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S. Vinod



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    P1.08 - Poster Session 1 - Radiotherapy (ID 195)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Radiation Oncology + Radiotherapy
    • Presentations: 2
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      P1.08-005 - Active Breathing Coordination to measure tumour motion in lung cancer patients: A feasibility study (ID 672)

      09:30 - 16:30  |  Author(s): S. Vinod

      • Abstract

      Background
      Lung tumour motion poses a significant challenge in accurate delivery of radiotherapy. To prevent geographical miss, a generic margin is often added to the CTV to create an internal target volume (ITV). Studies have shown the effectiveness of Active Breathing Coordinator (ABC) (Elekta, Crawley, UK) in reducing this internal margin. For the purpose of this study we wanted to evaluate the feasibility of utilising ABC for our patient population and of defining ITV margin based on breath-hold scans.

      Methods
      13 patients receiving radical radiotherapy were prospectively recruited. Each patient received a 1 hour training session prior to CT simulation to determine eligibility for the study and provide training for the breath hold procedure. A minimum of fourteen seconds breath-hold was required for patients to be eligible. If eligible, patients were positioned on the CT simulator as per department protocol with the addition of ABC. Standard departmental CT protocol for lung treatment was first performed with contrast. This scan was used to identify the tumour region. A breath-hold scan at normal inspiration and expiration was done in the region of visible tumour volume with the aid of ABC. A radiation oncologist defined ITV based on current departmental protocol and using the ABC scans. To verify accuracy of ABC volume, a 4D Cone Beam CT (4D CBCT) scan was done during week 1 of treatment. To verify the reproducibility of ITV and breath-hold position, a second ABC scan and 4DCBCT were performed mid-way through treatment. The planning ITV and ABC ITV were compared. Variation in tumour position and volume were quantified and compared.

      Results
      From the 13 patients recruited, only 5 patients were able to tolerate ABC. On average, eligible patients were able to maintain a 20 second breath-hold. The generic ITV margin was larger than the patient specific ABC ITV margin in all cases. A change in centre of volume was noted between simulation ABC GTV and mid treatment ABC GTV. There was an average overall difference of 0.8cm for the 3 dimensional vectors for two eligible patients. There was no correlation between breath hold ability and the patient’s pulmonary function.

      Conclusion
      ABC was not feasible for the cohort of patients recruited for this study. For the patients who could tolerate ABC scans, the ITV could be individualized and reduced from that based on generic population data.

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      P1.08-006 - Inter-observer variability of GTV delineation based on Lung MRI: impact of radiologist led workshop (ID 779)

      09:30 - 16:30  |  Author(s): S. Vinod

      • Abstract

      Background
      Magnetic Resonance Imaging (MRI) with its superior soft tissue contrast resolution has the potential to improve Gross Tumour Volume (GTV) delineation of lung cancer. The aim of this study was to assess the inter-observer variability between observers for MRI based GTV delineation for Lung cancer and evaluate whether this factor changed following a GTV delineation workshop with a thoracic radiologist.

      Methods
      Five radiation oncologists from three different institutions were asked to delineate GTV on 3 patient datasets. Each observer was given a planning CT, PET, T1 and T2 weighted 1.5 T MRI datasets along with patient history and relevant diagnostic test results. Each observer was instructed to delineate a primary GTV and nodal GTV as required on the T1 and T2 weighted MRI datasets (pre workshop contours). A workshop was then conducted. The aim of the workshop was to discuss each case with a thoracic radiologist and for the radiologist to educate each of the observers in how to review thoracic MRI for both T1 and T2 weighted images. Following the workshop each observer delineated a post workshop GTV. Conformity index (CI) was used to evaluate improvement in inter-observer variability between pre and post workshop contours.

      Results
      Results of two observers are presented here. For patients 1 and 3 slight improvement in CI was noted between pre and post primary and nodal GTV for T1 and T2 weighted datasets. Similarly for patient 3 slight improvements were noted in inter-observer variability for primary GTV for both T1 and T2 weighted images. However there was significant improvement in both T1 and T2 weighted nodal GTV. CI improved from 0.2 to 0.6 and 0-0.6 for T1 and T2 weighted images respectively.

