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M.M. Tin
Moderator of
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MO23 - Radiotherapy II: Lung Toxicity, Target Definition and Quality Assurance (ID 107)
- Event: WCLC 2013
- Type: Mini Oral Abstract Session
- Track: Radiation Oncology + Radiotherapy
- Presentations: 12
- Moderators:M.M. Tin, F. Macbeth
- Coordinates: 10/30/2013, 10:30 - 12:00, Bayside 204 A+B, Level 2
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MO23.01 - Four-dimensional Gallium-68 perfusion PET/CT scans can improve radiotherapy planning through functional avoidance of lung (ID 2490)
10:30 - 10:35 | Author(s): S. Siva, M. Hofman, T. Devereux, J. Callahan, P. Eu, D. Pham, T. Kron, N. Hardcastle, D. Steinfort, M. Bressel, M. Macmanus, R. Hicks, D. Ball
- Abstract
- Presentation
Background
[68]Ga-macroaggregated-albumin ([68]Ga-MAA) perfusion PET/CT is a novel molecular imaging technique for the assessment of functional lung volumes. This prospective study aims to investigate the utility of four-dimensional (4D) [68]Ga-perfusion PET/CT for functional adaptation of radiation therapy (RT) planning in patients with non-small cell lung cancer (NSCLC).Methods
An interim analysis was performed of a prospective clinical study of patients with NSCLC who underwent 4D-perfusion PET/CT scanning prior to curative intent RT. All patients were planned to 60Gy in 30fx with or without concurrent chemotherapy based on conventional anatomical lung volumes. Subsequently, a single nuclear medicine physician in conjunction with a single radiation oncologist contoured the functional ‘perfused’ lung using a visually adapted threshold. Functional lung was defined as lung parenchyma with Ga-MAA uptake. A second volume labeled as ‘high-perfused’ lung was created based on a visually adapted 30% max SUV threshold (figure 1). A single RT planner optimised the 3D conformal radiotherapy plan to spare the functionally ‘perfused’ and ‘high-perfused’ lung volumes respectively. Dose volumetrics were compared using mean lung dose (MLD), V5, V10, V20, V30, V40, V50 and V60 parameters. Figure 1 figure 1 - RT Plans optimised to each of the conventional, 'perfused' and 'high perfused' lung volumes.Results
14 consecutive patients had RT plans adapted to functional lung volumes based on perfusion PET/CT. This patient cohort consisted of ex-smokers with pre-existing airways disease, with a mean FEV1 of 1.87L (0.83L-2.82L) and DLCO of 54% (27%-87%). The average MLD of the original treatment plans was 11.44Gy using conventional anatomical lung measurements. When considering the functional ‘perfused’ lung and ‘high perfused’ lung, the original plan produced an average MLD of 11.12Gy and 12.41Gy respectively. Plans optimized for ‘perfused’ lung only showed significant improvement of the V60 dose parameter (median 1.00Gy, p=0.04). However, plans optimized for ‘high perfused’ lung improved MLD, V30, V40, V50 and V60 (all p-values <0.05). The MLD was improved by a median of 0.86Gy, p<0.01. The largest improvement was found in the V30 parameter, with a median difference of 1.76Gy.Conclusion
This is the first study of [68]Ga perfusion PET/CT for planning the treatment of lung cancer patients. RT plans adapted to ‘high perfused’ but not ‘perfused’ functional lung volumes allows for significant technical improvement of conventional RT for NSCLC patients. The clinical impact of this improvement in planning technique should be validated in the context of a prospective study measuring patient toxicity outcomes.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.02 - Quantification of radiation-induced lung damage with CT scans: The possible benefit for radiogenomics (ID 254)
10:35 - 10:40 | Author(s): D. De Ruysscher, H. Sharifi, G. Defraene, S.L. Kerns, K. De Ruyck, S. Peeters, J. Vansteenkiste, R. Jeraj, F. Van Den Heuvel, W. Van Elmpt
- Abstract
- Presentation
Background
Radiation-induced lung damage (RILD) is an important problem. Although physical parameters such as the mean lung dose are used in clinical practice, they are not suited for individualised radiotherapy. As radiosensitivity varies between patients, genetic correlations have been investigated, which appear to be difficult to repeat in validation studies. This may be due, in part, to differences in methods for measuring RILD across studies. Objective, quantitative measurements of RILD on a continuous instead of on an ordinal, semi-quantitative, semi-subjective scale, are needed.Methods
