ESTRO 2021 Abstract Book

S1216

ESTRO 2021

Materials and Methods On 26 February 2021 a Pubmed search via PICO was performed using the following terms: P(cancer patients and Covid) and I(radiotherapy). Only higher quality reports according to study design (Systematic Reviews, Clinical Trials and Practice Guidelines) were selected and analyzed. Results Among a total of 290 titles, 19 higher quality reports in RO were evaluated: 6 Systematic Reviews, 3 Clinical Trials and 10 Practice Guidelines. In particular, international expert consensus recommendations and proposals for managing cancer patients during COVID-19 pandemic were published with specific regard to the following tumors: breast and digestive cancers, as well as thoracic, haematological and gynecologic malignancies. Additionally, as an interestingly non-oncological result, whole-lung irradiation in a single fraction of 0.5 Gy was reported to obtain a response rate of 80% in a clinical trial enrolling oxygen-dependent patients with COVID-19 pneumonia. Conclusion We observed an exponential increase in the COVID-19 publications, also including literature in RO fields. Globally, the principal endpoint of published works was to support the balance between the risk of oncological disease progression and ill from COVID-19. In summary, the use of RADS (Remote, Avoid, Defer, Shorten) principles has been suggested, taking into account the necessity of personalized cancer treatments and pandemic containment (e.g. managing elderly or COVID-19 positive patients). The use of hypofractionated regimens is encouraged in selected cases. Defer radiotherapy (RT) could be proposed if clinically appropriate. RT avoidance could be considered in selected cases, exclusively if the evidence suggests marginal advantages or if alternative effective treatments are available. The evaluation of patient-specific risk factors and a multidisciplinary management are crucial. As preliminary knowledge, RT seems to be not associated with increased risk of exacerbation and mortality in SARS-CoV-2-infected cancer patients. To reduce risk of infection, separating patients and optimizing the resources (e.g. remote visits) are important strategies. PO-1485 Radiotherapy for Ledderhose disease: long-term efficacy, side effects and patient-rated outcome A. de Haan 1 , J. van Nes 2 , P. Werker 3 , J. Langendijk 1 , R. Steenbakkers 1 1 University Medical Center Groningen, Department of Radiation Oncology, Groningen, The Netherlands; 2 Radiotherapeutic Institute Friesland, Department of Radiation Oncology, Leeuwarden, The Netherlands; 3 University Medical Center Groningen, Department of Plastic Surgery, Groningen, The Netherlands Purpose or Objective Radiotherapy is considered a treatment option for Ledderhose disease. The main purpose of this study was to investigate the long-term effects of radiotherapy in a cohort of patients with Ledderhose disease. Materials and Methods In this cross-sectional cohort study participated patients with symptomatic Ledderhose disease, who were treated at our centre between 2008 and 2017. Patients were included if they completed their treatment at least 2 years ago. Radiotherapy was performed using 8 or 10 MeV electrons, depending on nodule thickness. Two separate courses of five daily fractions of 3 Gy each were administered, to a total dose of 30 Gy. The interval between the two courses was around 10 weeks. Data were collected by standardized survey questionnaires in 2019. These questionnaires addressed items such as pain from Ledderhose disease (Brief Pain Inventory), quality of life (Qol) (EQ-5D-5L), side effects from radiotherapy and patients’ satisfaction with the treatment. Descriptive statistics and non-parametric tests were used to analyse the results. Results A total of 102 feet were irradiated in 67 patients (28 male and 39 female). One patient was re-irradiated on both feet due to new nodules located outside the previous given radiation field. Thirteen patients (14 feet) had undergone surgery for Ledderhose disease prior to the radiotherapy. Mean follow-up time after radiotherapy was 5 years (range 2 - 11 years). Radiotherapy resulted in a statistically significant pain reduction. Mean pain score prior to radiotherapy was 5.7 and was 1.7 at the time of assessment (p-value < 0.001). Based on pain scores, the following pain response scores were reported: progressive pain in 0%, no change in 21% (22 feet), partial pain response in 37% (38 feet) and a complete pain response in 41% (42 feet). The most commonly reported side effects were dryness of the skin (n=23, 34%) and erythema (n=12, 18%). Dryness of the skin was still present at time of the questionnaires in 10 patients (15%). The majority of patients (78%) were satisfied with the effect obtained with radiotherapy and 57% of patients considered the treatment not burdensome. The mean single summary index score (societal perspective on QoL) was comparable to the reference value from the Dutch general population in the same age category: 0.856 versus 0.857. The mean self-reported VAS score (patient’s perspective on QoL) was above the reference value: 82.3 versus 80.6. Conclusion Radiotherapy has a long-term positive effect on pain in patients with Ledderhose disease. This treatment is well tolerated, patients feel satisfied with the result and have similar QoL as normal controls. Long-term side effects are mild. PO-1486 Should the spleen be an organ at risk? C. De La Pinta 1 , E. Fernández-Lizarbe 1 , D. Sevillano 2 , M. Garví 1 , V. Pino 1 , S. Sancho 1 1 Ramón y Cajal Hospital, Radiation Oncology, Madrid, Spain; 2 Ramón y Cajal Hospital, Medical Physics, Madrid, Spain

Purpose or Objective Low dose radiotherapy is used in the treatment of symptomatic splenomegaly, however, the dose received by