1. Selective Internal Radiation Therapy (Clinical Case example using Therasphere™)
Dr Richard J Owen – Interventional Radiology
Associate Professor University of Alberta
Canada

2. Right lobe tumor, Hepatitis B patient presenting with a mass on ultrasound
Confirmed at biopsy to be hepatocellular carcinoma, unusually high activity on PET Ct Prior to the treatment. (only about 15% of HCC’s are PET avid).

3. Pre procedure angiography
Catheter angiography, tip proximal to
GDA demonstrating anatomy. Catheter
advanced distally in next image. Prior left lobe resection for HCC.

4. Pre procedure angiography
Highly vascularized right lobe tumor is
seen. No abnormal vessels supplying
outside the liver are seen, Catheter tip is
distal to left hepatic and Gastroduodenal.
No embolization to redirect flow necessary

5. CTA with catheter in right hepatic artery
Intense tumor blush on the delayed (20 seconds post intra arterial injection) in right posterior lobe (Segment 7)

6. Nuclear Medicine Shunt study with SPECT CT
Demonstrates significant (15%) lung shunt, this will require careful calculation to ensure lung dose does not exceed 30 Gray for a single treatment or 50 Gray for cumulative lung dose

7. Calculation of Dose
The liver volume and corresponding mass determined using CT, either a direct CTA with catheter in situ or good dual phase liver mass CT.
Radioactivity required: GBq (1 x 109 decays/sec)
[Desired Dose (Gy)][Treatment Vol (L][1.03]
Dose to lung (Gy) = [treatment dose GBq][lung shunt %][50] 1
<50 Gy total <30 per rx
Delivery of the desired activity is accomplished by using the Yttrium-90 Physical Decay Table to determine the appropriate time of injection.

8. Decay Chart, activities relate to 10am Standard time

9. TheraSphere System Ready for Assembly
Administration (single use) tubing set located in blister pack
acrylic shield to house the dose, tubing and waste
various consumables – supplied by hospital
radiation meter – supplied by hospital

10. Post Y90 low dose PET (treatment day)
Activity concentrated in the region of the right libe tumor confirming a correct dose delivery, this is carried out after the treatment and takes advantage of the tiny proportion of Y90 decays that result in positron emission.

11. Follow up CT 2 months after treatment
Arterial and venous phase imaging demonstrates complete tumor necrosis, rim enhancement on the arterial phase is likely radiation induced injury to adjacent liver parenchyma

12. Follow up Ct at 7 months
Shrinkage and confirmed necrosis of right lobe tumor. Unfortunately there is tumor recurrence adjacent to the liver resection margin anteriorly. This could not be treated.