ESTRO 37 Abstract book

S830

ESTRO 37

participants must have been on antiretroviral treatment for a minimum of 6 months and have a CD4 count of above 200cells/mm3. Participants with bilateral hydronephrosis and a creatinine clearance below 60mL/min were excluded. Only FIGO stage IIb to IIIB patients were enrolled.Pet/CT scans were administered pre- and 6 months post treatment. Results 123 participants survived 6 months. 5 participants had confirmed disease progression before the PET/CT scan (1 in the HIV negative study group, 3 in the HIV positive control and 1 in the HIV negative control groups). Results from the PET/CT scans of 122 participants are available for analysis. 48% of participants in the study group are HIV positive and 51% in the control group are HIV positive. Complete response (CR) rates are as follows: HIV positive study: 67%; HIV negative study: 54%; HIV positive control: 57%; HIV negative control: 37%. 6 month survival in the HIV positive and negative study groups are 89% and 100% respectively, and in the HIV positive and negative control groups survival was 84% and 87.5% respectively. The frequency of grade 4 toxicities on treatment was higher in the HIV positive groups compared to the HIV negative groups. However the frequency of grade 3 toxicities was highest in the HIV negative control group. The most common toxicity was bladder. 1 Grade 3 skin toxicity was reported in both HIV positive groups and 1 in the HIV negative control group. At 3 months, skin and bladder toxicity was higher in the HIV positive study group than the HIV negative study group, with 2 grade 4 bladder toxicities in the HIV positive study group. The HIV negative control group reported the highest frequency of bladder toxicities: 3 grade 3 and 4 grade 4 toxicities. There were no grade 3 or 4 lower GI/rectal toxicities in the study group and 2 grade 4 toxicities in both control groups (HIV negative and positive). Conclusion Early results do not show an obvious pattern/relationship in the frequency/severity of toxicities in the HIV positive groups compared to the HIV negative groups, irrespective of the administration of mEHT. Overall the local disease control is improved in the study group. There is a higher CR rate in HIV positive groups of each arm. The 6 month survival does not show the same pattern of improvement in the HIV positive groups. Survival at 6 months is higher in the study group. The significance of this will be confirmed in a larger sample and longer follow up. H. Pérez Montero 1 , S. Guardado 2 , N. Gascón 2 , V. Rodríguez 2 , R. D'Ambrosi 2 , M. Fasano 2 , L. Asiáin 2 , J. Pérez-Regadera 2 1 Institut Català d´Oncologia, Radiation Oncology, Barcelona, Spain 2 Hospital Universitario 12 de Octubre, Radiation Oncology, Madrid, Spain Purpose or Objective The association between cervical cancer and HIV is well known, being one of the defining conditions of AIDS, and one of the most common neoplasms related to this disease. In addition, the evolution of HIV disease and response to treatment seems to be modified in this group of patients, having the tumor a more aggressive behavior and worse prognosis compared to non-HIV population. EP-1532 HIV and Cervical Cancer, dangerous combination for RT patients

Objective: Describe evolution of HIV patients with cervical cancer treated with radiotherapy in our center. Material and Methods Five HIV patients diagnosed with cervical cancer were treated with RT between 2001 and 2015 in our center. Patients presented a range of age at the time of treatment, from 32-47 years (Average 40.6 years, median 44 years). The stages were IB1, IB2, IIIB (2 patients) and IVA. All patients received External Beam Radiotherapy with concurrent Platine-based chemotherapy, except one case that received radiotherapy alone. During cancer treatment, patients continued prescribed HIV treatment. Average follow-up at the time of assessment was 54.2 We observed a worsening in CD4 count from baseline (average 321.39 CD4, median 338 CD4) to the end of radiotherapy treatment (average 69.4 CD4, median 66 CD4). Patients also worsened viral load except in 2 cases that remained stable (Table 1) months. Results In terms of the evolution of oncological disease: 3 patients relapsed and died. Disease-free intervals were 1, 3 and 30 months. The other 2 patients were alive and free from disease at last control. Conclusion From these data, it can be seen that HIV patients diagnosed with cervical cancer worse HIV course during cancer treatment, in probable relation with exposition during the treatment period to 2 immunosuppressive stimuli (HIV and radio-chemotherapy). Likewise, these patients present greater aggressiveness regarding cervical disease, probably related to the immunodeficiency status of the patients and HPV association of HIV. However, it is a small series of patients that will be expanded to draw solid conclusions. EP-1533 SBRT replacing brachytherapy boost in operated endometrial cancer: a pilot feasibility study M. Possanzini 1 , S. Vieira 1 , J. Stroom 1 , C. Greco 1 1 Champalimaud Foundation, Radiotherapy, Lisbon, Portugal Purpose or Objective to reproduce adjuvant high dose rate brachytherapy (HDR-BRT) dose distributions and treatments by means of external beam fractionated stereotactic body radiotherapy (SBRT) in patients operated for intermediate and high risk endometrial carcinoma refusing or not eligible for BRT Material and Methods after informed consent submission, since December 2016 to September 2017, 9 patients (pts) not eligible or refusing BRT received SBRT on the vaginal cuff, with or without whole pelvis radiotherapy, after complete surgical staging with radical hysterectomy, bilateral salpingo-oophorectomy, pelvic and lombo-aortic lymphadenectomy and intra-abdominal cytology analysis