ESTRO 37 Abstract book

ESTRO 37

S612

Material and Methods From 2008 to 2016 43 children diagnosed with sarcoma were treated with tomotherapy. Median age was 16 years (range 6-19 years). Toxicity during and after RT was graded according to the CTCAE criteria (v4.03) and classified into symptoms before and during RT, acute (0-6 months after RT) and late (>6 months after RT). Results As an ongoing study, we present the results of the first 20 patients analyzed. 60% (n=12) were diagnosed with Ewing’s sarcoma, 25% (n=5) with alveolar and 5% (n=1) with embryonal rhabdomyosarcoma. 10% (n=2) were diagnosed with fibromyxoid or osteosarcoma. Treated for primary disease (80%, n=16) tumors occurred on extremities (25%), thorax (38%), pelvis/abdomen (19%) and head/neck (13%). Four patients were treated for recurrent disease of the thorax (n=2) and lower extremities (n=2). In 50% RT was applied adjuvant after surgery; 19 patients received previous chemotherapy. 15 of those were also treated with concomitant chemotherapy. 55% (n=11) received a stem cell transplant after RT. Median total dose was 50 Gy (range 24-56 Gy) with a single dose of 1.8 Gy (range 1.44-2.00 Gy); 13 (65%) treatments had a simultaneous-integrated boost. Median follow-up was 13.0 months (range 0.1-63.4 months); median progression-free survival was 23.5 months (0.1-63.4 months); median survival was 23.2 months (0.5-63.4 months). Table 1 displays the recorded toxicities. Although skin toxicities were common with 70% during and 62.5% <6 months after RT, 4 patients had no skin toxicities in the entire treatment period and follow- up. Serious side-effects (grade 3 or 4) occurred in 50% of all cases during RT but improved continuously. Within 6 months after RT, six patients suffered from grade 3 or 4 toxicities: Grade 3 radiodermatitis was newly found in one case; one patient suffered from pneumonia grade 3 and sepsis; downgrading in mobility of extremities from grade 2 to 3 was recorded once. One patient showed new tumor manifestations within 6 months after RT and three patients >6 months. One patient suffered from grade 3 toxicities in consequence of pneumonia.

PO-1086 Benefits of ovarian transposition in young patients after pelvic irradiation R. Roncero 1 , N. Aymar 1 , I. Ortiz 1 , M. LLopis 2 , D. Morera 3 , M. Vidal 1 , L. Valencia 1 , X. Mestre 1,4 , J. Pardo 1,4 1 Hospital Universitari Son Espases, Radiation Oncology, Palma de Mallorca, Spain 2 Hospital Son Llatzer, Radiology Deparment, Palma de Mallorca, Spain 3 Hospital Universitari Son Espases, Medial Physics, Palma de Mallorca, Spain 4 Institut d`Investigacio Sanitaria de Illes Balears IdisBa, Radiation Oncology, Palma de Mallorca, Spain Purpose or Objective To assess the clinical benefit of ovarian transposition (OT) to preserve ovarian function, in young patientsafter pelvic irradiation. Material and Methods Twenty patients treated with pelvic radiotherapy were analysed in our Department, from 2012 to 2017. All of them younger than 40 years old (with an average age of 29+/- 17 years) and desire of ovarian function preservation. Seventeen patients ( 85%) had a cervical carcinoma (Stages IB1 to IV) and were treated either with radical or adjuvant chemo-radiotherapy when required (45Gy to pelvis). Three patients (15%) had locally advanced rectal carcinoma and were treated with neoadjuvant chemo-radiation before radical surgery. All patients were treated with a standard fractionation and different conformal radiotherapy techniques. Organs-at- risk were contoured for each patient including ovaries, in order to asses dose received and eventual effects of radiation. A bilateral laparoscopic ovarian transposition to psoas muscle was performed only in four patients (Stage IIB cervical carcinoma) without surgical complications. Ovarian function was assessed by performing hormonal tests. Follicle stimulating hormone (FSH) and estradiol in serum were measured after giving oral consent. Good ovarian reserve was related with FSH levels between 3- 20mIU/ml and low ovarian reserve with FSH levels >20mIU/ml. Estradiol levels under 30pg/ml indicates menopause. Results All patients completed radiotherapy (20). Ovaries mean volume was 8+/- 6cm 3 .Ovarian dose received in patients were OT was not performed was the same as dose prescribed to PTV: mean dose in right ovary (RO) was 50Gy (47-53) and left ovary ( LO) 46Gy ( 46-51). Patients with OT received less than 24Gy in both ovaries: mean dose in RO was 10Gy (4-17) and LO 11Gy (4-17).Ovarian function assessment was performed in 16 patients (2 patients died and 2 declined). FSH and estradiol levels were similar in both groups and showed an early menopause, achieving preservation of ovarian function just in one patient (Table 1). There was apparently no relationship between the time elapsed from treatment and the recovery of ovarian function. The statistical study was carried out by using SPSS_22.

Conclusion Our results showed low levels of acute and late toxicities. Hence, tomotherapy is a suitable treatment method for young patients especially with a tumor of complex anatomy or with multiple targets. Also, multitarget therapy is an effective and innovative treatment method. During further analysis, we will focus also on long-term toxicities rates (> 24 months) with special regard to growth and development disorders.