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May 09
2010
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What do we do with liver tumors in India?Posted by: Anuj Mishra on May 09, 2010  |
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Focal liver lesions pose a diagnostic challenge to radiologist and clinician alike. Many focal liver lesions remain undiscovered throughout the patients’ life only to be discovered on autopsy.
Most focal liver lesions are incidental findings, especially at ultrasound examinations performed as part of the follow-up of tumor patients or in screening programs for liver cirrhosis.
How many of our colleagues in India use contrast-enhanced ultrasound or diffusion weighted MRI for characterization of liver lesions? And what about the cost?
What comes after ultrasound?
The quality of ultrasound findings varies with the experience of the examiner and the quality of equipment. Contrast-enhanced ultrasound is generally the preserve of specialized centres. In this situation, according to the EASL Barcelona guidelines, a triphasic CT scan or contrast-enhanced dynamic MRI scan should also be performed before the lesion can be characterized.
Subcentimeter focal liver lesions incidentally discovered in a normal liver should always be considered benign.
But the scenario changes when a lesion is discovered in a cirrhotic liver or in the clinical setting of a primary colorectal cancer.
The choice of diagnostic method would then depend on the size of the lesion.
But many hepatobiliary departments in western world are quite aggressive in their imaging approach. They would go to any extent in order to characterize even those small subcentimeter focal lesions. This can be attributed to improved scan technology, availability of liver-specific contrast and improved MR sequences like diffusion.
Contrast-enhanced ultrasound is not specific to characterize liver lesions. The rapid ‘wash-out’ sign is not 100% sensitive.
Just last week we came across a patient with treated C.A. Breast on follow-up. Her Triphasic CT scan showed a large 4 cm. lesion in liver with absent ‘wash-out’ sign. We decided to recall her after three months for follow-up scan when this same lesion showed increase in size which led us to treat the lesion immediately.
So what do we do next?
We have the option to perform dynamic CT scan or MRI.
There is a new role of diffusion MRI in these patients coupled with dynamic MRI.
According to a recent paper by Taouli et.al. in Radiology 2010, diffusion-weighted imaging improves focal liver lesion detection as compared to gadolinium-enhanced MRI. It has better lesion-to-liver contrast-to-noise ratio especially for small 1-2 cm. lesions.
ADC allows to differentiate benign from malignant lesions on the basis of cellularity, with however an overlap.
The problem is not with the regenerative nodule or low-grade dysplastic nodule or overt HCC, but with equivocal nodules like high-grade dysplastic nodules and early HCC which does not show ‘wash-in’ or ‘wash-out’ sign on contrast imaging.
And these lesions are premalignant and need to be treated.
How do we characterize these lesions in India?
In a paper by Kim et al in Investigative radiology in 2008, they concluded that “hypointensity of the lesion in delayed phase is a sign of malignancy” with a sensitivity of 71.5% and specificity of 92%.
Therefore, a delayed scan must be added to the CT or MRI protocol for focal liver lesions.
We must understand that all these modalities incur huge costs to patients, especially in India where the general patients come from rural background.
And very often it is not possible to perform the battery of expensive radiological tests due to cost constraints.
In Indian setting and especially for a patient from low socio-economic status, I feel we should treat any focal liver lesion in a cirrhotic liver instead of subjecting the patient to advanced imaging, as there is evidence in literature of high probablility of this lesion to be malignant.
The problem is the focal liver lesion in normal liver. Clinical history of previous cancer or oral contraceptive use would help to clinch the diagnosis. Or the presence of ‘target’ appearance would suggest malignant etiology.
