Clinical Outcomes of Stereotactic Body Radiotherapy for Patients With Stage I Small-Cell Lung Cancer: Analysis of a Subset of the Japanese Radiological Society Multi-Institutional SBRT Study Group Database

Abstract

Stereotactic body radiotherapy (SBRT) is widely used as a curative treatment option for stage I non-small-cell lung cancer, but for patients with stage I small-cell lung cancer, the role of stereotactic body radiotherapy is unclear. In this study, we retrospectively analyzed the outcomes of a subset of patients with stage I small-cell lung cancer treated with stereotactic body radiotherapy in the database of the Japanese Radiological Society-Multi-Institutional stereotactic body radiotherapy Study Group. The 43 patients treated with stereotactic body radiotherapy for stage I small-cell lung cancer between 2004 and 2012 at 11 Japanese institutions were studied: median age = 77 years; 32 (74%) males and 11 females; and 80% were medically inoperable. The clinical stage was IA in 31 and IB in 12. In all patients, the lung tumors were pathologically proven as small-cell lung cancer. A total dose of 48 to 60 Gy was administered in 4 to 8 fractions. The median biologically effective dose (α/β = 10 Gy) was 105.6 Gy. Chemotherapy and prophylactic cranial irradiation were administered in only 8 patients, respectively. The median follow-up time was 23.2 months. The 2-year overall survival, progression-free survival, and distant metastasis-free survival rates were 72.3%, 44.6%, and 47.2%, respectively. The 2-year local control was 80.2%. Regarding the patterns of failure, distant metastasis, lymph node metastasis, and local recurrence were observed in 47%, 28%, and 16% of patients, respectively. No ≥grade 3 stereotactic body radiotherapy-related toxicities were observed. Although stereotactic body radiotherapy was thus revealed to be effective for the local control of stage I small-cell lung cancer, the incidence of distant metastases was high. Further investigations of larger cohorts are needed, including analyses of the effects of combined chemotherapy.

Stereotactic body radiotherapy versus conventional radiotherapy for early-stage small cell lung cancer

“…This is in stark contrast to a review of 43 patients in a Japanese study, where most patients (81.4%) were not treated with chemotherapy. 24 It is notable that the rate of distant metastases at two years was considerably higher at 28% in this study. The results of these series, taken together with our results, underscore the importance of systemic therapy in the control of early stage SCLC and, in particular, after the use SBRT.…”

CSC Radioresistance: A Therapeutic Challenge to Improve Radiotherapy Effectiveness in Cancer

“…Although many patients are still treated with conventional RT, other advanced RT techniques have been developed such as stereotactic body radiation therapy (SBRT) that uses with accuracy high doses of radiation delivered to target local tumors. SBRT has been applied to the treatment of several cancers [ 20 , 21 , 22 ] with promising results for early lung cancers, with local control rates above 80% [ 20 , 23 ]. In addition to SBRT, particle-beam therapy has demonstrated excellent therapeutic outcomes in various types of cancer with a growing number of patients undergoing this therapy [ 24 ].…”

Difference in Acquired Radioresistance Induction Between Repeated Photon and Particle Irradiation

“…SBRT has been applied to the treatment of various cancers, including lung (1), liver (2), and prostate cancer (3). The therapeutic outcomes of SBRT are particularly promising for early stage lung cancers, with local control rates exceeding 80% (1, 4) and clinical outcomes comparable to those of surgical resection (5, 6).…”