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

  • 12562

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    P3.08-018 - Stereotactic body radiotherapy for oligometastatic disease to the lung (ID 2371)

    09:30 - 09:30  |  Author(s): W. Rule
    • Abstract

    Background
    With the increasing penetration of stereotactic body radiotherapy (SBRT) into cancer practice, there is growing interest in applying this technique to patients with limited metastatic disease. We reviewed our single institution experience using SBRT in the treatment of oligometastatic pulmonary disease.

    Methods
    A retrospective review was performed to identify patients treated at our institution with SBRT for pulmonary metastases between 3/2008 and 1/2013. Treatment decisions were multidisciplinary and a biopsy was performed when feasible. The gross tumor volume (GTV) was non-uniformly expanded to create an internal target volume (ITV) to encompass tumor motion based on 4-dimensional computed tomography (CT). A 5 mm uniform expansion of the ITV was then applied to create the planning target volume (PTV). The most common dose/fractionation schedule was 48-50 Gy in 4-5 fractions. Cone beam CT was used for daily image guidance. Overall survival (OS), time to distant failure (TTDF), and local control (LC) were estimated from the end of the first SBRT procedure using the Kaplan-Meier method. Toxicity was scored based on CTCAEv4. Median follow up was 15 months (range 3-60).

    Results
    64 patients underwent 66 SBRT procedures to treat 74 lesions. There were 36 males (56%) and 28 females (44%) with a median age of 71 years (range 42-90). The most common primary disease sites were lung (n=23; 36%), colorectal (n=10; 16%), melanoma (n=9; 14%), and head and neck (n=5; 8%). The target lesion represented the only site of metastatic disease in 32 patients (50%); 20 patients (31%) had additional pulmonary metastases but no extra-thoracic disease; 12 patients (19%) had both pulmonary and non-pulmonary sites of metastases. Median lesion size was 2.3 cm (range 0.6-6.8). Median, 1-year, and 2-year OS was 21 months, 73%, and 49%, respectively. Distant metastatic disease progression was observed in 37 patients (58%) at a median time interval of 12 months. Patients (n=52) with no extra-thoracic disease at the time of SBRT had a significantly longer TTDF compared to patients (n=12) with concurrent extra-thoracic disease (median 13 vs. 5 months; 1-year failure rate 47 vs. 73%; p = 0.02) without a difference in OS (median OS not reached vs. 20 months; 1-year OS 75 vs. 63%; p=0.1). Local failure was observed for 4 lesions resulting in an 18-month LC rate of 88%. There were 11 toxicities observed in 10 patients including fatigue (n =1, grade 1), dyspnea (n=1, grade 1), dermatitis (n=1, grade 2), rib fracture (n=1, grade 2), and pneumonitis (n= 5, grade 2; n=2, grade 3).

    Conclusion
    SBRT is a reasonable treatment for patients with pulmonary metastases. High rates of local control can be achieved with acceptable toxicity. Only 2 patients (3%) developed grade 3 pneumonitis (oxygen indicated). In this high risk population, new distant metastatic progression was common, especially among patients who present for SBRT with known extra-thoracic sites of disease at the time of SBRT. However, among patients with solitary lung lesions or oligometastatic disease limited to the chest, survival was encouraging. We will continue to utilize SBRT in this population of oligometastatic disease with careful patient selection.