scholarly journals Does Motion Assessment With 4-Dimensional Computed Tomographic Imaging for Non–Small Cell Lung Cancer Radiotherapy Improve Target Volume Coverage?

2017 ◽  
Vol 11 ◽  
pp. 117955491769846 ◽  
Author(s):  
Naseer Ahmed ◽  
Sankar Venkataraman ◽  
Kate Johnson ◽  
Keith Sutherland ◽  
Shaun K Loewen
Keyword(s):  
Lung Cancer ◽  
Gross Tumor Volume ◽  
Tumor Volume ◽  
Target Volume ◽  
Data Sets ◽  
Nodal Disease ◽  
Dice Coefficient ◽  
Data Set ◽  
4D Ct ◽  
Ct Data

Introduction: Modern radiotherapy with 4-dimensional computed tomographic (4D-CT) image acquisition for non–small cell lung cancer (NSCLC) captures respiratory-mediated tumor motion to provide more accurate target delineation. This study compares conventional 3-dimensional (3D) conformal radiotherapy (3DCRT) plans generated with standard helical free-breathing CT (FBCT) with plans generated on 4D-CT contoured volumes to determine whether target volume coverage is affected. Materials and methods: Fifteen patients with stage I to IV NSCLC were enrolled in the study. Free-breathing CT and 4D-CT data sets were acquired at the same simulation session and with the same immobilization. Gross tumor volume (GTV) for primary and/or nodal disease was contoured on FBCT (GTV_3D). The 3DCRT plans were obtained, and the patients were treated according to our institution’s standard protocol using FBCT imaging. Gross tumor volume was contoured on 4D-CT for primary and/or nodal disease on all 10 respiratory phases and merged to create internal gross tumor volume (IGTV)_4D. Clinical target volume margin was 5 mm in both plans, whereas planning tumor volume (PTV) expansion was 1 cm axially and 1.5 cm superior/inferior for FBCT-based plans to incorporate setup errors and an estimate of respiratory-mediated tumor motion vs 8 mm isotropic margin for setup error only in all 4D-CT plans. The 3DCRT plans generated from the FBCT scan were copied on the 4D-CT data set with the same beam parameters. GTV_3D, IGTV_4D, PTV, and dose volume histogram from both data sets were analyzed and compared. Dice coefficient evaluated PTV similarity between FBCT and 4D-CT data sets. Results: In total, 14 of the 15 patients were analyzed. One patient was excluded as there was no measurable GTV. Mean GTV_3D was 115.3 cm3 and mean IGTV_4D was 152.5 cm3 ( P = .001). Mean PTV_3D was 530.0 cm3 and PTV_4D was 499.8 cm3 ( P = .40). Both gross primary and nodal disease analyzed separately were larger on 4D compared with FBCT. D95 (95% isodose line) covered 98% of PTV_3D and 88% of PTV_4D ( P = .003). Mean dice coefficient of PTV_3D and PTV_4D was 84%. Mean lung V20 was 24.0% for the 3D-based plans and 22.7% for the 4D-based plans ( P = .057). Mean heart V40 was 12.1% for the 3D-based plans and 12.7% for the 4D-based plans ( P = .53). Mean spinal cord Dmax was 2517 and 2435 cGy for 3D-based and 4D-based plans, respectively ( P = .019). Mean esophageal dose was 1580 and 1435 cGy for 3D and 4D plans, respectively ( P = .13). Conclusions: IGTV_4D was significantly larger than GTV_3D for both primary and nodal disease combined or separately. Mean PTV_3D was larger than PTV_4D, but the difference was not statistically significant. The PTV_4D coverage with 95% isodose line was inferior, indicating the importance of incorporating the true size and shape of the target volume. Relatively less dose was delivered to spinal cord and esophagus with plans based on 4D data set. Dice coefficient analysis for degree of similarity revealed that 16% of PTVs from both data sets did not overlap, indicating different anatomical positions of the PTV due to tumor/nodal motion during a respiratory cycle. All patients with lung cancer planned for radical radiotherapy should have 4D-CT simulation to ensure accurate coverage of the target volumes.

scholarly journals Lung Segmentation in 4D CT Volumes Based on Robust Active Shape Model Matching

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Gurman Gill ◽  
Reinhard R. Beichel
Keyword(s):  
Image Data ◽  
Active Shape Model ◽  
Data Sets ◽  
Segmentation Method ◽  
Data Set ◽  
Shape Model ◽  
Lung Segmentation ◽  
4D Ct ◽  
Active Shape ◽  
Ct Data

