What are the most appropriate imaging modalities for diagnosis and staging of BSTTs?

From Cancer Guidelines Wiki


Many bone and soft tissue tumours (BSTTs) are found unexpectedly when a General Practitioner (GP) orders an imaging test investigating a lump or pain. These initial tests may be an x-ray, ultrasound or computed tomography (CT) scan.

If a sarcoma is expected, it is recommended not to proceed to biopsy until there has been further imaging and review by a surgeon.

Aims of imaging at diagnosis and staging are:

  • Assess bone marrow involvement and extra-osseous soft tissue mass
  • Identify involvement of adjacent neurovascular bundles
  • Define location of soft tissue tumour within muscular compartments
  • Detect nodal and metastatic spread
  • Plan site and route for biopsy
  • Plan resection

Assessing the primary lesion

For bone and soft tissue masses in the extremities, magnetic resonance imaging (MRI) with intravenous contrast provides excellent visualisation of the tumour, soft tissue extension and relationship to surrounding structures. Post contrast, fat saturated MRI sequences help differentiate tumour from adjacent soft tissue oedema.[1][2][3] [4][5][6][7] If MRI is contra-indicated, contrast enhanced CT provides useful information.[8] CT is better at detecting subtle cortical erosion and periosteal reaction.[9][10] PET-CT can be useful for initial grading and guidance of biopsy.[11][12]

For soft tissue sarcomas (STS) in the abdominal cavity, a post contrast CT provides excellent multiplanar information regarding the relationship of the tumour to adjacent structures. There is limited evidence comparing CT and MRI in the abdominal cavity for STS, but in practice, contrast enhanced CT is a reliable investigation which can usually provide all of the required information. Only in selected cases is MRI required to add further relevant information for treatment planning.

MRI with magnetic resonance venography (MRV) is useful in primary intraluminal leiomyosarcoma of the Inferior vena cava (IVC).[13]

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Staging investigations

Aim to identify nodal and metastatic disease at the time of diagnosis.

A CT chest is commonly recommended at initial staging of all sarcomas due to the risk of metastases to the lungs. While this is included in many sarcoma guidelines, there is little evidence showing a significant detection rate in the setting of a normal chest x-ray at diagnosis. It is argued that the yield is low in T1 primary extremity STS.[14]

For lower limb soft tissue tumours, a CT abdomen and pelvis can be used to assess for lymph nodes.[15] In children ultrasound can be used to assess for regional lymph nodes.

Combined positron emission tomography and computed tomography (PET-CT) using 18F-fluorodeoxyglucose (FDG) can improve overall accuracy of staging soft tissue sarcomas. The degree of uptake varies with tumour grade and cell type. Whole body PET-CT can be useful for staging of STS, especially prior to radical surgery to identify unexpected metastases. However, suspicious lesions may need to be confirmed with biopsy due to a risk of false positives from inflammation. PET-CT can also guide biopsy to the most aggressive site within the primary mass.[11][12][16][17][18][19]

Whole body bone scan (WBBS) is a traditional staging investigation for bone metastases in sarcoma, but has an inferior sensitivity to PET-CT.[20][21][22]

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Ideally the biopsy is performed after the staging scans. This should be done after consultation with a surgeon and by a radiologist familiar with the issues of sarcoma biopsy. This takes into consideration the area of the tumour most likely to yield results and the likely surgical approach.

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Evidence summary and recommendations

Evidence summary Level References
For suspected bone and soft tissue tumours (BSTTs) in the extremities, MRI with intravenous contrast provides excellent visualisation of the mass, soft tissue extension and relationship to surrounding structures. III-2, IV [23], [2], [3], [4], [5], [6], [7]
Evidence-based recommendationQuestion mark transparent.png Grade
Magnetic resonance imaging is the imaging modality of choice for extremity tumours.

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CT is usually adequate for abdomino-pelvic masses.

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Further imaging and biopsy only performed after review by a surgeon or other member of a sarcoma team.

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CT chest be performed at diagnosis to assess for metastatic disease.

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PET-CT may be used prior to radical surgery of soft tissue sarcomas.

