A Case of Radiation Fibrosis Appearing as Mass-Like Consolidation after SBRT with Elevation of Serum CEA

Abstract EN

We report a case of radiation fibrosis appearing as mass-like consolidation, which was difficult to distinguish from local recurrence.

A 72-year-old woman was diagnosed as having primary lung cancer (cT1N0M0 stage IA) in the right upper lobe and was treated with SBRT of 48 Gy in 4 fractions.

After 12 months, mass-like consolidation appeared around the irradiated area, and after 13 months, it had increased in size.

FDG-PET revealed high uptake (SUV max=5.61) for the consolidation.

CT-guided biopsy was performed, but we could not confirm the diagnosis.

Considering her poor respiratory function and her age, short-interval follow-up was performed.

After 15 months, the consolidation enlarged at the dorsal side, and carcinoembryonic antigen (CEA) became elevated (14.6 ng/mL).

Serum KL-6 (436 U/mL) and SP-D (204 ng/mL) were also elevated.

However, after 16 months, serum CEA slightly decreased.

The consolidation gradually retracted on follow-up CT images.

CEA, KL-6, and SP-D were also decreased by degrees.

After 40 months, there is no evidence of local recurrence.