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FEATURE OncOlOgy


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nterventional Oncology is an exciting sub-specialty in interventional radiology encompassing a wide range of


procedures. Advent of new procedures is being made possible by constantly evolving technology. Interventional procedures in oncology are not only for symptom palliation but also are therapeutic. Therapeutic procedures include arterial embolization and ablative procedures for primary and metastatic tumours. Palliative procedures are more generic and are aimed to treat symptoms.


THERAPEUTIC PROCEDURES These are further detailed under the headings Arterial embolization and Ablative procedures.


Arterial embolization - Liver tumours Arterial embolization is employed for treatment of liver tumours such as Hepatocellular carcinoma (HCC), and liver metastases from colorectal tumours, neuroendocrine tumours of pancreas and carcinoid tumours. Arterial embolization is usually the only treatment option in patients with multiple lesions, numerous large lesions and lesions in high-risk


FIGS 1, 2, 3, 4, 5, 6 1 2 3


locations. Embolization may also be performed prior to surgery to shrink the tumour. Embolization techniques include, A. Transcatheter Arterial Embolisation (TAE) or Bland embolization; and B. Transcatheter Arterial Chemoembolisation (TACE) Several embolic agents may be used


for treatment. When the procedure is performed with an embolic agent loaded with a chemotherapeutic agent it is called TACE (see figures 1&2) and embolization without chemotherapeutic drug is called TAE. The basis of this treatment lies in inducing ischemia when the perfusion is reduced by embolization thereby causing tumour necrosis. In addition the chemotherapeutic agent acts at microscopic level inhibiting the cell multiplication thereby resulting in tumour reduction. TACE delivers the drug directly to the tumour increasing the concentration locally and hence reducing the systemic side effects. Polyvinyl Alcohol (PVA) particles ranging from 200 to 1000 microns size are commonly used in bland embolization however other embolic agents may be used. Doxorubicin is the most widely used chemotherapeutic agent in HCC, Irinotecan is used in colorectal liver metastases (CLRM).


 Bladder, prostate, pelvic and other malignancies may cause ureteric obstruction, which result in hydronephrosis


by clinical, biochemical and imaging evaluation to assess the patient’s suitability for embolization. Informed consent is taken from the patient and procedure performed under conscious sedation. Percutaneous access is gained in to the common femoral artery followed by catheter angiography of coeliac axis and superior mesenteric to delineate the vascular supply to the liver tumours. Super selective catheterization of the tumour vessels is achieved by using a microcatheter. Embolization is then performed with the agent appropriate to the liver tumour. Adequate analgesia, sedation and anti- emetics are given during the procedure. Post-procedure imaging is performed four weeks after the procedure to assess response and second treatment 


Pre-procedure work-up is performed A


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 Figure 1: Selective digital subtraction angiogram demonstrating a hepatocellular carcinoma  Figure 2: Digital subtraction angiogram after chemoembolisation  Figure 3: Right renal angiogram demonstrating a lower pole renal cell carcinoma  Figure 4: Right renal angiography following selective particle embolisation  Figure 5: Digital subtraction angiogram demonstrating vascularity of a left iliac bone metastasis  Figure 6: Digital subtraction angiography demonstrating ‘blush’ at the end of pre-operative embolisation using gelfoam


Imaging & Diagnostics Issue 4 2011 31


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