ESTRO 2023 - Abstract Book

S1158

Digital Posters

ESTRO 2023

Whole-pelvic radiotherapy in combination with intracavitary brachytherapy (ICBT) is the standard treatment for locally advanced cervical cancer. However, some patients are ineligible. Stereotactic body radiotherapy (SBRT) boost is a promising treatment for patients with cervical cancer who are ineligible for ICBT. The aim of this multicenter, single-arm, phase I/II study was to prospectively evaluate the efficacy and toxicity of SBRT boost. Materials and Methods ICBT-ineligible patients with untreated cervical cancer (International Federation of Gynecology and Obstetrics [2008] stage IB1–IIIB) were enrolled between April 2016 and October 2020. Patients underwent whole-pelvic radiotherapy (45 Gy in 25 fractions) with SBRT boost to the primary lesion. In the phase I dose-escalation cohort (3 + 3 design), patients were treated with SBRT boost of 21 or 22.5 Gy in 3 fractions in 3 days. Although dose-limiting toxicity was not confirmed, a dose of 21 Gy was selected for the phase II cohort, because of safety concerns. The primary endpoint was 2-year progression-free survival. Results Twenty-one patients (phase I, n = 3; phase II, n = 18) were enrolled between April 2016 and October 2020; 17 (81%) had clinical stage III–IV disease with para-aortic lymph node metastases. The median (range) follow-up was 29 (10–72) months. The initial response was complete response in 20 patients and partial response in one patient. The 2-year locoregional control, progression-free survival, and overall survival rates were 84%, 67%, and 81%, respectively. Grade ≥ 3 toxicity was confirmed in one patient each in the acute (diarrhea) and late (urinary tract obstruction) phase. Conclusion SBRT boost was effective and safe, even in patients with advanced disease in whom ICBT was not possible. These findings suggest that SBRT boost is an important treatment option for patients with cervical cancer who are ineligible for ICBT. L. Forlani 1 , A. Benini 1 , V. Laghi 1 , F. Medici 1 , J. Ma 1 , M. Ferioli 1 , C. Malizia 2 , A. Galuppi 3 , G. Macchia 4 , F. Deodato 4 , S. Cilla 5 , M. Buwenge 1 , S. Cammelli 1 , A.G. Morganti 1 , A. Arcelli 6 1 Radiation Oncology, Department of Experimental, Diagnostic and Specialty Medicine, DIMES, Alma Mater Studiorum University of Bologna, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 2 Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 3 Radiation Oncology Unit, IRCCS Azienda Ospedaliero Universitaria di Bologna, Bologna, Italy; 4 Radiation Oncology Unit, Gemelli Molise Hospital - Università Cattolica del Sacro Cuore, Campobasso, Italy; 5 Medical Physics Unit, Gemelli Molise Hospital - Università Cattolica del Sacro Cuore, Campobasso, Italy; 6 Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy Purpose or Objective Interest in radiotherapy (RT) about markers of systemic inflammation has spread due to their value in predicting outcomes in several tumors treated with RT. However, only few data are available on the impact of these markers in locally advanced cervical cancer (LACC) patients (pts). Moreover, in most studies, only one index with only a partial consideration of potential confounding factors was evaluated. Therefore, the aim of this study was to analyze a wide range of inflammation indices by including also other known prognostic factors. Materials and Methods We retrospectively analyzed pts undergoing chemoradiation (ChRT) for LACC from July 2007 to July 2021. Pretreatment values of several indices were calculated: neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), lymphocyte to monocyte ratio (LMR), monocyte to lymphocyte ratio (MLR), systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), and eosinophil to lymphocyte ratio (ELR). An univariate analysis (logrank test) on the impact of individual parameters on local control (LC), distant metastasis free survival (DMFS), disease free survival (DFS), and overall survival (OS), was performed. Furthermore, a multivariate Cox analysis on the same endpoints was performed including parameters significantly correlated with outcomes at univariate analysis. Results One hundred and seventy three patients were included in this analysis. The results of the univariate analysis are shown in Table 1 . On univariate analysis no index of systemic inflammation was significantly correlated with DMFS, DFS, and OS, while a significant correlation with better OS rates was observed for patients with physiological BMI values, with less advanced FIGO stage, and with higher hemoglobin levels. Instead, on univariate analysis, NLR, PLR, SII, LMR, and MLR were significantly correlated to LC. However, on multivariate analysis, higher LC rates were significantly correlated only to higher hemoglobin levels (HR 0.57; 95% CI: 0.46-0.71, p<0.001). Table I: Univariate analysis of overall survival, disease free survival, local control, and distant metastasis-free survival. PO-1432 The role of inflammation markers in cervical cancers undergoing definitive chemoradiation