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S. Senan



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    ED08 - Early-Stage NSCLC: State-of-the-Art Treatment and Perspectives (ID 276)

    • Event: WCLC 2016
    • Type: Education Session
    • Track: Early Stage NSCLC
    • Presentations: 1
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      ED08.02 - The Role of Radiotherapy in Early-Stage NSCLC (ID 6470)

      14:50 - 15:10  |  Author(s): S. Senan

      • Abstract
      • Presentation
      • Slides

      Abstract:
      Radiotherapy is a curative treatment for early-stage NSCLC. Following hypofractionated radiotherapy in 15 once-daily fractions of 4 Gy to biopsy-proven tumors, a prospective multicenter study reported a 3-year local control rate of 82.7% (95% CI = 69.7% to 90.5%) [Cheung PC, 2014]. In the past decade, stereotactic ablative radiotherapy (SABR or SBRT) has become established as the guideline-recommended standard of care for medically inoperable patients with a peripheral early-stage NSCLC, as 5-year local control rates of 90% have been reported [Louie AV, 2015]. SABR is usually delivered in 3-8 fractions, utilizes small margins for positional uncertainty, 4-dimensional computed tomography (4DCT) for treatment planning, multiple conformal beams or arcs for delivery, and cone-bean CT scans for daily setup. Where facilities for SABR are unavailable, hypofractionated radiotherapy delivered using 4DCT planning remains an acceptable curative treatment. Diagnosis Population studies reveal that a significant proportion of elderly patients, as well as those with severe co-morbidities, do not receive any treatment. Guidelines recommend that a tissue diagnosis be obtained before initiating treatment for early-stage NSCLC, but also permit the use of SABR following review by an expert tumor board, in tumors where the calculated probability of malignancy is high [Vansteenkiste J, 2014; Callister ME, 2015]. However, any decision to proceed to a FDG-PET directed SABR approach in less fit patients must take into account the likelihood of benign disease. Given a high incidence of pulmonary tuberculosis, guidelines for Asia have recommended performing early non-surgical biopsies in Asian patients [Bai C, 2016]. Toxicity Treatment-related grades 3-4 toxicity are uncommon following SABR to peripheral lung tumors, while local control rates are approximately 90% [Louie AV 2015]. Commonly reported toxicities are chest wall pain, rib fractures, and except in patients who have pre-existing interstitial lung disease (ILD), the incidence of high-grade radiation pneumonitis is low. A systematic literature review of SABR in patients with ILD reported a treatment-related mortality in 15% [Chen H, Proc ASTRO 2016]. Follow-up Guidelines recommend 6-monthly CT scans for up to 3 years following SABR, followed by annual scans thereafter. The assessment of radiological changes can be challenging in a sub-group of patients during long-term follow-op, and the so-called high-risk radiological features [HRF] can identify patients in whom a biopsy is warranted [Figure 1, Huang K, 2014]. The HRF’s identified in the literature are an enlarging opacity at primary site, a sequential enlarging opacity, enlarging opacity after 12-months, a bulging margin, loss of linear margin, loss of air bronchogram and cranio-caudal growth [Huang K, 2014]. Initial reports on surgery for local failures following SABR indicate that this salvage procedure can be performed safely [Allibhai Z, 2012; Hamaji M, 2015; Verstegen N, Proc ELCC 2015]. Figure 1 The observed rates for a second primary lung cancer following SABR appear similar to those following surgery [Verstegen N, 2015]. In this situation, a subsequent course of SABR can generally be performed safely. Operable patients The role of SABR in fit patients remains a topic of active debate. Indirect comparisons of outcomes following the two modalities have revealed conflicting results. The role of SABR in surgical patients is currrently being investigted in 3 prospective randomized studies (NCT02468024, NCT02629458, NCT01753414), with a fourth study (VALOR) scheduled to open shortly.



