Résumé
Background and purpose: MRI-Linac-guided adap1ve stereotac1c radiotherapy (SMART) represents an innovative therapy in the induction treatment of borderline (BR) or locally advanced unresectable (LANR) pancreatic adenocarcinoma (PA). This study evaluates the feasibility and safety of pancreatic surgery ader induction treatment with chemotherapy followed by SMART, compared with chemotherapy followed by standard radio-chemotherapy in patients with BR or LANR PA. We also assess its impact on histological response and distant oncological parameters.Material and methods: this bicentric retrospective study included all patients with BR ou LANR PA who underwent resection surgery ader induction treatment with CT followed by RCTC or SMART between January 2010 and December 2023. The primary endpoint was postopera1ve morbidity at 90 days based on the Clavien-Dindo score. Secondary endpoints were acute tolerance and response to induction therapy, postoperative complications, histological parameters and oncological outcomes. Prognostic factors of overall survival and progression free survival were also inves1gated.Results: 95 patients with AP BR or LANR underwent resection surgery ader induc1on treatment with CT followed by RCTC (n=67) or SMART (n=38). The initial characteristics of the two groups were similar. Our study found no significant difference in postoperative toxicity between the two groups (p=0.653). SMART showed beHer acute tolerance than RCTC (p=0.037). The histological response rate was significantly higher in the SMART group than in the RCTC group (p=0.001), par1cularly for major histological response greater than or equal to 90% (p<0.001). Median follow-up from surgery was 81.22 months in the RCTC group and 18.66 months in the SMART group. There was no significant difference in overall and recurrence-free survivals between the two groups.Conclusions: SMART represents a safe therapeutic option in the induction treatment of AP BR or LANR accessible to surgery. It achieves higher tumor response rates than RCTC, although no difference in overall and recurrence-free survivals has been demonstrated at 30 months. A longer follow-up will be needed to detect any differences between the two groups.