16 Liver Cancer

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16 Liver Cancer

Heidi R. Wassef

History

67-year-old male who has a history of hepatic ductal cancer with liver resection. He is currently on chemotherapy. The patient is being evaluated for recurrence in a suspicious lesion on CT.

Findings

On CT, the multiple clips in the liver inferiorly are consistent with prior liver resection. There are two discrete hypermetabolic nodules in the right posterior liver next to the kidney in the region of surgical clips consistent with local recurrence (Figures 16.1.1, 16.1.2, and Figure 16.1.3). Curvilinear uptake in the bowel is physiologic. No active adenopathy is evident above or below the diaphragm.

Impression

Evidence for hypermetabolism in the right posterior liver consistent with local recurrence.

Pearls and Pitfalls

• In primary liver cancer, there is a strong correlation between high-grade histopathol- ogy and intratumoral ﬁbrosis, but not with necrosis or cirrhosis.^1,2,6

Discussion

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide.

Most cases occur in individuals older than 40 years of age. It is more common in males than in females. Hepatitis B, hepatitis C, cirrhosis, aﬂatoxin, and Thorotrast are risk factors for HCC. AFP and ultrasonography are useful screening tools. AFP is usually present in 75% of the symptomatic cases, but AFP alone cannot distinguish between benign from malignant disease. Helical CT is a useful tool for subcentimeter lesion detection without the problems of respiratory misregistration. Angiographically assisted CT can characterize the lesions for resectability. Sonography is useful for

Case 16.1

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FIGURE16.1.1.

FIGURE16.1.2. FIGURE16.1.3.

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16 Liver Cancer 161

detecting hyperechoic lesions. Duplex and color Doppler are useful for the detection of vascular invasion. MRI with gadolinium enhancement is also useful for early detection of HCC.

History

68-year-old male who has a history of liver cancer status post liver transplant and chemotherapy. His most recent MRI study demonstrated suspicious lesions involving the right hepatic dome and right posterior lobe of the liver. Evaluation for recurrence is requested.

Findings

There is an intense focus of hypermetabolism in the dome of the liver laterally (Figures 16.2.1 and 16.2.2), which does not corresponds to a definite CT (noncontrast) abnor- mality. The surgical sutures in the right upper quadrant (Figure 16.2.3) are consistent with prior liver transplant. Abnormal multifocal sites of hypermetabolism are also seen within the mediastinum including the hila, prevascular space (Figure 16.2.4), AP window, right paratracheal, precarinal, and subcarcinal regions, highly suspicious for metastatic nodal disease. There is an approximately 1-cm noncalcified nodule (Figures 16.2.5 and 16.2.5A) seen in the posterior aspect of the left lower lobe, which is mildly hypermetabolic. Incidentally noted are three superficial hypermetabolic lesions in the buttocks (Figure 16.2.6) presumably inflammatory injection sites, two superior and one right inferior in location.Another separate superficial focus of hypermetabolism is seen located in the posterolateral aspect of the abdominal wall corresponding to subcuta- neous soft tissue thickening on CT attributed to probable inflammation. Inferior and posterior to the bladder in the prostate bed, there is moderate hypermetabolism, which probably represents benign prostatic hypertrophy (Figure 16.2.7); other prostate pathology cannot be excluded. The thickened gastric wall (Figure 16.2.8) with associ- ated hypermetabolism is compatible with gastritis. The spleen is prominent in size with heterogeneous tracer localization. The aortic wall is calcified. There is symmetric high tracer uptake in the larynx which is considered physiologic. The activities in the rectum and testes are also considered physiologic. An artifact in relation to the metallic dental work is noted.

Case 16.2

FIGURE16.2.1.

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FIGURE16.2.5A.

FIGURE16.2.6.

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Impression

1. Markedly abnormal study demonstrating at least one focal intensely hypermetabolic lesion at the dome of the liver, hypermetabolic multinodal disease in the chest and a noncalciﬁed pulmonary nodule in the posterior left lower lobe, all suspicious for recurrent metastatic disease. The differential diagnosis also includes post transplant lymphoproliferative disease.

2. Splenomegaly.

3. Moderate prostate hypermetabolism probably related to benign prostate hyper- plasia/hypertrophy; malignancy cannot be excluded.

4. Thickened gastric wall with moderate hypermetabolism suggestive of gastritis.

5. Probable injection site superﬁcial inﬂammation in the buttocks.

• 64% of HCC lesions accumulate FDG.^2,8

• PET can alter management in 28% of patients.^1,2,8

• PET-CT may potentially mislocate a lesion particularly at the dome of the liver and base of the lung owing to respiratory motion artifact. It is highly recommended to obtain breath-hold CT views for comparison.⁶

164 Part II Clinical Cases

History

59-year-old male who has a history of liver cancer status post liver transplant and was later treated with chemotherapy. His most recent AFP is 119 and is rising. Evaluation for recurrence is requested.

Findings

There is a large right upper quadrant focus in the sub hepatic region (Figures 16.3.1, 16.3.1A, and 16.3.2) along the bowel distribution that is metabolically active. Another smaller lesion is seen in the right lower quadrant (Figure 16.3.3). A third focus of activ- ity is also noted in the mid-abdomen just right of midline (Figure 16.3.4). These ﬁnd- ings appear both intense and focal and are suspicious for serosal, bowel, or omental involvement with metastatic disease. Other bowel pathology such as inﬂammatory bowel disease or polyposis also should to be considered. The surgical bed in the liver (Figure 16.3.5) is mildly active consistent most likely with post-surgical changes. The mild activity in the stomach is likely gastritis (Figure 16.3.6).