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    MA13 - Modern Technologies and Biological Factors in Radiotherapy (ID 395)

    • Event: WCLC 2016
    • Type: Mini Oral Session
    • Track: Radiotherapy
    • Presentations: 1
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      MA13.10 - Magnetic Resonance Imaging-Guided Delivery of Lung Stereotactic Radiotherapy Using Patient-Controlled Visual Guidance (ID 5293)

      17:00 - 17:06  |  Author(s): S. Senan

      • Abstract
      • Presentation
      • Slides

      Background:
      Treatment-related toxicity is more common following stereotactic ablative radiotherapy (SABR) for central lung tumors, than is the case for peripheral tumors [Tekatli 2015]. Further reductions in doses to critical central structures are possible using respiration-gated SABR delivery, but insertion of fiducial markers for gating is also associated with toxicity. We describe a novel approach for clinical delivery of breath-hold gated SABR under continuous MRI-guidance.

      Methods:
      The MRIdian® system permits tumor visualization at 4 frames/second during treatment delivery, with radiation beam-holds whenever the target is outside a prespecified gating window. The gating procedure is as follows: a 17 second inspiration breath-hold MR scan is performed for planning before each SABR fraction (resolution 1.6×1.6×3.0 mm). Image registration is performed, and contours adapted when necessary. A 3mm PTV margin is added, and planned dose distribution recalculated for the ‘anatomy of the day’, and reoptimized. A sagittal plane is chosen for tumor tracking and gating, with a planning target margin of 3 mm. The sagittal tracking view from the MRIdian console is projected on a MR-safe monitor (Cambridge Research), and patients can continuously observe the tracking image using a mirror inside the bore.

      Results:
      Since May 2016, 30 fractions of MR-guided gated delivery have been performed in 5 cancer patients with 6 central tumors. All MR-based breath-hold PTV’s were smaller (mean 19.8 ± 13.3 cc) than a conventional free-breathing, motion-encompassing approach (mean 36.1 ± 21.9 cc). Plans of a single case are shown in Figure 1. Video-assisted visual feedback achieved a breath-hold gating efficiency of 52% (range 27-88%).Figure 1



      Conclusion:
      For high-risk SABR cases, use of MR-guided, video-assisted breath-hold gated SABR delivery constitutes a novel treatment method, allowing for minimization of mobility- and setup margins, and for improved verification of SABR delivery. Data from additional patients undergoing treatment will be presented.

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    OA24 - Radiotherapy of Lung Cancer: Recent Developments (ID 411)

    • Event: WCLC 2016
    • Type: Oral Session
    • Track: Radiotherapy
    • Presentations: 1
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      OA24.01 - Radiotherapy Quality Assurance of Concurrent Chemoradiotherapy in PROCLAIM Phase III Trial (ID 4274)

      14:20 - 14:30  |  Author(s): S. Senan

      • Abstract
      • Presentation
      • Slides

      Background:
      Trials of chemoradiotherapy for different tumors, including lung cancer, have shown a correlation between protocol deviations and adverse outcomes. Radiation quality assurance (RTQA) was mandated for all patients treated in the PROCLAIM (NCT00686959) trial evaluating two different chemoradiotherapy regimens.

      Methods:
      The study was open to accrual between 2008-2012. Planned chemoradiotherapy dose was 60-66 Gy in daily 2 Gy fractions. Quality was assessed through review of radiation treatment plans and monitoring of protocol violations. Review of the radiation plan was mandated for all patients; prior to radiation start for the first enrolled patient at each site. Real-time review was performed randomly in 20% of additional patients with nonreal-time review performed for the remainder. Parameters assessed for major violations per protocol included: <95% of planned total volume (PTV) received by 93% of prescribed dose; >1 cm[3] contiguous volume within or outside the PTV received >115% of prescribed dose; V~20~ (volume of lung receiving ≥20 Gy) >38%; and maximum point dose to spinal cord of >48 Gy. Overall survival (OS) and progression-free survival (PFS) were analyzed using Kapan-Meier methodology and groups were compared by log-rank test and Cox proportional hazard modeling.

