In multiple myeloma (MM), a high number of focal lesions (FL) detected using positron emission tomography/computed tomography (PET/CT) was found to be associated with adverse prognosis. To design a new risk stratification system that combines the Revised International Staging System (R-ISS) with FL, we analyzed the data of 380 patients with newly diagnosed MM (NDMM) who underwent ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT upon diagnosis. The K-adaptive partitioning algorithm was adopted to define subgroups with homogeneous survival. The combined R-ISS with PET/CT classified NDMM patients into four groups: R-ISS/PET stage I (n = 31; R-ISS I with FL ≤ 3), stage II (n = 156; R-ISS I with FL > 3 and R-ISS II with FL ≤ 3), stage III (n = 162; R-ISS II with FL > 3 and R-ISS III with FL ≤ 3), and stage IV (n = 31; R-ISS III with FL > 3). The 2-year overall survival rates for stages I, II, III, and IV were 96.7%, 89.8%, 74.7%, and 50.3%. The 2-year progression-free survival rates were 84.1%, 64.7%, 40.8%, and 17.1%, respectively. The new R-ISS/PET was successfully validated in an external cohort. This new system had a remarkable prognostic power for estimating the survival outcomes of patients with NDMM. This system helps discriminate patients with a good prognosis from those with a poor prognosis more precisely.

在多发性骨髓瘤 (MM) 中，发现使用正电子发射断层扫描/计算机断层扫描 (PET/CT) 检测到的大量局灶性病变 (FL) 与不良预后相关。为了设计一个将修订的国际分期系统 (R-ISS) 与 FL 相结合的新风险分层系统，我们分析了 380 例接受¹⁸ F-氟脱氧葡萄糖 ( ¹⁸ F-FDG) PET/ CT 确诊。采用 K 自适应分区算法来定义具有同质生存的亚组。结合 R-ISS 与 PET/CT 将 NDMM 患者分为四组：R-ISS/PET I 期（n  = 31；R-ISS I FL ≤ 3），II 期（n  = 156；R-ISS I 与FL > 3 和 FL ≤ 3 的 R-ISS II)，III 期 (n  = 162; FL > 3 的 R-ISS II 和 FL ≤ 3 的 R-ISS III）和 IV 期（n  = 31；R-ISS III FL > 3）。I、II、III、IV期的2年总生存率分别为96.7%、89.8%、74.7%和50.3%。2年无进展生存率分别为84.1%、64.7%、40.8%和17.1%。新的 R-ISS/PET 在外部队列中成功验证。这个新系统在估计 NDMM 患者的生存结果方面具有显着的预后能力。该系统有助于更准确地区分预后良好的患者和预后不良的患者。