ESTRO 2023 - Abstract Book

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ESTRO 2023

the first day (FD), the 3rd or 4th week (MT) and the last day (LD) of treatment. For all parameters, difference was calculated as follow: MT – FD; LD – MT and LD – FD. Results The mean WL was -2.9 kg [-8.8; 1.8], -4 kg [-9.4; -0.9] and -6.2 kg [-15.6; -2.5] between (MT – FD), (LD – MT) and (LD – FD) respectively (p=0.016). The mean fat mass difference was -1.4 kg [-8.5; 4.2], -1.4 kg [-8.2; 7.8] and -2.6 kg [-11.2; 6.4] between (MT – FD), (LD – MT) and (LD – FD) respectively (p=0.4). The mean fat-free mass difference was -1.1 kg [-7.1; 4.7], -2.5 kg [-27.8; 0.5] and -3.6 kg [-28.1; 2.6] between (MT – FD), (LD – MT) and (LD – FD) respectively (p=0.014). Conclusion The weight loss is continuous during the CCR of the NPC but it is more important during the 2nd treatment phase. It is mainly related to fat-free mass during the 2nd phase. A protein supplement should be prescribed to patients during the last phase of treatment to prevent major fat-free mass loss and thus decrease global WL. 1 Kantonsspital Aarau, Center for Radiation Oncology KSA-KSB, Aarau, Switzerland; 2 Kantonsspital Aarau, Department of Otorhinolaryngology, Aarau, Switzerland; 3 Inselspital, Bern University Hospital, and University of Bern, Department of Radiation Oncology, Bern, Switzerland Purpose or Objective The aim of this review was to summarize the existing data and provide an overview of saliva changes in patients receiving radiotherapy (RT) to the head and neck region. To our knowledge, this is the first systematic review assessing the fluctuations in saliva pH, its buffering capacity, electrolyte and total protein concentrations as well as salivary amylase activity during and after RT. Materials and Methods The PubMed and Embase databases were searched independently by two reviewers for studies published in English between 1980 and 2022 analyzing the saliva composition of patients at several time points before, during and after RT to the head and neck region [Figure 1]. PO-1217 A systematic review of radiotherapy-associated changes in saliva composition M. Staruch 1 , M.M. Speth 2 , D.M. Aebersold 3 , O. Riesterer 1 , S. Stieb 1

Results Of 1,395 publications screened with the search term "saliva AND radiotherapy", 66 met the eligibility criteria [Figure 1]. Salivary pH changes and buffering capacity were examined in 27 and 11 studies, respectively, with a substantial decrease in values described in most of the studies during and post-RT. Ten studies depicted fluctuations in electrolyte concentration (natrium, potassium, chloride, calcium and others). The majority of those studies showed an initial elevation of natrium followed by a decrease during and post-RT, and reduced concentrations for potassium and magnesium post-treatment. A decrease in salivary total protein during RT and a slow increase thereafter were observed in the majority of the studies. Five studies investigated changes in salivary amylase. The authors described a continuous decrease in amylase activity during RT and a trend towards normalization post-treatment in most patients [Table1].