Hounsfield Unit (HU) changes before vs. 3 months post-radiotherapy were correlated per voxel with the radiotherapy dose. Deformable registration was used to register pre and post CT scans and the density increase was quantified for various dose bins. The dose-response curve for increased HU was quantified using the slope of a linear regression (HU/Gy). The end-point for the toxicity analysis was dyspnoea ≥ grade 2.Results
95 lung cancer patients were studied. Radiation dose was linearly correlated with the change in HU (mean R[2]=0.74 ± 0.28). No differences in HU/Gy between groups treated with stereotactic radiotherapy, conventional radiotherapy alone, sequential or concurrent chemo-radiotherapy were observed. In the whole patient group, 33/95 (34.7 %) had dyspnoea ≥ G2. Of the 48 patients with a HU/Gy below the median, 16 (33.3 %) developed dyspnoea ≥ G2, while in the 47 patients with a HU/Gy above the median, 17 (36.1 %) had dyspnoea ≥ G2 (not significant). Individual patients showed a nearly 21-fold difference in radiosensitivity, with HU/Gy ranging from 0 to 10 HU/Gy. Figure 1Conclusion
HU changes identify objectively the whole range of individual radiosensitivity on a continuous, quantitative scale. CT density changes may allow more robust and accurate radiogenomics studies.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.03 - Dutch Radiotherapy Lung Audit: Results of a National Pilot (ID 2128)
10:40 - 10:45 | Author(s): J. Belderbos, D. Henneman, C. Verhoef, M. Ploegmakers, J. Bussink, C. Tissing-Tan, E. Vonk, A. Van Der Wel, M. Verheij, A. Dekker
- Abstract
- Presentation
Background
The Dutch Society for Radiotherapy and Oncology (NVRO) aims to ensure transparency regarding clinical outcome, quality and safety of lung cancer treatments in radiotherapy departments throughout The Netherlands. Auditing is considered the best instrument to achieve this. The quality of the radiotherapy will become transparent by using objective and reliable data from accurate registration of clinical outcome linked to patient and treatment characteristics The results of the audit are communicated to the health professionals that supplied the data. This outcome registration will provide the local health professionals with a robust instrument to compare and improve their lung cancer treatments. The decision was made to seek collaboration with the thoracic surgeons as their group were already committed to the DICA (Dutch Institute for Clinical Auditing) .Methods
The Quality Assurance Committee of the NVRO, in collaboration with a platform of Dutch radiation oncologists dedicated to lung cancer treatment, received a grant to set-up a quality assurance program for lung cancer treatment. Quality indicators to be collected were defined within the platform of Dutch radiation oncologists and a database was setup in October 2012. All patients receiving primary thoracic radiation treatment with curative intent for (primary or recurrent) stage I-IIIB lung cancer will be included in the registry. Information will be collected on patient, tumor and treatment characteristics, the incidence and severity of acute toxicity, mortality within three months of radical radiotherapy and the time interval between diagnostic work-up and start of radiotherapy The adherence to the NVRO and Dutch guidelines will be registered and analyzed, as well as the use of new treatment techniques like stereotactic radiotherapy and image-guided radiotherapy. A pilot phase was initiated to test the feasibility of enrolling patients from six participating centers.Results
The pilot-database was tested in 6 Dutch centers: NKI-AVL (Amsterdam), MAASTRO clinic (Maastricht), RIF (Leeuwarden), RISO (Deventer), UMC Radboud (Nijmegen) and ARTI (Arnhem). A total of 196 patients were entered from January to June 2013. Analysis of the patients entered is ongoing. We expect to have a national roll-out in October 2013. The patient records were very complete with a few exceptions: lung function tests, the Mean Lung Dose / Lung V20, gross tumor volume (23% missing) and the non-mandatory follow-up items. The mean age was 68 years (range 41-90) with 57% males. Charlson comorbidity index ≥ 2 was scored in 39% of patients. Most patients (66%) were cN+ with 14% T4 tumours. Most patients received IMRT or VMAT irradiation. Ninety-five percent of patients completed treatment. All registered patients had position verification during irradiation, mostly 3D (70%). Acute 3-month toxicity (grade≥ III) was registered in 18% of patients and 3-month mortality was 4.4%.Conclusion
