Stereotactic body radiation therapy for the treatment of a post-chemotherapy remnant lung mass in extensive-stage small-cell lung cancer: A case report

Stereotactic body radiation therapy (SBRT) can significantly improve the treatment outcomes of patients with inoperable stage I non-small-cell lung cancer. Similarly, a few case studies have reported the effectiveness of SBRT for stage I small-cell lung cancer (SCLC). However, no study has investigated the use of SBRT for extensive-stage SCLC (ES-SCLC). Compared with conventional RT, SBRT is able to deliver a higher radiation dose precisely and safely to small targets in short-duration treatments. The present study reports the outcome of a patient with ES-SCLC who responded favorably to initial chemotherapy and received SBRT for a residual mass in the peripheral lung. A 62-year-old female presented with pathologically determined SCLC at clinical stage T4N3M0-T4 as separate tumor nodules were present in different ipsilateral lobes. The patient received 6 cycles of standard chemotherapy with cisplatin and etoposide. The response of the patient to chemotherapy was evaluated using contrast-enhanced chest computed tomography and 18 F-fluorodeoxyglucose positron emission tomography-computed tomography. The only suspected residual viable tumor was a 1.5-cm mass in the right upper lobe. Targeting this mass, intensity-modulated SBRT was performed with 48 Gy in 4 fractions and 6 MV photons. In addition, prophylactic cranial irradiation was conducted with 25 Gy in 10 fractions. The patient is alive with no evidence of disease 4 years after treatment. SBRT toxicity was limited to radiation pneumonitis or fibrosis without pulmonary symptoms. This case report suggests the efficacy of SBRT in select ES-SCLC patients with small residual lung disease following chemotherapy.