Comparison of treatment outcomes between involved-field and elective nodal irradiation in limited-stage small cell lung cancer.
OBJECTIVE
The present study was performed to assess the usefulness of involved-field irradiation and the impact of (18)F-fluorodeoxyglucose-positron emission tomography-based staging on treatment outcomes in limited-stage small cell lung cancer.


METHODS
Eighty patients who received definitive chemoradiotherapy for limited-stage small cell lung cancer were retrospectively analyzed. Fifty patients were treated with involved-field irradiation, which means that the radiotherapy portal includes only clinically identifiable tumors. The other 30 patients were irradiated with a comprehensive portal, including uninvolved mediastinal and/or supraclavicular lymph nodes, so-called elective nodal irradiation. No significant difference was seen in clinical factors between the two groups.


RESULTS
At a median follow-up of 27 months (range, 5-75 months), no significant differences were observed in 3 year overall survival (44.6 vs. 54.1%, P= 0.220) and 3 year progression-free survival (24.4 vs. 42.8%, P= 0.133) between the involved-field irradiation group and the elective nodal irradiation group, respectively. For patients who did not undergo positron emission tomography scans, 3 year overall survival (29.3 vs. 56.3%, P= 0.022) and 3 year progression-free survival (11.0 vs. 50.0%, P= 0.040) were significantly longer in the elective nodal irradiation group. Crude incidences of isolated nodal failure were 6.0% in the involved-field irradiation group and 0% in the elective nodal irradiation group, respectively. All isolated nodal failures were developed in patients who had not undergone positron emission tomography scans in their initial work-ups.


CONCLUSIONS
If patients did not undergo positron emission tomography-based staging, the omission of elective nodal irradiation resulted in impaired survival outcomes and raised the risk of isolated nodal failure. Therefore, involved-field irradiation for limited-stage small cell lung cancer might be reasonable only with positron emission tomography scan implementation.
Department of Radiation Oncology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, Republic of Korea. khjae@snu.ac.kr
Tae Jin
TJ
Han
Hak Jae
HJ
Kim
Hong-Gyun
HG
Wu
Dae-Seog
DS
Heo
Young Whan
YW
Kim
Se-Hoon
SH
Lee
D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D016190:Carboplatin / Q000008:administration & dosage; D059248:Chemoradiotherapy; D002945:Cisplatin / Q000008:administration & dosage; D005047:Etoposide / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D008198:Lymph Nodes / Q000528:radiation effects*; D015182:Lymphatic Irradiation; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D009367:Neoplasm Staging; D011379:Prognosis; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D055752:Small Cell Lung Carcinoma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D015996:Survival Rate; D014057:Tomography, X-Ray Computed
D005047:Etoposide; D016190:Carboplatin; D002945:Cisplatin