Repeat Computed Tomography Simulation among Patients with Head and Neck Cancer Experiencing Delayed Radiation Therapy During the COVID-19 Pandemic

  • Benedict Mihangel P. Crisostomo University of the Philippines-Philippine General Hospital
  • Lorelei L. Chavez University of the Philippines-Philippine General Hospital
Keywords: head and neck cancer, repeat simulation, radiotherapy delay, COVID-19 pandemic


Background. Delays in initiation and interruptions in the radiotherapeutic management of head and neck malignancies have radiobiologic implications in allowing for the accelerated repopulation of surviving tumor cells. This phenomenon has been demonstrated to translate into poorer survival outcomes and tumor control, typically manifesting as tumor progression that may require a new radiotherapy set-up. Such adjustments are accounted for with a repeat computed tomography (CT) simulation which entails increased resource costs, patient inconvenience and further treatment delays. Even with maximal efforts to minimize treatment delays, the real-world effects of the current pandemic on the logistics and compliance to daily radiotherapy remain significant. A comparison of the incidence of tumor progression before and during the pandemic is thus investigated, with repeat CT simulation utilized as a surrogate.

Objective. This study aims to compare the incidence of repeat CT simulation among patients with head and neck cancer treated before and during the COVID-19 pandemic. Various patient- and/or treatment-related factors, including treatment delay, that may associate with the likelihood of repeat simulation are also investigated in this review.

Methods. Medical and radiation treatment records of patients with head and neck malignancies who underwent CT simulation before and during the pandemic were retrospectively reviewed and prospectively followed up until completion of treatment.

Results. A total of 72 patients were included, with an average age of 45 years (range: 7–82). The median time to radiotherapy initiation was 37 days (SD ± 37, range of 0–278) from initial CT simulation and was similar between the groups (p = 0.774). Repeat simulation was observed more frequently in the pandemic group (76.2% vs 23.8%, p = 0.007). Patients who had delayed radiotherapy initiation (p = 0.005, OR 13.59; CI 2.23–82.87) or had treatment interruptions (p = 0.004, OR 23.21; CI 2.79–193.29) had a higher incidence of repeat simulation.

Conclusion. A higher incidence of repeat simulation was observed in this population treated six months into the pandemic. Delays in radiotherapy initiation and treatment interruptions were significantly associated with repeat simulation. Strategies should be employed to prevent disease progression among this subset of patients to minimize the burden on radiotherapy resources and preserve oncologic outcomes.