      Results:
      Of 598 patients randomized in 126 investigational sites, 554 received study assigned chemoradiotherapy. The median dose delivered was 66 Gy, with 92.6% of patients receiving planned chemoradiotherapy dose (60-66 Gy). A total of 40 patients, enrolled at twenty-eight sites had major RTQA violations. Seven sites enrolled ≥2 patients with major violations. Patients with major violations has a higher incidence of Stage IIIB disease (70.0% vs. 50.6%) and larger tumors (median planned PTV=653 vs. 523cc) than patients with no violations. Patients treated at sites with ≥2 patients with violations (n=86), had a lower median OS (median 21.1 vs. 29.8 months; HR 1.442) and median PFS (median 7.3 vs. 11.3 months; HR 1.345) than patients at sites where none had violations.

      Conclusion:
      Major chemoradiotherapy protocol violations were uncommon in the PROCLAIM study, which may be a reflection of the mandatory RTQA. Protocol violations were more frequent in patients with Stage IIIB and larger tumors, which generally require more complex chemoradiotherapy plans. The observation of discrepant outcomes at centres with multiple major RTQA violations is hypothesis-generating but should be interpreted with caution due to the small number of patients.

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    P1.05 - Poster Session with Presenters Present (ID 457)

    • Event: WCLC 2016
    • Type: Poster Presenters Present
    • Track: Early Stage NSCLC
    • Presentations: 1
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      P1.05-061 - Increased Treatment-Related Toxicity in Patients with Early-Stage Non-Small Cell Lung Cancer and Co-Existing Interstitial Lung Disease (ID 4622)

      14:30 - 14:30  |  Author(s): S. Senan

      • Abstract
      • Slides

      Background:
      Treatment options for early-stage non-small cell lung cancer (ES-NSCLC) are generally well-tolerated. Minimally-invasive surgical techniques, stereotactic ablative radiotherapy (SABR) and radiofrequency ablation (RFA) can all achieve post-treatment mortality of <1% in clinical trial settings. There has been increasing evidence to suggest that patients with interstitial lung disease (ILD) suffer severe toxicity after treatment for NSCLC. Treatment-related toxicity may result in death and may take the form of acute exacerbations of existing ILD following surgery or RFA, or severe radiation pneumonitis following SABR.

      Methods:
      We performed a systematic review of literature in compliance with PRISMA guidelines to investigate the rate of treatment-related toxicity and mortality following treatment for ES-NSCLC. The Medline and EMBASE databases were queried from respective dates of inception to January 2016. Treatment modalities included in the search strategy were surgery, SABR, RFA, particle beam therapy and conventionally-fractionated radiotherapy. Results were summarized with weighted statistics according to the sample size of individual studies.

      Results:
      A total of 3,054 unique records were screened and 282 full texts were reviewed. Forty-nine journal articles were included in the final analysis, with 92% of studies being retrospective in design. Thirty surgical studies with 1716 patients, 13 SABR studies with 122 patients, 3 RFA studies with 46 patients, 2 proton beam therapy (PBT) studies with 17 patients and one carbon ion beam therapy (CIBT) study with 5 patients were included. Most patients in non-surgical studies were medically inoperable. Treatment-related or 30-day post-operative mortality was 2.3%, 15.5%, 8.7%, 5.8% and 0%, respectively, for surgery, SABR, RFA, PBT and CIBT. Treatment-related acute exacerbation of ILD or radiation pneumonitis > grade 3 was 12%, 25%, 25%, 12.5% and 20%, respectively. For patients treated with surgery, 5-year overall survival (OS) was 31.4% to 61.6% (median 54.2%) for patients with ILD and 70.5% to 88.3% (median 83.0%) for patients without ILD. For medically inoperable patients treated with SABR, 2 to 3-year OS was 0% to 53.8% (median 48.8%) for patients with ILD and 54% to 86.7% (median 70.8%) for patients without ILD. Studies that included only patients with idiopathic pulmonary fibrosis reported higher treatment-related toxicity compared to other studies.

      Conclusion:
      An elevated level of treatment-related toxicity is observed in patients treated for ES-NSCLC with co-existing ILD. Medically inoperable patients experienced high levels of treatment-related mortality. For surgery and SABR, overall survival was worse for patients with ILD compared to those without ILD.

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