Ortner, GernotGernotOrtnerHoderlein, XeniaXeniaHoderleinBarbato, FrancescoFrancescoBarbatoBeyersdorff, DirkDirkBeyersdorffBudäus, LarsLarsBudäusBurger, Irene A.Irene A.BurgerEiber, MatthiasMatthiasEiberGraefen, MarkusMarkusGraefenHadaschik, BorisBorisHadaschikHaese, AlexanderAlexanderHaeseHerrmann, KenKenHerrmannMaack, LennartLennartMaackMaric, InesInesMaricMattei, AgostinoAgostinoMatteiRauscher, IsabelIsabelRauscherSalomon, GeorgGeorgSalomonSauer, MarkusMarkusSauerSchimmöller, LarsLarsSchimmöllerSchlaefer, AlexanderAlexanderSchlaeferSchlemmer, Heinz-PeterHeinz-PeterSchlemmerSpohn, Simon K.B.Simon K.B.SpohnUmutlu, LaleLaleUmutluWalz, Jochen ChristophJochen ChristophWalzWürnschimmel, ChristophChristophWürnschimmelKoehler, DanielDanielKoehlerMaurer, TobiasTobiasMaurer2025-12-032025-12-032025-11-06Journal of Nuclear Medicine 66 (11): (2025)https://hdl.handle.net/11420/59327The Pelvic Rosetta Classification (PRC) project aimed to develop an interdisciplinary, landmark-based pelvic lymph node map for patients with prostate cancer to improve communication between imaging specialists and urologists. Methods: After an intense development phase, we conducted 3 evaluation rounds including 19 clinical experts having consensus meetings after each evaluation round. Experts contoured lymph node areas (LNA) for 2 patients with prostate cancer. Contours were assessed qualitatively and quantitatively. The PRC was further validated by assignment of 30 prostate-specific membrane antigen PET/CT–positive lesions to LNAs. The interrater reliability was calculated using Fleiss κ. Based on the final PRC, a complete contour and a 3-dimensional model were created. Results: Eight pelvic (external iliac, cranial/caudal obturator fossa, dorsal internal iliac, vesico-prostatic pedicle, mesorectal/perirectal, presacral, preprostatic/retropubic) and 4 extrapelvic (common iliac, intercommon, sigmoid, inguinal) LNAs were defined using anatomic landmarks which are consistently recognizable on imaging and intraoperatively. Strong consensus between experts existed for smaller, well-defined LNAs (e.g., preprostatic/retropubic, mesorectal/perirectal LNAs) compared with regions with proportionally large borders (e.g., obturator fossa, vesico-prostatic pedicle LNAs). Overall, moderate agreement (κ = 0.53) was observed during validation. Discrepancies were mostly encountered for lesions adjacent to borders between LNAs. The final contour and 3-dimensional model were approved by all experts. Conclusion: The PRC project showed fair reproducibility and validity. Further external validation is needed to assess its influence on interdisciplinary communication and treatment outcomes.en2159-662X202511Soc.PSAmetastaseslymph node drainagesentinelstandardizationTechnology::610: Medicine, HealthJournal Article10.2967/jnumed.125.270667Journal Article