SmumuaryEighteen patients with inoperable hepatocellular carcinoma (HCC) were treated with intrahepatic arterial yttrium-90 microspheres. All these patients showed a lung shunting below 15% and a tumour-tonormal ratio higher than 2 as determined by diagnostic technetium-99m macroaggregated albumin (Tc-MAA) gamma scintigraphy. The treatment was given through an arterial port placed during laparotomy. The radiation doses to the liver and tumour were determined intraoperatively with a beta probe and liquid scintillation counting of multiple liver biopsies. The treatment was well tolerated without major complications. In all patients the tumour marker fell to a level which ranged from 41% to 0.2% of the pretreatment level. Tumour regression was found to be dose related. Progressive or static disease occurred in a higher proportion of patients whose tumours received <120 Gy (P = 0.005). Survival was better in those whose tumours received > 120 Gy (median survival = 55.9 weeks) than those whose tumours received lower doses (median survival = 26.2 weeks). This difference is statistically significant with P = 0.005. We conclude that yttrium-90 microsphere therapy is safe and that tumour response is dose related. A tumour dose of > 120 Gy is recommended.Surgery remains the only hope of cure for patients with hepatocellular carcinoma (HCC) (Maclintosh & Minuk, 1992). Unfortunately, most patients have inoperable tumours at the time of presentation, and their prognosis is so dismal that the median survival time is usually less than 2 months (Okuda et al., 1985; Shiu et al., 1990), although longer survivals have been reported in the literature (Yamada et al., 1983;Kajanti et al., 1986;Epstein et al., 1991). Extensive trials with systemic chemotherapy have yielded disappointing results (Friedman. 1983). An increased response rate is reported for hepatic arterial chemotherapy for these tumours, but there is no good evidence that this technique prolongs survival (Malik & Wrigley, 1988).In an attempt to improve on the results of locoregional therapy for inoperable HCC, intrahepatic arterial lipiodol iodine-131 or yttrium-90 microspheres have been used with varying degrees of success (Kobayashi et al., 1986; Park et al., 1987; Bretagne et al., 1988;Houle et al., 1989;Novell et al., 1991). A choice still exists between these two radioisotopes for therapeutic purposes (Park et al., 1987;Novell et al., 1991). Theoretically, yttrium-90 is more suitable for therapy for larger tumours because of its higher energy, thus providing a deeper penetration and a higher tumour dose rate (Park et al., 1987;Lau & Li, 1992). Radiation protection is also easier with a pure beta emitter (Lau & Li, 1992).The safety and efficacy of yttrium-90 microspheres have been attested in clinical studies involving reasonably large numbers of patients with metastatic liver cancer (Blanchard et al., 1989; Gray et al., 1992). The clinical experience in HCC is more limited. A phase I study was conducted on ten patients with HCC to determine the toxicities and tum...

Between October 1990 and March 1993, 124 patients who had hepatocellular carcinoma (HCC) underwent diagnostic pharmaco-scintigraphy with hepatic intraarterial technetium-99m macroaggregated albumin (TcMAA) to determine the tumourous to non-tumourous liver tissue uptake ratio (T/N ratio). There were 110 males and 14 females. Ages ranged from 16 to 73 with a median of 55 years. The range of T/N ratio was 0.7 to 19.3 with a median of 3.8. 12 patients with inoperable HCC were subsequently selected by predetermined criteria to undergo treatment with hepatic intraarterial yttrium-90 microspheres and the T/N ratios in these patients were validated by beta probe dosimetry and liquid scintillation count of multiple liver biopsies. The T/N ratio determined by preoperative diagnostic TcMAA scan correlated well with intraoperative beta probe dosimetry, with coefficient of correlation r = 0.82. Preoperative TcMAA scan also correlated well with liquid scintillation count of biopsy specimens, with r = 0.96. We conclude that TcMAA scan can be used to determine the T/N ratio in patients with HCC, thus allowing better selection of patients with inoperable tumours for loco-regional therapy.

Thallium-201 has been shown to be useful in predicting tumour viability in patients undergoing neoadjuvant chemotherapy for osteogenic sarcoma. Early studies relied upon qualitative assessment of analog images to obtain predictive results. Recently, the lesion to normal tissue uptake ratio of 201Tl has been used in evaluating bone and soft tissue sarcomas. This study attempts to quantitate changes in tumour to normal tissue ratio following chemotherapy. Eight consecutive patients with classical osteosarcoma received standard preoperative chemotherapy with a combination of cisplatin, adriamycin and high-dose methotrexate. 201Tl gamma scintigraphic images were obtained both before and after chemotherapy. The average counts taken over the tumour divided by that from the contralateral normal tissue area yielded a tumour-to-normal tissue (T/N) ratio. The percentage change in the T/N ratio before and after preoperative chemotherapy was correlated with the percentage of tumour necrosis from pathological section. The median post-chemotherapy T/N ratio was 1.85 (range 0.5-7.7). The median percentage change in T/N ratio after chemotherapy was -58% (range +26% to -83%). The median percentage of necrosis from pathological section was 80% (range 0%-95%). There was a good correlation between the percentage of tumour necrosis and the percentage change in T/N ratio (rank correlation coefficient r = 0.84, P = 0.0085). Quantitative assessment of changes in 201Tl uptake by osteosarcoma correlates well with tumour necrosis after preoperative chemotherapy. This method may be used to predict response to chemotherapy at an earlier stage, enabling the clinician to consider alternative chemotherapeutic regimens or salvage surgery.

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