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Enis Ozyar



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    P2.16 - Treatment of Early Stage/Localized Disease (Not CME Accredited Session) (ID 965)

    • Event: WCLC 2018
    • Type: Poster Viewing in the Exhibit Hall
    • Track:
    • Presentations: 2
    • Moderators:
    • Coordinates: 9/25/2018, 16:45 - 18:00, Exhibit Hall
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      P2.16-14 - Results of Stereotactic Radiation Therapy (SABR) in Early Stage Lung Cancer: Turkish Radiation Oncology Group (TROG) Study (ID 12612)

      16:45 - 18:00  |  Author(s): Enis Ozyar

      • Abstract
      • Slides

      Background

      To determine factors affecting treatment outcomes for SABR in inoperable early stage lung cancer (ESLC) patients treated by TROG member centers.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      A total of 386 ESLC patients treated with SABR between 2009-2017 were retrospectively analyzed. Factors related to disease, treatment and patients’ characteristics were recorded. Primary endpoints were overall survival (OS), progression free survival (PFS), local control (LC), regional control (RC) and radiation-related toxicities.

      4c3880bb027f159e801041b1021e88e8 Result

      Median follow-up was 21 months. Median SABR dose was 54Gy (30-70Gy), corresponding to a biological equivalent dose (BED) of 112Gy (48-180Gy) administered in median 5 fractions. Patient and treatment characteristics are in Table 1. Response evaluation was made in median 3 months after SABR and complete response; partial response, stable disease and progression rates were 48%, 36%, 5.7% and 0.5%, respectively. One and 3 years LC and RC rates were 97%, 91% and 93%, 86%, respectively.
      On multivariate analyzes BED10<90 Gy (HR 3.6;1.3-9.9), SCC histology (HR 2.2;1.2-4) and less than complete response (HR 3.5; 1.6-7.5) were predictive of worse LC. Tumor size >3cm was the only predictor of low RC (HR 2.1; 1.1-4.2).
      One and 3 years PFS and OS were 88%, 72% and 90%, 65%, respectively.
      T2 tumor (HR 2.5; 1.5-3.6), BED10<90Gy (HR 2.1; 1.1-4) and SCC (HR 1.4; 1.0-1.8) had lower PFS. OS was negatively affected by tumor size >28mm (HR1.6; 1.0-2.5)
      No severe acute side effects were observed. Overall 18 patients experienced =grade 3 pneumonitis, 11 chest wall pain and 1 rib fracture.

      table 1.jpg

      8eea62084ca7e541d918e823422bd82e Conclusion

      Results of this retrospective study have shown that SABR is an encouraging technique with satisfactory LC and OS rates and minimal toxicity in patients with inoperable ESLC. Higher dose and intensification of treatment in patient with large tumors, SCC histology and less than complete response may result in better LC, PFS and OS.

      6f8b794f3246b0c1e1780bb4d4d5dc53

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      P2.16-15 - Toxicities and Survival after Stereotactic Ablative Radiotherapy (SABR) for Centrally Located Lung Tumors (ID 13736)

      16:45 - 18:00  |  Author(s): Enis Ozyar

      • Abstract
      • Slides

      Background

      To evaluate factors associated with local control (LC), overall survival (OS) and toxicities after SABR to centrally located primary non-small cell lung (PL) and oligometastatic (OM) tumors.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      Seventy centrally located tumors ( abutting tracheobronchial tree [TBT], <2cm from TBT, or intersecting mediastinum) in 65 patients treated with linear accelerator-based SABR between 2009 and 2016 were retrospectively studied. Impact of patient, tumor, and treatment parameters on LC, OS and toxicity-free survival (TFS) were evaluated by multivariate analyses.

      4c3880bb027f159e801041b1021e88e8 Result

      Forty-eight PL and 22 OM lesions were analyzed, including 20 (28%) re-irradiation (Re-RT) cases. Median total, fractionated, and biological equivalent doses in BED10 and BED3 were 55 (30-60), 9.75 (4-18), 110 (41-151), and 228 (90-378) Gy, respectively. Doses given as Re-RT were lower (median Re-RT BED10 dose 94 vs. 110 Gy, P=0.009). Complete response (CR) was obtained in 43 (61%) lesions. None of the analyzed factors correlated to CR. After a median follow-up of 57 (48-65, 95%CI) months, 10 (14%) lesions had relapsed and 37 (57%) patients had died (2 and 5-year LC and OS rates were 84/70% and 52/28%, respectively). In univariate analysis, 2-year LC was lower for lesions with no CR and for colorectal cancer lesions. Only “no CR” was significant (100 vs. 51%; HR=18.2, CI 2.3-146, P=0.006) in final multivariate analyses. Median OS was significantly lower in patients with grade 3+ toxicity (5 months after grade 3+ toxicity, vs. 39 months in others [HR 4.7, CI 2-11.2,P<0.0001]). OS was marginally lower in patients with primary lung cancer compared to patients with OM tumors (19 vs. 49 months, HR 2.3, CI 1-5.6, P=0.06). Among 17 toxicities, 5 reached grade 5. For patients with grade 3+ toxicities, TFS was lower after Re-RT (2-year TFS 63% vs. 96%, HR 5.1, CI 1.3-20.3, P=0.022) but did not differ significantly for lesions abutting TBT (2-year TFS 69% vs. 93.4%, HR 3.5, CI 0.9-13.9, P=0.08).

      8eea62084ca7e541d918e823422bd82e Conclusion

      SABR is an effective treatment modality in centrally located lung tumors. SABR to re-irradiated lesions and possibly lesions abutting TBT may have the higher risks for serious toxicities. Further studies are indicated.

      6f8b794f3246b0c1e1780bb4d4d5dc53

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