This national audit on outcome after radiotherapy is directed towards an improvement of care for lung cancer patients and will help to direct evidence into clinical practice. It is expected to have an important impact on quality assurance ,safety and possibly patient mortality.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.04 - Is pre-trial quality assurance (QA) effective? A comparison of pre-trial QA versus ongoing QA for the CONVERT Trial. (ID 1809)
10:50 - 10:55 | Author(s): N. Groom, E.M. Wilson, E. Lyn, A. Price, M. Snee, R. McMenemin, N. Mohammed, C. Faivre-Finn
- Abstract
- Presentation
Background
CONVERT is an international randomised phase III trial comparing 45Gy in 30 fractions twice-daily and 66Gy in 33 fractions once-daily (given concurrently with cisplatin/etoposide) for good performance status patients with limited stage small cell lung cancer. A QA programme was set-up to standardise radiotherapy (RT) delivery across all centres.Methods
The pre-trial QA exercise (PQE) involved completion of a questionnaire and treatment planning exercise. Each participating clinician was asked to select a previously treated patient, who fitted the entry criteria for the trial, and provide disease and organs at risk (OAR) outlines and a treatment plan for both arms of the trial. QA guidelines, including an atlas for OAR outlining, were distributed to participating centres. Additionally, at least one RT plan per centre was randomly collected during the trial (ongoing QA exercise-OQE). A comparison was made between the PQE and OQE for each centre, including a review of eligibility criteria, OAR and gross tumour volume (GTV) outlining, expansion to clinical target volume (CTV) and planning target volume (PTV).Results
Twenty nine clinicians from 28 centres who had completed both the pre-trial QA and the ongoing QA were included in the analysis. From the pre-trial questionnaire it was reported that 3 centres were using beam energies of 10MV or more which was not permitted as per protocol. Subsequently the PQE showed that these all used acceptable beam energies. Four clinicians submitted ineligible patients for the PQE and none for the OQE. Twenty five clinicians (86.2%) used the correct GTV to CTV and CTV to PTV expansions for the PQE and OQE. Table 1 shows a comparison of adherence to protocol regarding OAR outlining between the PQE and OQE. Table 1
Organ at risk doses were found to be within the tolerances specified in the trial protocol for both PQE and OQE.Oesophagus outline Spinal canal outline Heart outline Lung-PTV outline PQE-OAR outline as per protocol (n=29) 19 (65.5%) 14 (48.3%) 4 (13.8%) 20 (68.9%) OQE-OAR outline as per protocol (n=29) 21 (72.4%) 18 (62.1%) 8 (27.6%) 20 (68.9%) Conclusion
A PQE improves clinicians’ compliance to trial protocol, and has been found in the OQE to reduce deviations across the participating centres that may confound the results of the study. Despite the fact that consistency of OAR outlining remained an issue in both the PQE and the OQE an overall improvement was seen following the PQE.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.05 - Changes in lung radiotherapy techniques during the CONVERT Trial. A survey of participating centres. (ID 1820)
10:45 - 10:50 | Author(s): N. Groom, E.M. Wilson, E. Lyn, A. Price, M. Snee, R. McMenemin, N. Mohammed, C. Faivre-Finn
- Abstract
- Presentation
Background
CONVERT is an international randomised phase III trial, comparing 45Gy in 30 fractions twice-daily or 66Gy in 33 fractions once-daily (given concurrently with cisplatin/etoposide) for good performance status patients with limited stage small cell lung cancer. A survey was sent out to 69 clinicians who had randomised patients into the trial with the aim of establishing how radiotherapy techniques for lung cancer have changed over the 5 years since the trial opened.Methods