      Conclusion
      Preliminary results from this study indicate that a radiologist led workshop assisted in improving inter-observer variability for MRI based GTV delineation. Further analysis of all observers is required to assess the significance of the impact of a radiologist led contouring workshop in improving inter-observer variability on MRI delineation of lung cancer.

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    P2.08 - Poster Session 2 - Radiotherapy (ID 198)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Radiation Oncology + Radiotherapy
    • Presentations: 2
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      P2.08-011 - Utility of MRI in Lung Cancer radiotherapy: a Literature Review (ID 1342)

      09:30 - 16:30  |  Author(s): S. Vinod

      • Abstract

      Background
      Lung cancer remains a challenging site to treat in radiotherapy. For tumour delineation CT combined with FDG PET is the current gold standard for delineating lung cancer volumes. MRI has been utilized in a limited number of cases such as superior sulcus tumours. However its use has been limited due to reduced MRI signal as a result of low proton density in lung, inhomogeneity of the magnetic field in lung and cardiac and respiratory motion. As technology improves, the utility of MRI in imaging lung cancer has become plausible. The aim of this literature review was to identify evidence to support the use of MRI in lung cancer imaging for radiotherapy.

      Methods
      Pubmed and Google Scholar were used to identify literature on MRI in Lung cancer using the keywords Lung Cancer, MRI, MR, thoracic imaging and radiotherapy. Articles were limited to human and phantom subjects. A total of 22 articles were identified between 1995 and 2013 and reviewed to assess the potential of MRI for lung radiotherapy imaging.

      Results
      Eighteen studies were performed on 1.5T and two on 3T magnets with magnet strength not specified in two studies. Gradient echo sequence and TrueFISP were most common sequences utilised. Thirteen articles examined tumour motion and nine concentrated on tumour volume analysis. One study illustrated minimal geometric distortion and inter-cycle reproducibility of tumour volume on free breathing MRI sequence. The possibility of defining tumour internal target volume for radiotherapy treatment was demonstrated in three studies Two further studies demonstrating variability of lung tumour motion based on location and variability of motion between tumour and non-tumour bearing lung. There was conflicting evidence on pulmonary node detection based on results from two studies. Four comparative studies with FDG PET and functional MRI sequences demonstrated diffusion weighted image (DWI) had higher specificity for lesion detection in the presence of inflammation. Correlation was seen between SUV and DWI value. Two studies demonstrated the potential for radiotherapy planning based on biological function by avoiding functional lung tissue.

      Conclusion
      This literature review indicates that improvement in MRI technology has overcome some of the initial limitations of utilising MRI for lung cancer imaging. MRI can not only provide the morphological information required for identifying lung cancer based on anatomical sequences but also functional information to identify both tumour activity and surrounding healthy or pathological structures. There is potential for MRI to be utilised in the clinical setting for defining tumour volumes for radiotherapy planning and in evaluating tumour response during and after treatment. However further research is required to determine protocols with defined standard sequences specific for lung cancer imaging.

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      P2.08-022 - Non-Small Cell Lung Cancer (NSCLC): Changes in volume during radiotherapy and potential adaptive radiotherapy planning (ID 2511)

      09:30 - 16:30  |  Author(s): S. Vinod

      • Abstract

      Background
      Curative radiotherapy for non-small cell lung cancer (NSCLC) is usually delivered over a time period of 5-7 weeks. Tumour regression has been observed over the course of curative radiotherapy. Currently, the entire radiotherapy treatment is delivered based on the original tumour volume. An evolving approach is adaptive radiotherapy planning whereby the radiotherapy plan is modified during a course of treatment to account for tumour and patient changes. This has the potential to reduce the size of radiotherapy fields, allowing dose escalation and normal tissue sparing.

      Methods
      A cohort of 20 consecutive NSCLC patients receiving a curative course of radiotherapy and who had weekly kV cone beam computer tomography (CBCT) images was identified. The gross tumour volume (GTV) and anatomical reference points were delineated on all CBCT scans. Volume and positional changes were recorded and analyzed.

