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Developing Multivariable Normal Tissue Complication Probability Model to Predict the Incidence of Symptomatic Radiation Pneumonitis among Breast Cancer Patients.

Lee TF, Chao PJ, Chang L, Ting HM, Huang YJ - PLoS ONE (2015)

Bottom Line: Symptomatic radiation pneumonitis (SRP), which decreases quality of life (QoL), is the most common pulmonary complication in patients receiving breast irradiation.Positive associations were demonstrated among the incidence of SRP, IV20, and patient age.Energy, BMI and T stage showed a negative association with the incidence of SRP.

View Article: PubMed Central - PubMed

Affiliation: Medical Physics and Informatics Laboratory of Electronics Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan, ROC; Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan, ROC.

ABSTRACT

Purpose: Symptomatic radiation pneumonitis (SRP), which decreases quality of life (QoL), is the most common pulmonary complication in patients receiving breast irradiation. If it occurs, acute SRP usually develops 4-12 weeks after completion of radiotherapy and presents as a dry cough, dyspnea and low-grade fever. If the incidence of SRP is reduced, not only the QoL but also the compliance of breast cancer patients may be improved. Therefore, we investigated the incidence SRP in breast cancer patients after hybrid intensity modulated radiotherapy (IMRT) to find the risk factors, which may have important effects on the risk of radiation-induced complications.

Methods: In total, 93 patients with breast cancer were evaluated. The final endpoint for acute SRP was defined as those who had density changes together with symptoms, as measured using computed tomography. The risk factors for a multivariate normal tissue complication probability model of SRP were determined using the least absolute shrinkage and selection operator (LASSO) technique.

Results: Five risk factors were selected using LASSO: the percentage of the ipsilateral lung volume that received more than 20-Gy (IV20), energy, age, body mass index (BMI) and T stage. Positive associations were demonstrated among the incidence of SRP, IV20, and patient age. Energy, BMI and T stage showed a negative association with the incidence of SRP. Our analyses indicate that the risk of SPR following hybrid IMRT in elderly or low-BMI breast cancer patients is increased once the percentage of the ipsilateral lung volume receiving more than 20-Gy is controlled below a limitation.

Conclusions: We suggest to define a dose-volume percentage constraint of IV20< 37% (or AIV20< 310cc) for the irradiated ipsilateral lung in radiation therapy treatment planning to maintain the incidence of SPR below 20%, and pay attention to the sequelae especially in elderly or low-BMI breast cancer patients. (AIV20: the absolute ipsilateral lung volume that received more than 20 Gy (cc).

No MeSH data available.


Related in: MedlinePlus

(a) A sample breast cancer treatment plan, (b) diagnosed with RP at 3 months after RT, (c) diagnosed with RP image fused with the original isodose curves.Abbreviation: RP: radiation pneumonitis; RT: radiotherapy.
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pone.0131736.g001: (a) A sample breast cancer treatment plan, (b) diagnosed with RP at 3 months after RT, (c) diagnosed with RP image fused with the original isodose curves.Abbreviation: RP: radiation pneumonitis; RT: radiotherapy.

Mentions: In total, 93 patients were included in the analysis. After radiotherapy, 48 (52%), 29 (31%), 14 (15%) and 2 (2%) patients had lung density changes of grades 0, 1, 2 and 3, respectively, according to Arriagada’s classification and CT images [25, 26]. There were 50 patients (54%), 43 (46%) and 0 (0%) patients with clinical symptomatic pneumonitis of grades 0, 1 and 2, respectively, based on the CTC-NCIC [5, 24]. Patients without SPR were classified as group 0 (n = 62) and those with SPR as group 1 (n = 31). In total, 33.3% (31/93) of the patients suffered from SPR (Table 1). A typical breast cancer treatment plan is shown in Fig 1(A), an SRP diagnosis after RT is shown in Fig 1(B), and an image of diagnosed SRP fused with the original isodose curves is shown in Fig 1(C). The initial dosimetric and clinical predictive factors are shown in Table 2. The most significant dosimetric and clinical predictive factors for the logistic regression NTCP model were determined using the LASSO technique. First, factors were ranked based on how strongly they were correlated using LASSO; second, the optimal number of risk factors was chosen based on the Hosmer-Lemeshow test and the area under the receiver operating characteristic curve (AUC). The risk factors in the multivariate logistic regression analysis were ranked according to LASSO predictions in descending order as shown in Table 3.