As part of the pre-trial quality assurance process each centre was asked to complete a facility questionnaire giving details of treatment planning, delivery and verification techniques. Recruitment to the trial began in April 2008 and in January 2013, a further facility questionnaire was sent to centres. The survey was completed using an on-line survey tool.Results
This analysis includes answers from the 34 clinicians who responded to the questionnaire. Changes in treatment planning techniques and verification since the beginning of the trial are summarised in table 1. Table 1 Figure 1 *Note that some centres reported using more than one beam arrangement, beam energy, planning algorithm or treatment verification technique. Out of the 34 clinicians who answered the questionnaire, 14 (41.1%) are currently using 4DCT, 3 (8.8%) are using breathold techniques and 16 (47.1%) are not using any technique to account for respiratory motion for simulation and treatment planning of lung patients. Data on management of respiratory motion were not available in 2008.Conclusion
During the 5 years the CONVERT Trial has been open there have been significant advances in radiotherapy treatment technology. Major changes include the use of Type B treatment planning algorithms and PET CT for planning, IMRT for treatment and CBCT for treatment verification of patients with small cell lung cancer.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.06 - DISCUSSANT (ID 3935)
10:55 - 11:10 | Author(s): P. Van Houtte
- Abstract
- Presentation
Abstract not provided
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MO23.07 - Impact of a gradient-based FDG-PET auto-contouring method on non-small cell lung cancer delineation (ID 1993)
11:10 - 11:15 | Author(s): J. Jochem, W. Vogel, J. Van De Kamer, M. Kruis, J. Van Diessen, J. Knegjens, M. Kwint, K. De Jaeger, S. Peeters, A. Van Baardwijk, C. Slump, J. Belderbos
- Abstract
- Presentation
Background
Manual target volume delineation using CT/FDG-PET is the standard method used for radiotherapy treatment planning of non-small cell lung cancer (NSCLC) patients. Since manual delineation is prone to inter-observer variability and is time consuming, many FDG-PET auto-contouring methods were proposed in literature. The purpose of this study was to investigate to what extent a gradient-based FDG-PET auto-contouring method reduces observer variation, reduces delineation time and influences delineation behavior in radiotherapy treatment planning for NSCLC patients.Methods
Seven radiation oncologists (observers) dedicated to lung cancer treatment delineated the primary tumor (PT) and involved lymph nodes (LN) for 10 patients with stage IIA-IIIB NSCLC on a co-registered CT/FDG-PET scan. The study was separated in two phases. In the first phase, the observers manually delineated the PT and LN for all patients. For the second phase (four months later), auto-contours were generated for both the PT and LN using a gradient-based FDG-PET segmentation method. Bone and air tissue were removed from these auto-contours using CT thresholding. These auto-contours were provided as initial delineation and were adapted by the observers. Delineation times, delineated contours and agreement with the auto-contour were analyzed. Delineated contours were analyzed based on volume, the ratio between the common volume and the encompassing volume (C/E), Dice Index (DI), local standard deviation (SD) and the local distance between median surface and delineated surface. Regions were identified where the observers did or did not change the provided auto-contours.Results
The observers agreed with the provided auto-contour for 37.3% of the PT and for 42.6% of the LN. Notable regions of agreement were the tumor/bone and tumor/air interfaces. The mean delineation time was reduced by 23.9% from 25.5 minutes in phase 1 to 19.4 minutes for phase 2 (p=0.000). The mean delineated volume was smaller in phase 2 compared to phase 1: 8.9% for the PT (155.8 to 142.0 cm[3], p=0.000) and by 9.1% for the LN (13.2 to 12.0 cm[3], p=0.001), respectively. The C/E ratio and DI both did not change significantly and were 0.79 and 0.88 for the PT and 0.54 and 0.67 for the LN in both phases. The mean local SD for the PT was 1.7 mm and 1.5 mm and for the LN was 1.5 mm and 1.4 mm and both did not change significantly, for both phases respectively. The mean distance between the median surface and PT delineations was slightly reduced from 2.1 to 1.8 mm for phase 2, and was 2.0 mm for the LN in both phases.Conclusion
