Assessment of Gross Tumor Volume Regression and Motion Changes During Radiotherapy for Non–Small-Cell Lung Cancer as Measured by Four-Dimensional Computed Tomography

Britton, K.; Starkschall, George; Tucker, Susan L.; Pan, Tinsu; Nelson, Christopher Lee; Chang, Joe Y.; Cox, James D.; Mohan, Radhe; Komaki, Ritsuko

doi:10.1016/j.ijrobp.2007.01.021

Cited by 163 publications

(146 citation statements)

References 35 publications

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“…In our study, CT imaging was repeated after 44 Gy and we observed an average reduction in PTV by about 50% which is in agreement with data reported by Britton et al and JuhlerNottrup et al 11,12 . Similar results of tumor repression have been observed by Guckenberger et al who reported a continuous tumor regression by 1.2% per day 7 .…”

Section: Discussionsupporting

confidence: 93%

Effective Adaptive Radiotherapy for Locally Advanced Lung Cancer Treated with 3D Conformal Technique

Salem

Sayed

Amin

2017

Kasr-Al-Aini J.of Clin. Onc. and Nuc. Med.

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Background:The reduction in tumor volume during the treatment of locally advanced non-small cell lung cancer (NSCLC) with chemoradiotherapy allows the application of adaptive radiotherapy strategy. Adaptive planning has the potential for improving radiotherapy planning indices and dose escalation while respecting the dose to the organs at risk (OARs). Aim: To evaluate the benefit of adaptive radiotherapy in patients with advanced NSCLC treated with conformal technique. Methods: In this dosimetric planning study, we included computerized tomography data-sets from 10 patients with locally advanced NSCLC who responded to the first 22 fractions (44 Gy) and achieved ˃ 20% regression in gross tumor volume. We designed for each patient two plans. Plan 1 (conventional planning) in which the whole prescribed dose (64 Gy) was delivered to the planning target volume 1 (PTV1). Plan 2 (adaptive planning) was divided into plan 2A delivering 44 Gy to PTV1 and plan 2B delivering 20 Gy to PTV2. In plan 2B we re-delineated the PTV and all the target volumes on the repeated CT images to deliver the rest of the prescribed dose (20 Gy). Plan 2A and Plan 2B were summed to measure the accumulated dose delivered to OARs. Results: The mean PTV2 was significantly smaller than the mean PTV1 (p<0.001) with 53% reduction. Adaptive planning resulted in 13.2% mean reduction in the maximum dose to the spinal cord (p<0.001), 10.4% in esophagus V35 (p<0.001), 11.4% in esophagus V50 (p<0.001), 24.3% in mean lung dose (p=0.001) and 19.7% in lung V20 (p<0.001). The reduction in heart d-max and heart mean dose was not significant. Conclusion:The adaptive radiotherapy technique used in our study can reduce the irradiated volume and minimize the dose delivered to OARs. This simple applicable technique can be easily implemented in limited resources centers.

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Section: Discussionsupporting

confidence: 93%

Effective Adaptive Radiotherapy for Locally Advanced Lung Cancer Treated with 3D Conformal Technique

Salem

Sayed

Amin

2017

Kasr-Al-Aini J.of Clin. Onc. and Nuc. Med.

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“…Breathing patterns can change during the course of treatment (24). The apparent volume visible on the MVCT will change if breathing amplitude changes because MVCT acquisition is similar to a slow CT scan.…”

Section: Discussionmentioning

confidence: 99%

Adaptive Radiotherapy Planning on Decreasing Gross Tumor Volumes as Seen on Megavoltage Computed Tomography Images

