A practical approach to pulmonary risk assessment in the radiotherapy of lung cancer
Section snippets
Pretreatment evaluation
Because no two patients are the same; individualized evaluation is critical. A thorough history and physical examination should be performed with particular emphasis to exercise capacity, preexisting cardiopulmonary conditions, smoking history, performance status, active respiratory tract infection, bronchospasm, and fluid overload. CT scanning of the thorax is typically performed as part of the staging process and should also be reviewed for evidence of emphysema, fibrosis, pleural effusion,
Optimization
After the initial evaluation, it is important to treat any reversible processes, such as bronchospasm, infection, ischemic heart disease or pulmonary embolic. There may be circumstances where such treatment could render a medically inoperable patient operable. Lifestyle changes, such as smoking cessation and regular exercise, should be encouraged. In any event, the patient’s ability to tolerate radical RT/CHT is much likely to be greater with an optimized medical condition.
Risk assessment before surgery
Radiation oncologists can learn about pulmonary toxicity risk assessment from surgical data, as lung resection may be considered the ultimate local toxicity. Much of the data are anecdotal and retrospective, accumulated during the last 50 years. Nonetheless, given the number of patients treated, there is a great volume of information and experience.
A model of a typical algorithm for selection of patients suitable for lung resection is shown in Fig 1.20, 21, 22 Assessment of operability is
Risk assessment before RT
Because surgical predictors for postresection functional changes are suboptimal, it should come as no surprise that predictions of RT-toxicity/functional changes are even less accurate. Surgical resection respects anatomic boundaries, while RT fields do not. The areas of lung impacted by RT are not typically defined by anatomic units, as with surgery.
Surgery is, thus, an all-or-nothing modality; a portion of lung is either resected or not. RT-induced lung injury is more complex. Regional
Predictors of RT-induced lung injury
The quality of prediction is likely to be related to the endpoints chosen-ie, radiographic changes, symptoms—therefore it is important to decide what is called “lung injury.” The potential outcomes in patients can be divided into subclinical (ie, asymptomatic, but measurable) versus clinical (symptomatic). Likewise, these parameters can be subdivided into partial organ or whole organ effects (Table 4). Subclinical alterations are more likely to become manifest the longer the patient lives, due
Conclusions
Optimizing radiation therapy efficacy, while minimizing toxicity, is a complex process in the treatment of patients with lung cancer. We have presented an approach to risk assessment in patients with lung cancer based on the data currently available. It is our hope that with prospective observation, added information from clinical trials, the addition of new cytoprotectors and treatment delivery techniques, the proposed assessment algorithm can be improved.
Acknowledgments
Supported in part by NIH grants CA69579. Jane Hoppenworth for assistance with the manuscript preparation.
References (73)
- et al.
Risk factors for development of radiation pneumonitis following radiation therapy with or without chemotherapy for lung cancer
Int J Radiat Oncol Biol Phys
(1997) - et al.
Hyperfractionated accelerated radiation therapy for non-small cell lung cancerClinical phase I/II trial
Int J Radiat Oncol Biol Phys
(1997) - et al.
Radiation-induced pulmonary toxicitya dose-volume histogram analysis in 201 patients with lung cancer
Int J Radiat Oncol Biol Phys
(2001) - et al.
Palliative radiotherapy for inoperable carcinoma of the lungFinal report of a RTOG multi-institutional trial
Int J Radiat Oncol Biol Phys
(1985) - et al.
Radiation pneumonitis in patients treated for breast cancer
Radiother Oncol
(1985) - et al.
The time course of radiation therapy-induced reductions in regional perfusiona prospective study with >5 years of follow-up
Int J Radiat Oncol Biol Phys
(2002) - et al.
Radiation-induced hypoxia may perpetuate late normal tissue injury
Int J Radiat Oncol Biol Phys
(2001) - et al.
Radiation-induced lung injury
Semin Radiat Oncol
(2003) - et al.
Preoperative evaluation of patients undergoing lung resection surgery
Chest
(2003) - et al.