The gradient-based FDG-PET auto-contouring method reduced delineation time by 24%, but was sufficient in only 37.3% of the primary tumors and 42.6% of the involved lymph nodes; most notably at the tumor/bone and tumor/air interfaces segmented using the CT scan. The results suggest the FDG-PET auto-contour is currently primarily used for localization, and not so much for delineation. Multi-modal auto-contouring has the potential to reduce inter-observer variation when further developed in close collaboration with radiation oncologists.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.08 - Inter-observer Variability in Gross Tumour Volume Delineation on Kilo-voltage Cone Beam Computed Tomography (CBCT) Scans for Lung Cancer Radiotherapy Treatment Verification (ID 3294)
11:15 - 11:20 | Author(s): S.C. Watt, S.K. Vinod, M. Dimigen, J. Descallar, B. Zogovic, J. Atyeo, S. Wallis, L. Holloway
- Abstract
- Presentation
Background
The use of CBCT is essential for precise treatment delivery of radiotherapy for lung cancer. The current work practice at many centres is to use bony landmarks to match on-treatment CBCT to the radiotherapy planning CT to verify treatment. To take full advantage of this imaging modality for lung cancer, soft-tissue matching is preferred as it ensures that the actual lung cancer is within the radiotherapy fields regardless of bony anatomy. However Radiation Therapists (RTs) are trained in bony matching and not soft tissue matching. The purpose of this study was to determine the level of inter-observer variability in lung cancer gross tumour volume (GTV) delineation on CBCT and alignment of the CBCT with a planning GTV between Radiation Therapists (RTs), a Radiation Oncologist (RO) and a Radiologist (RD)Methods
Ten RTs, one RO and one RD independently delineated the lung cancer GTV for fifteen lung cancer patients on Elekta Synergy CBCT image datasets taken on the first treatment fraction. The window and level settings used by each observer were recorded. Each observer then performed an alignment of the CBCT GVT to the radiotherapy planning GTV and translational errors were recorded. The difference in the isocentre corrections for the alignment shifts and Centre of Volume, Volume and Concordance Index (CI) for the contoured volumes were calculated to determine the level of agreement between the RT’s and the RD and between the RTs and the RO, in comparison to the variation between the RD and RO. In an ideal setting the difference between the RTs and the RO and the RTs and the RD would be at least equivalent to the difference between the RD and RO.Results
The difference between the RT’s and RO and RD was found to be not statistically equivalent to the difference between the RD and RO. The mean isocentre difference between the RO and RD was 0.40cm, compared with 0.42cm and 0.51cm between the RT’s and the RO and RD respectively. The mean CI between the RD and RO was 0.56 (0.44,0.69), which was smaller than the lower bound of the 95 % confidence intervals (95%) of the RT’s compared to the RD (0.5, 0.56) and RO (0.52,0.59). The mean log COV difference was -0.82cm between the RD and RO and -0.54 and -0.65cm between the RT’s and RO and RD respectively. The volume results showed that only 6 of thirty comparisons were equivalent. The mean volume difference between the RD and RO was 0.44cm[3] and 4.73 cm[3] and 5.7cm[3] between the RT’s and RO and RD respectively.Conclusion
The variation between the RTs and the RO and RD was greater than the variation between the RO and RD. Advanced training is necessary to educate the RTs on soft-tissue matching on CBCT for lung cancer radiotherapy.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.09 - Intra Thoracic Anatomical Changes (ITAC) in lung cancer patients during the course of radiotherapy (ID 2699)
11:20 - 11:25 | Author(s): M. Kwint, S. Conijn, E. Schaake, J. Knegjens, M. Rossi, P. Remeijer, J. Belderbos, J. Sonke
- Abstract
- Presentation
Background
