Abstract book - ESTRO meets Asia

S2 ESTRO meets Asia 2018

SP-006 Hypoxia: imaging driven strategies for modern radiotherapy TBC

As the healthcare implementation in the LMICs is undergoing major changes, there is a significant interest in these countries to embrace new and state of the art technologies. As they embrace advanced technologies in radiation therapy, one of the major challenges is to have adequately trained human resources for safe operation of the equipment and regular maintenance. The other challenges are to have adequate financial resources for maintenance of the equipment, importing spare parts within a short time frame and providing regulated electric power to operate the equipment. Results : The challenges in these countries in implementing advanced technology in radiation therapy are multi- dimensional. Though there is keen interest among the radiotherapy healthcare professionals in LMICs to learn and adapt the newer technologies, there is lack of trained senior healthcare professionals in Radiation therapy Physics in these countries to train the new staff in safe use of the advanced technologies. Similarly, shortage of trained human resources among the equipment maintenance staff is also evident. Conclusion : It is necessary for international organisations to support these countries in capacity building, particularly with respect to addressing the need for training of personnel. Providing structured interactive online training programs with adequate hands-on training in a well-equipped institution in the region could be one of the ways to address this issue. SP-005 Strategy for radiosensitization by increasing tumor tissue oxygen tension M. Masahiko 1 1 Tokyo Medical and Dental University, Department of Oral Radiation Oncology, Tokyo, Japan In radiotherapy for head and neck cancer, hypoxia has been attracting much attention. Indeed, plenty of studies have been reported regarding hypoxic fractions and prognosis or hypoxic modification and radiosensitization. Meta-analysis of randomized clinical trials proved that hypoxic modification by varying methodologies is statistically valid. Recently, particularly in oropharynx cancer, human papilloma virus (HPV) or its surrogate marker p16 expression becomes an important biomarker. The DAHANCA study revealed that a hypoxic radiosensitizer, nimorazole, significantly enhanced local control for HPV-negative larynx and pharynx tumors, but not for HPV-positive cases. The same results were obtained when restricted to oropharynx tumors. Interestingly, analysis using hypoxic imaging like FAZA- PET/CT exhibited no significant difference in hypoxic fractions between HPV-negative and -positive tumors. Enhanced reoxygenation in HPV-positive cases during radiotherapy is suggested as its possible mechanism. Despite such high level of clinical evidence regarding hypoxic modification and extensive basic research, it is peculiar that there are no widely-used hypoxic modifiers yet in clinical practice. Such situation is called “adored and ignored” by Overgaard. In this lecture, I will review hypoxia-associated translational research on head and neck cancer and consider its perspective. I will also introduce our unique radiosensitizer possessing the ability to transiently increase tumor tissue oxygen tension. Teaching lecture: Head and neck oropharynx

Abstract not received

Teaching lecture: Cell death mechanisms, cell & tissue survival assays

SP-007 Cell death mechanisms, cell & tissue survival assays E. Hau 1 1 Sydney West Radiation Oncology Netword, Radiation Oncology, Sydney, Australia Abstract text Following radiation, tumour and normal cells undergo various forms of cell death. This lecture will cover the various types of cell death, its mechanisms and also methods which are used to quantify the cell survival including clonogenic assays in vitro and in vivo assays. Symposium: Putting knowledge into practice: Oropharynx SP-008 Is HPV related oropharyngeal cancer more chemo- radiosensitive than HPV negative OPC in Chinese patients? X. Wang 1 1 Fudan University Shanghai Cancer Center, Department of Radiation Oncology, Shanghai, China Abstract text HPV related oropharyngeal squamous cell carcinoma (OPSCC) is steadily increasing in USA and Europe. A series of studies have demonstrated that HPV related OPSCC has a superior treatment response, prognosis and survival rates compared to traditional OPSCC ， which has sparked interest in de-escalation treatment for patients with HPV related OPSCC. However, whether HPV positive OPSCC is sensitive to chemotherapy and radiotherapy remains unknown for Chinese patients. In our center, locally advanced OPSCC is routinely given induction chemotherapy followed by radiotherapy alone or concurrent chemoradiotherapy (CCRT) regardless of HPV status, while surgery is only reserved for salvage. We explored the correlation between chemosentivity and HPV status, EGFR expression, gender, smoking and drinking status in OPSCC. Our study demonstrated that HPV status, gender, smoking and drinking status could not predict chemosensitivity for Chinese OPSCC. Our results suggested that de-escalation treatment according to HPV status alone might not be feasible for Chinese OPSCC at the present. SP-009 Chemotherapy in HPV+ patients in IMRT era J.Bouhris 1 1 Centre Hospitalier Universitaire Vaudois, Department of Radiation Oncology, Lausanne Vaud, Switzerland

Abstract not received