ESTRO 38 Abstract book

S1177 ESTRO 38

TraceIT was placed between cervix and bladder. A space of 8x20x38mm and 13x39x31mm (APxLLxCC), respectively, in each patient was created (Figure 1). The bladder D2cc were 6.20Gy and 5.11Gy, respectively, with a HR-CTV D90 >85Gy EQD2 in both cases (Figure 2).

32.9% vs. 39.5% and for D0.1cc was 52.4% vs. 46.7% and in sigmoid colon the D2cc was 49.5% vs. 53.6%, for D1cc was 57.7% vs. 61.5% and for D0.1cc was 78% vs. 81.9%. The results demonstrated lower doses to risk organs in all electronic brachytherapy plans. The acute toxicity for electronic brachytherapy in cases of mucositis was two cases with grade 1 toxicity and one case with grade 2 toxicity, without cases of rectal toxicity and one case with grade 1 urinary toxicity and no relapses have occurred to date. Conclusion The first results of treatment with the Axxent eBT unit for the 8 patients are very promising, as no recurrence has been observed and the toxicity of the treatment is very low. Despite the increase in V150 and V200 there has been no increase in the toxicity of the vaginal mucosa, and the doses in the OAR are lower than in the implemented plans of HDR-BT with Ir192. Electronic brachytherapy is a good alternative for treating cervical cancer in centers without the availability of conventional HDR. To date, there are few published studies reporting on the outcomes of patients treated with electronic brachytherapy, and none on patients treated for cervical cancer. EP-2127 Hydrogel bladder and rectal spacer (TraceIT) for brachytherapy in locally advanced Cervical cancer D. Najjari Jamal 1 , C. Gutiérrez 1 , L. Martí 2 , S. Marin 1 , A. Slocker 1 , G. Rodriguez 1 , S. Moreno 3 , M. Garcia 1 , F. Guedea 1 1 ICO Hospitalet, Radiation Oncology, Hospitalet de Llobregat, Spain; 2 Hospital de Bellvitge, Gynaecology, Hospitalet de Llobregat, Spain; 3 ICO Hospitalet, Physics, Hospitalet de Llobregat, Spain Purpose or Objective Treatment for locally advanced cervical cancer (LACC) comprises concomitant radiochemotherapy (RCHT) followed by brachytherapy (BT). Assessment of toxicity is important in radiotherapy, since is necessary to define therapeutic ratio and determine the specific benefit of a given treatment. The injection of an hydrogel to space the bladder and rectum from cervix may help to organ-at-risk (OaR) sparing during BT treatment and therefore reach higher doses to the D90 in the HR-CTV to improve local control. The aim of this study, therefore, is to place the hydrogel around cervix and evaluate the benefit on the plan dosimetry at time of BT. Appropiate approvals by local ethic comittee was obtained. Material and Methods The preliminary prospective study includes 3 patients diagnosed with LACC and treated with concomitant radio(chemo)therapy + IGABT. The radio-opaque hydrogel (TraceIT) is placed between rectum-cervix and bladder- cervix after conclude RCHT and at time of BT. We approached the technique using transrectal ultrasound (TRUS) and transvaginal injections. A stepper was used to stabilize the image and allow two hands to manipulate the needle and the speculum. A hydro-dissection technique with saline was used to open the space to advance the needle into this space 1cm at a time. Injection of 3-6ml of TraceIT created the space around cervix and bladder. The distance from cervix to OaR was measured before and after the hydrogel injection in CT-scan and (TRUS). At time of BT the distance was measured again in TRUS. A total nominal dose of 21Gy in 7Gy/fraction with HDR was prescribed. The D2cc for bladder and rectum and EQD2 (OaR alpha/beta=3 and tumor alpha/beta=10) HR-CTV D90 were calculated. Results TraceIT placement was performed in 2 of the 3 selected patients. The third patient was not a good candidate due to pouch of Douglas prolapse. The 2 performed cases were diagnosed with stage IIB cervical cancer. Before BT, the first patient had complete response and de second patient a partial response with more than >50%. At time of BT,

Conclusion TraceIT injection is easily reproducible in the 2 cases. In addition, the hydrogel can be easily identified in both MRI and CT-planning for BT. Compared to historical controls the rectum and bladder D2cc were lower without decreasing the HR-CTV D90 dose. Therefore, TraceIT can help to improve the dosimetry in IGABT for LACC and may help to raise the dose to D90 HR-CTV>85Gy without increasing the dose in bladder. No acute symptoms were described. Further investigations are needed to improve the technique and to perform rectum-cervix placement and furthermore to evaluate the benefit of TraceIT in dosimetry improvement at time of BT. EP-2128 Rectal toxicity with MUPIT Interstitial Brachytherapy – Predictors, clinical and dosimetric outcomes V. Pareek 1 , R. Bhalavat 2 , M. Chandra 2 , C. Bakshi 3 , N. Bhambhani 4 1 Jupiter Hospital, Radiation Oncology, Mumbai, India; 2 Jupiter Hospital, Radiation Oncology, Thane, India; 3 Jupiter Hospital, Medical Oncology, Thane, India; 4 Jupiter Hospital, Surgical Oncology, Thane, India Purpose or Objective Late rectal toxicities are a concern associated with Interstitial Brachytherapy for various indications in pelvic malignancies. In this study we evaluate the rectal toxicities associated and look in to the clinical correlation with the predictive factors associated with such toxicities associated with high dose rate pelvic interstitial brachytherapy. Material and Methods From January 2010 to December 2016, 35 patients with residual or bulky cervical disease and vaginal vault recurrence were included in the study. Patients received