Endocrine Abstracts

Introduction: Selective internal radiation therapy (SIRT) is a novel intervention used to treat both primary and metastatic malignant liver lesions. Adrenocortical carcinoma (ACC) is a rare cancer with limited treatment options; evidence for SIRT use in ACC liver metastases is limited to case reports only. In this case we report prolonged and successful disease control using recurrent SIRT in a gentleman with liver-limited ACC.

Case study: A 49-year-old gentleman, initially presenting with hypertension, underwent left-sided adrenalectomy for suspected phaeochromocytoma in August 2010. Histological examination of resected tissues was suggestive of ACC. As microscopic tumour cells were present at resection margins, adjuvant radiotherapy (45Gy to 25#) was given to the resection bed. Following re-presentation in January 2014 with liver-limited relapse, he underwent a left-sided hepatectomy. Two further hepatic lesions were subsequently identified on MRI in March 2015; radiofrequency ablation was used to achieve remission. Having reviewed the literature on mitotane toxicity, the patient declined its use in adjuvant and metastatic settings. In April 2018, follow-up imaging identified two further liver lesions too large for resection. Considering the non-surgical options available, SIRT was undertaken in July 2019, resulting in no toxicities and radiological response. This subsequently provided 18 months of progression-free survival with good quality of life. Following hepatic disease progression, repeat SIRT was performed in January 2021, inducing shrinkage of all new lesions without toxicity. Post-radiation fibrosis (described as ‘residual arterial enhancement’) at the site of recent SIRT was subsequently noted, managed with bland embolization in October 2021. In March 2022, a third round of SIRT was undertaken for hepatic relapse in previously untreated segments, alongside subsequent ablation of residual disease in May 2022. After presenting in July 2022 with spinal and base of skull metastases, the patient sadly passed away in September 2022.

Conclusion: Substantial unmet need exists for effective treatments in ACC, mindful that 75% patients present with incurable disease at diagnosis. Though ultimately developing widespread disease, SIRT offered 2 years of progression-free survival in our patient; the procedure was well tolerated on multiple occasions with minimal residual liver impairment. Its use in ACC liver-limited disease warrants further investigation.