d'Abadie P, Walrand S, Hesse M, Amini N, Lhommel R, Sawadogo K, Jamar F. Accurate non-tumoral 99mTc-MAA absorbed dose prediction to plan optimized activities in liver radioembolization using resin microspheres.
Phys Med 2021;
89:250-7. [PMID:
34438353 DOI:
10.1016/j.ejmp.2021.07.032]
[Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 07/23/2021] [Accepted: 07/28/2021] [Indexed: 12/19/2022] Open
Abstract
AIM
The manufacturers' recommended methods to calculate delivered activities in liver radioembolization are simplistic and only slightly personalized. Activity planning could also be based on a 99mTc-macroaggregated albumin SPECT/CT (MAA) using the partition model but its accuracy is controversial. This study evaluates the dose parameters in the normal liver and in the tumor compartments using MAA SPECT/CT (pre-therapeutic imaging) and 90Y TOF-PET/CT (post-therapy imaging). Finally, we propose a prescription of the activity as a function of the normal liver MAA distribution.
METHOD
66 procedures of RE (with resin microspheres) corresponding to 171 lesions were analyzed. Tumor to normal targeted liver uptake (T/NTL), tumor absorbed dose (TD) and whole normal liver absorbed (WNLD) were assessed with MAA and 90Y imaging. Secondly, activities were recalculated using the MAA distribution in the normal liver compartment to reach the maximal tolerable liver dose. These Activities were compared to activities defined with the BSA method.
RESULTS
Compared to 90Y imaging, our study demonstrated an accurate estimation of the WNLD using MAA imaging (Pearson's R = 0.97, p < 0.001). On the contrary, significant variations were found for TD (R = 0.65, p < 0.001). The MAA T/NTL ratio has a 85% positive predictive value in identifying patients who will get a 90Y T/NTL ratio above 1.5. Moreover, activities calculated using the MAA distribution in the normal liver compartment were significantly higher to activities defined with the BSA method.
CONCLUSION
Whole normal liver absorbed doses are accurately predicted with MAA imaging and could be used to optimize the activity planning.
Collapse