Thallium-201/technetium-99m-phytate (colloid) subtraction imaging of hepatocellular carcinoma.

This paper evaluates the clinical usefulness of 201Tl to image hepatocellular carcinoma (HCC), using 201Tl, 99mTc-phytate (colloid) and a three-headed SPECT camera.

METHODS

The tumor-to-nontumor ratios (T/N) of 201Tl for different categories of HCC were generated. Tumors were emphasized by image subtraction (201Tl-99mTc-colloid). Thirty-three lesions in 16 patients (18 studies) with HCC were evaluated. There were 19 untreated nodular, five untreated diffuse, five local recurrent and four necrotic lesions after interventional therapy.

RESULTS

The mean T/N were as follows: untreated nodular 1.54 +/- 0.31 (mean +/- s.d.), untreated diffuse 1.28 +/- 0.26, local recurrence 1.50 +/- 0.29 and necrosis 0.22 +/- 0.06. All the tumors (except necrotic areas) were enhanced by the image subtraction.

CONCLUSIONS

Thallium-201 is useful for liver tumor imaging but 99mTc-phytate (colloid) is essential to discriminate 201Tl tumor uptake from normal liver accumulation. Image subtraction (201Tl/99mTc-colloid) is helpful in detecting HCC.