Abstract Book

S818

ESTRO 37

Material and Methods We prospectively evaluated the safety among patients with gynecological cancer who had undergone insertion procedure of titanium marker. Patients with severe coagulation disorder, severe comorbidities, and pregnancy (possible pregnancy) were ineligible. The decision to implant titanium marker was at the discretion of each radiation oncologist. Titanium markers were manufactured by severing ligating clips for surgery into 3– 6 mm pieces and sterilized. We inserted 18-gauge injection needle containing titanium marker before titanium marker was extruded by 22-gauge longer needle or shape memory alloy wire into tumor or tissue close to tumor. Severe complications after implantation were scored according to the National Cancer Institute’s Common Terminology Criteria for Adverse Events version 4.0. Results Between August 2016 and August 2017, we enrolled 29 patients. The median (range) follow-up was 6 months (2– 13) and the median (range) age was 59 (27–87) years. The most common primary site was cervix (26 patients), followed by vagina (2 patients) and uterine corpus (1 patient). Fourteen patients underwent definitive radiotherapy of primary cancer, 12 postoperative radiotherapy, and 3 definitive radiotherapy of recurrence. The majority of the reason for insertion was to clarify the location of vaginal vault and help delineation in radiotherapy planning. To clarify the area of vaginal invasion of cancer was the second most reason. Loss of titanium marker was observed in one patient within one month after insertion. No grade 3 or higher complications occurred. One patient experienced grade 2 hematoma formation 2 weeks after insertion. Thirteen patients underwent the cumulative total of 24 times of 1.5 or 3 Tesla magnetic resonance imaging (MRI) after insertion. No adverse effect and migration related to performing MRI were observed. Conclusion Our unique insertion technique of home-made titanium marker was secure. To use titanium markers clinically, we need larger number patients for longer follow-up time. EP-1510 Clinical Impact of Image Guided Radiation Therapy for locally advanced cervical cancer C. Salas 1 , L. Gutiérrez Bayard 1 , M.J. Macias Lozano 1 , S. Garduño Sanchez 1 , R. Rodríguez Sanchez 1 , V. Díaz Díaz 1 , E. González Calvo 1 , I. Villanego Beltrán 1 , J. Jaén Olásolo 1 1 Hospital Universitario Puerta del Mar, Comprehensive Care Department Cancer- Radiation Oncology Service- University Hospital Puerta del Mar., Cadiz, Spain Purpose or Objective To evaluate the clinical impact of Intensity Modulated Radiation Therapy using Simultaneous Integrated boost (IMRT-SIB) and Intracavitary Brachytherapy (BT) High Dose Rate (HDR) to conformal three-dimensional radiotherapy (3DCRT), in locally advanced cervical cancer. Material and Methods Patients who were diagnosed with locally advanced cervical cancer between 2008 – 2016 and treated with RTC3D or IMRT-SIB and concurrent weekly cisplatin (CP) with a minimum follow up of 13 months were included in this retrospective analysis. A total of 45Gy was given to PTV1: cervix, parametria, uterus, superior third of the vagina and the common, external and internal iliac and presacral lymph nodes

for definitive radiochemotherapy in 2010 - 2012. The patients were examined both with MRI and FDG-PET/CT at diagnosis. MRI and clinical examination under anesthesia provided the base for treatment planning, but in case FDG-PET/CT showed signs of additional tumor spread this locus was included in the prescribed radiation volume. Radiation doses to the involved lymph nodes were modified accordingly. Outcome was evaluated four years after end of treatment. Results Median age at diagnosis was 58 years (range 32 - 77 years). Squamous cell carcinoma accounted for 21/25 tumors and adenocarcinomas for 4/25 tumors, grade 3 was more common than grade 2 in both groups. All but one patient had cisplatinum concomitantly, the number of cycles varied depending on toxicity. Median overall treatment time (OTT) of radiotherapy was 44 days (range: 39-53 days). Performing pre-treatment FDG- PET/CT in addition to MRI enabled detection of undiagnosed nodal tumor involvement in 46 % (11/24) of the patients resulting in change of treatment strategy with extended para-aortic fields or extended pelvic volumes and dose escalation. Of the eleven patients, who had their treatment changed due to additional information, seven (64 %) were alive and without evidence of disease at four year’s follow up. The two patients where the MRI showed pelvic tumor involvement that was not detectable on FDG-PET/CT had received extended treatment volumes and were alive and without evidence of disease at four year’s follow up.

Conclusion In 11/25 consecutive patients with advanced cervical cancer scheduled for radiochemotherapy, pre-treatment FDG-PET/CT added information as compared to information from pre-treatment MRI, resulting in treatment modification. Seven of these patients were alive without disease after four years. Pre-treatment FDG-PET/CT markedly increased the chances of survival in this group. The study facilitated the introduction of a new imaging technique, FDG-PET/CT, into regional clinical practice and has since been adopted by our National Guidelines for Cervical Cancer. EP-1509 Prospective study on safety of home-made marker insertion for gynecological cancer by unique method S. Sekii 1 , K. Tsujino 1 , H. Kubota 1 , Y. Matsumoto 1 , Y. Ota 1 , T. Soejima 1 1 Hyogo Cancer Center, Department of Radiation Oncology, Akashi, Japan Purpose or Objective To verify safety of original titanium marker for radiotherapy of gynecological cancer.