RESUMEN
BACKGROUND: Carbon-ion radiotherapy(CIRT)has an advantage over conventional radiotherapy by its dose distribution and biological effect for locally advanced unresectable pancreatic cancer(UR-PC). Conversion surgery(CS)might be attempted for UR-PC with favorable response by chemotherapy and radiotherapy. CASE PRESENTATION: A 67-year-old female who have a history of distal gastrectomy. CT scan revealed locally advanced UR-PC with invasion to celiac artery, 60 mm in size. Systemic chemotherapy with gemcitabine and nab-paclitaxel was continued for 15 months, showing decrease of tumor markers and radiological shrinkage of the tumor. The patient was referred to our hospital for surgical consultation. Since there was no metastasis in staging laparoscopy, CIRT with gemcitabine was administered for 3 weeks. After completion of CIRT, distal pancreatectomy with celiac axis resection and total remnant gastrectomy for direct invasion of the tumor was performed as CS, resulting R0 resection. Her postoperative course was uneventful with 17 days of hospital stay. DISCUSSION: CS after CIRT was safely performed. Clinical trial of total neoadjuvant therapy with systemic chemotherapy, CIRT, followed by CS for locally advanced CIRT is ongoing in our hospital. CIRT could be an effective treatment in locally advanced UR-PC in the context of multi-modal treatment including CS.