Effects of ongoing smoking on the development of radiation-induced pneumonitis in breast cancer and oesophagus cancer patients

The Evaluation and Management of Visceral Complications in Radiation Fibrosis Syndrome Part 1

Abstract

External beam ionizing radiation is a fundamental component of cancer treatment and is incorporated into approximately 50% of cancer treatments. Radiation therapy causes cell death directly by apoptosis and indirectly by disruption of mitosis.

Purpose of Review

This study aims to inform rehabilitation clinicians of the visceral toxicities of radiation fibrosis syndrome and how to detect and diagnose these complications.

Recent Findings

Latest research indicates that radiation toxicity is primarily related to radiation dose, patient co-morbidity, and concomitant use of chemotherapies and immunotherapies for the treatment of cancer. While cancer cells are the primary target, surrounding normal cells and tissues are also affected. Radiation toxicity is dose dependent, and tissue injury develops from inflammation that may progress to fibrosis. Thus, radiation dosing in cancer therapy is often limited by tissue toxicity. Although newer radiotherapeutic modalities aim to limit delivery of radiation to non-cancerous tissues, many patients continue to experience toxicity.

Summary

To ensure early recognition of radiation toxicity and fibrosis, it is imperative that all clinicians are aware of the predictors, signs, and symptoms of radiation fibrosis syndrome. Here, we present part 1 of the visceral complications of radiation fibrosis syndrome, addressing radiation-related toxicity in the heart, lungs, and thyroid gland.

Graphical abstract

Impact of adjuvant radiotherapy on patient-reported shortness of breath in patients with breast cancer using the ESAS

BACKGROUND AND PURPOSE

As breast cancer radiotherapy (RT) has been shown to give rise to adverse pulmonary outcomes, such as radiation pneumonitis, trends in patient-reported shortness of breath (SOB) associated with RT were investigated. Adjuvant RT is commonly administered for local and/or regional control of breast cancer and was therefore included.

METHODS

The Edmonton Symptom Assessment System (ESAS) was used to observe changes in SOB during RT, up to 6 weeks after RT completion, and one to three months post-RT. Patients with at least one completed ESAS were included in the analysis. Generalized linear regression analysis was performed to identify associations between demographic factors and SOB.

RESULTS

A total of 781 patients were included in the analysis. There was a significant association between ESAS SOB scores and adjuvant chemotherapy when compared to neoadjuvant chemotherapy (p=0.0012). Meanwhile, loco-regional RT had no significant impact on ESAS SOB scores in comparison to local RT. SOB scores were stable over time (p>0.05) from baseline to follow-up appointments.

CONCLUSION

The findings of this study suggest that RT was not associated with changes in SOB from baseline to 3 months post-RT. However, patients who underwent adjuvant chemotherapy reported significant higher SOB scores over time. Additional research is recommended to analyze the lasting effects of adjuvant breast cancer RT on SOB during physical activity.

Pneumonitis and fibrosis after breast cancer radiotherapy: occurrence and treatment-related predictors

BACKGROUND

Radiation pneumonitis (RP) and radiation fibrosis (RF) are common side effects after breast cancer (BC) radiotherapy (RT). However, there is a great variation in the frequency of RP and RF. This study presents the occurrence of- and the treatment-related predictors for RP and RF. Further, physician- and patient-reported pulmonary symptoms during the first year after postoperative RT for BC are demonstrated.

MATERIALS AND METHODS

From 2007 to 2008, 250 BC patients referred for postoperative RT were included in a prospective cohort study and followed during the first year after RT. High-resolution computed tomography of the lungs and symptom registration were performed before RT and 3, 6, and 12 months after RT. Patient-reported symptoms were registered by standard quality of life questionnaires. Logistic regression analyses were applied to estimate treatment-related predictors for radiological RP (rRP), clinical RP (cRP), radiological RF (rRF), and clinical RF (cRF).

RESULTS

The occurrence of rRP and cRP at three months was 78% and 19%, while 12 months after RT rRF and cRF was 89% and 16%, respectively; all reported as grade 1. In multivariable analyses, mastectomy predicted cRP at three months (OR = 2.48, p = .03) and cRF at six months, ipsilateral lung volume receiving 20 Gray or more (V20), V30, and mean lung dose (MLD) predicted rRP at six months (OR = 1.06, p = .0003; OR = 1.10, p = .001; and OR = 1.03, p = .01, respectively). Endocrine treatment predicted cRF at 12 months (OR = 2.48, p = .02). Physicians reported significant more dyspnea at 3 months (p = .003) and patients reported 'a little dyspnea' more at 3 and 12 months compared to baseline (p = .007).

