Discrimination of Postradiotherapy Lung Fibrosis from Recurrence by Gallium-67 Scan in Lung Cancer / 대한치료방사선과학회지

ABSTRACT

The differentiation between post-radiotherapy lung fibrosis and tumor recurrence is often a dilemma to physicians. Twenty two patients with lung cancer who had received 45~60 Gy to the chest were chosen to study the possible role of gallium-67 scan. Seventeen squamous cell carcinomas were treated with only radiotherapy, 3 small cell carcinomas with combination chemotherapy, 2 adenocarcinomas with lobectomy. A total of 8 patients with pneumonitis with or without fibrosis and recurrence showed uptake of gallium at the site of inflammation. Of the 12 recurrences and residual diseases after radiotherapy, positive gallium uptake was present in 11 cases (92%). Of the 10 recurrence-free cases, all the 5 patients with pneumonitis revealed gallium accumulation. However, 4 of the 5 patients (805) with recurrence-free fibrosis have not accumulated gallium in the fibrotic areas. Fibrosis in 6 patients were developed after 8 months of completion of radiotherapy. These facts suggest that gallium-67 scan after 1 year post-treatment may aid for the discrimination of fibrosis from tumor recurrence unless pneumonitis is present.