      Results
      Six patients with non-small cell lung cancer who received curative radiotherapy were assessed so far. Five patients had sufficient image quality for contouring. There was a mean percent decrease of 24.8% by fraction 16 and 37.2% by fraction 26. Average tumour migration was 0.4cm. Progressive anatomical changes were more prominent where there was tumour associated with atelectasis. Updated results for the whole cohort will be presented.

      Conclusion
      Tumour regression was observed in all patients and a proportion showed significant reduction. Adaptive planning was a feasible option in selected patients.

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

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Radiation Oncology + Radiotherapy
    • Presentations: 2
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      P3.08-002 - An evidence-based estimation of survival and local control benefit of radiotherapy for lung cancer (ID 271)

      09:30 - 16:30  |  Author(s): S. Vinod

      • Abstract

      Background
      Evidence-based Radiotherapy utilisation benchmarks [Delaney G et al, Cancer 2003] have been used as the basis for planning radiotherapy services both nationally and internationally. These utilisation models have been further expanded to estimate the benefit for each radiotherapy indication in individual cancer sites using evidence-based approach [Shafiq J et al, Radiotherapy and Oncology 2007].

      Methods
      Our study aimed at estimating the benefit of definitive or adjuvant radiotherapy to overall survival and local control of lung cancer patients if the entire lung cancer population are treated according to evidence-based treatment guidelines. The optimal radiotherapy utilization model previously reported for small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) was extended to incorporate overall survival and local control benefit from radiotherapy (radiotherapy vs no radiotherapy, radiotherapy and concurrent chemotherapy vs radiotherapy alone) from published data (1990-2010). Palliative benefits were not considered.

      Results
      The overall gains in 5-year local control and survival were 11% (95% CI 9.5%-12.3%) and 5% (95% CI 3.6%-6.7%) respectively if optimal radiotherapy was applied for all lung cancer patients. The optimal gains for all lung cancer from concurrent chemotherapy and radiotherapy over radiotherapy alone were 5% (95% CI 1.7%-7.6%) for local control and 4% (95% CI 1.0%-6.0%) for survival. The overall local control benefit for radiotherapy including concurrent chemotherapy for SCLC and NSCLC were 10% and 17%; 5 year survival benefit proportions were: SCLC 2% and NSCLC 10%.

      Conclusion
      Our model provides a quantitative estimate of benefit of curative radiotherapy for lung cancer at the population level if evidence-based guidelines were applied. The model predicted that guidelines-recommended application of radiotherapy treatment could save 900 extra lives per 10 000 cases of lung cancer for up to 5 years and prevent 1600 local recurrences in that period.

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      P3.08-010 - The potential use of MRI to delineate lung cancer volumes for radiotherapy (ID 1344)

      09:30 - 16:30  |  Author(s): S. Vinod

      • Abstract

      Background
      The use of MRI for lung cancer volume delineation for radiotherapy is rare. This has been due to poor image quality as a result of physical and physiological factors such as low proton density, susceptibility effects and respiratory and cardiac motion. However as MRI technology has improved, imaging of lung abnormalities has become more feasible. A prospective study was therefore conducted to evaluate image quality for lung tumour delineation on a 1.5T (Tesla) and 3T MRI scanner. The aim of the study was to identify potential scan sequences that could be used clinically for tumour delineation for radiation therapy treatment.