CONCLUSION

RP and RF are prevalent in the first year after BC radiation. Mastectomy predicted cRP at three months. V20, V30, D25, and MLD predicted rRP at 6 months, and endocrine treatment predicted cRF at 12 months. Patients and physicians reported dyspnea differently.

Stereotactic Body Radiotherapy for Patients with Lung Oligometastatic Disease: A Five-Year Systematic Review

For several years, oligometastatic disease has represented an intermediate state between localized disease accessible to local treatment and multimetastatic disease requiring systemic therapy. The lung represents one of the most common metastatic locations. Stereotactic body radiation therapy (SBRT) appears to be the treatment of choice for these patients. There are few data defining the place of radiotherapy and reporting outcome after SBRT in lung metastases. This 5-year review aimed to determine areas of SBRT usefulness and methods for the management of pulmonary metastasis in oligometastatic patients. A search for articles on PubMed allowed selection of the most relevant studies. Eighteen articles were selected according to pre-established criteria for this purpose. The analysis concludes that SBRT is an effective and safe treatment in selected patients when the disease remains localized from one to three organs.

The impact of smoking on adjuvant breast cancer radiation treatment: A systematic review

BACKGROUND

The influence of cigarette smoking on cancer risk has been well-studied. Similarly, exposure to ionizing radiation from radiotherapy (RT) can produce detrimental effects on an individual's health. In patients administered RT, there has been an observed relationship in other primary carcinomas. The purpose of this systematic review was to summarize the influence of cigarette smoking on outcomes post adjuvant RT in breast cancer patients.

METHODS

OVID Medline, Cochrane and Embase were searched and 1893 articles were identified. A total of 71 articles were included in the review. Study type, published year and sample size, age, systemic therapies, RT techniques and treatment side effects were collected if available.

RESULTS

The review found 198 different outcomes which fell into 7 categories and similar outcomes were recorded. 40% of skin reaction outcomes, 50% of cardiovascular outcomes, 71% of reconstruction outcomes, 29% of pulmonary function outcomes, 33% of mortality outcomes and 42% of secondary recurrence outcomes reported significant differences between smokers and non-smokers. None of the articles reported non-smokers to have a higher risk than smokers.

CONCLUSION

Cigarette smoking can pose a higher risk of post-treatment complications that can influence an individual's quality of life, survival rate and/or recurrence risk. This review further assessed the impact of smoking on various patient outcomes and side-effects in the adjuvant breast RT setting. The information provided in this review suggest that smoking cessation programs would help educate patients to understand their risks of being a current or former smoker when undergoing RT.

Radiation pneumonitis in lung cancer patients treated with chemoradiation plus durvalumab

Introduction

Durvalumab after concurrent chemoradiation (cCRT) is now standard of care for unresected stage III non–small cell lung cancer (NSCLC). However, there is limited data on radiation pneumonitis (RP) with this regimen. Therefore, we assessed RP and evaluated previously validated toxicity models in predicting for RP in patients treated with cCRT and durvalumab.

Methods

Patients treated with cCRT and ≥ 1 dose of durvalumab were evaluated to identify cases of ≥ grade 2 RP. The validity of previously published RP models was assessed in this cohort as well a reference cohort treated with cCRT alone. The timing and incidence of RP was compared between cohorts.

Results

In total, 11 (18%) of the 62 patients who received cCRT and durvalumab developed ≥ grade 2 RP a median of 3.4 months after cCRT. The onset of RP among patients treated with cCRT and durvalumab was significantly longer vs the reference cohort (3.4 vs 2.1 months; P = .01). Numerically more patients treated with cCRT and durvalumab developed RP than patients in the reference cohort (18% vs 9%, P = .09). Among patients treated with cCRT and durvalumab, 82% (n = 9) were responsive to treatment with high‐dose glucocorticoids. Previously published RP models widely underestimated the rate of RP in patients treated with cCRT and durvalumab [AUC ~ 0.50; p(Hosmer‐Lemeshow): 0.98‐1.00].

