Table 1 Recommendations for diagnostic reporting of post-radioembolization ⁹⁰ Y PET/CT

Continuity of care

Post-radioembolization ⁹⁰Y PET/CT is best reported by the same attending nuclear medicine physician who has followed through the entire planning-therapy continuum from exploratory angiography, predictive dosimetry, to ⁹⁰Y radioembolization.

PET display threshold setting for non-target ⁹⁰Y activity detection

For detection of non-target ⁹⁰Y activity, the operator should actively adjust the upper PET visual display threshold setting to deliberately increase the background noise to moderate levels.

Criteria for technical success

1. ⁹⁰Y activity present in the majority of targeted tumors, or good overall activity coverage of large targeted tumors; and

2. The absence of clinically significant non-target ⁹⁰Y activity; and

3. All findings are in keeping with pre-therapy radiation planning expectations.

Criteria for a technically unsuccessful ⁹⁰Y radioembolization

1. The complete, or near-complete absence of ⁹⁰Y activity in the majority of targeted tumors, or poor overall activity coverage of large targeted tumors; or

2. The presence of any non-target ⁹⁰Y activity where ⁹⁰Y PET dose quantification predicts a high likelihood of clinically significant radiation toxicity; or

3. Any other situation where the ⁹⁰Y activity biodistribution is adversely inconsistent with pre-therapy radiation planning expectations.

Criteria for non-target ⁹⁰Y activity

1. Non-random pattern of activity distribution; and

2. Conforms morphologically to an untargeted anatomical structure on CT; with or without

3. A plausible vascular etiology to account for its presence.

Criteria for noise spikes

1. Small, discrete, ovoid activity foci; and

2. Random pattern of distribution which do not conform to underlying anatomy on CT; and

3. No plausible vascular etiology to account for its presence.