RADIOLOGICAL APPROACH TO malignant bone tumors.pptx

Malignant (cancerous) tumors are more rare than benign tumors - and more dangerous. The term malignant means there is moderate to high probability the tumor will spread beyond where it first develops. The cancer cells spread by traveling in the blood or through the lymph vessels. Malignant bone tumors most commonly spread to the lungs or to other bones.

Malignant bone tumors can occur at almost any age. Osteosarcoma and Ewing's sarcoma, two of the most common malignant bone tumors, are usually found in people age 30 or younger. In contrast, chondrosarcoma, malignant tumors that grow as cartilage-like tissue, usually occur after the age of 30.

Malignant bone tumors include:

Chondrosarcoma
Chordoma
Ewing's sarcoma
Neuroblastoma
Osteosarcoma
Treatment
In the past 15 years, dramatic improvements have been made in treating malignant bone tumors. There has been an increase of five to 10 times in the likelihood of a cure for high-grade osteosarcoma, the most common malignant bone tumor. Today the chance of a cure is approaching 80%. In addition, the combination of better surgical techniques and better ways to reconstruct function after surgery now means patients lead fuller, more active lives after surgery. Spinal tumors can be treated with stereotactic systems similar to brain surgery. Newly designed prosthesis allow for more than 90% of the limb to be saved with surgery. The orthopedic surgeons at Cedars-Sinai are specialists in this surgery.

In all cases, the best treatment requires a thorough evaluation by an experienced doctor. Optimal treatment demands the combined skills of an exceptional surgeon, pathologist, radiologist, radiotherapist, medical oncologist and sometimes a plastic surgeon.Primary malignant bone tumors are much less common than metastatic bone tumors, particularly in adults. Primary malignant bone tumors include multiple myeloma, osteosarcoma, adamantinoma, chondrosarcoma, chordoma, Ewing sarcoma of bone, fibrosarcoma and undifferentiated pleomorphic sarcoma, lymphoma of bone, and malignant giant cell tumor. (See also Overview of Bone and Joint Tumors and Overview of Leukemia.)

The two most widely used systems for staging these tumors are

The American Joint Committee on Cancer (AJCC) Cancer Staging Manual, 8th edition: For osteosarcoma, chondrosarcoma, and Ewing sarcoma, staging is based on distinct tumor category, histologic grade, size, nodal involvement, and metastases (TNM classification). The manual classifies tumors into 4 stages and is used for reporting cancer data.

The Musculoskeletal Tumor Society (MSTS) staging system: Used by orthopedic oncology surgeons based on histologic grade (eg, Stage I-low-grade histology and Stage II-high-grade histology, whether the tumor is contained entirely within the bone (A) or has broken outside of the cortex into surrounding soft tissue (B), and metastases Stage III). The typical (conventional) osteosarcoma with an associated soft tissue mass without metastases is Stage IIB .done

1. MALIGNANT BONE TUMORS DR. SHIVANGI LAHOTY

2. The age of the patient plays an important role in establishing the diagnosis and may lead to the correct histological diagnosis even when the tumor is radiographically atypical.

3. The site of origin or location of a lesion is also of diagnostic significance with respect to which bone is involved and which portion of the bone, i.e., epiphysis, metaphysis, or diaphysis, is involved.

4. IMAGING MODALITIES 1 .CONVENTIONAL RADIOGRAPHY Conventional radiographic techniques still remain the mainstay in initial diagnosis and work-up of a patient suspected to have any bony pathology. Plain radiographs can demonstrate the location of the lesion, the pattern of bone destruction, size and shape of the lesion, presence and nature of the visible tumor matrix, trabeculation, periosteal response, and the presence and characteristics of the adjacent soft-tissue mass. Malignant lesions are generally poorly defined lesions with a wide zone of transition, a moth- eaten or permeative pattern of bone destruction, an interrupted periosteal reaction of the sunburst or onion-skin type, and an adjacent soft-tissue mass.

5. 2. MRI MRI is the best imaging modality - (1) in assessing intra- and extra compartmental extent of bone tumors (2) in assessing neurovascular and juxta-articular involvement (3) in detecting skip lesions, leading to a more accurate staging The MRI protocol for bone tumor evaluation should include an initial large field of view T1 or inversion recovery sequence to detect any skip lesions and for planning subsequent sequences. T1 and T2 or inversion recovery sequences of the involved area should then be acquired in axial, coronal, and/or sagittal planes, to show the complete extent of the tumor in all three dimensions, along with its relation to the adjacent joint and neurovascular bundle.

6. Both benign and malignant tumors are generally seen as low signal on T1-weighted (T1W) and high signal on T2-weighted (T2W) images. Thus, intraosseous extent and skip lesions are well evaluated on T1W images due to the contrast between the high signal marrow and the low signal tumor, whereas the extraosseous extent is better assessed on T2W images due to the contrast provided by the low signal muscles to the high signal tumor.

