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Liqiao Hou
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EP1.17 - Treatment of Early Stage/Localized Disease (ID 207)
- Event: WCLC 2019
- Type: E-Poster Viewing in the Exhibit Hall
- Track: Treatment of Early Stage/Localized Disease
- Presentations: 1
- Now Available
- Moderators:
- Coordinates: 9/08/2019, 08:00 - 18:00, Exhibit Hall
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EP1.17-35 - CBCT Radiomics May Predict Short-Term SBRT Effect in Early Stage Lung Cancer Patients (Now Available) (ID 501)
08:00 - 18:00 | Presenting Author(s): Liqiao Hou
- Abstract
Background
This study aimed to determine whether radiomics features can be obtained from cone-beam CT (CBCT) through the linac based onboard-imaging systems.
Method
Thirty consecutive patients with early stage lung cancer treated with stereotactic body radiation therapy (SBRT) (Total dose:50-60Gy, Fraction:5-8) were included. CBCT scan were performed before delivery of each SBRT treatment. Diagnostic CT scan before Radiation Therapy (diagnostic CT) and follow-up CT at one month after radiotherapy (follow-up CT) were analyzed. Primary tumors were delineated manually and modified on diagnostic CT, CBCT and follow-up CT. Tumor size on diagnostic CT and follow-up CT were used to calculate the reduction rate. The primary endpoint was average daily tumor reduction rate. Radiomics features were extracted from first fraction CBCT (CBCT first), last fraction CBCT (CBCT last) and diagnostic CT by Imaging Biomarker Explorer (IBEX) software. Radiomic features were selected using correlation coefficient and LASSO dimensionality reduction based on R.
Result
A total of 222 radiomics features were obtained from CBCT first, CBCT last and diagnostic CT of each patient. Based on correlation coefficients>0.70 and with LASSO dimensionality reduction, 5, 4 and 5 features were selected in diagnostic CT, CBCT first and CBCT last, respectively. Comparing the features in three CT subsets, two features were same between diagnostic CT and CBCT first, three features were the same between diagnostic CT and CBCT last. Two features are common in all three CT imaging sets. (Table 1)
ConclusionTable 1 Different characteristic values of different CT radiomics be predicted SBRT reduction rate.
Images
diagnostic CT
CBCT first
CBCT last
Feature
Inverse Variance
Inverse Variance
Inverse Variance
Percentile
Percentile
Percentile
Complexity
Cluster Shade
Cluster Shade
Correlation
Max3D Diameter
Correlation
Inverse Diff Moment Norm
Information MeasureCorr1
A few radiomics features may be robust to the noise in daily CBCT images which are often considered of poor quality. Study with larger sample size are needed to verify this interesting finding.
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OA06 - Refining Lung Cancer Screening (ID 131)
- Event: WCLC 2019
- Type: Oral Session
- Track: Screening and Early Detection
- Presentations: 1
- Now Available
- Moderators:Tomasz Grodzki, Lluis Esteban Tejero
- Coordinates: 9/09/2019, 11:00 - 12:30, Hilton Head (1978)
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OA06.07 - Discrimination of Lung Invasive Adenocarcinoma with Micropapillary Pattern Based on CT Radiomics (Now Available) (ID 399)
11:00 - 12:30 | Author(s): Liqiao Hou
- Abstract
- Presentation
Background
To develop and validate the radiomics nomogram on the discrimination of lung invasive adenocarcinoma (IAC) with micropapillary pattern from non-micropapillary pattern lesion and improve the diagnostic accuracy rate of lung invasive adenocarcinoma with micropapillary pattern before operations and provide guidance for follow-up treatments.
Method
Forty-one pathologically confirmed lung invasive adenocarcinomas with micropapillary pattern from January 2014 to December 2018 were included. Eighty-two pathologically confirmed lung invasive adenocarcinomas without micropapillary pattern from January 2018 to December 2018 were collected. Select 86 patients (70%) randomly from the 123 patients as the primary cohort, and the other 37 patients (30%) were set as an independent validation cohort. Least absolute shrinkage and selection operator (Lasso) was used for feature selection based on contrast enhancement CT images and then radiomics signature building. ROC analysis and AUC were used to value the ability to identify the lung invasive adenocarcinomas with micropapillary pattern.
