Abstract book - ESTRO meets Asia

S47 ESTRO meets Asia 2018

Conclusion The EORTC QLQ-PRT20 is designed to be used in addition to the EORTC QLQ-C30 to measure quality of life in patients who receive pelvic radiotherapy. The EORTC QLQ-PRT20 is quick to complete, acceptable to patients, has good content validity and high reliability.

boost even if ultra-high dose (50Gy IMRT + 2x15 Gy HDR boost) was applied. OC-120 International validation of the EORTC QLQ-PRT20 module for symptoms relating to radiation proctitis G. Halkett 1 , C.A. Wigley 2 , S. Aoun 2,3 , M. Portaluri 4 , F. Tramacere 4 , L. Livi 5 , B. Detti 5 , S. Arcangeli 6 , J.A. Lund 7 , A. Kristensen 7 , N. McFadden 8 , A. Grun 9 , E. Greimel 10 , N. Spry 11,12 1 Curtin University, School of Nursing- Midwifery and Paramedicine, Perth, Australia 2 University of Notre Dame, Institute for Health Research, Perth, Australia 3 LaTrobe University, Palliative Care Unit- School of Psychology and Public Hea lth, Melbourne, Australia 4 “A. Perrino" General Hospital- ASL, Radiation Oncology, Brindisi, Italy 5 University of Florence, Radiation Oncology, Florence, Italy 6 San Camillo and Forlanini Hospitals, Radiation Oncology, Rome, Italy 7 St. Olavs University Hospital, Cancer Clinic, Trondheim, Norway 8 Universitaire de Sherbrooke-, Centre Hospitalier, Quebec, Canada 9 Charité, University Medicine, Berlin, Germany 10 Medical University Graz-, Department of Obstetrics and Gynecology, Graz, Austria 11 Genesis Cancer Care, Radiation Oncology, Perth, Australia 12 Sir Charles Gairdner Hospital, Radiation Oncology, Perth, Australia Purpose or Objective Although patients experience radiation proctitis post radiotherapy no internationally tested instruments exist to measure these symptoms. The aim of this Phase IV study was to test the scale structure, reliability and validity and cross-cultural applicability of the EORTC proctitis module (QLQ-PRT23) in patients who were receiving pelvic radiotherapy. Material and Methods Patients (n=358) from six countries completed the EORTC QLQ-C30, QLQ-PRT23 and EORTC Quality of Life Group debriefing questions. Patients were recruited from Australia, Italy, Norway, Canada (French speaking), France and Germany. Patient questionnaires were completed at four time-points (prior to radiotherapy treatment; during first week of treatment; end of treatment; and at the three to six months scheduled follow-up appointment). Clinicians completed the EORTC Radiation Therapy Oncology Group scale for comparison at each time-point. The module’s scale structure was examined and validated using standard psychometric analysis techniques. Results The reliability, validity and psychometric properties of the EORTC QLQ-PRT23 in an international sample of 358 patients receiving pelvic radiotherapy were examined. Individual items and the internal structure of the scale were reviewed. Three items were dropped from the module (QLQ-PRT23 → QLQ-PRT20). Factor analysis identified five factors in the module: bowel control; bloating and gas, emotional function/lifestyle, pain and leakage. Inter-item correlations were within r =0.3–0.7. Test-Retest reliability was high. All multi-item scales discriminated between patients showing symptoms and those without symptomology. The module discriminated symptoms from the clinician completed scoring and for age, gender and comorbidities.

Poster viewing: Stimulating topics for discussion (physics)

PV-121 A dosimetric study of the brachytherapy treatment of carcinoma cervix using a female pelvic phantom , M. Joan 1 , S. Saminathan 2 , R. Manikam 2. A. Sinha 1 1 SMS Medical College and Hospitals, Department of Radiological Physics, Jaipur, India 2 Kidwai Memorial Institute of Oncology, Department of Radiation Physics, Bangalore, India Purpose or Objective The objective of the study was to fabricate an anthropomorphic heterogenous female pelvis phantom suitable for dosimetric evaluation of various brachytherapy applications for the treatment of carcinoma cervix where different dosimeters could be used. Material and Methods The design criteria were suitability for evaluation of cervix treatments, phantom materials to have physical and electronic densities radiologically equivalent to real tissue, able to accommodate a variety of dosimeters in clinically relevant locations, able to be rapidly assembled and disassembled and overall weight suitable for manual handling. Computed tomography (CT) images were obtained as per departmental protocols; delineated structures and external contour were altered or smoothed in shapes as required for milling. The phantom design data was separated according to each transverse CT slice. The organ and bone structure for each individual slice was milled using a Pinnacle milling machine. Moulds were created using the external contour for the organs. After the organs solidified, detector locations were drilled and labelled. The electron density of the materials chosen for fabrication was based on HU to electron density calibrations. A cylindrical apparatus which can be filled by water was made to allow the positioning of intracavitary and interstitial brachytherapy applicators. Results Physical& Dosimetric properties The phantom was simple to assemble and reassemble with positioning rods and the phantom slices could be repositioned with no discernable displacement. The CT numbers of the phantom materials and those of the delineated regions on the CT of the patient used to model the phantom were sampled using the Eclipse planning system and indicates agreement. ICBT Treatment planning and measurements using the fabricated phantom The dose measured with the TLDs were compared with TPS calculated dose in different locations in the phantomlike point A, bladder, rectum, left femoral head and right femoral head. The average measured dose agreed with the TPS calculated dose.