there was dramatic accumulation of tracer in the soft tissues of the abdomen. CT revealed calcifying soft tissue metastases on the liver surface, the bowel serosa, and in the pelvis corresponding to the abnormal areas of Tc-99m MDP uptake. Tumor necrosis and ongoing calcification within the metastatic sites are possible explanations for this unusual soft tissue concentration of the bone-seeking radiopharmaceutical. In patients with metastatic ovarian carcinoma, careful review of extraosseous regions on bone scan images may provide valuable diagnostic information.     

SPECT/CT in the Diagnosis of Skull Base Osteomyelitis

Skull base osteomyelitis is a potentially fatal disease. We demonstrate here the utility of SPECT/CT in diagnosing this entity, which was not obvious on a planar bone scan. A ^99mTc MDP bone scan with SPECT/CT was carried out on a patient with clinically suspected skull base osteomyelitis. Findings were correlated with contrast-enhanced CT (CECT) and MRI. Planar images were equivocal, but SPECT/CT showed intense uptake in the body of sphenoid and petrous temporal bone as well as the atlas corresponding to irregular bone destruction on CT and MRI. These findings indicate that SPECT/CT may have an additional role beyond planar imaging in the detection of skull base osteomyelitis.     

Determination of extent and activity with radionuclide imaging in Erdheim-Chester disease.

Erdheim-Chester disease usually involves the diaphyseal and metaphyseal regions of tubular bones and various visceral organs. A 56-year-old woman presented with the histologically confirmed diagnosis of Erdheim-Chester disease. A Tc-99m MDP bone scan revealed the entire extent of the skeletal disease and showed unusual involvement of the epiphyses and axial skeleton. In addition to MRI, a Ga-67 citrate scan including SPECT showed extensive soft-tissue infiltration of different organs. Both Tc-99m MDP and Ga-67 scintigraphy are useful tools in determining the distribution of this rare disease.     

The role of Tc-99m (V) DMSA scintigraphy in the evaluation of superscan on bone scintigraphy

PURPOSE: This study evaluated the biodistribution of Tc-99m (V) DMSA in patients with superscans on bone imaging and defined its role in differentiating the underlying cause. METHODS: Nine patients (five with metastatic and four with metabolic bone disease) with classical superscans were entered into the study. All patients had the necessary radiologic and biochemical studies and a final diagnosis was reached accordingly. Tc-99m (V) DMSA scintigraphy was performed 1 week after Tc-99m MDP whole-body bone imaging. RESULTS: In four of five patients with widespread skeletal metastases, Tc-99m (V) DMSA scan showed diffusely increased bone uptake. In the remaining patient, the Tc-99m (V) DMSA scan showed a normal distribution pattern. All patients with metabolic bone disease had increased bone uptake on Tc-99m (V) DMSA scans. CONCLUSION: Tc-99m (V) DMSA shows increased bone uptake in patients having a superscan appearance in metastatic or metabolic bone disease. Tc-99m (V) DMSA imaging may play a role in the evaluation of patients with equivocal bone scan findings for a superscan.     

Cavernous angioma mimicking a differentiated thyroid carcinoma brain metastasis

A 30-year-old man diagnosed with follicular thyroid carcinoma treated previously with total thyroidectomy was referred to radioiodine treatment. Post-therapy scan performed 10 days after a 150 mCi 131NaI revealed radioiodine uptake in left temporal region. To elucidate the abnormal head uptake, Tc-99m MDP bone scan and head magnetic resonance image was performed. No anomalous uptake was observed in the bone scan. Head magnetic resonance image found a well-circumscribed lesion in temporal was compatible with a vascular malformation. Angioresonance confirmed the diagnosis of cavernous angioma, a benign vascular tumor.     

Bilateral Paget disease of the calcaneus diagnosed by conventional bone scintigraphy

An 85-year-old woman who had an invasive ductal carcinoma of the breast and elevated alkaline phosphatases (420 U/L) was referred for Tc-99m MDP bone scintigraphy for initial evaluation of skeletal metastases. Bone symptoms were limited to chronic pain in both knees. A bone scan revealed pagetoid findings in both calcanei. Feet and toes on plain x-rays of the calcaneus were unremarkable. Findings were stable in the 2-year follow up, excluding other potential diagnosis as extensive metastases or stress fractures.     

Diagnosis of discitis by SPECT technetium-99m MDP scintigram. A case report

A 29-year-old male presented with a two month history of intermittent low back pain following a febrile illness. Two planar bone scans performed with Tc-99m MDP were normal despite roentgenographic and SPECT scintigraphic evidence of discitis. This case demonstrates the increased sensitivity of SPECT in the diagnosis of discitis.     

Atypical Paget's disease with quantitative assessment of tracer kinetics

INTRODUCTION: Paget's disease of bone is characterized by alterations in skeletal metabolism, affecting a single or multiple bones. Paget's is usually confined to an individual bone and typically does not spread or extend across joints. A patient with an unusual pattern of disease is presented together with quantitative assessment of the tracer kinetics pre- and posttreatment. MATERIAL AND METHODS: A 75-year-old lady patient presented to her general practitioner in May 2002 with a history of lethargy. Clinical examination was unremarkable and further investigations such as blood tests (alkaline phosphatase levels), Tc-99m MDP bone scan, biopsy, and CT scan were carried out. RESULTS: Alkaline phosphatase levels were greater than 2000 IU/L (Normal: 31-116 IU/L). The Tc-99m MDP bone scan showed strikingly increased uptake in the central skeleton involving the thoracic vertebrae and the adjoining ribs. The bone biopsy was inconclusive. CT scan revealed symmetrical expansion of the ribs with bridging osteophytes across the ribs and spine. The patient was treated with risedronate and quantitative analysis of the pre- and posttherapy bone scans showed reduced plasma clearance in the pagetic bones. CONCLUSIONS: This case illustrates an unusual distribution of bone lesions in Paget's disease, which we think could be due to the result of degenerative disease leading to bridging and allowing direct extension of disease from one bone to another.     

Technetium-99m diphosphonate imaging of psammocarcinoma of probable ovarian origin: case report and literature review

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.