Result
According to GrayLevelCooccurenceMatrix3, Intensity Histogram and Shape, nine hundred and eighty-five radiomics features were extracted by IBEX. And after data pre-processing such as eliminating missing items, strong correlation variables and multicollinear variables, the features were reduced to 40 features. Based on Mann-Whitney U Test, 28 features were figured out from the 40 features. Then Lasso was used to reduce the features to 3 features (10-1clusterprominenc, -333-4clusterprominence, 8-1contrast) as the most meaningful discriminators to build the radiomics signatures (Table 1). According to SPSS21.0 binary logistic regression analysis, ROC analysis and AUC show that the radiomics signature have effective discrimination performance of lung invasive adenocarcinoma with micropapillary pattern from non- micropapillary pattern lesion (AUC=0.766) and it reflects better in the independent validation cohort (AUC=0.807) (Figure 1).
Table 1 Three characteristic prediction parameters in radiomics label
prediction parameter P value U value W value AUC 10-1clusterprominence <0.005 765.000 4168.000 0.772 -333-4clusterpromise <0.005 790.000 4193.000 0.765 8-1contrast <0.005 919.000 4322.000 0.727
Conclusion
The radiomics signature established in this study have effective prediction of lung invasive adenocarcinoma with micropapillary pattern and non- micropapillary pattern lesion.
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P1.14 - Targeted Therapy (ID 182)
- Event: WCLC 2019
- Type: Poster Viewing in the Exhibit Hall
- Track: Targeted Therapy
- Presentations: 1
- Moderators:
- Coordinates: 9/08/2019, 09:45 - 18:00, Exhibit Hall
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P1.14-40 - EGFR-TKIs May Sensitize Radiation Lung Damage in Stereotactic Body Radiotherapy Based on Intensity Analyzing (ID 297)
09:45 - 18:00 | Author(s): Liqiao Hou
- Abstract
Background
To measure early radiographic changes of acute radiation pneumonitis after stereotactic body radiotherapy (SBRT) and compare the differences between patients treated with and without the epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs).
Method
Patients with SBRT with 3-month follow-up CT scans were eligible. 20 patients treated with EGFR-TKIs a month before stereotactic body radiotherapy (Target-SBRT group) were formed the primary study population. Another 20 patients received SBRT alone were selected from our SBRT data bank to serve as control, by matching dose prescription, tumor size and location. Pre- and post-SBRT CT scans from these 40 patients were registered to each other and the mean value of CT intensity (Hounsfield unit, HU) were extracted for regions of the lungs receiving the same dose at 10 Gy intervals to generate dose-response curves (DRC). The frequency of density changes＞200 HU was modeled depending on the fractionation using a Probit model for different treatments.
Result
There were significant differences in the DRC of pre-SBRT, post-SBRT and the differences of HU value (△HU) in lung between the SBRT alone and Target SBRT groups (all P＜0.050)(Figure 1). The respective dose for a 50% complication risk (TD50) for changes＞200HU was 72Gy (95% confidence interval (CI 58-107) in SBRT alone group versus 52Gy (CI 46-59) in targeted SBRT group (Figure 2).
Conclusion
Compared to SBRT alone, targeted SBRT group has a lower TD50 and m value, both suggesting an increased complication probability of normal lung tissue.
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P1.18 - Treatment of Locoregional Disease - NSCLC (ID 190)
- Event: WCLC 2019
- Type: Poster Viewing in the Exhibit Hall
- Track: Treatment of Locoregional Disease - NSCLC
- Presentations: 1
- Moderators:
- Coordinates: 9/08/2019, 09:45 - 18:00, Exhibit Hall
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P1.18-15 - Dosimetric and Toxicity Benefits of Adaptive IMRT in Patients with Stage III Non-Small Cell Lung Cancer (ID 396)
09:45 - 18:00 | Author(s): Liqiao Hou
- Abstract
Background
Multiple studies observed anatomical changes or tumor shrinkage during concurrent chemoradiotherapy in patients with non-small cell lung cancer (NSCLC). Mid-treatment CT based adaptive radiotherapy targeting to the shrunken tumor can reduce the dose to adjacent normal tissue or potentially deliver a higher dose to the tumor. We aimed to quantitatively analyze the benefit of intensity-modulated radiotherapy (IMRT) adapting to CT changes at the 20th fraction in stage III NSCLC patients.