Cone beam-CT (CBCT) guidance is routinely used for setup verification of lung cancer patients treated with radiotherapy. CBCT’s frequently show intra-thoracic anatomical changes (ITAC) during treatment. We developed a protocol as a decision support system to guide the radiation technologist in prioritizing these changes. The purpose of this study was to quantify these ITAC during the radiotherapy course and evaluate the current decision protocol.Methods
The CBCT-scans (made the first 3 fractions and weekly thereafter) of all lung cancer patients treated in 2010 in our institute with radical radiotherapy were evaluated. Each CBCT-scan was visually compared with the planning-CT and all visible ITAC were scored. Additionally, our decision protocol called “traffic-light protocol” was retrospectively applied to all CBCT-scans. The traffic-light protocol has three urgency levels: 1) red: ITAC that likely have a considerable impact on the delivered dose to the primary tumor and/or involved lymph-nodes such as tumor shifts outside the high dose region, large in- or decrease of atelectasis; 2) orange: ITAC with likely moderate impact on the dose distribution such as tumor progression, minor in- or decrease of atelectasis, pleural effusion and post obstructive pneumonia; 3) green: ITAC with likely negligible impact on the dose distribution such as tumor regression without considerable centre of mass displacement or other anatomical changes. For level red changes, the radiation oncologist needs to be consulted immediately before the treatment fraction is delivered. For level orange, the radiation oncologist will be informed by email and a response is required before the next fraction. For level green, the radiation oncologist is informed but no response is required.Results
In total 1500 CBCT-scans of 177 patients were evaluated. All patients received radical radiotherapy (≥50 Gy); 97 patients with concurrent chemoradiation, 23 with sequential chemoradiation and 57 with radiotherapy only. In 128 patients (72%) ITAC were observed with maximum level red, orange and green in 12%, 36% and 24% respectively. Fourteen patients (10%) required a new CT and treatment plan to account for the changed anatomy. Most ITAC occurred in the first week (55%). Of all patients with ITAC during treatment, 45%, 36% and 17% had 1, 2, and ≥3 ITAC respectively. Types of observed ITAC were evident regression (36%), considerable tumor baseline shift (28%), changes in atelectasis (15%), tumor progression (11%), pleural effusion (7%) and pneumonia (3%). Progression seen on the CBCT had a significant correlation with changes in week 1 (p<1e3), and level red changes (p=0.01).Conclusion
ITAC have been observed in 72% of all lung cancer patients during radical radiotherapy. In 12% of the patients the radiation oncologist needed to respond immediately and in 10% of the patients a new planning-CT was made to mitigate the risk of tumor under dosing. Volumetric image guided radiotherapy in combination with a decision protocol is recommended for lung cancer patients treated with radical radiotherapy. In our institute we implemented daily CBCT guidance for accurate patient alignment and simultaneously capture ITAC as soon as possible.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.10 - Addition of EBUS-mapping of the mediastinum to PET/CT based selective nodal irradiation in NSCLC decreases geographical miss and nodal GTV volume (ID 2841)
11:25 - 11:30 | Author(s): S.T.H. Peeters, C. Dooms, J. Vansteenkiste, H. Decaluwé, P. De Leyn, K. Nackaerts, W. De Wever, C. Deroose, D. De Ruysscher
- Abstract
- Presentation
Background
FDG-PET/CT based selective lymph node (LN) irradiation is the standard when using 3D-conformal techniques (3D-CRT) for locally advanced NSCLC. With 3D-CRT, adjacent LN not included in the target volume still receive a substantial radiation dose. With current new techniques (IMRT/VMAT), the radiation dose to non-involved LN decreases, which raises the question whether selective nodal irradiation based on PET/CT is still safe. We therefore evaluated the impact of adding EBUS-TBNA (endobronchial ultrasound guided transbronchial needle aspiration)-mapping of the mediastinal LN to PET/CT in avoiding geographical miss, and on the size of nodal GTV (gross tumor volume).Methods
Consecutive NSCLC-patients referred for radiotherapy (RT) in 2012 who underwent EBUS-TBNA were included. False negative (FN) LN for different constellations of PET, CT and EBUS-TBNA based on literature data were calculated, to evaluate the safety of excluding LNs based on CT, PET and EBUS findings. A practical algorithm when to include LN in the GTV was made, and tested on our patients. Results are expressed as mean +/- SD and range.Results
