Ultra Low Doses of Therapy With Radiation Applicated to COVID-19

Low Doses of Lung Radiation Therapy in Cases of COVID-19 Pneumonia: Prospective Multicentric Study in Radiation Oncology Centers

The host response against the coronavirus 2 (SARS-CoV-2) appears to be mediated by a 'cytoquine storm' developing a systemic inflammatory mechanism and an acute respiratory distress syndrome (ARDS), in the form of a bilateral pneumonitis, requiring invasive mechanical ventilation (IMV) in an important group of patients.

In terms of preventing progression to the critical phase with the consequent need of admission to the intensive care units (ICU), it has been recently proposed that this inflammatory cytoquine-mediated process can be safely treated by a single course of ultra-low radiotherapy (RT) dose < 1 Gy.

The main purpose of the study was to analyze the efficacy of ultra low-dose pulmonary RT, as an anti-inflammatory intention in patients with SARS-Cov-2 pneumonia with a poor or no response to standard medical treatment and without IMV.

The exceedingly high mortality rates of severe and critical COVID-19 warrant the evaluation of novel therapies that could potentially mitigate the advanced disease manifestations. In this context, is proposes a prospective multicenter study. It will include 15 patients, to assess the feasibility and efficacy of low-dose lung irradiation in COVID-19 pneumonia.

Inclusion Criteria:

1. Age > 18 years-old.

2. Diagnosis of pneumonia due to COVID-19 serologically proven by polymerase chain reaction (PCR) or highly suspected to be COVID-related.

3. Charlson Comorbidity Index (CCI) less than 6 score.

4. Poor or no response to standard medical treatment, based on:

   *% Sat02 <93%

   • Oxygen therapy escalation (Understanding from less to more need for support: Nasal Cannula-NC-; Ventimask -VMK- and VMK with reservoir)
   • Pa02 / Fi02 (blood gas analysis) <300 mmHg
   • 1 or more inflammatory and immunological analytical parameters such as lymphocytes, IL-6, D-dimer, ferritin, LDH, C Reactive Protein (CRP) and fibrinogen with values above the normal range, except lymphocytes.
   • Radiological impairment defined as worsening of TSS throughout admission or score at admission: TSS> 5 by a diagnostic baseline CT scan.

5. Eastern Cooperative Oncology Group (ECOG) Status < or = 3

6. Life expectancy (LE)> 1 month at hospital admission for COVID-19

7. No previous thoracic RT (relative-individualization criteria) or chemotherapy (chemoinduced pulmonary toxicity, eg Bleomycin).

8. Verbal information on the procedure, objective and secondary effects, acceptance and signing of informed consent by the patient or legal guardian.

Exclusion Criteria:

• Failure to meet the inclusion criteria.
• Any uncontrolled intercurrent illness that would put the patient at greater risk or limit compliance with study requirements in the opinion of the investigator.
• Patients admitted in ICU.
• Refusal of treatment after verbal information.