Developing Multivariable Normal Tissue Complication Probability Model to Predict the Incidence of Symptomatic Radiation Pneumonitis among Breast Cancer Patients.

Lee TF, Chao PJ, Chang L, Ting HM, Huang YJ - PLoS ONE (2015)

(a) A sample breast cancer treatment plan, (b) diagnosed with RP at 3 months after RT, (c) diagnosed with RP image fused with the original isodose curves.Abbreviation: RP: radiation pneumonitis; RT: radiotherapy.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492617&req=5

pone.0131736.g001: (a) A sample breast cancer treatment plan, (b) diagnosed with RP at 3 months after RT, (c) diagnosed with RP image fused with the original isodose curves.Abbreviation: RP: radiation pneumonitis; RT: radiotherapy.
Mentions: In total, 93 patients were included in the analysis. After radiotherapy, 48 (52%), 29 (31%), 14 (15%) and 2 (2%) patients had lung density changes of grades 0, 1, 2 and 3, respectively, according to Arriagada’s classification and CT images [25, 26]. There were 50 patients (54%), 43 (46%) and 0 (0%) patients with clinical symptomatic pneumonitis of grades 0, 1 and 2, respectively, based on the CTC-NCIC [5, 24]. Patients without SPR were classified as group 0 (n = 62) and those with SPR as group 1 (n = 31). In total, 33.3% (31/93) of the patients suffered from SPR (Table 1). A typical breast cancer treatment plan is shown in Fig 1(A), an SRP diagnosis after RT is shown in Fig 1(B), and an image of diagnosed SRP fused with the original isodose curves is shown in Fig 1(C). The initial dosimetric and clinical predictive factors are shown in Table 2. The most significant dosimetric and clinical predictive factors for the logistic regression NTCP model were determined using the LASSO technique. First, factors were ranked based on how strongly they were correlated using LASSO; second, the optimal number of risk factors was chosen based on the Hosmer-Lemeshow test and the area under the receiver operating characteristic curve (AUC). The risk factors in the multivariate logistic regression analysis were ranked according to LASSO predictions in descending order as shown in Table 3.

Bottom Line: Symptomatic radiation pneumonitis (SRP), which decreases quality of life (QoL), is the most common pulmonary complication in patients receiving breast irradiation.Positive associations were demonstrated among the incidence of SRP, IV20, and patient age.Energy, BMI and T stage showed a negative association with the incidence of SRP.

View Article: PubMed Central - PubMed

Affiliation: Medical Physics and Informatics Laboratory of Electronics Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan, ROC; Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan, ROC.

ABSTRACT

Purpose: Symptomatic radiation pneumonitis (SRP), which decreases quality of life (QoL), is the most common pulmonary complication in patients receiving breast irradiation. If it occurs, acute SRP usually develops 4-12 weeks after completion of radiotherapy and presents as a dry cough, dyspnea and low-grade fever. If the incidence of SRP is reduced, not only the QoL but also the compliance of breast cancer patients may be improved. Therefore, we investigated the incidence SRP in breast cancer patients after hybrid intensity modulated radiotherapy (IMRT) to find the risk factors, which may have important effects on the risk of radiation-induced complications.

Methods: In total, 93 patients with breast cancer were evaluated. The final endpoint for acute SRP was defined as those who had density changes together with symptoms, as measured using computed tomography. The risk factors for a multivariate normal tissue complication probability model of SRP were determined using the least absolute shrinkage and selection operator (LASSO) technique.

Results: Five risk factors were selected using LASSO: the percentage of the ipsilateral lung volume that received more than 20-Gy (IV20), energy, age, body mass index (BMI) and T stage. Positive associations were demonstrated among the incidence of SRP, IV20, and patient age. Energy, BMI and T stage showed a negative association with the incidence of SRP. Our analyses indicate that the risk of SPR following hybrid IMRT in elderly or low-BMI breast cancer patients is increased once the percentage of the ipsilateral lung volume receiving more than 20-Gy is controlled below a limitation.

Conclusions: We suggest to define a dose-volume percentage constraint of IV20< 37% (or AIV20< 310cc) for the irradiated ipsilateral lung in radiation therapy treatment planning to maintain the incidence of SPR below 20%, and pay attention to the sequelae especially in elderly or low-BMI breast cancer patients. (AIV20: the absolute ipsilateral lung volume that received more than 20 Gy (cc).

No MeSH data available.


Related in: MedlinePlus