Dynamic and longitudinal lung CT imaging produce 4D lung image data sets, enabling applications like radiation treatment planning or assessment of response to treatment of lung diseases. In this paper, we present a 4D lung segmentation method that mutually utilizes all individual CT volumes to derive segmentations for each CT data set. Our approach is based on a 3D robust active shape model and extends it to fully utilize 4D lung image data sets. This yields an initial segmentation for the 4D volume, which is then refined by using a 4D optimal surface finding algorithm. The approach was evaluated on a diverse set of 152 CT scans of normal and diseased lungs, consisting of total lung capacity and functional residual capacity scan pairs. In addition, a comparison to a 3D segmentation method and a registration based 4D lung segmentation approach was performed. The proposed 4D method obtained an average Dice coefficient of0.9773±0.0254, which was statistically significantly better (pvalue≪0.001) than the 3D method (0.9659±0.0517). Compared to the registration based 4D method, our method obtained better or similar performance, but was 58.6% faster. Also, the method can be easily expanded to process 4D CT data sets consisting of several volumes.

scholarly journals TC simulation versus TC/PET simulation for radiotherapy in lung cancer: volumes comparison in two cases

2013 ◽  
Vol 2 (1) ◽  
Author(s):  
P. Franzone ◽  
A. Muni ◽  
E. Cazzulo ◽  
L. Berretta ◽  
G. Pozzi ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Early Diagnosis ◽  
Treatment Planning ◽  
Gross Tumor Volume ◽  
Tumor Volume ◽  
Target Volume ◽  
Radiotherapy Treatment Planning ◽  
Pulmonary Cancer ◽  
Radiotherapy Treatment

CT/PET is useful in early diagnosis, staging, follow-up and in radiotherapy treatment planning especially for tumors located in motion involved anatomic areas (chest and abdomen). We analysed the treatment planning for radiotherapy of two pulmonary cancer patients. A comparison was performed between GTV (Gross Tumor Volume) and PTV (Planning Target Volume) identified with CT images alone and GTV and PTV evaluated with CT/PET images. CT/PET imaging was demonstrated to significantly modify the target volume if compared with CT imaging: volumes were reduced by 32-49%.

The impact of four dimensions CT simulation on planning target volume in radiotherapy for primary lung cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e20091-e20091
Author(s):  
Fawzi Jamil Abuhijla ◽  
Lubna Abdelrahman Hammoudeh ◽  
Ramiz Ahmad Abu-Hijlih ◽  
Jamal Khader
Keyword(s):  
Lung Cancer ◽  
Planning Target Volume ◽  
Tumor Volume ◽  
Multivariable Analysis ◽  
Primary Lung Cancer ◽  
Free Breathing ◽  
Target Volume ◽  
4D Ct ◽  
Ct Simulation ◽  
The Impact

e20091 Background: 4D CT simulation has been evolved to estimate the internal body motion and considered as a useful tool for intra-thoracic tumor definition. This study aimed to evaluate the impact of using 4D simulation on the planning target volume (PTV) for primary lung tumor. Methods: Patients who underwent CT simulation for primary lung cancer radiotherapy between 2012-2016 using 3D- (free breathing) and 4D- (respiratory gated) institutional protocol were included in this retrospective review. For each patient, gross tumor volume (GTV) was contoured in free breathing scan (3D-GTV), exhale scan (e-GTV) and inhale scan (i-GTV). The corresponding CTVs (3D-CTV, e-CTV and i-CTV) were created by adding 1 cm in all directions. 3D-internal target volume (3D-ITV) was generated by 0.5 cm cranio-caudal expansion of 3D-CTV, while 4D-ITV was created by combination of e-CTV and i-CTV. Subsequently, a 0.5 cm margin was added to generate the 3D-PTV and 4D-PTV respectively. The volumes of 3D-PTV and 4D-PTV were compared to examine the impact of 4D CT simulation on changes in the volume of PTV. Univariable and multivariable analysis were performed to test the impact of volume and location of GTV on the changes of PTV volume by more than 10 % between free breathing and respiratory gated scans. Results: A total of 10 patients were identified. The median [range] GTV, i-GTV, e-GTV volumes were 13.55 [1.44-628.66], 13.17 [1.77-627.36], 12.85 [1.34-630.25] cc respectively. The 3D-CTV, i-CTV, e-CTV volumes were 86.37 [23.76-1209], 84.97 [25.5- 1220.4], 83.40 [23.36-1224.12] cc respectively. 3D-ITV and 4D-ITV median volume was 106.06 [3.99-1422.8], 88.02 [20.51-1338.18] cc respectively. 3D-PTV was significantly larger than the 4D-PTV; median [range] volumes were 182.79 [58.65- 1861.05] vs. 158.21 [52.76-1771.02] cc, p = 0.0068). On multivariable analysis, neither the volume of GTV (p = 0.4917), nor the location of the tumor (peripheral, p = 0.4914 or lower location, p = 0.9594) had an in impact on PTV differences between free breathing and respiratory gated scans. Conclusions: The use of 4D simulation reduces the PTV for primary lung cancer, and it should be routinely implemented in clinical practice regardless the tumor volume or location.

