Abstract
BACKGROUND: Hepatocellular carcinoma (HCC) and liver-dominant metastases remain major causes of cancer mortality, and yttrium-90 transarterial radioembolization (TARE) offers a vital treatment option for unresectable cases. Accurate dosimetry is critical for maximizing tumor control while minimizing lung toxicity, yet conventional planar scintigraphy may overestimate lung shunt and compromise therapeutic efficacy. This study evaluated the value of Q.Liver software in planning yttrium-90 TARE for liver cancer. METHODS: A total of 45 patients with liver cancer scheduled for treatment with yttrium-90 resin microspheres TARE were enrolled. Treatment planning was conducted via the partition model with two approaches for each case: the traditional method based on planar scintigraphy and the Q.Liver software based on single-photon emission computed tomography-computed tomography (SPECT/CT) imaging. Differences in liver and lung volume between the two methods were compared. Differences in lung shunt fraction (LSF) were analyzed in 43 patients, and yttrium-90-prescribed activity, liver-absorbed dose (D(Liver)), and lung-absorbed dose (D(Lung)) were compared between the two methods for the same patient. In the planar method, liver and lung volumes were obtained by enhanced CT, and LSF was obtained by planar scintigraphy; in the Q.Liver method, LSF, liver and lung volumes were obtained via SPECT/CT. The yttrium-90-prescribed activity, D(Liver), and D(Lung) of each method were calculated. RESULTS: (I) The liver and lung volumes in the planar and Q.Liver methods were 1,809 and 1,820 mL (P=0.36), respectively, and 3,279 and 2,587 mL (P<0.05), respectively. (II) The LSF in the planar method was higher than that in the Q.Liver method (6.08% vs. 3.96%). (III) Yttrium-90-prescribed activity was higher in the planar method than in the Q.Liver method (2.02 vs. 1.82 GBq), The sum of D(Lung) was 345.53 Gy in the planar method and 221.82 Gy in the Q.Liver method. (IV) With D(Lung) being constant in the treatment planning system, the yttrium-90 prescribed activity, DTumor and D(Liver), were higher in the Q.Liver method than in the planar method. This led to changes in 44.19% (19/43) of the treatment plans. CONCLUSIONS: SPECT/CT-based Q.Liver software was able to simplify yttrium-90 treatment. Planar scintigraphy overestimated LSF and D(Lung) as compared to SPECT/CT imaging. If D(Lung) remained constant, Q.Liver software increased DTumor and D(Liver), leading to changes in 44.19% of the treatment plans involving yttrium-90 resin microsphere TARE.