Joseph Y. Young, Presenter: Nothing to Disclose

Bassel Atassi, Abstract Co-Author: Nothing to Disclose

Shadi Saleem, Abstract Co-Author: Nothing to Disclose

Robert J. Lewandowski MD, Abstract Co-Author: Nothing to Disclose

Reed A. Omary MD, Abstract Co-Author: Nothing to Disclose

Riad Salem MD, MBA, Abstract Co-Author: Consultant, MDS Inc, Ottawa, Canada

The upper limit of tolerable Y90 radiation for partial liver volumes is unknown. We assessed the effects of multiple selective Y90 treatments on liver toxicity in HCC patients.

63 HCC patients received ≥ 2 Y90 glass microsphere treatments to the same lobe or segments. Patients were stratified by prior entire liver irradiation (whole liver category vs. single lobe category), and by lobar or segmental re-treatments, leading to 4 patient categories: whole liver lobar, whole liver segmental, single lobe lobar, and single lobe segmental. The segmental categories were further stratified by volume of treatment site >15%. We measured cumulative radiation dose to each re-treated site. Patients were followed for grade 3-4 liver toxicities and worsening ascites. Statistical analysis was performed using t-test (p=0.05) and Kaplan-Meier.

There were 32 Okuda I and 31 Okuda II patients, and toxicities occurred in 8 (25%) and 9 (29%) of the patients respectively. According to our stratification, there were 6 whole liver lobar (average dose: 251 Gy) (0 with toxicities), 3 whole liver segmental (1 with toxicities), 20 single lobe lobar (average dose: 185 Gy) (7 with toxicities), and 34 single lobe segmental (9 with toxicities) patients. All 3 whole liver segmental patients had re-treated site volumes >15%, with an average dose of 315 Gy. For single lobe segmental patients, larger doses were administered to re-treated sites 15% (365 Gy) (p15% (56%) compared to Okuda II patients (28%) (p=0.046). Median survival was 660 and 424 days for Okuda I and II patients respectively.

HCC patients can tolerate lobar or segmental re-treatments once the entire liver has been radiated, and Okuda I patients can have larger segmental volumes irradiated compared to Okuda II patients. For sites less than 15% of total liver volume, high radiation doses can be administered without inducing more toxicities than lower doses to larger liver volumes.

Multiple radioembolization treatments may be performed in selected HCC patients.

Young, J, Atassi, B, Saleem, S, Lewandowski, R, Omary, R, Salem, R, Radiation Tolerance of Hepatic Parenchyma Following Multiple Treatments Using Yttrium-90 Radioembolization for Hepatocellular Carcinoma.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5009572.html