Abstract | INTRODUCTION: METHODS: On the basis of PSMA-targeted 68Ga-PSMA-11 PET/CT, 32 consecutive mCRPC patients were selected for 177Lu-PSMA-617 therapy (6 GBq/cycle, 2 to 6 cycles, 6-10 weeks apart) and followed until death. Post- therapy whole-body (WB) dosimetry and 68Ga-PSMA-11 PET/CT data were compared and related to progression free and overall survival. RESULTS:
177Lu-PSMA-617 dosimetry after the first cycle indicated high tumor doses for skeletal (4.01 ± 2.64; range 1.10-13.00 Gy/GBq), lymph node (3.12 ± 2.07; range 0.70-8.70 Gy/GBq), and liver (2.97 ± 1.38; range 0.76-5.00 Gy/GBq) metastases whereas the dose for tissues/organs was acceptable in all patients for an intention-to-treat activity of 24 GBq. Any PSA decrease after the first cycle was found in 23/32 (72%), after the second cycle in 22/32 (69%), after the third cycle in 16/28 (57%), and after the fourth cycle in 8/18 (44%) patients. Post- therapy 24 h WB scintigraphy showed decreased tumor-to-background ratios in 24/32 (75%) after the first therapy cycle, after the second cycle in 17/29 (59%), and after the third cycle in 13/21 (62%) patients. The median PFS was 7 months and the median OS 12 months. In the group of PSA responders (n = 22) the median OS was 17 months versus 11 months in the group of non-responders (n = 10), p < 0.05. Decreasing SUVmax values were found for parotid (15.93 ± 6.23 versus 12.33 ± 4.07) and submandibular glands (17.65 ± 7.34 versus 13.12 ± 4.62) following treatment, along with transient (n = 6) or permanent (n = 2) xerostomia in 8/32 (25%) patients. In 3/32 patients, nephrotoxicity changed from Grade 2 to 3, whereas neither Grade 4 nephrotoxicity nor hematotoxicity was found. In most patients a good agreement was observed for the visual interpretation of the tracer accumulation between 24 h WB and PET/CT scans. However, no significance could be calculated for baseline-absorbed tumor doses and SUVmax values of tumor lesions. 5/32 (16%) patients showed a mixed response pattern, which resulted in disease progression over time. CONCLUSION: Serial PSA measurements and post- therapy 24 h WB scintigraphy seems to allow a sufficiently accurate follow-up of 177Lu-PSMA-617-treated mCRPC patients whereas 68Ga-PSMA-11 PET/CT should be performed for patient selection and final response assessment.
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Authors | Johanna Maffey-Steffan, Lorenza Scarpa, Anna Svirydenka, Bernhard Nilica, Christian Mair, Sabine Buxbaum, Jasmin Bektic, Elisabeth von Guggenberg, Christian Uprimny, Wolfgang Horninger, Irene Virgolini |
Journal | European journal of nuclear medicine and molecular imaging
(Eur J Nucl Med Mol Imaging)
Vol. 47
Issue 3
Pg. 695-712
(03 2020)
ISSN: 1619-7089 [Electronic] Germany |
PMID | 31776632
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Dipeptides
- Gallium Radioisotopes
- Heterocyclic Compounds, 1-Ring
- Radiopharmaceuticals
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Topics |
- Dipeptides
(therapeutic use)
- Follow-Up Studies
- Gallium Radioisotopes
- Heterocyclic Compounds, 1-Ring
(therapeutic use)
- Humans
- Male
- Neoplasm Metastasis
- Positron Emission Tomography Computed Tomography
- Prostatic Neoplasms, Castration-Resistant
(diagnostic imaging, radiotherapy)
- Radiopharmaceuticals
- Tomography, X-Ray Computed
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