CASE 18228 Published on 12.08.2023
0

Symptomatic radiation recall pneumonitis induced by immunotherapy

Section

Chest imaging

Case Type

Clinical Cases

Authors

Laida Etxeberria Kaiuela, Helena Gómez Herrero, Hector Lajusticia Andrés, Iván Vicaría Fernández, José Manuel Hidalgo Gómez de Travecedo

Hospital Universitario de Navarra, Pamplona, Spain

Connected authors
Patient

77 years, male

Categories
Area of Interest Thorax ; Imaging Technique CT
Download as PDF Print Show related cases Notify admin
Clinical History

A 77-year-old man was diagnosed with lung adenocarcinoma in right lower lobe with mediastinal and cervical lymphadenopathies. He was treated with chemotherapy and sequential radiotherapy. 21 months after the diagnosis, due to progression, he was treated with anti-PD-L1 Atezolizumab. Three months later, the patient developed a process of respiratory failure.

Imaging Findings

Axial chest CT images at diagnosis revealed a solid lobulated mass in right lower lobe that corresponds to primary lung neoplasm with cervical and subcarinal lymphadenopathies.

Three months after immunotherapy initiation, the patient was admitted at hospital with acute respiratory symptoms and a chest CT was performed showing signs of lung fibrosis from previous radiotherapy and new ground glass opacities in paramediastinal region, localised within the previously irradiated area.

Pulmonary infection was ruled out by blood and sputum culture and the images were not suggestive of neoplasm recurrence. The clinical evolution was good just with supportive care. Based on the above facts, it was suggested that the patient had radiation recall pneumonitis induced by Atezolizumab, and prednisolone was administered.

Discussion

Radiation recall pneumonitis (RRP) manifests as acute inflammation confined to previously irradiated lung tissue, which can occur months or even as late as 5 years after radiotherapy in response to treatment [1]. Several studies reported that chemotherapy agents and molecular target-agents could cause RRP [2], and lately there are reported cases with immunotherapy. Currently, the specific pathophysiological mechanism of RRP still remains unclear. There are some hypotheses suggested, including idiosyncratic drug hypersensitivity reactions, changes in the function of stem cells in the irradiated field, vascular injuries or inflammatory cascades [3].

The clinical manifestation varies from completely asymptomatic to severely symptomatic with non-productive cough and dyspnea on exertion [2].

The radiologic images show ground-glass or consolidative opacities confined to prior radiation field, as opposed to ICI-related pneumonitis, which is typically diffuse [1]. The most common radiologic pattern is organizing pneumonia (OP) [4].

The treatment for RRP includes discontinuation of the systemic anti-tumour agents, administration of corticosteroids and supportive medical care [2].

In conclusion, RRP is a delayed complication of radiotherapy triggered by antineoplasm treatments including immunotherapy that can be easily misdiagnosed. In the future, with the increasing use of ICIs in advanced lung cancer, we can expect that previously irradiated patients will be more exposed to radiation recall pneumonitis, enhancing the importance of understanding and recognizing it [1].

Differential Diagnosis List
Radiation recall pneumonitis induced by immunotherapy
ICI-related pneumonitis
Radiation pneumonitis
Infectious processes
Final Diagnosis
Radiation recall pneumonitis induced by immunotherapy
Case information
URL: https://eurorad.org/case/18228
DOI: 10.35100/eurorad/case.18228
ISSN: 1563-4086
License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

Axial chest CT images at diagnosis

Disseminated lung neoplasm with solid lobulated mass in right lower lobe that corresponds to primary lung neoplasm (Figure 1a; Figure 1b) and subcarinal (Figure 1c) and cervical (Figure 1d) lymphadenopathies
Disseminated lung neoplasm with solid lobulated mass in right lower lobe that corresponds to primary lung neoplasm (Figure 1a; Figure 1b) and subcarinal (Figure 1c) and cervical (Figure 1d) lymphadenopathies
Disseminated lung neoplasm with solid lobulated mass in right lower lobe that corresponds to primary lung neoplasm (Figure 1a; Figure 1b) and subcarinal (Figure 1c) and cervical (Figure 1d) lymphadenopathies
Disseminated lung neoplasm with solid lobulated mass in right lower lobe that corresponds to primary lung neoplasm (Figure 1a; Figure 1b) and subcarinal (Figure 1c) and cervical (Figure 1d) lymphadenopathies
Disseminated lung neoplasm with solid lobulated mass in right lower lobe that corresponds to primary lung neoplasm (Figure 1a; Figure 1b) and subcarinal (Figure 1c) and cervical (Figure 1d) lympadenopathies
Disseminated lung neoplasm with solid lobulated mass in right lower lobe that corresponds to primary lung neoplasm (Figure 1a; Figure 1b) and subcarinal (Figure 1c) and cervical (Figure 1d) lymphadenopathies
Disseminated lung neoplasm with solid lobulated mass in right lower lobe that corresponds to primary lung neoplasm (Figure 1a; Figure 1b) and subcarinal (Figure 1c) and cervical (Figure 1d) lymphadenopathies
Disseminated lung neoplasm with solid lobulated mass in right lower lobe that corresponds to primary lung neoplasm (Figure 1a; Figure 1b) and subcarinal (Figure 1c) and cervical (Figure 1d) lymphadenopathies
Figure 2

Axial and coronal chest CT images before (Figure 2a; Figure 2b) and after (Figure 2c; Figure 2d) immunotherapy

Signs of paramediastinal lung fibrosis with bronchiectasis and right pleural effusion from previous radiotherapy (Figure 2a-b
Signs of paramediastinal lung fibrosis with bronchiectasis and right pleural effusion from previous radiotherapy (Figure 2a-b-c-d) and new ground glass opacities in paramediastinal region, localised within the previously irradiated area after immunotherapy (Figure 2c; Figure 2d)
Signs of paramediastinal lung fibrosis with bronchiectasis and right pleural effusion from previous radiotherapy (Figure 2a-b
Signs of paramediastinal lung fibrosis with bronchiectasis and right pleural effusion from previous radiotherapy (Figure 2a-b-c-d) and new ground glass opacities in paramediastinal region, localised within the previously irradiated area after immunotherapy (Figure 2c; Figure 2d)
Signs of paramediastinal lung fibrosis with bronchiectasis and right pleural effusion from previous radiotherapy (Figure 2a-b
Signs of paramediastinal lung fibrosis with bronchiectasis and right pleural effusion from previous radiotherapy (Figure 2a-b-c-d) and new ground glass opacities in paramediastinal region, localised within the previously irradiated area after immunotherapy (Figure 2c; Figure 2d)
Signs of paramediastinal lung fibrosis with bronchiectasis and right pleural effusion from previous radiotherapy (Figure 2a-b
Signs of paramediastinal lung fibrosis with bronchiectasis and right pleural effusion from previous radiotherapy (Figure 2a-b-c-d) and new ground glass opacities in paramediastinal region, localised within the previously irradiated area after immunotherapy (Figure 2c; Figure 2d)