ESTRO 2020 Abstract book

S180 ESTRO 2020

regular follow-up (FUP). Crude incidence was calculated using the maximum grade of late fatigue over all FUPs (starting at 6 months). Persistent late mild/moderate fatigue was defined, when G≥1/G≥2 was scored in at least half of the FUPs. Risk factors were evaluated with univariate and multivariable (MVA) logistic regression analyses. Results Overall, 1340 patients from 23 centers were treated according to protocol; of those 1177 had information on late morbidity (median FUP: 51 months). Crude incidence of fatigue was 62.8% (739 patients) for G≥1 and 24.1% (284) for G≥2. Persistent late G≥1 and G≥2 fatigue was present in 36.8% (433 patients) and 7.1% (83), respectively. Significant risk factors for persistent late G≥1 fatigue in MVA were: younger age, being overweight, baseline fatigue G≥1; of borderline significance were obesity and larger EBRT V57Gy (volume treated with ≥57Gy in external beam radiotherapy, taken to represent nodal boost). For persistent late G≥2 fatigue, significant independent risk factors in MVA were baseline fatigue G≥1, larger EBRT V57Gy and larger V60Gy EQD2 (isodose surface volume treated with EBRT and BT dose of ≥60Gy, in equivalent dose), with a trend for pre-existing chronic diseases [table 1]. In patients with no lymph node boost (V57Gy=0), limited (V57Gy<182ccm 3 ) and high volume boost (V57Gy>182ccm 3 ), the incidence of persistent, late G≥2 fatigue was 4-6%, 6-9% and 13-20%, respectively, further differentiated by size of BT volume [table 2].

fatigue may be mediated by each of these factors needs further study.

OC-0318 Neurotoxicity of early prophylactic cranial radiation and hippocampal avoidance in SCLC (SAKK 15/12) H. Vees 1 , F. Caparrotti 2 , E.I. Eboulet 3 , A. Xyrafas 3 , A. Fuhrer 4 , U. Meier 5 , M. Mark 6 , O. Elicin 7 , D.M. Aebersold 7 , D.R. Zwahlen 6 , T. Finazzi 8 , A. Said Allal 9 , P.M. Putora 10 , F. Martucci 11 , C. Biaggi Rudolf 4 , K. Ribi 12 1 Hirslanden Klinik Zürich, Radiotherapie, Zürich, Switzerland ; 2 University Hospital of Geneva, Radiation Oncology, Geneva, Switzerland ; 3 SAKK Coordinating Center, Informatics, Bern, Switzerland ; 4 SAKK Coordinating Center, Coordinating Center, Bern, Switzerland ; 5 Cantonal Hospital of Winterthur, Radiation Oncology, Winterthur, Switzerland ; 6 Cantonal Hospital of Graubünden, Departement of Hematology/Oncology, Chur, Switzerland ; 7 Inselspital- Bern University Hospital, Department of Radiation Oncology, Bern, Switzerland ; 8 University Hospital of Basel, Clinic of Radiotherapy and Radiation Oncology, Basel, Switzerland ; 9 Cantonal Hospital of Fribourg - HFR, Radiation Oncology, Fribourg, Switzerland ; 10 Cantonal Hospital of St. Gallen, Radiation Oncology, Sst. Gallen, Switzerland ; 11 Oncology Institute of Southern Switzerland, Radiation Oncology, Bellinzona, Switzerland ; 12 SAKK Coordinating Center, Quality of Life Office and International Breast Cancer Study Group IBCSG Coordinating Center, Bern, Switzerland Purpose or Objective To evaluate neurocognitive function (NCF) and clinical outcomes after early hippocampal avoidance (HA) prophylactic cranial irradiation (PCI) in limited disease (LD) small-cell lung cancer (SCLC) in a multicenter phase In a phase II trial, patients with LD SCLC received HA-PCI of 25 Gy in 10 fractions concomitant to the 2nd cycle of chemotherapy (CHT) and thoracic radiotherapy. All patients underwent objective NCF testing at baseline, 6 weeks, 6 and 12 months after HA-PCI. NCF tests included Hopkins Verbal Learning Test Revised (HVLT-R), Controlled Oral Word Association (COWAT), and Trail Making Tests (TMT) A and B. The primary endpoint was NCF decline at 6 months after HA-PCI. We assumed a rate of ≤ 30% of patients with no NCF decline as unpromising. Secondary endpoints included brain metastases free survival (BMFS), overall survival (OS), and safety of the concomitant treatment. Results Among the 44 patients enrolled in the trial, 38 had evaluable NCF assessment at 6 months after HA-PCI. The rate of evaluable patients showing no NCF decline at 6 and 12 months was 34.2% (90% CI: 21.6 - 48.8%) and 48.5% (95% CI: 30.8 - 66.5%), respectively (Figure 1). Median follow- up was 13.2 months (95% CI: 12.6 - 14.1). At 12 months, the rate of BMFS was 84.2% (95% CI: 68.1 - 92.8%), and of OS was 87.7% (95% CI: 73.0 - 94.7%). Four patients died due to SCLC, 1 due to respiratory failure, 1 due to hemorrhage, and 1 for unknown reason. The most frequently reported grade ≥ 3 acute adverse events were anemia (21.4%), febrile neutropenia (19.1%) and fatigue (14.3%). II trial (SAKK 15/12). Material and Methods

Conclusion Mild but persistent fatigue is experienced by >1/3 of patients; 7% suffer moderate persistent fatigue after treatment. Fatigue fluctuates over time, shown in the discrepancy between crude incidence and persistent grading. Large high dose volumes (lymph node or BT boosts) are associated with increased risk of late persistent fatigue, along with patient factors at diagnosis such as younger age, body-mass index, presence of baseline fatigue and chronic disease. How post-radiotherapy