Woodford

Yartsev

Dar

et al. 2007

International Journal of Radiation Oncology*Biology*Physics

159

155

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Purpose: To evaluate gross tumor volume (GTV) changes for patients with non-small-cell lung cancer by using daily megavoltage (MV) computed tomography (CT) studies acquired before each treatment fraction on helical tomotherapy and to relate the potential benefit of adaptive image-guided radiotherapy to changes in GTV. Methods and Materials: Seventeen patients were prescribed 30 fractions of radiotherapy on helical tomotherapy for non-small-cell lung cancer at London Regional Cancer Program from Dec 2005 to March 2007. The GTV was contoured on the daily MVCT studies of each patient. Adapted plans were created using merged MVCT-kilovoltage CT image sets to investigate the advantages of replanning for patients with differing GTV regression characteristics.Results: Average GTV change observed over 30 fractions was À38%, ranging from À12 to À87%. No significant correlation was observed between GTV change and patient's physical or tumor features. Patterns of GTV changes in the 17 patients could be divided broadly into three groups with distinctive potential for benefit from adaptive planning. Conclusions: Changes in GTV are difficult to predict quantitatively based on patient or tumor characteristics. If changes occur, there are points in time during the treatment course when it may be appropriate to adapt the plan to improve sparing of normal tissues. If GTV decreases by greater than 30% at any point in the first 20 fractions of treatment, adaptive planning is appropriate to further improve the therapeutic ratio. Ó 2007 Elsevier Inc.

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“…Feng et al (2009) thought that the GTV would change after the radiotherapy dose was increased to 40-50 Gy, and in cases for which the radiotherapy dose was 58 Gy, the average GTV reduction was 26% (range = +15 to -75%). Erridge et al (2003) used an electronic portal imaging device to evaluate 25 patients and determined that 40% patients had tumor volume reductions that exceeded 20% during radiotherapy, while Britton et al (2007) observed that during radiotherapy, the primary tumor volume reductions in 50% of the patients exceeded 40%. van Zwienen et al (2008) evaluated 114 lung cancer patients; among them, 40% of the patients presented significant tumor regression, while the tumor volumes of 8% of the patients decreased by 25% in the third week and more than 17% in the fourth week.…”

Section: Discussionmentioning

confidence: 99%

Clinical three-dimensional conformal radiotherapy research using repeated computed tomography scans for field reduction in older non-small-cell lung cancer patients

Fu¹,

Gu²,

Zhang³

et al. 2014

Genet. Mol. Res.

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ABSTRACT. This study investigated the curative and toxic effects of three-dimensional conformal radiotherapy (3D-CRT), using repeated CT scans for field reduction in older non-small-cell lung cancer (NSCLC) patients. 3D-CRT was administered to 36 older patients with NSCLC, and irradiation fields included the primary lesion and metastatic lymph nodes. After CT localization scanning, images were fed into a treatment planning system to delineate the gross tumor volume (GTV)1 and prepare Plan 1. After the DT50 (dose of the tumor is 50 Gy) increased from 50 Gy in 25 fractions to 54 Gy in 27 fractions, secondary CT localization scanning was performed to delineate GTV2 and prepare Plan 2; radiotherapy was administered continuously. When the DT increased to 60-65 Gy, tertiary CT scanning was performed to prepare another plan. The field was reduced to boost irradiation to the residual target volume until the total DT increased to 68-74 Gy. Compared with GTV1, the median absolute volume regression and median relative regression amounts for GTV2 were 68.85 cm 3 and 31.17%, respectively (Z = -2.673, P = 0.021). There were 8 cases of complete remission (22.2%), 20 of partial remission (55.6%), 7 of stable disease (19.4%), and 1 of progressive disease (2.8%). The total effectiveness rate was 77.8% and the 1-and 2-year survival rates were 63.9 and 27.8%, respectively. Radiation esophagitis and radiation pneumonia, the main toxic side effects, were tolerable. 3D-CRT, using repeated CT scans for field reduction in older NSCLC patients, could increase the local control and survival rates and relieve the toxic radiotherapy side effects.

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Assessment of Gross Tumor Volume Regression and Motion Changes During Radiotherapy for Non–Small-Cell Lung Cancer as Measured by Four-Dimensional Computed Tomography

Cited by 163 publications

References 35 publications

Effective Adaptive Radiotherapy for Locally Advanced Lung Cancer Treated with 3D Conformal Technique

Effective Adaptive Radiotherapy for Locally Advanced Lung Cancer Treated with 3D Conformal Technique

Adaptive Radiotherapy Planning on Decreasing Gross Tumor Volumes as Seen on Megavoltage Computed Tomography Images

Clinical three-dimensional conformal radiotherapy research using repeated computed tomography scans for field reduction in older non-small-cell lung cancer patients

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