Conclusions

Our data suggest a delayed onset of RP in patients treated with cCRT and durvalumab vs cCRT alone, and for RP to develop in a greater number of patients treated with cCRT and durvalumab. Previously published RP models significantly underestimate the rate of symptomatic RP among patients treated with cCRT and durvalumab.

Radiation-Induced Lung Injury: Assessment and Management

Radiation-induced lung injury (RILI) encompasses any lung toxicity induced by radiation therapy (RT) and manifests acutely as radiation pneumonitis and chronically as radiation pulmonary fibrosis. Because most patients with thoracic and breast malignancies are expected to undergo RT in their lifetime, many with curative intent, the population at risk is significant. Furthermore, indications for thoracic RT are expanding given the advent of stereotactic body radiation therapy (SBRT) or stereotactic ablative radiotherapy (SABR) for early-stage lung cancer in nonsurgical candidates as well as oligometastatic pulmonary disease from any solid tumor. Fortunately, the incidence of serious pulmonary complications from RT has decreased secondary to advances in radiation delivery techniques. Understanding the temporal relationship between RT and injury as well as the patient, disease, and radiation factors that help distinguish RILI from other etiologies is necessary to prevent misdiagnosis. Although treatment of acute pneumonitis is dependent on clinical severity and typically responds completely to corticosteroids, accurately diagnosing and identifying patients who may progress to fibrosis is challenging. Current research advances include high-precision radiation techniques, an improved understanding of the molecular basis of RILI, the development of small and large animal models, and the identification of candidate drugs for prevention and treatment.

Developing of predictive models for pneumonitis with forward variable selection and LASSO logistic model for breast cancer patients treated with 3D-CRT

Purpose: To develop a multiple logistic regression model as normal tissue complication probability model by least absolute shrinkage and selection operator (LASSO) technique in breast cancer patients treated with three-dimensional conformal radiation therapy (3D-CRT), we focused on the changes of pulmonary function tests to achieve the optimal predictive parameters for the occurrence of symptomatic radiation pneumonitis (SRP).

Materials and methods: Dosimetric and spirometry data of 60 breast cancer patients were analyzed. Pulmonary function tests were done before RT, after completion of RT, 3, and 6 months after RT. Multiple logistic regression model was used to obtain the effective predictive parameters. Forward selection method was applied in NTCP model to determine the effective risk factors from obtained different parameters.

Results: Symptomatic radiation pneumonitis was observed in five patients. Significant changes in pulmonary parameters have been observed at six months after RT. The parameters of mean lung dose (MLD), bridge separation (BS), mean irradiated lung volume (ILVmean), and the percentage of the ipsilateral lung volume that received dose of 20 Gy (IV20) introduced as risk factors using the LASSO technique for SRP in a multiple normal tissue complication probability model in breast cancer patients treated with 3D-CRT. The BS, central lung distance (CLD) and ILV in tangential field have obtained as 23.5 (20.9-26.0) cm, 2.4 (1.5-3.3) cm, and 12.4 (10.6-14.3) % of lung volume in radiation field in patients without pulmonary complication, respectively.

Conclusion: The results showed that if BS, CLD, and ILV are more than 23 cm, 2 cm, and 12%, respectively, so incidence of SRP in the patients will be considerable. Our multiple NTCP LASSO model for breast cancer patients treated with 3D-CRT showed that in order to have minimum probability of SRP occurrence, parameters of BS, IV20, ILV and especially MLD would be kept in minimum levels. Considering dose-volume histogram, the mean lung dose factor is most important parameter which minimizing it in treatment planning, minimizes the probability of SRP and consequently improves the quality of life in breast cancer patients.

Abnormal pulmonary function tests predict the development of radiation-induced pneumonitis in advanced non-small cell lung Cancer

BACKGROUND

Radiation pneumonitis (RP) is a frequent complication of concurrent chemoradiotherapy (CCRT) and is associated with severe symptoms that decrease quality of life and might result in pulmonary fibrosis or death. The aim of this study is to identify whether pulmonary function test (PFT) abnormalities may predict RP in non-small cell lung cancer (NSCLC) patients.

