Recent Australian study: Lu-177 dose personalization

"In most radionuclide therapies, a fixed amount of radionuclide is administered, which does not take into account individual patient variability in tumor and normal tissue uptake, and hence absorbed dose. 'Dosimetry-led' administration, on the other hand, where administered activity is adjusted based upon predictable tumor and normal tissue absorbed doses, has the potential to greatly improve therapeutic outcomes."

Using dosimetry to check patients' treatment response calls for multiple SPECT/CT scans, and therefore has not been used outside of clinical trials, Violet and colleagues noted (of Peter MacCallum Cancer Center in Melbourne). To address this challenge, the group developed a dose-response estimation approach from a single post-treatment SPECT/CT scan to evaluate lutetium-177-labeled prostate-specific membrane antigen (PSMA)-617 therapy for metastatic prostate cancer (J Nucl Med, 1 July 2020, Volume 61:7, pp. 1030-1036).

In the study, 29 patients treated with lutetium-177-labeled PSMA-617 underwent SPECT/CT imaging at four, 24, and 96 hours to track the tracer's behavior in both tumors and normal tissue. The researchers used the data from these scans to create a PSMA radiotherapeutic agent clearance model for tumors and healthy organs. The researchers found that using the model for PSMA retention with data from the scan performed after 72 hours best allowed them to estimate a patient's radiation absorbed dose in a single image measurement.

Full text:

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[tango65]

Thanks for posting. I hope this technique leads to better control of the cancer.

[tennis4life]

Good stuff JF!