CT patterns and serial CT Changes in lung Cancer patients post stereotactic body radiotherapy (SBRT)

Rashid Al-Umairi; Usman Tarique; Rahim Moineddin; Laura Jimenez-Juan; Lan Chau Kha; Patrick Cheung; Anastasia Oikonomou

doi:10.1186/s40644-022-00491-1

CT patterns and serial CT Changes in lung Cancer patients post stereotactic body radiotherapy (SBRT)

Cancer Imaging. 2022 Sep 16;22(1):51. doi: 10.1186/s40644-022-00491-1.

Authors

Rashid Al-Umairi¹, Usman Tarique¹, Rahim Moineddin², Laura Jimenez-Juan³, Lan Chau Kha¹, Patrick Cheung⁴, Anastasia Oikonomou⁵

Affiliations

¹ Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Toronto, ON, M4N3M5, Canada.
² Department of Family and Community Medicine, Dalla Lana School of Public Health, University of Toronto, 500 University Avenue, Toronto, ON, M5G1V7, Canada.
³ Department of Medical Imaging, St. Michael's Hospital, University of Toronto, 30 Bond St, Toronto, ON, M5B 1W8, Canada.
⁴ Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Toronto, ON, M4N3M5, Canada.
⁵ Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Toronto, ON, M4N3M5, Canada. anastasia.oikonomou@sunnybrook.ca.

Abstract

Background: To evaluate computed tomography (CT) patterns of post-SBRT lung injury in lung cancer and identify time points of serial CT changes.

Materials and methods: One hundred eighty-three tumors in 170 patients were evaluated on sequential CTs within 29 months (median). Frequencies of post-SBRT CT patterns and time points of initiation and duration were assessed. Duration of increase of primary lesion or surrounding injury without evidence of local recurrence and time to stabilization or local recurrence were evaluated.

Results: Post-SBRT CT patterns could overlap in the same patient and were nodule-like pattern (69%), consolidation with ground glass opacity (GGO) (41%), modified conventional pattern (39%), peribronchial/patchy consolidation (42%), patchy GGO (24%), diffuse consolidation (16%), "orbit sign" (21%), mass-like pattern (19%), scar-like pattern (15%) and diffuse GGO (3%). Patchy GGO started at 4 months post-SBRT. Peribronchial/patchy consolidation and consolidation with GGO started at 4 and 5 months respectively. Diffuse consolidation, diffuse GGO and orbit sign started at 5, 6 and 8 months respectively. Mass-like, modified conventional and scar-like pattern started at 8, 12 and 12 months respectively. Primary lesion (n = 11) or surrounding injury (n = 85) increased up to 13 months. Primary lesion (n = 119) or surrounding injury (n = 115) started to decrease at 4 and 9 months respectively. Time to stabilization was 20 months. The most common CT pattern at stabilization was modified conventional pattern (49%), scar-like pattern (23%) and mass-like pattern (12%). Local recurrence (n = 15) occurred at a median time of 18 months.

Conclusion: Different CT patterns of lung injury post-SBRT appear in predictable time points and have variable but predictable duration. Familiarity with these patterns and timeframes of appearance helps differentiate them from local recurrence.

Keywords: CT patterns; Computed tomography; Lung cancer; Radiation induced lung injury; Stereotactic body radiotherapy.

MeSH terms

Cicatrix / pathology
Humans
Lung Injury*
Lung Neoplasms* / pathology
Radiosurgery* / adverse effects
Radiosurgery* / methods
Tomography, X-Ray Computed / methods