PSMA ligand PET/MRI for primary prostate cancer : Staging performance and clinical impact
Menée auprès de 122 patients atteints d'un cancer de la prostate, cette étude évalue, par rapport aux analyses histologiques, la précision d'une méthode utilisant simultanément une IRM et une tomographie numérique par émission de positrons à base du radioconjugué [68Ga]Ga-PSMA-11 (gallium 68 combiné à un ligand ciblant l'antigène membranaire spécifique de la prostate) pour stadifier la maladie, puis évalue l'impact de cette méthode sur les décisions thérapeutiques
Purpose : Primary staging of prostate cancer (PC) relies on modalities, which are limited. We evaluate simultaneous [68Ga]Ga-PSMA-11positron emission tomography (PSMA-PET)/magnetic resonance imaging (MRI) as a new diagnostic method for primary TNM-staging compared to histology and its impact on therapeutic decisions.
Patients and Methods : We investigated 122 patients with PSMA-PET/MRI prior to planned radical prostatectomy (RP). Primary endpoint was the accuracy of PSMA-PET/MRI in tumor staging as compared to staging-relevant histology. Additionally, a multidisciplinary team reassessed the initial therapeutic approach to evaluate its impact on the therapeutic management.
Results : PSMA-PET/MRI correctly identified PC in 119 of 122 patients (97.5%). 81 patients were treated with RP and pelvic lymphadenectomy. The accuracy for T-staging was 82.5% (95%CI 73-90; P<0.001), for T2-stage: 85% (95%CI 71-94; P<0.001), T3a-stage: 79% (95%CI 43-85; P<0.001), T3b-stage: 94% (95%CI 73-100; P<0.001) and 93% (95%CI 84-98) for N1-stage (P<0.001). PSMA-PET/MRI changed the therapeutic strategy in 28.7% of the patients with either the onset of systemic therapy/radiotherapy (n=16) or active surveillance (n=19).
Conclusion : PSMA-PET/MRI can provide an accurate staging of newly diagnosed PC. Additionally, treatment strategies were changed in almost a third of the patients due to the information of this hybrid imaging technique.
Clinical Cancer Research , résumé, 2017