Twenty-five consecutive patients with a full EBUS-TBNA mapping before RT were included: 11 women, 14 men; 17 adenocarcinoma, 8 squamous cell carcinoma; 14 right-sided and 11 left-sided tumors. Mean age: 62.5 +/- 9.7 years. All patients had stage III-disease based on PET-CT. LN stations 1,2R,2L,3,4R,4L,5,6,7,8,9,10-11L,10-11R were analyzed on CT- and PET-scan (=325 LN). Sixty-seven were enlarged (≥10mm), of which 63 were PET-positive. Twelve normal-sized LNs were PET-positive. Fifty LNs were investigated with EBUS-TBNA (mean: 2/patient +/-0.96;1-5): 28 were malignant, 22 normal. EBUS-TBNA detected 1 cancer-containing normal-sized LN without FDG-uptake, thus 1/25 geographical miss (4%). The cancer prevalence, taking into account the FN rate of EBUS of 20%, was calculated (Fig.1). With addition of EBUS, in PET-negative patients FN decreases with 10% for enlarged LN, and with 5% for normal-sized LN. An algorithm when to include a LN in the GTV is proposed (Fig.1). According to this algorithm, in our population 3/79 (4%) enlarged or PET-positive LN would be excluded from the GTV. At patient level, this was a GTV decrease in 3 (12%) patients.Conclusion
When incidental nodal irradiation is low such as in IMRT or VMAT, EBUS-TBNA should be added to FDG-PET/CT for mediastinal staging. This avoids geographical miss in 4% of patients, and decreases the radiation volume in 12% of patients. A practical algorithm is proposed.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.11 - DART - bid (dose-Differentiated Accelerated Radiation Therapy, 1.8 Gy twice daily): A novel therapeutic approach for locoregionally advanced, nonresected non-small cell lung cancer (ID 2826)
11:30 - 11:35 | Author(s): K. Wurstbauer, H. Deutschmann, K. Dagn, F. Zehentmayr, P. Kopp, C. Fussl, P. Porsch, B. Maurer, M. Blaukovitsch, M. Studnicka, F. Sedlmayer
- Abstract
- Presentation
Background
A modern treatment approach for non-resected NSCLC comprises radiation dose intensification and short overall treatment times. We report on patients treated within a prospective trial, correlating doses to tumor volume, combined with chemotherapy sequentially.Methods
Radiation doses to primary tumors were aligned along increasing tumor size within 4 groups (<2.5 cm/ 2.5-4.5 cm/ 4.5-6.0 cm/ >6.0 cm; mean number of three perpendicular diameters). ICRU-doses of 73.8 Gy/ 79.2 Gy/ 84.6 Gy/ 90.0 Gy, respectively, were applied. Macroscopically involved nodes were treated with a median dose of 59.4 Gy, nodal sites about 6 cm cranial to involved nodes electively with 45 Gy. Fractional doses were 1.8 Gy twice daily (bid). 2 cycles chemotherapy were given before radiotherapy; the interval between chemotherapy and radiotherapy was preferentially shorter than 8 days. With a median follow up time of 56.1 months (range 43.2 – 97.1 ) for patients alive, mature results for locoregional tumor control, survival and toxicity are presented.Results
Between 2004 and 2009,123 continuously referred, unselected patients with 127 histologically/ cytologically proven NSCLC were enrolled; Stage II: 6 pts.; IIIA: 70 pts.; IIIB: 47 pts. Weight loss >5%/ 3 months: 26%; Karnofsky Index ≤ 70%: 46% of the patients. The local tumor control rate at 2-/ 5 years is 73%/ 70%, respectively; the regional tumor control rate 91%/ 89%, respectively. The median overall survival time is 24.6 months, the 2- and 5-year overall survival rates are 52% and 19%, respectively. 2 treatment-related deaths (progressive pulmonary fibrosis) occurred in patients with pre-existing pulmonary fibrosis. Further toxicity was mild or moderate: Pneumonitis grade 2/ 3 (n=10/ 6); esophagitis grade 2/ 3 (n=16/ 7). Lung late grade 2 (n=13), esophagus late grade 3 (n=1).Conclusion
Locoregional tumor control is high; as are survival times for this unselected patient cohort. In all outcome parameters DART-bid seems to compare favourably with simultaneous chemo-radiotherapies, at present considered ‘state of the art’; simultaneous treatments however are applicable only to a minority of referred patients, patients in good general condition.Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.
