Sites of recurrent disease in SCLC patients treated with radiochemotherapy – is selective nodal irradiation safe?


Sites of recurrent disease in SCLC patients treated with radiochemotherapy – is selective nodal irradiation safe?

Gumina, C.; Valentini, C.; Bütof, R.; Appold, S.; Baumann, M.; Troost, E. G. C.

Background: Concurrent radiochemotherapy (CCRT) is the standard treatment in locally advanced small cell lung cancer (SCLC) patients. Even though elective nodal irradiation (ENI) had been advocated, its use in routine clinical practice is still limited [van Loon, 2010]. Therefore, the purpose of this study is to assess the sites of recurrent disease in SCLC patients and to evaluate the feasibility of selective nodal irradiation (SNI) versus ENI.

Methods: A retrospective single-institution study was performed in stage I-III SCLC patients treated with radical CCRT. After state-of-the-art staging, all patients underwent three-dimensional conformal radiotherapy to a total dose of 45 Gy in twice-daily fractions of 1.5 Gy starting concurrently with the first or second cycle of chemotherapy (etoposide, cisplatinum) cycle. The gross tumor volume (GTV) consisted of the primary tumor and SNI visualized on CT and/or FDG-PET, or confirmed by cytology. The clinical target volume (CTV) was obtained by expanding the GTV, adjusting it for anatomical boundaries, and electively adding the supraclavicular lymph node stations. Thereafter, the CTV was expanded to a planning target volume based on institutional guidelines. After CCRT, prophylactic whole-brain irradiation (WBI; 30 Gy in 15 fractions) was administered to patients with a (near-complete) response. Follow-up consisted of a CT-thorax 6-8 week after completing treatment, followed by a 3-monthly chest x-ray or CT-scan. For this retrospective analysis, we reviewed all imaging data used for radiation treatment planning and during follow-up. The site of loco-regional relapse was correlated to the initial site and dose delivered.

Results: between April 2004 and December 2013, 54 patients underwent CCRT (followed by WBI in 63%). After a median time of 11.5 months, 17 patients (31.5%) had relapsed locally or regionally: six within the initial primary tumor volume, five within the initially affected lymph nodes, three metachronously within the primary tumor and initially affected lymph nodes, and three inside and outside of the initial nodal disease. Only one patient developed isolated supraclavicular lymph node metastases in the electively treated volume. All sites of loco-regional recurrence had received 92%-106% of the prescribed dose. Thirty-seven patients (69%) developed distant metastases (37.8% liver, 35% brain).

Conclusion: In this retrospective analysis, most patients recurred in the initially affected primary tumor or lymph nodes, or distantly. So, in order to reduce toxicity, one may consider omitting irradiation of the supraclavicular lymph node stations in those patients with affected lymph nodes in the lower hilar and mediastinal lymph node stations.

References:

Loon J, De Ruysscher D, Wander S, et al. Selective Nodal Irradiation on Basis of 18FDG-PET Scans in Limited-Disease Small-Cell Lung Cancer: A Prospective Study. Int J Radiat Oncol Biol Phys 2010,77(2):329-336.

Keywords: SCLC; selective nodal irradiation

  • Contribution to proceedings
    IASLC 17th World Conference on Lung Cancer, 04.-07.12.2016, Wien, Österreich
  • Abstract in refereed journal
    Journal of Thoracic Oncology 12(2016)1, S1038-S1039

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Publ.-Id: 23928