7. Coronal T1-weighted sequence demonstrates the intraosseous extent Axial T2-weighted sequence demonstrates the extraosseous extent. The periosteum is intact and the neurovascular bundle (arrow) is well separated from the tumor.

8. 3. COMPUTED TOMOGRAPHY CT still remains superior to MRI in detection and characterization of matrix mineralization (osteoid or chondroid), in picking up subtle calcification, and in the assessment of cortical involvement, bone trabeculation, and periosteal reaction. CT can be used to demonstrate the morphological features of the tumor in areas which are not well evaluated by plain radiography, e.g., pelvis, shoulder, and vertebrae and where MRI is contraindicated. CT is also the investigation of choice for detecting pulmonary metastases. It helps to evaluate treatment response as bone tumors ossify as they heal. CT-guided procedures allow accurate placement of biopsy needles. It also guides probes for tumoral ablation with ultrasound radiofrequency, microwave, chemical, or cryoablation.

9. 4. NUCLEAR MEDICINE In the patient with a documented bone tumor, FDG-PET can (1) guide a biopsy to the most active tissue (2) predict overall survival (3) distinguish recurrent tumor from post- therapeutic changes (4) monitor response to neoadjuvant chemotherapy (5) may also identify poorly responding patients earlier in therapy

10. OSTEOSARCOMA Osteosarcoma is the most common primary osseous malignancy. It mostly affects patients younger than 20 years of age. The typical lesion affects the metaphyseal region of the growing end of a long bone. Majority are found in the distal femur or the proximal tibia. Distant spread is mainly via the bloodstream with early metastases to the lungs.

11. IMAGING FEATURES On plain radiographs, t he classical appearance is that of a focal lesion in the metaphyseal end of a long bone showing a moth-eaten pattern of destruction with a wide zone of transition. The tumor breaks through the cortex early in the course of the disease leading to a soft-tissue mass. This mass later shows ill-defined tumor bone within it. Mineralization of the tumor osteoid leads to a cloud-like density in the region known as the cumulus cloud appearance .

12. Radiograph showing a destructive lesion in the distal femur with extensive cloud-like mineralization in the intra- and extraosseous component.

13. A Codman triangle may form at the margin of the lesion due to subperiosteal extension of the tumor lifting the periosteum. Radiograph showing a classical osteosarcoma with mixed lytic and sclerotic areas, extraosseous mass with tumor bone formation, and Codman triangles at the upper and lower margins of the lesion.

14. Bone spicules can be seen perpendicularly or radially in a “ sunburst” or “sunray” pattern. Radiographs of the leg show a lesion in metadiaphyseal region of tibia with a large soft tissue component and the characteristic “sunburst” or spiculated periosteal reaction.

15. Magnetic resonance imaging is the investigation of choice following conventional radiographs. A heterogeneous tumor can be seen within the bone, often associated with a soft-tissue mass, with low-signal intensity on T1W images and high-signal intensity on short tau inversion recovery (STIR) or T2W images. Coronal T1-weighted MR image (A) shows the large tumor as a predominantly hypointense mass with evidence of cortical destruction and axial T2-weighted image (B) shows the cortical disruption with soft tissue extension of the tumor mass.

16. TELANGIECTATIC OSTEOSARCOMA It is characterized by the formation of large septated blood- filled cavities with a rim containing high-grade osteosarcomatous cells. A predominant expansile, lytic lesion with remodelling, cortical destruction, and periosteal reaction is seen on plain radiographs. Radiograph of the distal femur shows a predominantly lytic lesion in the distal femur with irregular cortical destruction - Telangiectatic osteosarcoma.

17. Extensive hemorrhage and blood–fluid levels can be seen on both CT and MRI . T2W fat-suppressed magnetic resonance image shows the characteristic blood–fluid levels within the tumor.

18. CHONDROSARCOMA Chondrosarcoma is a malignant tumor of chondrogenic origin that remains essentially cartilaginous throughout its evolution. It is most commonly seen in the sixth decade. The common sites are the pelvis, the ribs, and the proximal ends of the femur and the humerus. In the long bones, chondrosarcoma is located in the metaphysis or metadiaphysis.

19. IMAGING FEATURES Radiologically, these tumors are seen as large, osteolytic, expansile, round, or oval lesions which are well marginated with endosteal thickening or thinning. Plain radiograph shows an osteolytic, expansile lesion in the upper end of the fibula with faint calcification seen within.

20. There is evidence of cartilaginous matrix mineralization. CT may show calcification of the matrix when it is not visible on plain radiographs. A large expansile lesion is noted in the anterior end of the left 7th rib; CT shows specks of calcification within the lesion.