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MO23.12 - DISCUSSANT (ID 3936)
11:35 - 11:50 | Author(s): A. Brade
- Abstract
- Presentation
Abstract not provided
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Author of
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MO14 - Mesothelioma II - Surgery and Multimodality (ID 121)
- Event: WCLC 2013
- Type: Mini Oral Abstract Session
- Track: Mesothelioma
- Presentations: 1
- Moderators:E. Lim, B. McCaughan
- Coordinates: 10/29/2013, 10:30 - 12:00, Bayside Gallery B, Level 1
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MO14.13 - DISCUSSANT (ID 3971)
11:35 - 11:50 | Author(s): M.M. Tin
- Abstract
- Presentation
Abstract not provided
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P3.14 - Poster Session 3 - Mesothelioma (ID 197)
- Event: WCLC 2013
- Type: Poster Session
- Track: Mesothelioma
- Presentations: 1
- Moderators:
- Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level
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P3.14-004 - Adjuvant Hemithoracic Radiotherapy After Extrapleural Pneumonectomy For Malignant Pleural Mesothelioma: Experience At The Sydney Cancer Centre (ID 1249)
09:30 - 09:30 | Author(s): M.M. Tin
- Abstract
Background
Radiotherapy reduces local recurrence following extrapleural pneumonectomy (EPP), and forms part of a potentially curative, multimodality treatment of malignant pleural mesothelioma. Hemithoracic radiotherapy poses a significant dosimetric challenge. Conventional techniques have suffered with marked dose uncertainty, while modern IMRT techniques have been associated with increased pulmonary toxicity. We conducted a retrospective review of all patients referred to our institution for hemithoracic radiotherapy following EPP, with the aim of assessing treatment toxicity and outcomes. The present study is, to our knowledge, the largest Australian series of adjuvant radiotherapy for this disease.Methods
53 patients were referred following EPP for malignant pleural mesothelioma, with or without neoadjuvant chemotherapy, between 2004 and 2012. 4 patients were excluded or did not commence radiotherapy due to poor performance (n = 3) or disease progression (n = 1). Radiotherapy involved a 3D conformal, mixed photon and electron technique, delivering 45-55 Gy in 25-28 fractions (2004-2009, n=31), and a 9-field IMRT technique, delivering 50.4-60 Gy in 28-30 fractions (2009-2012, n=18). We assessed toxicity, disease progression and survival in all patients who commenced radiotherapy (n = 49). Toxicity was assessed using the Common Terminology Criteria for Adverse Events version 4.0 and survival was calculated from the date of EPP using the Kaplan-Meier method.Results
31 patients (59%) received neoadjuvant chemotherapy, with a combination of platinum agent and pemetrexed. 41 patients (84%) completed treatment as prescribed. 6 patients stopped prematurely due to toxicity, and 2 due to disease progression. Most patients discontinuing due to toxicity (n = 5) received over 90% of the prescribed dose. Low grade nausea, anorexia and fatigue were near universal, however severe (grade 3) skin toxicity, nausea and oesophagitis were 8%, 6% and 2%, respectively. One patient developed a grade 4 Pneumocystis carinii infection, however there were no cases of radiation pneumonitis. Late toxicities were rare, with the exception of a persistent elevation in the liver enzymes alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT). Of the patients treated with right-sided disease (n = 26), 9 (35%) developed grade 2-3 elevations in ALP or GGT. Grade 2-3 liver toxicity was more common in patients treated with a conventional technique (53%) than with IMRT (11%). No patients developed clinical hepatitis. With a median follow up of 19 months (range 2-102 months), median progression-free survival and overall survival were 22 and 30 months, respectively. 2-year overall survival was 53.8%. 7 patients (14%) were alive beyond 5 years.Conclusion
Hemithoracic radiotherapy can be safely delivered in selected patients following EPP. Although associated with significant early toxicity, most patients complete treatment and late toxicity is uncommon. Our outcomes compare favourably with recently-published international series.
