Reduced splenic uptake of [Ga]Ga-Pentixafor following first-line chemotherapy is associated with poor prognosis in patients with newly diagnosed multiple myeloma.

BACKGROUND

We aim to investigate the prognostic value of [Ga]Ga-Pentixafor PET/CT in multiple myeloma (MM) patients.

RESULTS

This is a retrospective analysis of a prospective cohort study. Twenty-five patients with treatment-naïve, newly diagnosed MM were included. All participants underwent [Ga]Ga-Pentixafor PET/CT scans at baseline and after first-line chemotherapy. The endpoints included the time to progression (TTP) and the time to next treatment (TTNT). The correlation between PET/CT characteristics and survival was then analyzed. Patients with a decline in SUVmax of bone marrow of less than 40% from baseline demonstrated significantly shorter TTP and TTNT (estimated median TTP, 27.5 months [95% CI, 16.7-38.2] vs. not reached, P = 0.047; estimated median TTNT, 31.8 months [95% CI, 20.8-42.8] vs. not reached, P = 0.012). Patients with visually reduced splenic uptake in the follow-up [Ga]Ga-Pentixafor PET/CT from baseline exhibited significantly shorter TTP and TTNT (estimated median TTP, 24.4 months [95% CI, 7.9-24.4] vs. not reached, P = 0.018; estimated median TTNT, 31.9 months [95% CI, 18.5-31.9] vs. not reached, P = 0.043). A 20% reduction in splenic SUVmax was identified as a predictive indicator for shorter TTP and TTNT (estimated median TTP, 24.4 months [95% CI, 14.5-24.4] vs. not reached, P = 0.025; estimated mean TTNT, 31.9 months [95% CI, 18.5-31.9] vs. not reached, P = 0.048). Patients with splenic SUVmax < 5.0 at follow-up also exhibited significantly shorter TTP and TTNT. However, the splenic SUVmax at baseline PET/CT was not predictive of TTP or TTNT (P > 0.05).

CONCLUSION

Reduced splenic uptake of [Ga]Ga-Pentixafor following first-line chemotherapy was predictive for poor prognosis in patients with newly diagnosed MM, while baseline splenic uptake is not associated with prognosis.

TRIAL REGISTRATION

ClinicalTrials. NCT03436342 Registered 25 October 2017, https://register.

CLINICALTRIALS

gov/prs/app/action/SelectProtocol?sid=S0007IL2&selectaction=Edit&uid=U0001JRW&ts=6&cx=-3sdpwu .

CLINICALTRIALS

NCT04504526 Registered 6 August 2020, https://clinicaltrials.gov/study/NCT04504526?cond=NCT04504526&rank=1 .