Clinical gastric complications from adjacent yttrium-90 glass microspheres

Objectives Intra-arterial infusion of yttrium-90 (Y-90) microspheres is a method of radiation therapy for inoperable hepatic tumors. Gastric ulcers from the delivery of microspheres are a recognized complication. The goal of this study was to retrospectively evaluate patients treated with the Y-90 glass microspheres to the left hepatic lobe to evaluate a possible relationship between the volume of irradiated stomach and presence of gastric clinical complication.

Methods The MR/CT images of 10 patients treated with the Y-90 glass microspheres in the left hepatic lobe were reviewed. Clinical follow-up for complications associated with gastric irradiation were also examined. Specifically, images in which the left lobe treated tumor was within 1cm of the gastric wall were viewed. In each of these patients, the whole volume of the stomach as well as the volume of the stomach that was within 1cm of the treated tumor within the left hepatic lobe was determined. Utilizing these volumes, the approximate percentage of the stomach that was exposed to radiation from the Y-90 microspheres was determined.

Results None of the patients showed any clinical indication of gastric irradiation by beta particles. The average left hepatic lobar dose was 106.37±36.73 Gy (range: 25.90 to 144.98). For the whole stomach, the average volume was 67.85±17.13 mL (range: 34.1 to 96.35). The average exposed stomach volume was 0.67±0.22 mL (range: 0.4 to 1.1) with the associated average percent irradiated volume being 1.0%±0.2% (range: 0.6% to 1.4%).

Conclusions For the patients in this study, the percentage of the stomach that was irradiated from the Y-90 microspheres was less than 1.4% percent. As anticipated, none of the patients showed clinical indication of gastric complication.