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  1. Fukuda K, Ehara S, Aoki J, Ohashi K, Sugimoto H, Harasawa A, et al. Is CT necessary in the diagnosis of soft tissue masses? Japan Medical Association Journal 2005 Jan 1;48(11):532-538.
  2. 2.0 2.1 Oudenhoven LF, Dhondt E, Kahn S, Nieborg A, Kroon HM, Hogendoorn PC, et al. Accuracy of radiography in grading and tissue-specific diagnosis--a study of 200 consecutive bone tumors of the hand. Skeletal Radiol 2006 Feb;35(2):78-87 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/16247641.
  3. 3.0 3.1 Rafique MZ, Bari V. Magnetic resonance imaging in the diagnosis and local staging of primary bone tumors. J Coll Physicians Surg Pak 2004 Jan;14(1):10-3 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/14764253.
  4. 4.0 4.1 van Trommel MF, Kroon HM, Bloem JL, Hogendoorn PC, Taminiau AH. MR imaging based strategies in limb salvage surgery for osteosarcoma of the distal femur. Skeletal Radiol 1997 Nov;26(11):636-41 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/9428070.
  5. 5.0 5.1 Elias DA, White LM, Simpson DJ, Kandel RA, Tomlinson G, Bell RS, et al. Osseous invasion by soft-tissue sarcoma: assessment with MR imaging. Radiology 2003 Oct;229(1):145-52 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/14519874.
  6. 6.0 6.1 Gronemeyer SA, Kauffman WM, Rocha MS, Steen RG, Fletcher BD. Fat-saturated contrast-enhanced T1-weighted MRI in evaluation of osteosarcoma and Ewing sarcoma. J Magn Reson Imaging 1997 May;7(3):585-9 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/9170046.
  7. 7.0 7.1 Schima W, Amann G, Stiglbauer R, Windhager R, Kramer J, Nicolakis M, et al. Preoperative staging of osteosarcoma: efficacy of MR imaging in detecting joint involvement. AJR Am J Roentgenol 1994 Nov;163(5):1171-5 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/7976895.
  8. Panicek DM, Gatsonis C, Rosenthal DI, Seeger LL, Huvos AG, Moore SG, et al. CT and MR imaging in the local staging of primary malignant musculoskeletal neoplasms: Report of the Radiology Diagnostic Oncology Group. Radiology 1997 Jan;202(1):237-46 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/8988217.
  9. Hogeboom WR, Hoekstra HJ, Mooyaart EL, Freling NJ, Veth RP, Postma A, et al. MRI or CT in the preoperative diagnosis of bone tumours. Eur J Surg Oncol 1992 Feb;18(1):67-72 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/1737596.
  10. Kuleta-Bosak E, Kluczewska E, Machnik-Broncel J, Madziara W, Ciupi?ska-Kajor M, Sojka D, et al. Suitability of imaging methods (X-ray, CT, MRI) in the diagnostics of Ewing's sarcoma in children - analysis of own material. Pol J Radiol 2010 Jan;75(1):18-28 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/22802757.
  11. 11.0 11.1 Bastiaannet E, Groen H, Jager PL, Cobben DC, van der Graaf WT, Vaalburg W, et al. The value of FDG-PET in the detection, grading and response to therapy of soft tissue and bone sarcomas; a systematic review and meta-analysis. Cancer Treat Rev 2004 Feb;30(1):83-101 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/14766127.
  12. 12.0 12.1 Charest M, Hickeson M, Lisbona R, Novales-Diaz JA, Derbekyan V, Turcotte RE. FDG PET/CT imaging in primary osseous and soft tissue sarcomas: a retrospective review of 212 cases. Eur J Nucl Med Mol Imaging 2009 Dec;36(12):1944-51 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/19593561.
  13. Huang J, Liu Q, Lu JP, Wang F, Wang L, Jin AG. Primary intraluminal leiomyosarcoma of the inferior vena cava: value of MRI with contrast-enhanced MR venography in diagnosis and treatment. Abdom Imaging 2011 Jun;36(3):337-41 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/20981422.
  14. Fleming JB, Cantor SB, Varma DG, Holst D, Feig BW, Hunt KK, et al. Utility of chest computed tomography for staging in patients with T1 extremity soft tissue sarcomas. Cancer 2001 Aug 15;92(4):863-8 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/11550159.
  15. King DM, Hackbarth DA, Kilian CM, Carrera GF. Soft-tissue sarcoma metastases identified on abdomen and pelvis CT imaging. Clin Orthop Relat Res 2009 Nov;467(11):2838-44 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/19636646.
  16. Fletcher JW, Djulbegovic B, Soares HP, Siegel BA, Lowe VJ, Lyman GH, et al. Recommendations on the use of 18F-FDG PET in oncology. J Nucl Med 2008 Mar;49(3):480-508 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/18287273.
  17. Kneisl JS, Patt JC, Johnson JC, Zuger JH. Is PET useful in detecting occult nonpulmonary metastases in pediatric bone sarcomas? Clin Orthop Relat Res 2006 Sep;450:101-4 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/16906103.
  18. Ricard F, Cimarelli S, Deshayes E, Mognetti T, Thiesse P, Giammarile F. Additional Benefit of F-18 FDG PET/CT in the staging and follow-up of pediatric rhabdomyosarcoma. Clin Nucl Med 2011 Aug;36(8):672-7 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/21716019.
  19. Tateishi U, Yamaguchi U, Seki K, Terauchi T, Arai Y, Kim EE. Bone and soft-tissue sarcoma: preoperative staging with fluorine 18 fluorodeoxyglucose PET/CT and conventional imaging. Radiology 2007 Dec;245(3):839-47 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/18024454.
  20. Arora B, Gulia S, Kurkure PA, Rangarajan V, Basu S, Shah S, et al. Use of FDG-pet with non-contrast breathhold CT-thorax obviates the need for conventional imaging tools for staging patients with Ewing's sarcoma: A large prospective study of 190 patients. Pediatric Blood and Cancer 2010;55(5):879.
  21. Györke T, Zajic T, Lange A, Schäfer O, Moser E, Makó E, et al. Impact of FDG PET for staging of Ewing sarcomas and primitive neuroectodermal tumours. Nucl Med Commun 2006 Jan;27(1):17-24 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/16340719.
  22. Fukuda K, Ehara S, Aoki J, Ohashi K, Sugimoto H, Harasawa A, et al. Is CT necessary in the diagnosis of soft tissue masses? Japan Medical Association Journal 2005 Jan 1;48(11):532-538.

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