Impression

Multiple intense hypermetabolic foci in the abdomen as described above suspicious for serosal, bowel, or omental involvement with malignant process.

• CEA is not a sensitive indicator for liver cancer recurrence. Only 59% of recurrent disease demonstrates an elevated serum CEA level.^1,2

Case 16.3

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FIGURE16.3.1.

FIGURE16.3.1A.

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16 Liver Cancer 167

• The positive predictive value for detecting a locally recurrent lesion after treatment with PET is 80%; the negative predictive value is 100%.^5,7,8

FIGURE16.3.6.

History

58-year-old male with a history of liver cancer status post partial liver resection. He was later treated with radiotherapy and chemotherapy. His AFP level has increased from 11.0 to 53.9. Evaluation for recurrence is requested.

Findings

There is a focus of activity near the anterior abdominal wall left of midline (Figures 16.4A.1 and 16.4A.2), which corresponds to a mass seen below the liver on CT. This is new compared to a previous PET done 5 months ago. This is suspicious for metastases either from an implant on the transverse colon wall or peritoneal surface. The mild to moderate focal hypermetabolism along the liver edge (Figure 16.4A.3) near the surgi- cal resection noted is minimally increased since the last PET study. A loop of bowel is seen as protruding into the right hepatic cavity consistent with the history of right hepatic lobe resection.

Case 16.4A

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FIGURE16.4A.1.

FIGURE16.4A.2.

FIGURE16.4A.3.

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16 Liver Cancer 169

Impression

1. New malignancy seen in the anterior abdominal wall left of midline with modest increased activity in the hepatic surgical bed.

1. Possible locally recurrent disease at the surgical margin as described above.

Discussion

The degree of tumor differentiation is closely related to the rate of proliferation in hepatocellular carcinoma. Patients with the worst prognosis tend to have histologically undifferentiated lesions and lesion size exceeding 1 cm in diameter. The 5-year survival rate of HCC is 90% if the lesion is 1 cm in diameter or less and well differentiated.

A high cure rate is possible only with resection. Fifty percent of the patients with advanced disease will beneﬁt from liver transplantation as the most salient treatment for a cure.

History

58-year-old male who has a history of liver cancer with the prior PET demonstrating hypermetabolism involving the left anterior abdominal wall and liver. He later under- went anterior abdominal wall resection. Evaluation for malignancy is requested.

Findings

There is a small focus of activity along the superolateral aspect of the residual liver (Figures 16.4B.1 and 16.4B.2) at the site of the surgical resection and clips that is unchanged from the prior study. The lesion in the left anterior abdominal wall is no longer visible.

Case 16.4B

FIGURE16.4B.1.

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Impression

Interval resolution involving the left anterior abdominal wall abnormality with residual liver activity suspicious from post surgical changes; suggest a repeat scan in 3 months to monitor for disease progression.

• FDG accumulation varies with the degree of tumor differentiation.^1,2

• ¹¹C-acetate may be used as an alternative to ¹⁸F-FDG since it demonstrates a detection sensitivity of 87.3% as opposed to 47.3% in the detection of individual tumor lesions using FDG.^3,4

Discussion

In normal hepatocytes, glucose-6-phosphatase degrades the phosphorylated FDG resulting in poor intracellular accumulation of the tracer. Well-differentiated HCC con- tains an abundance of glucose-6-phosphatase, accounting for decreased accumulation.

Only 55% of the malignant tumors have been reported to have a higher intensity of FDG uptake than normal livers. Thirty percent of the malignant tumors have an uptake intensity equal to uptake intensity in normal liver and 15% have uptake less than that of normal liver.

FIGURE16.4B.2.

History

41-year-old patient with cirrhosis secondary to hepatitis-B and known hepatoma status post embolization therapy. The current exam is to evaluate for metastatic disease and consideration for potential liver transplant.

Case 16.5

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16 Liver Cancer 171

Findings

On CT the liver surface is irregular, and the spleen mildly enlarged (Figures 16.5.1 and 16.5.2) with some omental portosystemic collaterals. These are consistent with the history of cirrhosis. The primary hepatocellular carcinoma is visible as a hypermeta- bolic mass replacing much of the lateral segment of the left lobe of the liver (Figure 16.5.3). Radiodensities within the lateral segment on CT are consistent with contrast given with chemoembolization. The largest contrast collection is devoid of activity. A small collection is seen within the tumor, which has a hypometabolic center and a hypermetabolic periphery, consistent with treated hepatocellular carcinoma with FIGURE16.5.1.

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viable tumor at the periphery. No other hypermetabolic liver lesion is apparent. The remainder of the study appears normal with prominent but symmetrical presumed physiologic tonsillar, bowel, and testicular activity. There is no evidence for skeletal metastatic disease. Lung window images of the chest were reviewed, and there is no evidence for pulmonary metastasis.

Impression

Moderately intense hypermetabolism within the lateral segment of the left lobe of the liver with central photopenia, consistent with hepatocellular carcinoma status post embolization therapy. There is a background of cirrhosis with portal hypertension.

However, there is no evidence for metastatic disease.

Discussion

PET imaging can guide the biopsy of large, metabolically active tumors, identify distant metastases, monitor patient response to treatment for hepatic chemoembolization, and detect recurrent disease.