ESTRO 2020 Abstract book

S382 ESTRO 2020

be relevant to study in this context is to characterize the 3D shape of the parotid isodoses into a shape feature signature. Ultimately, these techniques might result in a higher accuracy NTCP model giving 3D guidance for sparing the relevant regions from the relevant dose level. In conclusion, this lecture will give an overview of the existing NTCP models in head and neck cancer with their dosimetric limitations. The small animal and human data on sub-parotid radiosensitivity will be discussed. This data will bring us to potential improvements of NTCP models using 3D dose map-based prediction modeling. SP-0620 Management of Radiation Toxicity in Head and Neck Cancers M. Hickman 1 1 University Hospital Birmingham, Radiotherapy, Birmingham, United Kingdom Abstract text Oral mucositis is an expected and a debilitating complication of radiation therapy with or without systemic therapy. There are several points in the radiation pathway where interventions are being trialled to decrease the incidence of mucositis, although not all will have mucositis as their endpoint. The presentation will discuss the role of radiation de-escalation, dose distribution and synchronous agents. In addition the introduction of contouring strategies (5+5), laser therapy and topical agents may also be relevant endpoints in the prevention of mucositis. There is also a strong relationship between oral mucositis and quality of life (QOL). Patient reported outcome measures (PROMS) especially severity and interference of oral mucositis are relevant endpoints in the prevention and management of oral mucositis. SP-0621 Multidisciplinary treatment of hepatocellular cancer: the radiation oncologist's point of view V. Vitolo 1 1 Fondazione CNAO, Radiation Oncology, Pavia, Italy Abstract text The Role of RT in management of inoperable HCC is recently emerging. Since few years ago, RT has been considered one of the possible treatment for patients not eligible to other local approaches. The reasons have to be found in the lack of consistent data from the literature: most of the results were from observational studies and monocentric experiences. After the results of a recent randomized trial the International Guidelines on HCC have been updated and EBRT appears to have an expanding role in treating HCC, especially in case of lesions larger than 3 cm and with major vessels involvement. Several ongoing trials are investigating the potential benefits of EBRT and immuno therapy in combination. Modern radiation therapy modalities including particle therapy, with its known superiority in terms of biological effectiveness and physical selectivity, have certainly an emerging role in the management of HCC. Future clinical randomized trials are need to demonstrated the potentiality of such new technological advances. Symposium: Multidisciplinary treatment of hepatocellular cancer

SP-0622 The medical oncologist's point of view J. Dekervel 1 1 UZ Leuven, Digestive Oncology, Leuven, Belgium Abstract text The development of new systemic treatments has revolutionized the landscape of advanced HCC. Recent phase III trials showed benefit of several new agents in first line (vs sorafenib) and second line (vs placebo). Systemic treatment of HCC is no longer a desperate choice after maximal exhaustion of locoregional approaches, but a valid option to consider at the MDT in all patients not candidate for treatments with curative intent. This lecture will cover when to consider systemic treatment options vs embolization techniques in intermediate stage HCC. Moreover, it is important to define embolization refractory HCC. The different systemic options available will be discussed, as well as a word on treatment sequencing. SP-0623 The interventional radiologist's point of view O. Van Delden Amsterdam UMC, Amsterdam, The Netherlands Abstract text Hepatocellular carcinoma (HCC) seems to become more important even in western countries. Main risk factors are liver cirrhosis of any etiology and chronic viral hepatitis. In recent years, rising incidences of non-alcoholic steatohepatitis (NASH)-related hepatocellular carcinoma have been reported. Surgical treatment options are liver transplantation and liver resection. The choice of treatment is related to the extension of the HCC and the quality of liver parenchyma. For HCC without liver cirrhosis liver resection is the treatment of choice. Noteworthy that NASH-livers are sometimes worse in the postoperative course than cirrhotic livers. Regarding liver cirrhosis as a precancerous lesion for HCC, liver transplantation is the optimal treatment for HCC in cirrhotic livers. However, it has been shown that oncological results are only acceptable if HCC meet MILAN criteria or slightly extended MILAN criteria as the University of California San Francisco (UCSF) criteria. The worldwide lack of organs for transplantation leads to the fact that liver resection is becoming more important in the treatment of HCC. Several classification systems and treatment algorithms for HCC are available. Many of them as the Barcelona Clinic Liver Cancer (BCLC) classification from 1999 are old and nowadays not acceptable in its current form from a surgical point of view with an urgent need for revision. Staged hepatectomy and salvage liver transplantation in the setting of multimodal treatment are good options to treat primary or recurrent HCC. This talk will cover the controversy of resection versus ablation of hepatocellular carcinomas up to 3 cm as well as the treatment of hepatocellular carcinomas within and outside the Milan criteria with an analytic view on old treatment algorithms. Furthermore, the special aspect of liver surgery of NASH-related HCC will be discussed. Abstact not receievd SP-0624 The surgeon's point of view C. Riediger 1 , J. Weitz 1 1 University Hospital- University Of Dresden- Germany, Department Of Visceral- Thoracic And Vascular Surgery, Dresden, Germany