Use of breast cancer ultra-hypofractionated radiation treatments during and post COVID19 pandemic
Jean-Michel Caudrelier,
Canada
PO-1087
Abstract
Use of breast cancer ultra-hypofractionated radiation treatments during and post COVID19 pandemic
Authors: -jean-michel -caudrelier1, Katie Lekx-Toniolo2, Christiane Hache3, Suzanne Comino3
1The Ottawa Hospital Cancer Centre, radiation Medicine, Ottawa, Canada; 2The Ottawa Hospital Cancer Centre, Medical Physics, Ottawa, Canada; 3The Ottawa Hospital Cancer Centre, Radiation Medicine, Ottawa, Canada
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Purpose or Objective
To evaluate the changes of breast cancer radiation treatments fractionation, in a Canadian comprehensive cancer center over the COVID19 pandemic time, when actions have been taken to mitigate infection risks. The number of radiotherapy sessions freed from Linac will be estimated.
Material and Methods
Care plans dedicated to breast cancer treatments have been reviewed over the period of time 2008 to now. Radiation treatments as: whole breast irradiation (WBI), partial breast irradiation (PBI) or loco-regional irradiation, fractionation prescribed and time from ready-to-treat to start date have been computed per year.
Results
Numbers of breast cancers treated yearly by radiotherapy has increased from 602 in 2008 up to 917 in 2021. The number of linacs did not increase over that period, nor did the number of breast radiation oncologists. Since 2017 (7 years after the 10 years follow-up publication of the hypofractionated Canadian trial), all whole breast irradiations are prescribed the 3 weeks regimen. In 2020, with COVID19 and UK forward and fast-forward trials published, 5 fractions started to be prescribed for 10% of treatments, but that number increased to 38% over the first 9 months of 2022 (up to now, a total of 297 patients treated WBI 5 fractions, average age 74y +/- 8y).
PBI 3 weeks started to be prescribed in 2018 but was replaced by Accelerated PBI 5 fractions in 2020 and in 2022 is representing 15% of all breast-only radiation treatments (up to now a total of 128 patients treated APBI, average age 68y +/- 8y)
For Loco-regional treatments: 3 weeks regimen was used for 60% of patients in 2019 but jumped to 85% in 2020 and since 2021 is the standard of care.
Considering the radiation treatment prescriptions we have used in 2019, the fractionation prescription changes seen since mid-2020 and until Sept 2022 have freed up from linacs a total of around 6000 breast sessions.
Since 2018, the time from ready-to-treat to radiation-start date has stayed stable with an average of 11 days
Conclusion
The COVID19 pandemic combined with the UK trials publication has facilitated the adoption of APBI 5 fractions. WBI using 5 fractions is now used in 38% of patients, aged around 74y old. Three weeks regimen is now the standard of care for loco-regional treatments. These fractionation changes may have facilitated keeping waiting time for treatment low, in a challenging time.