Treating leptomeningeal metastases from primary hepatic neuroendocrine carcinoma with combined radiotherapy and immunotherapy: A case report

Radiotherapy has been applied for decades as a treatment modality in the management of various type of cancer, either in curative or palliative intent. Recently, evidence accumulated that immune checkpoint inhibitors may have noninferior treatment effects when compared with conventional systemic therapy. Because ionizing radiation induces local inflammatory effects, it is postulated that the response to checkpoint blockade immunotherapy may be improved if it is administered in conjunction with radiotherapy in treating malignancy. This interesting phenomenon has been observed in many types of cancers. Here we reported a 62-year-old woman who was diagnosed as having primary hepatic neuroendocrine carcinoma (NEC) with diffuse metastases including leptomeningeal metastases (LM) accompanied with deteriorated conditions. She underwent whole-brain radiotherapy followed by immunotherapy. She adequately tolerated the treatment, and her symptoms were alleviated rapidly with improved consciousness. Magnetic resonance imaging (MRI) conducted 1 month after the treatment revealed significant disappearance of the LM, but tumors elsewhere progressed. The patient's overall survival time was 27 months, and she had survived for 3 months from the time of diagnosis of LM. Reported clinical trials and retrospective studies combining immunotherapy and radiotherapy demonstrated a therapeutic potency due to the augmentation of the immune-mediated responses, and more studies are still on going. Treating LM with radiation-assisted immunotherapy is a feasible treatment option with potential clinical benefit, and further study of its utilities and risks is warranted.