Possible management algorithm can be as follows:
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Reviewed by Team Iradix May 13, 2010
Reviewed by Anuj Mishra May 09, 2010
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Alok Varshney
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... Very informative article Dr Anuj. When I find a focal hepatic lesion which is not obviously a cyst, I call for the previous studies (CT/MR and even USG)to compare. If the lesion was not there previously, I consider it as malignant unless proven otherwise. Isolated focal lesion in a normal liver with no previous history of cancer is a diagnostic challenge, specially when it is small in size ( |
Dr. Anuj Mishra
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... Thanks dr. alok for your views. Do you use contrast-enhanced ultrasound (CEUS) in your practice? There are some centres in Europe where CEUS is a routine in all oncology patients. And what they do is to use 2.4 cc of Inj. Sonovue as a bolus followed with saline chase and wait for a minute before scanning the liver. This technique is very useful to pick up small liver secondaries not seen by routine plain ultrasound. Also the role of CEUS is becoming very crucial to characterize focal liver lesions. New trend is to perform CEUS for lesions detected by CT or MRI in order to characterize the lesion as the sensitivity and positive predictive value of either modality ranges between 70 - 85% while that of CEUS can reach upto 98&, ofcourse depending on operator experience. |
Alok Varshney
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... CEUS does appear exciting but at present the cost is prohibitive. With in the restraints of Indian private practice,it is almost impossible to routinely use CEUS. Even abroad, the acceptance of CEUS in diagnostic protocols is still far from certain. Granted that few centers have had excellent results, but just as you say, its very operator dependent. Comparatively CT and MR are less so, hence I prefer CT/MR for evaluation of focal hepatic lesions at present. Some academic institutions in India have used CEUS and they also proclaim initial good results. But somehow I am still skeptical about the use of CEUS and whether it will gain much prominence in our protocols. |
Anuj Mishra
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... Many thanks Dr. Alok for your invaluable comments. I agree with you that our experience with contrast-enhanced ultrasound (CEUS) is very limited. And also the availability of ultrasound contrast is an issue. But can CEUS replace MDCT or MRI?? There is ample evidence in literature to support the fact that CEUS can play a very important role in diagnosing and characterizing focal liver lesions and that it is complementary to MDCT & MRI. In a recent article by Rafaelsen et al (Colorectal Dis. 2010 Apr 19), they compared the sensitivity and specificity of contrast enhanced ultrasonography (CEUS) and multidetector-computed tomography (MDCT) in the detection of liver metastases in 271 patients with colorectal cancer and found that specificity (97.6%) and positive predictive value (75%) of CEUS was higher than MDCT. In another article by Cantisani et al (Ultraschall Med. 2010 Apr 20), CEUS increased the sensitivity of plain ultrasound from 67.4 - 71.6 % to 93.4 - 95.8 % which was statistically significant. My friend Dr. Bartolotta from Italy compared CEUS with 64-MDCT & CE-MRI(Primovist) in characterizing focal liver lesions undetermined by plain ultrasound, and found that the need for further radiological evaluation decreased by 24.6% after CEUS which was statistically significant. (Radiol Med. 2010 Jan 15). They thereby concluded that CEUS can be considered an effective alternative to MDCT and MRI. But what about the cost factor to the patient if we wish to include it in our routine protocol? A CEUS examination in Europe costs 80 euros while the MDCT costs 110 euros. I am sure the cost of MDCT or dynamic MRI would be higher in India as well as compared to the cost of CEUS. There are few centres around the world which use CEUS in every oncology patient to scan the liver for detection or exclusion of liver secondaries. From this we see that CEUS can play an important role in diagnosing and characterizing focal liver lesions and can be cost-effective too. In our institution, we have experienced similar results, albeit with low cohort of patients, due to limited availability of ultrasound contrast. So the real problem seems to be a LOGISTICAL one. I just hope that ultrasound vendors can include contrast harmonics in their standard package. We also expect the cost of ultrasound contrast to come down in years to come. Only then we can include CEUS in our routine liver imaging practice. |
Dr. Sridhar V
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... Thank you very much for this, a very interesting article. Dr.Anuj Mishra , You made our job much easier by the simplified management algorithm for solving the Focal Liver Lesions.( in Indian Context ) I am not sure about centers in India using CEUS technique regularly I wonder any body in India having enough experience .Neither any idea of cost factors involved. I believe 1. Ultrasound contrast agents are not being used in India,to the extent it is supposed to be diagnostic 2. Not much encouragement from Manufacturers in terms of cost factor. 3. Most of our knowledge about USG contrast is theoretical. 4. I am not sure whether any MD or DNB candidate had an opportunity to do thesis on USG contrast medium . If any Member doing the CEUS studies in their Institutes( in India) please share your experience. |
Anuj Mishra
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... I am sure if the ultrasound contrast begins to be locally manufactured, just like CT scan contrast, its cost would drastically reduce. The contrast vendors should give us the freedom and opportunity to use their product effectively. Anybody having any idea about the present costs of contrast-enhanced US, dynamic MRI and Triphasic MDCT in India should let us know. |
Ramesh Pandey
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... Thannks Dr Anuj for the simple and effective Algorithm. It's really simple and useful. I have not seen a single centre using US Contrast agent in last 10 years of my limited Rdaiology experience. In Indian context where many patients are poor and the lesion becomes dicey and complex, then after CECT /MRI I usually prefer to go ahead with FNAC/FNAB and Lab tests (CEA). Though will now try to strealine it more. |
Anuj Mishra
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... Thanks Dr. Pandey for your kind appreciation. There is enough evidence in literature against routine biopsies of focal liver lesions, especially in cirrhotic livers. According to the EASL guidelines, biopsy has a very limited role, and that too in normal livers. The problem in cirrhotic liver is the differentiation between low dysplastic nodule, high dysplastic nodule and early HCC, as the latter two would require immediate treatment while the former one would need just follow-up. Very often, we can see a dysplastic nodule and early HCC in the same setting. And if we are able to characterize these small lesions at early stage, we can easily treat them with radio-frequency ablation or percutaneous ethanol injection. My experience with such small lesion characterization has been quite encouraging and I have managed to 'cure' quite a few of them. I just hope the application of CEUS becomes more widespread and easily accessible to poor patients too. |
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