Author of

• 12544

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  P3.08 - Poster Session 3 - Radiotherapy (ID 199)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Radiation Oncology + Radiotherapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 12555

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    P3.08-011 - Stereotactic Ablative Radiotherapy: A Potentially Curable Approach to Multiple Primary Lung Cancer (ID 1454)

    09:30 - 09:30  |  Author(s): Z. Zhu
    • Abstract

    Background
    Lung parenchymal recurrent or multiple lobe cancer is typically considered to have metastatic disease and treated with palliative approach such as chemotherapy. However, some of these patients may have multiple primary lung cancer (MPLC) that could be potential curable. Surgical resection has been the standard treatment for early-stage multiple primary lung cancer (MPLC). However, a significant proportion of patients with MPLC cannot undergo surgery. We explored here the role of stereotactic ablative radiotherapy (SABR) for patients with MPLC.

    Methods
    We reviewed MPLC cases treated with SABR (50 Gy in 4 fractions) for the second tumor. Four-dimensional CT–based planning/volumetric image-guided treatment was used for all patients. Patients underwent chest CT scanning every 3 months for 2 years after the SABR and then every 6 months for another 3 years. PET scans were recommended at 3–12 months after SABR. Toxic effects were scored according to the National Cancer Institute Common Terminology Criteria for Adverse Effects version 4.

    Results
    For the 101 patients treated with SABR, at a median follow-up interval of 36 months and median overall survival of 46 months, 2-year and 4-year in-field local control rates were 97.4% and 95.7%. 2- and 4-year rates of overall survival (OS) were 73.2% and 47.5% and progression-free survival (PFS) were 67.0% and 58.0%. Patients with metachronous tumors had higher OS and PFS than did patients with synchronous tumors (2-year OS 80.6% metachronous vs. 61.5% synchronous; 4-year OS 52.7% vs. 39.7%; p=0.047; 2-year PFS 84.7% vs. 49.4%; 4-year PFS 75.6% vs. 30.4%; p=0.0001). For patients whose tumors were both of the same histology (meaning that the second lesion could have been a satellite, a metastasis, or a recurrent lesion), the 2-year and 4-year OS rates were 76.4% and 51.2%, which were no different from the OS rates for patients with tumors of different pathology (2-year OS: 66.7% and 4-year OS: 40.5%; p=0.406). The 2- and 4-year OS of patients in whom both tumors were classified as stage I were 76.1% and 55.2%, which was better than the OS rates for the patients whose index tumors were of higher stage (2-year OS 66.7%, 4-year OS 26.6%; p=0.049). For patients whose index tumor was treated with surgery or SABR, the incidence of grade ≥3 radiation pneumonitis was 3% (2/71), but this increased to 17% (5/30) for patients whose index tumor was treated with conventional radiotherapy. Other grade ≥3 toxicities included grade 3 chest wall pain (3/101, 3%) and grade 3 skin toxicity (1/101, 1%).

    Conclusion
    1. SABR achieves an excellent long-term tumor control and promising PFS and OS in early-stage MPLC. 2. Toxicity could happen but within the scope of SABR in stage I disease. 3. Caution should be taken integrating SABR with prior conventional radiotherapy for stage II/III disease. SABR could be an effective alternative to surgery for curative treatment of early-stage MPLC tumors.