21. A soft-tissue mass out of proportion to the size of the intraosseous lesion may be present. Anteroposterior and lateral radiographs of the ankle show an ill-defined lytic sclerotic lesion involving the calcaneum with a large soft tissue swelling along the posterolateral aspect of the ankle joint. T1-weighted sagittal MR image show a lobulated lesion in the calcaneum with a large extraosseous soft tissue component extending laterally, the lesion appears hypointense on T1.

22. In the pelvic tumors, the soft tissue mass mass is not easily demonstrated on conventional radiography. CT and MRI can demonstrate the soft-tissue extension with much greater accuracy. On MRI, cartilage shows increased signal intensity on T2W images and a multilobulated and septated appearance. The lesion is slightly hypointense to muscle on T1W images. Radiograph of the hemipelvis (A) shows a mass extending from the left iliac blade with the characteristic “popcorn” calcification of a cartilaginous matrix. T1-weighted MR image (B) shows the large soft tissue component of the chondrosarcoma as a low signal intensity lobulated mass. On coronal T2-weighted MR image (C), the tumor is seen as lobulated mass of high signal intensity with septations of low signal intensity.

23. EWING SARCOMA It is most frequently seen in the first three decades of life. Most commonly affected sites include femur, ilium, tibia, humerus, fibula, ribs, and sacrum. Long tubular bone involvement is more common proximally than distally, the lesion is seen in the diaphysis but the involvement can often be metadiaphyseal. Usually, a single bone is involved, but multiple lesions may also occur at presentation.

24. Ewing sarcoma with skeletal metastases. Pelvic radiograph shows the primary tumor as a large predominantly lytic lesion in the left iliac bone with multiple lytic bony metastases in the right iliac blade and both the femor, humeral shaft (B), and skull (C).

25. IMAGING FEATURES On radiography, Ewing sarcoma appears as an aggressive lesion with bone destruction showing a moth-eaten pattern. The lesion shows a wide zone of transition. Cortical destruction associated with a soft-tissue mass is also commonly seen. Ewing sarcoma of the femur shows an ill-marginated, lytic-sclerotic lesion with cortical irregularity and a large soft tissue mass in the metadiaphyseal region.

26. Periosteal reaction is also frequently seen and can be lamellated (onion skin), spiculated (sunburst or hair on end) or marginal (Codman triangle). Conventional radiograph shows spiculated periosteal reaction better appreciated on the axial computed tomography (CT) scan.

27. Computed tomography demonstrates aggressive bony destruction with soft-tissue mass , areas of focal cortical destruction can be seen. Plain radiograph; Axial computed tomography (CT) section of left shoulder shows a dense sclerotic involvement of the scapula with a large soft tissue mass.

28. Magnetic resonance imaging shows marrow replacement, cortical destruction, and soft-tissue mass. Ewing sarcoma of ulna. Radiograph of forearm (A) shows a lesion involving the diaphysis of the ulna with cortical thickening and periosteal reaction. T1-weighted (T1W) (B), T2-weighted (T2W) © images show marrow replacement in the diaphysis of the ulna with a large associated soft tissue component appearing hypointense on T1W and hyperintense on T2W images.

29. METASTATIC BONE DISEASE Metastases are the most common malignant tumors of the skeletal system. The most common primary sites are in the breast, lung, prostate, kidney, thyroid, and bowel. In children <5 years, skeletal metastases usually occur from neuroblastoma. Metastases between the age group of 10 and 25 years commonly occur from Ewing sarcoma and osteosarcoma, and between 20 and 35 years, they occur from Hodgkin lymphoma. In females, the carcinoma of the breast is responsible for majority of all bone metastases. In males, carcinoma prostate is the most common primary focus. They are most often found in the axial skeleton .Thus, the common sites for metastases are vertebrae, pelvis, proximal femur and humeri, skull, sternum, and ribs.

30. IMAGING FEATURES Bone metastases may be lytic, sclerotic, or mixed lytic and sclerotic. The majority of metastases are osteolytic eg :Breast cancer. Lateral radiographs of the skull show multiple ill-defined lytic lesions of varying sizes in the calvarium.

31. Skeletal metastases from prostate are predominantly blastic or mixed. AP and lateral radiographs of the lumbar spine show characteristic osteoblastic metastases; (B) Radiograph of pelvis shows diffuse sclerosis in the right iliac bone and left femoral head.(Seen in Ca Prostate )

32. Metastases from the lung occur most commonly to the axial skeleton ; however, metastases to hand and foot are most commonly from bronchogenic carcinoma. Carcinoma of the left lung with metastases to right humerus and vertebrae(Sclerotic lesions).

33. Metastasis from bronchogenic carcinoma . A lytic lesion involves the terminal phalanx of the index finger.

34. Hypernephroma and thyroid carcinoma generally show lytic, expansile metastases, also called “blow-out metastases” Metastasis from a hypernephroma. A large lytic lesion is seen in the left iliac blade.

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