Method
We retrospectively evaluated consecutive patients with unresectable stage III NSCLC treated with adaptive IMRT from November 2017 to August 2018. The eligibility criteria included a mid-treatment CT simulation for replanning at the 20th fraction and a follow-up of at least 6 months. The prescribed dose was 64-66 Gy in 30 fractions unless exceeding the dose limit. Normal tissues were delineated according to RTOG1106 atlas on organs at risk under the supervision of a senior physician. Dose-volume histograms were calculated for the initial plans, composite adaptive plans, and lung isotoxic boost plans. Radiation pneumonitis (RP) and esophagitis (RE) were graded per CTCAE v4.03. Univariate logistic regression was applied to analyze the correlation between dosimetric factors and adverse events.
Result
53 patients were eligible in this study. The average GTV shrinkage was -40.9% at the 20th fraction. Comparing the dosimetric factors of the composite adaptive plans to the initial ones, the GTV coverage was found marginally higher (P=0.002). The doses to normal tissues were significantly lower (all Ps<0.001) in heart mean dose by 109.5 cGy, esophagus V60 by 1.53%, cord maximum dose by -272.7 cGy, lung V20 and mean lung dose (MLD) by 1.11% and 79.2 cGy, respectively. The tumor targets could potentially get an average lung isotoxic boost of 481 cGy. Eight patients (15.1%) had grade 2 RP while no grade 3 or higher RP occurred. Twenty-three patients (43.4%) developed grade ≥ 2 RE. MLD was significantly associated with grade 2 RP with an odds ratio of 1.39 per 100 cGy increase (95% CI, 1.01 to 1.91; P=0.042). Esophagus V60 was significantly associated with grade ≥ 2 RE with an odds ratio of 1.15 per 1% increase (95% CI, 1.04 to 1.28; P=0.009). （Table 1）
ConclusionFactors
Initial Plans
Adaptive Plans
Mean difference
95%CI
P Value
Targets
PGTV (%)
92.96
93.81
0.85
0.33
1.37
0.002
PTV(%)
94.13
94.54
0.41
0.35
0.80
0.033
Lung
V5(%)
46.77
45.72
-1.05
-0.70
-1.41
<0.001
V20(%)
25.15
24.04
-1.11
-0.80
-1.42
<0.001
V30(%)
18.62
17.60
-1.02
-0.77
-1.27
<0.001
MLD (cGy)
1411.4
1332.2
-79.2
-60.1
-98.4
<0.001
Heart
V30(%)
17.40
15.11
-2.29
-0.94
-3.62
0.001
V40(%)
10.87
9.06
-1.81
-0.98
-2.64
<0.001
V55(%)
4.06
2.79
-1.27
-0.76
-1.77
<0.001
Mean Dose(cGy)
1504.5
1395.0
-109.5
-67.88
-151.22
<0.001
Pericardium
V30(%)
32.17
30.43
-1.74
-0.77
-2.70
0.001
V40(%)
25.70
24.00
-1.7
-0.76
-2.64
0.001
V55(%)
13.87
11.87
-2
-1.34
-2.66
<0.001
Mean Dose(cGy)
2192.9
2091.2
-101.7
-60.00
-143.3
<0.001
Esophagus
V40(%)
39.43
36.49
-2.94
-1.62
-4.27
<0.001
V50(%)
27.89
24.08
-3.81
-2.36
-5.27
<0.001
V60(%)
7.57
6.04
-1.53
-0.96
-2.09
<0.001
Max Dose(cGy)
6498.3
6336.7
-161.6
-101.99
-221.3
<0.001
Cord
Max Dose(cGy)
4113.0
3840.3
-272.7
-209.51
-335.93
<0.001
By adapting to the changes on CT scans at the 20th fraction, the adaptive IMRT approach provides significant dosimetric benefits and has the potential to lower the risk of symptomatic pneumonitis and esophagitis in stage III NSCLC.
