Rittberg Rebekah, Chan Elisa, Yip Stephen, Alex Deepu, Ho Cheryl
Medicine, University of British Columbia, Vancouver, CAN.
Medical Oncology, BC Cancer, Vancouver, CAN.
Cureus. 2022 Feb 12;14(2):e22159. doi: 10.7759/cureus.22159. eCollection 2022 Feb.
Abscopal effect is a rare phenomenon in which treatment benefit from radiotherapy (RT) is seen outside the target field due to activation of the immune system inducing an anti-tumor effect. This phenomenon has been reported in cancer patients receiving immune checkpoint inhibitors (ICI). Here we report a case of presumed abscopal effect in malignant mesothelioma. The patient received second-line single-agent pembrolizumab however had disease progression after four cycles leading to palliative RT (20 Gray) to the right mainstem bronchus. Follow-up radiographic imaging confirmed benefit and pembrolizumab was continued. Follow-up computed tomography (CT) five months after RT, showed marked radiographic improvement of all measurable diseases with improvement in right-sided aerated lung volume. Because of the original disease progression on pembrolizumab, with marked improvements within and outside the RT field after RT, treatment response was presumed due to the abscopal effect.
远隔效应是一种罕见现象，即由于免疫系统激活诱导抗肿瘤效应，在放疗（RT）靶区外可见放疗带来的治疗益处。这种现象已在接受免疫检查点抑制剂（ICI）的癌症患者中报道过。在此，我们报告一例恶性间皮瘤疑似远隔效应的病例。该患者接受二线单药帕博利珠单抗治疗，但四个周期后疾病进展，遂对右主支气管进行姑息性放疗（20格雷）。随访影像学检查证实有获益，于是继续使用帕博利珠单抗。放疗五个月后的随访计算机断层扫描（CT）显示，所有可测量病灶在影像学上均有显著改善，右侧肺通气量增加。由于最初使用帕博利珠单抗时疾病进展，而放疗后放疗野内外均有显著改善，因此推测治疗反应归因于远隔效应。
