ESTRO 2022

Session Item

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Session Type: Poster (digital)

Track: Interdisciplinary

Journey:

Survival Analysis for Whole Lung Radiation in Patients with Acute Respiratory Syndrome for COVID-19

Cindy Sharon Ortiz Arce, Mexico

Presentation Number: PO-1060

Abstract

Abstract Title:

Survival Analysis for Whole Lung Radiation in Patients with Acute Respiratory Syndrome for COVID-19

Authors:

Cindy Sharon Ortiz Arce¹, Miguel Angel Souto del Bosque², Alejandro Olmos Guzmán³, Diana Hernández Hernández⁴, Cesar Aurelio Trujillo Rodríguez⁴, David Calderon Mendoza³, Placido Domingo Esqueda Guerrero³, Flavio Manuel Calva Barrera⁵, Arcadio Betancourt Fuentes⁵, Miriam Patricia Ramírez De la Paz³, Graciela Cervantes Aguilar³, Juan German Celis Quintal⁶, Luis Ricardo Nolazco Muñoz⁷

¹UMAE N°1, Instituto Mexicano Seguro Social, Radiotherapy, Leon, Mexico; ²UMAE N°25, Instituto Mexicano del Seguro Social, Radiotherapy, Monterrey, Mexico; ³UMAE N°1, Instituto Mexicano del Seguro Social, Radiotherapy, León, Mexico; ⁴UMAE N°1, Instituto Mexicano del Seguro Social, Internal Medicine, León, Mexico; ⁵UMAE N°1, Instituto Mexicano del Seguro Social, Physics Department, León, Mexico; ⁶UMAE N°1, Instituto Mexicano del Seguro Social, General Director, León, Mexico; ⁷UMAE N°1, Instituto Mexicano del Seguro Social, Medical Director, León, Mexico

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Purpose or Objective

Infections caused by SARS-CoV-2 (COVID-19) have resulted in a pandemic and health emergency; multiple studies with antibiotics and monoclonal antibodies have been used; however, have not been conclusive regarding the benefit. Treatment with radiation therapy (RT) at low doses generates an anti-inflammatory effect, that are effective and safe in reducing the symptoms produced by COVID-19.

The present study was carried out with the objective of determine survival in patients treated with Low Doses of Whole Lung Irradiation (LD-WLI) for COVID-19 moderate or severe pneumonia.

Material and Methods

In this matched, prospective, comparative cohort study, patients were matched by age, sex and ARDS.

We included PCR-confirmed COVID-19 pneumonia patients older than 18 years of age, with confirmed pneumonia by chest tomography. Control group received treatment based on the national protocol for COVID-19 pneumonia, and the intervention group additionally received low doses of radiotherapy to both lungs.

After signed informed consent, patients were treated with Varian with 6 MV AP/PA open fields in supine or prone position. Physical planning was performed using diagnostic tomography upon admission, considering the middle of the depth of the thorax as the isocentre. Treatment plans were manually calculated by a medical physicist with a single dose of 1 Gy to both lungs.

Results

The study was conducted from April 1st to August 30th, 2020. We included 59 patients; 30 were included in the treatment group, and 29 were included in the control group.

Mortality among patients in the radiotherapy group was 27.5% compared with 58.6% in the control group (P<0.05). When ARDS severity was analysed, survival among patients with moderate ARDS was significantly better for the radiotherapy group, 100% vs 40%, respectively (P<0.01).

Furthermore, there was no difference in survival among patients with severe ARDS (P 0.90), with 22% for the radiotherapy group and 0% for the control group (Fig. 1).

Regarding the requirement for orotracheal intubation (OTI), there was a non significant tendency toward a decrease in patients treated with radiotherapy, with 33% intubated patients compared with 58% in the control group (p=0.51). In the subgroup analysis, none of the moderate cases in the control group required OTI, while 45% of the control group required OTI (p<0.001). In severe ARDS, there was no difference in the requirement of OTI (Fig 2)

Conclusion

The results obtained in this study show that LD-WLI could be an alternative to lessen the mortality of patients with COVID-19 pneumonia. These results encourage future study of the clinical impacts of including radiotherapy as an additional treatment for COVID-19 patients who do not interact with other treatments implemented. In addition, reducing the requirement of mechanical ventilation can impact the mortality of patients with moderate ARDS, particularly in low- and middle-income countries that lack access to novel treatments used in developed countries.