Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Int J Radiat Oncol Biol Phys. 2024 May 1;119(1):193-199. doi: 10.1016/j.ijrobp.2023.11.039. Epub 2023 Dec 8.
Radiation therapy (RT) is the standard treatment for solitary plasmacytoma (SP); however, the optimal management of RT-refractory SPs is unknown. We examined outcomes after early systemic therapy, surgical resection, or observation for patients with RT-refractory disease and assessed the potential impact of treatment selection on disease outcomes.
We retrospectively reviewed patients with SP treated with definitive radiation and evaluated at a single institution with persistent disease on imaging or biopsy. Descriptive statistics were used to characterize patient and disease characteristics and treatment outcomes.
Of 102 total SP patients, 17 (17%) were RT-refractory. The median RT dose was 45 Gy, and median follow-up was 71 months from end of RT. Fifteen patients had additional treatment for refractory disease at a median time of 9.5 months after RT, with the following subsequent interventions: surgical resection (n = 4), additional RT (n = 2), systemic therapy without evidence of multiple myeloma (MM; n = 4), systemic therapy for progression to MM (n = 5), and observation (n = 2). Of 4 patients treated with surgical resection, 3 progressed to MM 22 to 43 months after diagnosis. Of 2 patients treated with additional RT, neither responded, and both had pathologic confirmation of residual disease after the second course. Four patients treated with systemic therapy without MM all had complete responses on positron emission tomography and no subsequent MM progression. Eight patients were initially observed after RT for ≥12 months (n = 8) or ≥24 months (n = 6). Of the 2 patients in continued observation, both had stable/unchanged avidity after radiation treatment for 12 and 22 months and ultimately had a slow decrease of disease avidity over multiple years.
Patients with RT-refractory SPs can achieve good local control with alternative therapies, such as surgery or systemic therapy, if needed. Additional RT does not seem to be effective. Given the known high rates of progression from SP to MM, close observation of asymptomatic persistent disease until disease progression is likely sufficient in most cases.
放射治疗（RT）是孤立性浆细胞瘤（SP）的标准治疗方法；然而，RT 抵抗性 SP 的最佳治疗方法尚不清楚。我们研究了 RT 抵抗性疾病患者早期全身治疗、手术切除或观察的结果，并评估了治疗选择对疾病结局的潜在影响。
我们回顾性分析了在一家机构接受确定性 RT 治疗且影像学或活检显示持续性疾病的 SP 患者。使用描述性统计数据来描述患者和疾病特征以及治疗结果。
在 102 例 SP 患者中，有 17 例（17%）为 RT 抵抗性。RT 剂量中位数为 45 Gy，从 RT 结束到中位随访时间为 71 个月。15 例患者在 RT 后 9.5 个月的中位时间内接受了难治性疾病的额外治疗，随后进行了以下干预：手术切除（n=4）、额外 RT（n=2）、无多发性骨髓瘤（MM）证据的全身治疗（n=4）、进展为 MM 的全身治疗（n=5）和观察（n=2）。4 例接受手术切除的患者中，3 例在诊断后 22 至 43 个月进展为 MM。2 例接受额外 RT 治疗的患者均未缓解，且在第二疗程后均有残留疾病的病理证实。4 例无 MM 的全身治疗患者的正电子发射断层扫描均完全缓解，且无后续 MM 进展。8 例患者在 RT 后观察至少 12 个月（n=8）或至少 24 个月（n=6）。在持续观察的 2 例患者中，2 例在 RT 治疗后 12 个月和 22 个月时的疾病活性均稳定/无变化，最终在多年内疾病活性缓慢下降。
如果需要，RT 抵抗性 SP 患者可以通过替代治疗（如手术或全身治疗）获得良好的局部控制。额外的 RT 似乎没有效果。鉴于从 SP 到 MM 的进展率已知很高，在大多数情况下，直到疾病进展，对无症状持续性疾病进行密切观察可能就足够了。
