Final report of a prospective randomized study on thoracic radiotherapy target volume for limited‐stage small cell lung cancer with radiation dosimetric analyses

Abstract

BACKGROUND:The thoracic radiotherapy (TRT) target volume for limited-stage small-cell lung cancer (SCLC) has been controversial for decades. In this report, the final results of a prospective randomized trial on the TRT target volume before and after induction chemotherapy are presented. METHODS: After 2 cycles of etoposide and cisplatin, patients arm were randomized to receive TRT to the postchemotherapy or prechemotherapy tumor volume in a study arm and a control arm. Involved-field radiotherapy was received in both arms. TRT consisted of 1.5 grays (Gy) twice daily in 30 fractions to up to a total dose of 45 Gy. Lymph node regions were contoured, and intentional and incidental radiation doses were recorded. RESULTS: The study was halted early because of slow accrual. Between 2002 and 2017, 159 and 150 patients were randomized to the study arm or the control arm, respectively; and 21.4% and 19.1% of patients, respectively, were staged using positron emission tomography/computed tomography (P = .31). With a median follow-up of 54.1 months (range, 19.9-165.0 months) in survivors, the 3-year local/regional progression-free probability was 58.2% and 65.5% in the study and control arms, respectively (P = .44), and the absolute difference was −7.3% (95% CI, −18.2%, 3.7%). In the study and control arms, the median overall survival was 21.9 months and 26.6 months, respectively, and the 5-year overall survival rate was 22.8% and 28.1%, respectively (P = .26). Grade 3 esophagitis was observed in 5.9% of patients in the study arm versus 15.5% of those in the control arm (P = .01). The isolated out-of-field failure rate was 2.6% in the study arm versus 4.1% in the control arm (P = .46), and all such failures were located in the supraclavicular fossa or contralateral hilum. The regions 7, 3P, 4L, 6, 4R, 5, and 2L received incidental radiation doses >30 Gy. CONCLUSIONS: TRT could be limited to the postchemotherapy tumor volume, and involved-field radiotherapy could be routinely applied for limited-stage SCLC. Cancer 2020;126:840-849.

Thoracic radiotherapy in small cell lung cancer—a narrative review

“…BD involved-field radiotherapy was applied in both arms and 20% of patients had a baseline PET/CT. Survival outcomes did not differ between arms, but pre-chemotherapy tumour volume was associated with more G3 esophagitis (15.5% vs. 5.9%; P=0.01) (7,37). Using pre-chemotherapy volume procedure, only 3 out of 27 patients included in a phase II trial developed an isolated nodal failure (11%) and all of these were in the ipsilateral supraclavicular region (38).…”

G9a Regulates Cell Sensitivity to Radiotherapy via Histone H3 Lysine 9 Trimethylation and CCDC8 in Lung Cancer

“… 1 Radiotherapy is widely used for lung cancer therapy. 2 , 3 However, the resistance of cancer cells to radiotherapy is one of the major factors that closely related to the unsatisfactory outcome of lung cancer treatment. Thus, more efforts are required to explore the mechanism underlying lung cancer radioresistance.…”

Final report of a prospective randomized study on thoracic radiotherapy target volume for limited-stage small cell lung cancer with radiation dosimetric analyses—reply

“…Thank you for your interest in our study and we appreciate your constructive editorial comments on our recent publication: "Final report of a prospective randomized study on thoracic radiotherapy target volume for limited-stage small cell lung cancer with radiation dosimetric analyses" (1).…”