      Methods
      Ten patients with lung cancer underwent MRI, five on a 1.5T GE scanner using a body phased array coil and five on a 3T Phillips scanner. Scans on the 1.5T scanner were undertaken with breath hold and scans on the 3T scanner were performed with respiratory and peripheral pulse gating to give optimal image quality. The thorax was imaged with T2 and T1 weighted sequences on both field strengths. Cine mode imaging to compare tumour motion was also acquired. Scan sequence was matched for the 1.5T and 3T scanners. The quality of images for lung cancer delineation was assessed by an experienced thoracic radiologist and thoracic radiation oncologist using a four point scale. A consensus score ranging from 1(superior) to 4 (inferior) was given for each sequence based on four categories; tumour edge detection, image artefacts, noise affecting edge detection and overall image quality. A score of 2 or below was considered clinically acceptable

      Results
      Both magnet strengths provided reasonable image quality to define tumour volume on lung MRI. The average score for overall image quality between the two scanners was 1.8 for 1.5T and 1.3 for the 3T scanner. For the 1.5T scanner the sagittal and coronal T2 weighted scan scored the best for overall image quality for tumour delineation (1.53), due to limited respiratory motion distortion. However these image planes are not compatible with radiotherapy planning systems. For the 3T scanner the axial T2 images scored best for overall image quality (1.05). For tumour edge detection the sagittal and coronal and T1 weighted images scored best (1.75) for the 1.5T scanner. The axial T2 weighted image and the sagittal cine mode performed best for tumour edge detection (1). Overall sequences on the 3T scanner were rated higher than those on the 1.5T scanner

      Conclusion
      It is feasible to utilise commercially available MRI sequences to acquire images of acceptable quality for the purposes of lung cancer delineation in radiotherapy. Both magnet strengths gave acceptable image quality for clinical use in radiotherapy, with the 3T magnet displaying slightly better image quality. A future study will compare lung cancer delineation between the current standard practice of CT&PET with MRI.

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    P3.09 - Poster Session 3 - Combined Modality (ID 214)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Combined Modality
    • Presentations: 1
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      P3.09-012 - A decade of community-based outcomes of patients treated with curative radiotherapy (RT) +/- chemotherapy for Non-Small Cell Lung Cancer (NSCLC). (ID 2046)

      09:30 - 16:30  |  Author(s): S. Vinod

      • Abstract

      Background
      There are many clinical trials reporting good outcomes of patients treated with curative RT. However, clinical trials populations are highly selected and there are limited data on whether these outcomes are seen in community practice in the Australian setting. The aim of the study was to evaluate the outcomes and toxicity of patients treated with curative RT +/- chemotherapy for NSCLC.

      Methods
      Electronic medical records at Liverpool and Macarthur Cancer Therapy Centres, NSW, Australia were queried to retrieve data on patients with Stage I-III NSCLC who were treated with curative RT (minimum dose 60Gy) between 1/1/2000-31/12/2010. Patient death records were available up until 16/1/2013 with a minimum follow up time for patients of 2 years. Patient demographic data, tumour, and treatment details were retrieved. The records were retrospectively reviewed to collect data on patient comorbidities and treatment toxicities. The Simplified Comorbidities Score (SCS) was used to score comorbidity. The median follow up time was 22 months. For Cancer Specific Survival (CSS), patients were censored if they had died from another cause or survived until the last date of follow up, and for Overall Survival (OS), patients were censored if they survived until the end of the study. Univariate and multivariate Cox proportional hazards models were used to assess predictors of CSS and OS.

      Results
      One hundred and sixty patients were treated with curative RT over this period. The median age was 69 years (range 36-89). Seventy-six patients received RT alone, 59 received concurrent chemo-radiation, and 25 received sequential chemo-radiation. Twenty-nine patients had stage I disease, 28 had stage II, and 103 had stage III. Median overall survival was 29 months for patients with stage I NSCLC, 26 months for stage II, and 18 months for stage III. For stage II and III patients treated with concurrent chemo-radiation, median survivals were 29 and 18 months and 2-year OS were 64 and 42% respectively. On multivariate analysis, stage II or III and weight loss ≥5% were predictive of cancer specific survival with hazard ratio 4.47 (95% CI: 10.8-18.55, p=0.039) and 2.23 (95% CI: 1.13-4.39, p=0.021). Toxicity was acceptable with 2% grade ≥3 radiation pneumonitis, 6% grade ≥3 oesophagitis, and 2% grade ≥3 febrile neutropenia. There was no treatment-related death. Performance status, age, SCS, respiratory function, pathology, and grade were not predictive of survival.

