Imaging in Bone Metastases
Joko Santoso1410029053
Fakultas KedokteranUniversitas Mulawarman
Samarinda2015
Overview
• Metastases to bone the most common malignant tumors involving bone.
• Imaging detection, diagnosis, prognostication, treatment planning, and follow up of bone metastases.
Overview
• Bone metastases multiple at time of diagnosis.
• In adult occur in the axial skeleton and other sites with residual red marrow.
• 90% site of bone metastases vertebra, pelvis, proximal part of femur, ribs, proximal part of humerus, and skull.
Overview
• Certain carcinoma may have a predilection skeletal sites.
• 50% bone metastases to hands and feet ca lung.
• Tumor from pelvis lumbosacral spine.
Pathophysiology
• Direct extension
• Retrograde venous flow metastased from intra abdominal cancer
• Seeding with tumor emboli via blood circulation
Patophysiology
• Metastatic lession grow in the medullarycavity surrending bone is remodeled by of either osteoblastic or osteoclastic proccessdepands on type and location original cancer
Differential Diagnosis
• Bone island• Eosinophilic granuloma of the skeleton• Bone lymphoma• Osteomalacia• Renal osteodystrophy• Chronic osteomyelitis• Paget disease• Pelvic insufficiency fractures• Stress fractures• Tuberous sclerosis• Secondary OA
Radiography
• Maybe osteolytic, sclerotic, or mixed predominantly osteolytic
• Arise in medulla destroying cortex
• Without periosteal reaction
• Soft tissue extention is relative uncommon
Radiography
• Specific appearance of bone metastases is useful in suggesting of underlying primary malignancy.
• Osteolytic lession carcinoma of breast, lung, renal, thyroid.
• Osteoblastic lession carcinoma of prostate, stomach, carcinoid, colon, breast (10%), bladder, melanoma, and sof tissue sarcoma.
Radiography
• In vertebrae, clue of metastases pediculardestruction, associated soft-tissue mass, and angular or irregular deformity of vertebral endplates
Radiography
• Response of therapy initial manifestation of healing in osteolytic metastases is a sclerotic rim of reactive bone.
• Response therapy of mixed lessionmanifestation of healing is uniform lesionalsclerosis.
• For sclerosis lession difficult to assess compare to previous radiograph manifestation of healing is shrink or complately disappear.
Degree of Confident
• Relative insensitive only ≥ 2 cm lession are radiographically apparent.
• Apparent in radiograph after loss of 50% bone mineral content.
False Positives/Negatives
• On radiograph, destructive lesions of the trabecular bone may not be visible particularly in absence of reactive new bone or cortical envolement especially in elder.
• Osteolytic lesion can mimic OA, amyloidosis, cystic angiomatosis, infiltrative bone marrow lesions.
• Osteoblastic lesion can mimic bone island, tuberous sclerosis, mastocytosis, osteopoikilosis.
Computed Tomography
• Useful in further assessment of radiographically negative areas in patients who are symptomatic and in whom metastases are sugested clinically.
Degree of Confidence
• CT scanning is vastly superior to radiography in detection of trabecular and cortical bone destruction, soft tissue extension, and involvement of neurovascular structures.
• Usefulness on detecting early deposits in bone marrow is limited.
Magnetic Resonance Imaging
• MRI is more sensitive than 99Tc bone scitiscanning in detection of bone metastases.
• Metastatic seeding in bone marrow is characterized by long T1 relaxation times, whereas T2 relaxation times are variable, depending on tumor morphology.
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• Lesions are seen as focal or difuse areas of hypointensity on T1-weighted images and as areas of intermediate or high signal intensity on T2-weigted images
• The Bull’s eye or halo sign useful in distinguishing metastatic with benign lesions.
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• In vertebrae, additional criteria for malignancy include bulging of the posterior margin of the vertebral body, signal intensity changes that intense into the pedicle, and paraosseustumor spread.
Degree of Confidence
• MRI depicts early hematogenousdissemination of the tumor to the bone marrow before reaction in adjacent bone are detectable on 99mTc Scintiscan.
• Flickinger and Sanal reported sensitivities of 100% for MRI and 62% for scintiscanning and specificities of 62% for MRI and 100% for scintiscanning.
Nuclear Imaging
• 99mTc bone scintigraphy is an effective method for screening the whole body for bone metastases.
• Detecting metastatic bone deposits by the increased osteoblastic activity they induce.
Indications for bone scintiscanning
• Staging in asymptomatic patients.
• Evaluating persistent pain in the presence of equivocal or negative radiographic findings.
• Determining the extent of bone metastases in patients with positive radiograph finding.
• Differentiating metastatic from trauma fractures.
• Determining the therapeutic response to metastases.
• PET scan can identifying bone metastases at an early stage of growth, before host reaction to the osteoblast occur.
• PET scan detecting early increased glucose metabolism in neoplastic cells.
• Isotop imaging methods depict bone metastatic lesions as areas of increased tracer uptake.
• The classical pattern appears as presence of multiple randomly distributed focal lesions througout the skeleton.
• Finding of a solitary scintigraphic abnormality or just a few lesions may present special problems in interpretation of findings.
Terima Kasih
