Comprehensive treatment for intracranial invasive sinonasal intestinal-type adenocarcinoma with a focus on radiotherapy dosage and immunological combination therapy: A case report.

For sinonasal intestinal-type adenocarcinoma (ITAC), no standardized treatment exists, particularly for cases with advanced-stage disease with intracranial invasion or recurrence. The present study describes the case of a 60-year-old male patient with ITAC and intracranial invasion who underwent surgery followed by radiotherapy; however, this was terminated early after 25 of 30 sessions [equivalent dose in 2-Gy fractions (EQD2), 54.72 Gy] due to the risk of damaging the optic nerve. The tumor recurred in the same place 12 months after the surgery. A biopsy revealed a combined positive score (CPS) of 5, indicating that the tumor was programmed death-ligand 1-positive (PD-L1-positive), leading to treatment with albumin-bound paclitaxel, cisplatin and camrelizumab for 4 cycles, followed by 12 cycles of maintenance therapy with camrelizumab. The patient maintained progression-free survival for 11 months. On the whole, the present case report highlights the need for sufficient radiotherapy (≥66 Gy EQD2) for ITAC in complex anatomical areas, highlighting the role of advanced techniques to overcome dose limitations. Moreover, the 'chemo-immuno induction plus immuno-maintenance' approach in PD-L1-positive patients exhibits potential for long-term disease control, providing a novel treatment model for advanced-stage ITAC.