Rubio Pedro M, Galán Victor, Rodado Sonia, Plaza Diego, Martínez Leopoldo
Pediatric Hemato-Oncology Department, Hospital Universitario La Paz, Madrid, Spain.
Investigación Traslacional en Cáncer Infantil, Trasplante Hematopoyético y Terapia Celular, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid, Spain.
Front Med (Lausanne). 2020 May 28;7:173. doi: 10.3389/fmed.2020.00173. eCollection 2020.
Neuroblastoma causes 15% of cancer mortality in children. High risk neuroblastoma has poor prognosis, with high relapse rate and mortality despite multimodal treatment. 123-I-meta-iodo-benzyl-guanidine (mIBG) scintigraphy is one of the current standard diagnostic procedures in neuroblastoma. mIBG can also be used therapeutically, labeled with 131-I, as a radiopharmaceutical agent, delivering targeted radiotherapy to tumoral sites. But published data of this strategy show heterogeneous results. One concern is that in most reports the infused activity is only based in body-weight, which could lead to infra or over-treatment, depending on inter-patient variability in radiation absorption. Activity adjustment by whole-body dosimetry can be used to homogeneize the treatment. Also, mIBG avid tumors may lose avidness along the treatment. As mIBG is used both for treatment and response evaluation, this could result in undetected progressions in patients with apparent complete response. We present a retrospective single-center review of neuroblastoma patients who received therapeutic 131-I-mIBG, focusing on cases with dosimetry-adjusted activity. Dosimetry allowed for a more precise delivery of radiation, reducing 81.1% of deviation from absorption target of 4 Gray (Gy), from 23.4% (±0.936 Gy) to 4.4% (± 0.176 Gy). Patients who showed partial or complete response had better and longer survival. Relapse/progression in non-responders was an early event (within 3 months from treatment). We also present one case of progression with apparent complete response due to loss of mIBG avidness, detected in our series.
神经母细胞瘤导致15%的儿童癌症死亡。高危神经母细胞瘤预后较差，尽管采用了多模式治疗，但其复发率和死亡率仍很高。123I-间碘苄胍（mIBG）闪烁扫描是目前神经母细胞瘤的标准诊断程序之一。mIBG也可用于治疗，用131I标记，作为放射性药物，对肿瘤部位进行靶向放疗。但该策略的已发表数据显示结果参差不齐。一个问题是，在大多数报告中，注入的活度仅基于体重，这可能导致治疗不足或过度治疗，具体取决于患者间辐射吸收的差异。通过全身剂量测定进行活度调整可用于使治疗同质化。此外，mIBG摄取性肿瘤可能在治疗过程中失去摄取性。由于mIBG既用于治疗又用于疗效评估，这可能导致在表面上完全缓解的患者中未检测到病情进展。我们对接受治疗性131I-mIBG的神经母细胞瘤患者进行了一项回顾性单中心研究，重点关注剂量测定调整活度的病例。剂量测定使辐射传递更精确，将与4格雷（Gy）吸收目标的偏差从23.4%（±0.936 Gy）降低到4.4%（±0.176 Gy），降低了81.1%。显示部分或完全缓解的患者生存情况更好且更长。无反应者的复发/进展是一个早期事件（在治疗后3个月内）。我们还展示了我们系列中检测到的一例因mIBG摄取性丧失而表面完全缓解但病情进展的病例。
