Correlation of an Index-Lesion-Based SPECT Dosimetry Method with Mean Tumor Dose and Clinical Outcome after Lu-177-PSMA-617 Radioligand Therapy

Völter, Friederike; Mittlmeier, Lena; Gosewisch, Astrid; Brosch-Lenz, Julia; Gildehaus, Franz Josef; Zacherl, Mathias Johannes; Beyer, Leonie; Stief, Christian G.; Holzgreve, Adrien; Rübenthaler, Johannes; Cyran, Clemens C.; Boning, Guido; Bartenstein, Peter; Todica, Andrei und Ilhan, Harun (2021): Correlation of an Index-Lesion-Based SPECT Dosimetry Method with Mean Tumor Dose and Clinical Outcome after Lu-177-PSMA-617 Radioligand Therapy. In: Diagnostics, Bd. 11, Nr. 3, 428

Abstract

Background: Dosimetry can tailor prostate-specific membrane-antigen-targeted radioligand therapy (PSMA-RLT) for metastatic castration-resistant prostate cancer (mCRPC). However, whole-body tumor dosimetry is challenging in patients with a high tumor burden. We evaluate a simplified index-lesion-based single-photon emission computed tomography (SPECT) dosimetry method in correlation with clinical outcome. Methods: 30 mCRPC patients were included (median 71 years). The dosimetry was performed for the first cycle using quantitative Lu-177-SPECT. The response was evaluated using RECIST 1.1 and PERCIST criteria, as well as changes in PSMA-positive tumor volume (PSMA-TV) in post-therapy PSMA-PET and biochemical response according to PSA changes after two RLT cycles. Results: Mean tumor doses as well as index-lesion doses were significantly higher in PERCIST responders compared to non-responders (10.2 +/- 12.0 Gy/GBq vs. 4.0 +/- 2.9 Gy/GBq, p = 0.03 and 13.7 +/- 14.2 Gy/GBq vs. 5.9 +/- 4.4 Gy/GBq, p = 0.04, respectively). No significant differences in mean tumor and index lesion doses were observed between responders and non-responders according to RECIST 1.1, PSMA-TV, and biochemical response criteria. Conclusion: Compared to mean tumor doses on a patient level, single index-lesion-based SPECT dosimetry correlates equally well with the response to PSMA-RLT according to PERCIST criteria and may represent a fast and feasible dosimetry approach for clinical routine.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• Sprache: Englisch