Elective Nodal Irradiation in Non-Small Cell Lung Cancer: A Controversy Resolved?

Strategic Insights -

According to a study by E.P. Sulman and colleagues from the University of Texas, the exclusion of prophylactic irradiation of uninvolved lymph node stations in non-small cell lung cancer (NSCLC) patients treated with definitive radiotherapy appears to have minimal impact on elective nodal failure. The researchers analyzed a cohort of 115 patients with NSCLC staged with positron emission tomography (PET)/computed tomography (CT) and treated with 3-dimensional conformal radiotherapy (3D-CRT) that excluded uninvolved lymph node stations. The study found that the majority of patients died from distant metastases, and the overall rate of distant metastases was 36%. The frequencies of in-field failure (IFF), elective nodal failure (ENF), and isolated ENF were 26%, 4.3%, and 1.7%, respectively.

Key Takeaways:

  • The exclusion of prophylactic irradiation of uninvolved lymph node stations in NSCLC patients treated with definitive radiotherapy appears to have minimal impact on elective nodal failure.
  • The majority of patients died from distant metastases, with an overall rate of 36%.
  • The frequencies of IFF, any ENF, isolated ENF, and DM were 26%, 4.3%, 1.7%, and 36%, respectively.
  • The researchers observed only a 4.3% recurrence of any ENF and a 1.7% recurrence of isolated ENF in patients with NSCLC treated with definitive 3D-CRT without prophylactic irradiation of uninvolved lymph node stations.
  • The study suggests that distant metastasis and IFF remain the primary causes of treatment failure and cancer death in patients with NSCLC.
  • The study has implications for the role of elective nodal irradiation in NSCLC treatment protocols.

Statistics:

  • 115 patients with NSCLC were treated with definitive radiation therapy with or without concurrent chemotherapy.
  • The median follow-up time was 18 months (3 to 44 months) among all patients and 27 months (6 to 44 months) among survivors.
  • The median overall survival, 2-year actuarial overall survival, and disease-free survival were 19 months, 38%, and 28%, respectively.
  • 31 patients experienced local regional failure, with 26 (22.6%) experiencing IFF and 5 (4.3%) experiencing ENF.
  • For 88 patients with stage IIIA/B disease, the frequencies of IFF, any ENF, isolated ENF, and DM were 23 (26%), 3 (9%), 1 (1.1%), and 36 (40.9%), respectively.
  • For 22 patients with early stage node-negative disease (stage IA/IB), the frequencies of IFF, any ENF, isolated ENF, and DM were 3 (13.6%), 1 (4.5%), 0 (0%), and 5 (22.7%), respectively.

Sources:

  • Sulman, E.P. et al. (2009). Exclusion of elective nodal irradiation is associated with minimal elective nodal failure in non-small cell lung cancer. Radiation Oncology, 4, 5.
  • Cancer Weekly (2009). Elective Nodal Irradiation in Non-Small Cell Lung Cancer: A Controversy Resolved? Cancer Weekly, published in NewsRx.com.