To the Editor:
On March 11, 2020, the World Health Organization declared the COVID-19 outbreak a
global pandemic. Public health officials have urged communities to minimize transmission
by changing their habits, including posttravel self-isolation, increased hygiene vigilance,
remote working, and social distancing.
To accommodate these measures, radiation therapy departments are adapting by limiting
on-site staff, patient visits, and patient-to-staff interactions, reconciling the
goals of minimizing exposure for both patients and health care providers while maintaining
quality cancer care.
During this pandemic, opportunities exist to reduce patient visits and thus potential
exposure to COVID-19 and to judiciously allocate radiation therapy operation resources
by implementing alternative hypofractionated regimens for select, safe treatment sites.
Radiation therapy for patients with breast cancer represents a significant proportion
of treatment delivery workload in any radiation therapy department. Some centers may
consider omission or deferral of radiation therapy in those patients perceived to
have a lower risk of adverse outcomes, such as patients with ductal carcinoma in situ
or early stage disease with low-risk features. However, with an unknown and potentially
lengthy timeline for the pandemic, many patients and clinicians are not comfortable
with these options. Modeling studies predict that this pandemic may take months to
peak, and these heightened public health measures may remain in place for many months.
Therefore, strategies to adapt to this “new normal” are crucial to maintaining access
to radiation therapy for patients with cancer. Our strategy is based on the appropriate
use of hypofractionation and accelerated partial breast irradiation (APBI).
The focus on breast radiation therapy is crucial because of its significant impact
on radiation therapy resources. The adoption of hypofractionation for patients, including
those requiring locoregional irradiation, and the option of APBI for suitable patients
based on international consensus guidelines can serve to significantly reduce the
number of radiation therapy fractions and, as a result, minimize patient exposure
during treatment and counteract increased pressure on the health care system.
Hypofractionation regimens, such as 42.5 Gy in 16 fractions or 40 Gy in 15 fractions,
have demonstrated equivalent local control and cosmetic outcomes in most patients
after breast conserving therapy.
Although less commonly used in postmastectomy with regional nodal irradiation, hypofractionation
is comparable to standard fractionation with favorable long-term efficacy results
and low overall toxicity.
More recently, 1-week 5-fraction regimens have been compared with the 40 Gy in 15
fractions whole breast radiation in the UK FAST FORWARD trial for treatment of early
stage disease, with favorable acute toxicity.
We are now awaiting the local control and survival data outcomes from this trial.
Compared with the conventional 5-week fractionation of 50 Gy in 25 fractions, these
shortened courses save patients between 9 and 20 visits to the cancer center.
The evidence supporting APBI for early stage breast cancer is also maturing. In 2019,
2 separate phase 3 randomized control trials—RAPID and NSABP B39/Radiation Therapy
Oncology Group (RTOG) 0413—reported on the efficacy of APBI fractionation regimens
compared with whole breast irradiation.
The results are favorable, showing no statistical difference in overall survival and
comparable local control for patients treated in the APBI arm. The evidence supporting
APBI agrees with the American Society of Radiation Oncology
patient selection guidelines. Many centers have adopted the use of APBI in a limited
capacity, primarily for patients on clinical trials. Publications describing APBI
techniques that meet major trial constraints with simple 3-dimensional conformal techniques,
and more recently advanced techniques for improved dosimetry, are available to support
Implementing an APBI fractionation of 27 Gy in 5 fractions can save a further 10,
11, or 20 treatment visits for select patients.
In our tertiary care facility, the majority of patients with breast cancer (all stages;
intact breast and postmastectomy locoregional) receive the standard 3-week regimen
of 42.5 Gy in 16 fractions. In consideration of COVID-19 and after a multidisciplinary
review, our center is now offering a 5-fraction APBI option for eligible patients.
A review of the last 3 months of patient treatment data was performed at our institution
to determine the impact of this change on radiation therapy resources. Across all
tumor sites, 770 total patients were treated; of these, patients with breast cancer
represented 30% of all delivered fractions. For our patient population, approximately
40% of patients with breast cancer are suitable candidates for APBI. Over a 3-month
span, a 5-fraction regimen of APBI for these eligible patients with breast cancer
could reduce the number of daily treatment visits by approximately 500 and 900 for
16- and 25-fraction regimens, respectively. Across all radiation therapy resources,
this overall reduction is approximately 5% to 10% of total daily fractions.
Flattening the COVID-19 curve may necessitate careful adoption of measures that decrease
interaction within radiation therapy departments and minimize treatment interruptions,
without compromising cancer outcomes. At a time when health care systems aim to minimize
stress on the system’s resources, radiation therapy can do its part to adapt. As noted
by Achard et al,
the use of practical measures to ensure the treatment of patients undergoing radiation
therapy must balance pragmatism and safety. The use of hypofractionated regimens and
APBI may be the treatment option that best fits the balance of patient and staff safety
while maintaining access to quality cancer care during the pandemic.