METHODS

A prospective multi-institutional study was conducted with locally advanced and oligometastatic NSCLC patients. All participants were evaluated at baseline, end of CCRT, week 6, 12, 24, and 48 post-CCRT. They completed forced spirometry with a bronchodilator, body plethysmography, impulse oscillometry, carbon monoxide diffusing capacity (DLCO), molar mass of CO2, six-minute walk test and exhaled fraction of nitric oxide (FeNO). Radiation pneumonitis was assessed with RTOG and CTCAE. The protocol was registered in www.clinicaltrials.gov (NCT01580579), registered April 19, 2012.

RESULTS

Fifty-two patients were enrolled; 37 completed one-year follow-up. RP ≥ Grade 2 was present in 11/37 (29%) for RTOG and 15/37 (40%) for CTCAE. Factors associated with RP were age over 60 years and hypofractionated dose. PFT abnormalities at baseline that correlated with the development of RP included lower forced expiratory volume in one second after bronchodilator (p = 0.02), DLCO (p = 0.02) and FeNO (p = 0.04). All PFT results decreased after CCRT and did not return to basal values at follow-up.

CONCLUSIONS

FEV1, DLCO and FeNO prior to CCRT predict the development of RP in NSCLC. This study suggests that all patients under CCRT should be assessed by PFT to identify high-risk patients for close follow-up and early treatment.

Reliability of dose volume constraint inference from clinical data

Dose volume histogram points (DVHPs) frequently serve as dose constraints in radiotherapy treatment planning. An experiment was designed to investigate the reliability of DVHP inference from clinical data for multiple cohort sizes and complication incidence rates. The experimental background was radiation pneumonitis in non-small cell lung cancer and the DVHP inference method was based on logistic regression. From 102 NSCLC real-life dose distributions and a postulated DVHP model, an 'ideal' cohort was generated where the most predictive model was equal to the postulated model. A bootstrap and a Cohort Replication Monte Carlo (CoRepMC) approach were applied to create 1000 equally sized populations each. The cohorts were then analyzed to establish inference frequency distributions. This was applied to nine scenarios for cohort sizes of 102 (1), 500 (2) to 2000 (3) patients (by sampling with replacement) and three postulated DVHP models. The Bootstrap was repeated for a 'non-ideal' cohort, where the most predictive model did not coincide with the postulated model. The Bootstrap produced chaotic results for all models of cohort size 1 for both the ideal and non-ideal cohorts. For cohort size 2 and 3, the distributions for all populations were more concentrated around the postulated DVHP. For the CoRepMC, the inference frequency increased with cohort size and incidence rate. Correct inference rates  >[Formula: see text] were only achieved by cohorts with more than 500 patients. Both Bootstrap and CoRepMC indicate that inference of the correct or approximate DVHP for typical cohort sizes is highly uncertain. CoRepMC results were less spurious than Bootstrap results, demonstrating the large influence that randomness in dose-response has on the statistical analysis.

Normal Tissue Complications following Hypofractionated Chest Wall Radiotherapy in Breast Cancer Patients and Their Correlation with Patient, Tumor, and Treatment Characteristics

INTRODUCTION

Normal tissue complications following chest wall radiotherapy (RT) are inevitable, and the long-term data on hypofractionation are still limited. To quantify the late effects of hypofractionated RT on cardiac, pulmonary, brachial plexus, and regional lymphatics and their correlation with patient, tumor, and treatment characteristics is the main objective of this study.

MATERIALS AND METHODS

Two hundred and sixteen breast cancer patients following mastectomy were treated with hypofractionated schedules either 40 Gy in 15 fractions or 42.5 Gy in 16 fractions. Common Toxicity Criteria version 3.0 was utilized to quantify the late effects of hypofractionation on cardiac, pulmonary, brachial plexus, and lymphedema at a maximum follow-up of 5 years.

RESULTS

Median follow-up was 42 months. Median age was 49 years. 14.8% developed ≥Grade (Gr) 2 late cardiac toxicity. 10.2% developed ≥Gr2 late pulmonary toxicity. There were 28.7% patients who developed ≥Gr2 lymphedema. Sixty-seven out of 216 patients had symptomatic brachial plexopathy at 5-year follow-up. Variables found to increase the incidence of these adverse events included smoking, hypertension, diabetes mellitus, body mass index ≥25, extent of axillary dissection, and use of supraclavicular field.

CONCLUSION

Hypofractionation leads to increased risk of normal tissue complications partly influenced by some patient- and treatment-related factors, but these were manageable and minimally disabling.