508 A simple method to reconstruct a representative CT scan from a 4D CT data set for use in treatment planning of lung cancer

2005 ◽  
Vol 76 ◽  
pp. S217
Author(s):  
E. Damen ◽  
J. Wolthaus ◽  
C. Schneider ◽  
M. Rossi ◽  
J. Belderbos ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Ct Scan ◽  
Treatment Planning ◽  
Data Set ◽  
Simple Method ◽  
4D Ct ◽  
Ct Data

Selection of patient for gated treatment based on the information from 4DCT imaging in stereotactic body radiotherapy of non-small cell lung cancer

2018 ◽  
Vol 18 (02) ◽  
pp. 175-179
Author(s):  
N. V. N. Madhusudhana Sresty ◽  
A. Krishnam Raju ◽  
S. D. Sharma ◽  
T. Anil Kumar ◽  
Shabbir Ahamed ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Small Cell Lung Cancer ◽  
Stereotactic Body Radiotherapy ◽  
Target Volume ◽  
Small Cell ◽  
Data Sets ◽  
Dose Delivery ◽  
Small Cell Lung ◽  
Motion Management ◽  
Ct Data

AbstractPurposeStereotactic body radiotherapy (SBRT) is widely used for the treatment of stage-I non-small cell lung cancer (NSCLC). Patient-specific motion correlated with 4DCT could be essential for hypofractionated SBRT. All patients undergoing SBRT do not require motion management during the dose delivery. The objective of this study was to evaluate which patient may benefit from Gated SBRT.Materials and methodsTreatment planning of 20 patients of stage-I NSCLC was analysed. Conventional and 4DCT scans were taken. Internal target volume as well as planning target volume (ITV and PTV) were determined in the CT data sets. PTVall phases created using 4DCT data sets and PTV15mm created using conventional CT data were compared. Also, ITVall phases were compared with ITV created from maximum intensity projections (ITVMIP). Suitability of patients for motion management-based treatment delivery was also evaluated.ResultsThe average ITVMIP to ITVall phases ratio is 1·06 indicating good agreement between them. Based on the ratio of intensity projections, 9 out of 17 patients were found suitable for our existing gated treatment.Conclusion4D CT is the main requirement in SBRT to identify the patients who can benefit from motion management during the dose delivery.

Computed Tomographic–Pathologic Correlation of Gross Tumor Volume and Clinical Target Volume in Non–Small Cell Lung Cancer

2001 ◽  
Vol 125 (11) ◽  
pp. 1469-1472
Author(s):  
Roscoe Chan ◽  
Yu He ◽  
Abida Haque ◽  
Joseph Zwischenberger
Keyword(s):  
Lung Cancer ◽  
Small Cell Lung Cancer ◽  
Cell Lung Cancer ◽  
Gross Tumor Volume ◽  
Clinical Target Volume ◽  
Tumor Volume ◽  
Target Volume ◽  
Small Cell ◽  
Small Cell Lung ◽  
Computed Tomographic

Abstract Context.—Computed tomographic (CT) scan data are used regularly in radiation treatment planning for patients with lung cancer. To our knowledge, the relationship of the CT images of tumors and their corresponding microscopic extent has not yet been studied in detail. Objective.—To correlate tumor sizes on CT with tumor sizes measured microscopically (ie, the gross tumor volume [GTV]-clinical target volume margin) in non–small cell lung cancers. Design.—Prospective pilot study. Setting.—Single institution. Patients.—Patients with operable non–small cell lung cancer were identified preoperatively. Interventions.—Once the surgical specimen was available, it was oriented with the surgeon and the pathologist. Seven whole-mount, cross-sectional histologic glass slides were made from 5 tumors using formalin fixation and hematoxylin-eosin staining. The pathologist then outlined the cancer-containing area under the microscope (Micro-GTV) and the area of surrounding inflammatory response (Micro-GTV + inflammation). Preoperative CT scans were used for outlining tumor on the corresponding slice (CT-GTV). Main Outcome Measures.—Correlation of the areas of Micro-GTV, Micro-GTV + inflammation, and CT-GTV was performed. Results.—There was an obvious trend that the CT-GTV was bigger than the Micro-GTV, except in specimen 1, in which the 2 areas were about equal. However, on comparing the values for the CT-GTV and the Micro-GTV + inflammation, the difference between the 2 areas became smaller. Conclusions.—Modern CT scans might overestimate the GTV in non–small cell lung cancer. The GTV–clinical target volume margin could actually be zero or even a negative value. The findings in this small study are interesting and provoking. Further study with a larger number of patients and more rigid quality control is warranted to confirm our findings.

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