SPECT/CT imaging can assist handle sufferers present process radiopharmaceutical remedy (RPT) with Pluvicto for superior prostate most cancers, in keeping with a examine revealed August 8 within the Journal of Nuclear Drugs.
In a retrospective evaluation, a gaggle at College of California San Francisco (UCSF) discovered that qualitative post-treatment SPECT/CT triggered a change in administration in 49% of sufferers, with adjustments based mostly on development occurring principally after two and 4 cycles of the drug and adjustments based mostly on response occurring principally after three and 4 cycles.
“One of many struggles with [prostate-specific membrane antigen] RPT is the right way to determine when to cease remedy,” famous lead creator Surekha Yadav, MD, and colleagues.
Lutetium-177 (Lu-177) prostate-specific membrane antigen 617 (PSMA-617) RPT (Pluvicto) was authorised for grownup sufferers with PSMA-positive metastatic castration-resistant prostate most cancers in March 2022.
At UCSF, clinicians carry out post-treatment SPECT/CT on all sufferers present process Pluvicto RPT to visualise the distribution of the remedy and to carry out quantitative dosimetry, the authors defined. But whether or not SPECT/CT can be utilized to find out illness development or response has but to be delineated, they famous.
To that finish, the group assessed the affect of SPECT/CT imaging on 122 sufferers who had acquired a minimal of two cycles of Pluvicto and had post-treatment scans after every cycle.
A graphical summary of the examine.Picture courtesy of the Journal of Nuclear Drugs
In keeping with the findings, post-treatment SPECT/CT prompted a change in administration in 49% (60/122) of sufferers. Of those, Pluvicto was stopped early based mostly on post-treatment imaging in 58 (97%): 34 sufferers had a change based mostly on illness development and 24 sufferers had a change based mostly on response, the researchers reported. In two sufferers (3%), post-treatment imaging led to miscellaneous adjustments, they added.
Of the 34 sufferers with adjustments because of illness development, most adjustments occurred after cycle two (47%; 16/34) and cycle 4 (26%; 9/34). Of the 24 sufferers with administration adjustments made because of response, most adjustments occurred after cycle three (38%; 9/24) and cycle 4 (29%; 7/24), the group famous.
Additionally, sufferers who stopped remedy due to response demonstrated improved survival outcomes in contrast with those that stopped due to development, the researchers discovered.
“Integrating posttreatment SPECT/CT into the routine PSMA RPT workflow can streamline personalised affected person administration by serving as a response marker to RPT,” the group wrote.
Finally, imaging tumor response in Pluvicto sufferers is a very troublesome difficulty, with the very best strategy but to be decided, the group wrote. CT could be helpful to measure morphologic adjustments, however most sufferers have bone illness, which isn’t effectively evaluated utilizing CT or bone scans, they wrote. Interim PSMA-PET has been proposed, however PET isn’t as broadly accessible as SPECT and is dearer, they added.
“Additional work aiming at standardization of posttreatment imaging is warranted,” the group concluded.
The complete examine is on the market right here.
