ESTRO 38 Abstract book

S802 ESTRO 38

Material and Methods 46 consecutive LACC patients were included. Patients received CRT, 50.4Gy in 28 fractions and brachytherapy 21Gy in 3 fractions. Pre-treatment radiotherapy planning contrast enhanced CT scans and non-contrast enhanced brachytherapy CT scans (with the tandem and ovoids in situ) were exported from Aria (Varian, USA). The DICOM images were anonymised and imported into the TexRad system (Feedback Medical, UK). The CT slice which corresponded to the most FDG avid part of the tumour on staging PET-CT was used for contouring the region of interest (ROI). Laplacian of a Gaussian filters were applied to the image to highlight features between 2-6mm (labelled SSF 2 to SSF6). Mann-Whitney U test was used to compare TA values for mean, standard deviation (SD), mean positive pixels (MPP), entropy, kurtosis and skewness between a group of patients that achieved a complete response (CR) on the 3-month post-treatment MRI and those patients that achieved a partial response (PR). Results Disease was staged as IB1 in 2%, IB2 in 13%, IIA 2%, IIB 52%, IIIB 13%, IVA 9% and IVB 9%. 33 patients achieved a CR and 13 patients achieved a PR. The TA parameters that yielded significant results from the pre-treatment CT were the SD, entropy and MPP at a spatial scaling factor of 4, 5 and 6 (see figure 1 and table 1) with partial responders having higher values for these parameters than complete responders. 36 patients had brachytherapy scans available which showed significant differences in entropy and skewness at SSF0 (p=0.038 and 0.017), and in the mean at SSF2 (p=0.022) between the patients achieving a CR and those achieving a PR.

Conclusion In this cohort, mean values for SD, entropy and MPP from the pre-treatment CT scan were higher in patients who had a partial response compared to those who had a complete response to CRT. TA from the brachytherapy scans was less predictive of response. TA on pre-treatment CT scans could potentially be used in the future to identify patients who need an escalation of treatment. Further work is suggested to examine the correlation of TA parameters with other known prognostic factors for cervical cancer such as stage and nodal status. These results also need to be validated in an independent cohort of patients. EP-1480 Radiation therapy for Uterine Cervical Cancer with lung metastases including oligometastases Y. Mukai 1 , I. Koike 1 , E. Miyagui 2 , M. Hata 1 1 Yokohama City University Graduate School of Medicine, Radiation Oncology, Yokohama, Japan ; 2 Yokohama City University Graduate School of Medicine, Gynecology, Yokohama, Japan Purpose or Objective We investigated the role of, and optimal regimen for, radiation therapy (RT) for patients with lung (oligo) metastases from uterine cervical cancer. Material and Methods We enrolled 23 consecutive uterine cervical cancer patients with lung metastases who received pelvis RT between November 2005 and July 2017 (median age: 52 years; range: 39–78 years). All patients had histopathological diagnoses of uterine cervical cancer (squamous cell carcinoma: n=13, 56.5%); 10 had lung metastases only (including 6 with oligometastases, defined as ≤ 4 lung metastases); 13 had distant metastases to other sites (para-aortic lymph node, liver, bones, peritoneum and ovary). All patients had bleeding from primary tumors; 5 patients received blood transfusions before RT (median total dose: 59 Gy; 2 Gy per fraction- equivalent dose [α/β=10], delivered to all patients’ uterine cervical cancer tumors). Sixteen patients (69.6%) received concurrent chemotherapy (cisplatin: n=14, 40 mg/m2 of body surface area; docetaxel/cyclophosphamide: n=2). Results For the 22 patients (95.7%) who completed RT without interruption, 9 (39.1%) had complete response (CR) for primary tumors and 10 (43.5%) had partial responses (PR; initial CR+PR rate: 82.6 %). The 1-year primary progression-free rate was 95.2 %. Bleeding greatly decreased after treatment (objective hemostatic rate: 100 % excluding 2 patients who discontinued RT or who had neuroendocrine carcinoma).