Eligibility for 177 Lu-PSMA Therapy Depends on the Choice of Companion Diagnostic Tracer: A Comparison of 68 Ga-PSMA-11 and 99m Tc-MIP-1404 in Metastatic Castration-Resistant Prostate Cancer

The Journal of Nuclear Medicine

article

Gary J.R. Cook¹  Wai-Lup Wong²  Bal Sanghera²  Stephen Mangar³  Amarnath Challapalli⁴  Amit Bahl⁴  Paul Bassett⁵  Darren Leaning⁶  Christian Schmidkonz⁷ 

[1]Cancer Imaging Department, School of Biomedical Engineering and Imaging Sciences, King’s College London

[2]Paul Strickland Scanner Centre, Mount Vernon Hospital

[3]Department of Oncology, Charing Cross Hospital, Imperial College Healthcare NHS Trust

[4]Department of Clinical Oncology, Bristol Cancer Institute

[5]Statsconsultancy Ltd

[6]Department of Clinical Oncology, James Cook University Hospital

[7]Department of Nuclear Medicine, University Hospital Erlangen

[8]Department of Industrial Engineering and Health, Technical University of Applied Sciences Amberg-Weiden

关键词: 177Lu-PSMA-617;    68Ga-PSMA-11;    99mTc-MIP-1404;   

DOI  :  10.2967/jnumed.122.264296

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

177Lu-prostate-specific membrane antigen-617 (177Lu-PSMA-617) is an effective therapy for metastatic castration-resistant prostate cancer (mCRPC), with evidence of improved survival over standard care. The VISION trial inclusion criteria required a metastatic lesion-to-liver ratio of greater than 1 on 68Ga-PSMA-11 PET scans. We aimed to determine whether an equivalent ratio is suitable for a SPECT tracer, 99mTc-MIP-1404, and to compare lesion and lesion–to–normal-organ ratios between the 2 radiotracers. Methods: Two cohorts of patients with mCRPC matched for age, prostate-specific antigen level, and total Gleason score, with either 99mTc-MIP-1404 SPECT/CT (n = 25) or 68Ga-PSMA-11 PET/CT (n = 25) scans, were included for analysis. Up to 3 lesions in each site (prostate/prostate bed, lymph nodes, bone and soft-tissue metastases) as well as normal liver, parotid gland, spleen, and mediastinal blood-pool SUVmax were measured. Results: 99mTc-MIP-1404 SPECT lesion SUVmax was not significantly different from 68Ga-PSMA-11 PET (median, 18.2 vs. 17.3; P = 0.93). However, 99mTc-MIP-1404 liver SUVmax was higher (median, 8.5 vs. 5.8; P = 0.002) and lesion-to-liver ratios were lower (median, 2.7 vs. 3.5; P = 0.009). There was no significant difference in parotid gland or splenic SUVmax or lesion–to–parotid gland ratios between the 2 tracers although there was a small difference in lesion-to-spleen ratios (P = 0.034). Conclusion: There are differences in biodistribution and, in particular, liver activity, between 68Ga-PSMA-11 and 99mTc-MIP-1404. Therefore, if 99mTc-MIP-1404 is used to assess eligibility for 177Lu-PSMA-617 therapy, a lower adjusted lesion-to-liver ratio should be used.

【 授权许可】

CC BY