30-Second Takeaway
- Two-week FDG-PET in de novo metastatic breast cancer strongly predicts later CT response and survival.
- Guidelines now largely align on 177Lu-PSMA-617 for PSMA-positive mCRPC after ARPI and taxane, with cautious earlier use.
- Early PSMA SUV changes and baseline inflammatory markers refine prognosis and selection for PSMA radioligand therapy.
Week ending April 18, 2026
PET-guided tailoring of systemic therapy and emerging standards in PSMA theranostics
Two-week FDG-PET predicts CT response and survival in de novo metastatic breast cancer
This multicenter cohort enrolled 200 patients with newly diagnosed, nonrapidly progressive metastatic breast cancer starting first-line systemic therapy. FDG-PET was repeated at 2 weeks, and early non-progressive disease had a 94.7% negative predictive value for non-progression on 8-week CT. Patients with standard-of-care therapy and non-progression on early FDG-PET had substantially longer progression-free and overall survival than those with early metabolic progression. Patients with progression on early PET but non-progression on 8-week CT still had clearly worse outcomes than fully non-progressive cases.
Guidelines converge on indications and dosing for 177Lu-PSMA-617 in advanced prostate cancer
This review synthesizes recommendations from six major society guidelines plus EANM/SNMMI procedural guidance on 177Lu-PSMA radioligand therapy. Most current guidelines endorse 177Lu-PSMA-617 for PSMA-positive metastatic castration-resistant prostate cancer after prior androgen receptor pathway inhibitor and taxane chemotherapy. Following PSMAfore, NCCN 2025 and EAU 2025 cautiously extend use to selected taxane‑naïve patients progressing after androgen receptor pathway inhibition. A commonly recommended regimen is 7.4 GBq every 6 weeks for up to six cycles with ongoing androgen deprivation and multidisciplinary oversight.
Day-15 PSMA SUVmean increase predicts poor enzalutamide outcomes but benefits from added 177Lu-PSMA-617
This ENZA-p substudy assessed 68Ga-PSMA PET SUVmean at baseline and day 15 in metastatic castration-resistant prostate cancer treated with enzalutamide ± 177Lu-PSMA-617. Among 154 evaluable patients, SUVmean increased in 68%, indicating frequent early PSMA upregulation under androgen receptor blockade. With increasing SUVmean, median PSA progression-free survival was markedly shorter on enzalutamide alone than on combination therapy, with a hazard ratio of 0.38. When SUVmean decreased, adding 177Lu-PSMA-617 did not significantly improve PSA progression-free survival compared with enzalutamide alone.
References
Numbered in order of appearance. Click any reference to view details.
Additional Reads
Optional additional studies from this edition.