PO-1100 Implementation of FAST-Forward during COVID19: Report of acute skin toxicity /resource implications

Abstract

Purpose or Objective In March 2020, a 1-week hypofractionated adjuvant breast radiotherapy schedule, 26 Gy in 5 fractions was adopted to reduce the risk of COVID 19 exposure for patients and staff without compromising on cancer outcomes. This study aimed to confirm acceptable acute toxicity rates for patients receiving this 1-week schedule (+/- sequential boost) and to quantify the positive impact of implementing this schedule on linac capacity. Materials and Methods This is a multicentre prospective observational study of consecutive patients receiving 26 Gy in 5 fractions adjuvant breast cancer radiotherapy (+/- boost) Mar-Aug 2020. Consensus was obtained on planning procedure protocols which included dose-volume evaluation and mandatory radiation quality assurance objectives. Standardised virtual consultations assessed acute skin toxicity during treatment and at weeks 1, 2, 3 and 4 post treatment using CTCAE V5 scoring criteria. Toxicity was compared between patients who received a boost and those that did not. The total number of linac minutes saved was estimated accounting for boost and DIBH use Results In total, 135 women were included, 33 (24%) received a boost. 128/135 (95%) patients, including 31/33 boost patients, completed at least 3/5 acute toxicity assessments. 0/128 (0%) reported moist desquamation not confined to skin folds or minor bleeding (grade 3 toxicity). 41/128 (31%) reported brisk erythema, moist desquamation confined to skin folds or breast swelling (Grade 2) and 63/128 (50%) reported faint erythema or dry desquamation (Grade 1) as their worst reported acute skin toxicity. The highest prevalence of grade 2 toxicity occurred at week 1 following treatment (19.5%), which reduced to 2.6% by week 4. There was no statistically significant difference in acute toxicity between boost and no boost patients (p= 1.00). Delivering a 1-week schedule to 135 patients over a six month period led to a saving of 21,300 linac minutes and 1485 hospital visits compared to delivering a moderately hypofractionated regimen of 3 weeks duration. 6,300 LINAC minutes were saved and 462 hospital visits avoided for patients > 70 years and cocooning under national guidance $Φg $Φg Conclusion This study demonstrates the feasibility of rapidly implementing a 1-week hypofractionated adjuvant breast radiotherapy schedule in clinical practice and how this landmark change has a considerable impact on linac capacity. This change in practice has ensured ongoing access to treatment for patients during the COVID-19 pandemic and greatly reduced the risks of infection for patients and staff. It further confirms acceptable acute skin toxicity even when followed by boost.