Prediction of postpneumonectomy pulmonary function using quantitative macroaggregate lung scanning
Chest
(1974)
Exercise testing, 6-min walk, and stair climb in the evaluation of patients at high risk for pulmonary resection
Chest
The physiologic evaluation of patients with lung cancer being considered for resectional surgery
Chest
Assessment of operative risk in patients undergoing lung resectionImportance of predicted pulmonary function
Chest
Quantitative effect of combined chemotherapy and fractionated radiotherapy on the incidence of radiation-induced lung damageA prospective clinical study
Int J Radiat Oncol Biol Phys
Radiation-induced pneumonitis in the “nonirradiated” lung
Mayo Clin Proc
Radiation and the lunga reevaluation of the mechanisms mediating pulmonary injury
Int J Radiat Oncol Biol Phys
Long-term changes in pulmonary function tests after definitive radiotherapy for lung cancer
Int J Radiat Oncol Biol Phys
Prospective prediction of post-radiation therapy lung function using quantitative lung scans and pulmonary function testing
Int J Radiat Oncol Biol Phys
Lung cancer in patients with borderline lung functions—zonal lung perfusion scans at presentation and lung function after high dose irradiation
Radiother Oncol
Observations on the predictive value of perfusion lung scans on post-irradiation pulmonary function among 210 patients with bronchogenic carcinoma
Int J Radiat Oncol Biol Phys
Factors predicting severe radiation pneumonitis in patients receiving definitive chemoradiation for lung cancer
Int J Radiat Oncol Biol Phys
The influence of field size and other treatment factors on pulmonary toxicity following hyperfractionated irradiation for inoperable non-small cell lung cancer (NSCLC)—analysis of a Radiation Therapy Oncology Group (RTOG) protocol
Int J Radiat Oncol Biol Phys
Dosimetric predictors of radiation-induced lung injury
Int J Radiat Oncol Biol Phys
Strategy for dose escalation using 3-dimensional conformal radiation therapy for lung cancer
Ann Oncol
Estimations of pneumonitis risk in three-dimensional treatment planning using dose-volume histogram analysis
Int J Radiat Oncol Biol Phys
Clinical dose-volume histogram analysis for pneumonitis after 3D treatment for non-small cell lung cancer (NSCLC)
Int J Radiat Oncol Biol Phys
Evaluation of two dose-volume histogram reduction models for the prediction of radiation pneumonitis
Radiother Oncol
Dose-volume factors contributing to the incidence of radiation pneumonitis in non-small cell lung cancer patients treated with three-dimensional conformal radiation therapy
Int J Radiat Oncol Biol Phys
Predictive value of dose-volume histogram parameters for predicting radiation pneumonitis after concurrent chemoradiation for lung cancer
Int J Radiat Oncol Biol Phys
Receiver operator curves (ROC) analysis of predictors for radiation-induced symptomatic lung injury
Int J Radiat Oncol Biol Phys
Changes in plasma transforming growth factor-beta levels during pulmonary irradiation
Int J Radiat Oncol Biol Phys.
Predicting the risk of symptomatic radiation-induced lung injury using both the physical and biologic parameters V30 and transforming growth factor B
Int J Radiat Oncol Biol Phys
Radiation pneumonitis and early circulatory cytokine markers
Semin Radiat Oncol
Injury to the lung from cancer therapyclinical syndromes, measurable endpoints, and potential scoring systems
Int J Radiat Oncol Biol Phys
Effects of ongoing smoking on the development of radiation-induced pneumonitis in breast cancer and oesophagus cancer patients
Radiother Oncol
Dose-effect relations for early local pulmonary injury after irradiation for malignant lymphoma and breast cancer
Radiother Oncol
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Phase i study of concurrent high-dose three-dimensional conformal radiotherapy with chemotherapy using cisplatin and vinorelbine for unresectable stage III non-small-cell lung cancer
2012, International Journal of Radiation Oncology Biology PhysicsResponse to "Helical Tomotherapy for Simultaneous Multitarget Radiotherapy for Pulmonary Metastasis." (Int J Radiat Oncol Biol Phys 2009;75:703-710)
2010, International Journal of Radiation Oncology Biology PhysicsHelical Tomotherapy for Simultaneous Multitarget Radiotherapy for Pulmonary Metastasis
2009, International Journal of Radiation Oncology Biology PhysicsCitation Excerpt :We tried to decrease the risk of pulmonary toxicity by reducing the mean lung dose (MLD) and the percentage of lung volume receiving more than 25 Gy (V25). An MLD of less than 25 Gy and a V25 of less than 35% in the favorable group and an MLD less than 15 Gy and a V25 less than 20% in the unfavorable group were used as the guidelines, according to the recommendations of Miller et al.(18). The treatment was delivered once daily in 10 fractions over 2 weeks.
The Challenge of Scoring Radiation-induced Lung Toxicity
2009, Clinical OncologyCitation Excerpt :This case was scored as having grade 3 lung toxicity based on the RTOG/EORTC scale, and as having grade 0 lung toxicity based on the NCI-CTC scale. Radiation-induced lung toxicity has always been a concern with the use of curative radiation treatment in lung cancer due to the high sensitivity of the normal lung to ionising radiation [2,11,12]. The tolerance radiation dose of the lung with standard fractionation is about 20 Gy, whereas the curative dose has always been above 50–60 Gy [5,12,13].
The importance of patient characteristics for the prediction of radiation-induced lung toxicity
2009, Radiotherapy and OncologyLocal Correlation Between Monte-Carlo Dose and Radiation-Induced Fibrosis in Lung Cancer Patients
2008, International Journal of Radiation Oncology Biology PhysicsCitation Excerpt :Many investigators have developed methods to relate the dose–volumetric parameters to the risk of RT-induced lung injury (1–7). Models that consider dosimetric and patient-specific parameters, such as pulmonary function tests, have also been investigated (8, 9). These studies have generally demonstrated that the risk of RT-induced lung injury increases with increasing dose–volumetric parameters such as the mean lung dose (MLD) (5, 7), mean normalized total dose (5), percentage of lung volume that received a dose of ≥20 Gy (6), percentage of lung volume that received a dose of ≥30 Gy (7), and normal tissue complication probability (NTCP) (4, 7).
Portions of this work have been adapted from Marks LB, Yu X, Vujaskovic Z, et al: Radiation-induced lung injury. Semin Radiat Oncol 13:333–345, 2003.