      Conclusion
      Curative intent RT +/- chemotherapy is well tolerated and effective treatment for inoperable or locally advanced NSCLC. Tumour outcomes and toxicities were comparable to those reported in clinical trials. Higher SCS was not correlated with worse survival in this cohort.

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    P3.12 - Poster Session 3 - NSCLC Early Stage (ID 206)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Medical Oncology
    • Presentations: 1
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      P3.12-009 - Patterns of care in patients receiving adjuvant chemotherapy for resected non-small cell lung cancer (NSCLC) in South Western Sydney Local Health District (SWSLHD) (ID 2093)

      09:30 - 16:30  |  Author(s): S. Vinod

      • Abstract

      Background
      Randomised controlled trials have shown that adjuvant chemotherapy is the standard of care for patients with resected, stages II and IIIA NSCLC. The benefit in stage IB disease remains inconclusive. There are limited data regarding the patterns of care, benefits and toxicities of adjuvant chemotherapy in the non-clinical trial population. We reviewed patterns of care and survival outcomes in patients with resected NSCLC receiving adjuvant chemotherapy.

      Methods
      We retrospectively reviewed medical records for patients with resected, pathologic stages IB-IIIA NSCLC diagnosed between 1/1/2005 and 31/12/2012 in SWSLHD. Patients were identified using an institutional electronic database. Staging was according to the American Joint Commission on Cancer (AJCC) 6[th] edition tumour-node-metastasis (TNM) system. Information was extracted on baseline patient and tumour characteristics, treatment modalities, chemotherapy delivery, treatment-related toxicities and patient outcomes. Survival analysis was performed using Kaplan-Meier method.

      Results
      We identified 137 patients who underwent surgical resection, 63 (46%) received adjuvant chemotherapy and are presented in this analysis. The main reasons that patients did not receive adjuvant chemotherapy included stage IB disease (32%), advanced age/comorbidities (24%), patient preference (14%), prior neoadjuvant treatment (7%) and non referral (7%). The median age at diagnosis was 64 (range 45 - 77) with 57% male, 81% were ex- or current smokers and 80% had an ECOG performance status of 0 or 1. Adenocarcinoma and squamous cell carcinoma histology accounted for 54% and 27%, respectively. Forty one patients (65%) had lobectomy and 22 (35%) had pneumonectomy. Pathological stage was: 1B 5 patients (7.9%), IIA 11 (17.5%), IIB 13 (20.6%) and IIIA 34 (54%). Adjuvant chemotherapy commenced within 90 days of surgery in 94% with a median time to treatment of 60 days (range 25-110). Adjuvant radiotherapy was given to 18 patients (29%), with 52% of patients with N2 disease receiving radiotherapy. Platinum doublet chemotherapy was administered to 62 patients (98%) and cisplatin/vinorelbine was the most common regimen given to 41 patients (65%). The number of planned treatment cycles was completed by 40 patients (63%), and of these, 11 patients (17%) completed all chemotherapy on schedule without dose modification. Eighteen patients (29%) required hospitalisation during treatment. Febrile neutropaenia occurred in 10 (16%), with an additional 24 (38%) developing non-febrile neutropaenia, thrombocytopenia or anaemia. Other clinically significant non-haematological toxicities included: vomiting (11%); renal impairment (10%); ototoxicity (6%); peripheral neuropathy (16%); fatigue (6%); allergy (2%) or myalgias (3%). There were no toxic deaths. With a median follow-up of 18.6 months (range 3.4 to 96 months), 56% had developed recurrent disease with a median disease-free survival of 18.9 months. The majority (94%) developed recurrent disease within 3 years. The median overall survival was 25.6 months. A total of 34 (54%) had died, including 3 non-cancer related deaths.

      Conclusion
      The utilisation of adjuvant chemotherapy rate is moderate but is consistent with other reports. Our results demonstrated a higher rate of febrile neutropenia and shorter median overall survival than the clinical trial population. Therefore, careful selection of patients to undergo adjuvant chemotherapy is essential.