Radiation Pneumonitis

Radiation-induced lung injury is a well-known complication of thoracic radiation for patients with breast, lung, thymic, and esophageal malignancies, and mediastinal lymphomas. Improvements in radiation technique, as well as the understanding of the pathophysiology of radiation injury, have led to lower rates of pneumonitis and improved symptom control. Here, the authors provide an overview of the pathophysiology, diagnosis, and management of patients with radiation pneumonitis as a complication of treatment of chest malignancies.

The Influence of Patient-related Constutional and Environmental Factors on Early Results of a Combined Modality Therapy of Esophageal Cancer

Among many various factors affecting the outcome of cancer treatment one can distinguish patient, tumor- and treatment-related factors. The association of patient-related factors and results of a combined modality therapy of esophageal cancer has not been extensively explored. The aim of the study was to analyze the impact of patient-related constitutional and environmental factors on early results of combined modality therapy of esophageal squamous cell carcinoma.

MATERIAL AND METHODS

We retrospectively analyzed prospectively collected data of 84 patients with esophageal cancer randomly assigned to a combined modality treatment. We evaluated the relationship between early outcome of neoadjuvant therapy (overall toxic events, serious toxic events, treatment-related mortality, clinical and pathological response to the treatment) or surgical treatment (postoperative morbidity, mortality and curative resections - R0) and constitutional (age, gender, height, body mass index, Karnofski Performance Status - KPS, blood type) or environmental (inhabitation, smoking duration and intensity, frequency and amount of alcohol consumption and occupational exposure) patient-related factors.

RESULTS

Significantly more neoadjuvant therapy related deaths were found in patients with KPS 70-80 (p=0.0016). Interestingly, significantly more toxic events (p=0.0034) after neoadjuvant therapy and a higher postoperative morbidity rate (p=0.0293) were observed in nonsmokers. Similarly, significantly more toxic events (p=0.0029) after neoadjuvant therapy and a higher postoperative mortality rate (p=0.0405) were found in light drinkers.

CONCLUSIONS

Smoking and consumption of excessive amount of alcohol may attenuate toxic effect of neoadiuvant and surgical therapy in patients treated due to esophageal cancer. The information regarding the mentioned above addictions should not result in giving up an attempt to provide a curative treatment.

[Consequences of tobacco smoking on lung cancer treatments]

In France, in 2010, tobacco induced 81% of deaths by lung cancer corresponding to about 28,000 deaths. Continued smoking after diagnosis has a significant impact on treatment. In patients with lung cancer, the benefits of smoking cessation are present at any stage of disease. For early stages, smoking cessation decreases postoperative morbidity, reduces the risk of second cancer and improves survival. Previous to surgery, smoking cessation of at least six to eight weeks or as soon as possible is recommended in order to reduce the risk of infectious complications. Tobacco could alter the metabolism of certain chemotherapies and targeted therapies, such as tyrosine kinase inhibitors of the EGF receptor, through an interaction with P450 cytochrome. Toxicity of radiations could be lower in patients with lung cancer who did not quit smoking before treatment. For patients treated by radio-chemotherapy, overall survival seems to be better in former smokers but no difference is observed in terms of recurrence-free survival. For advanced stages, smoking cessation enhances patients' quality of life. Smoking cessation should be considered as full part of lung cancer treatment whatever the stage of disease.

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

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).

The effect of smoking and major vein resection on post-therapy lymphedema in soft tissue sarcomas treated with neoadjuvant radiation and limb-salvage surgery

BACKGROUND

Neoadjuvant therapy with radiation +/- chemotherapy is an accepted management for soft tissue sarcomas (STS). The incidence of post-therapy lymphedema is around 30%. The purpose of this study was to identify variables that predict for post-therapy lymphedema.

METHODS

From 2000 to 2010, 132 patients with STS were treated with neoadjuvant radiation +/- chemotherapy followed by resection. Patient variables and treatment outcomes were reviewed. Presence of lymphedema was determined by the treating physician. The Fisher exact test was used for univariate analysis and logistic regression was used for multivariate analysis.

RESULTS

Median follow-up was 3.1 years. Of the lower extremity STS, major veins were sacrificed in 34% of patients. Lymphedema occurred in 22.4% of patients. Smoking negatively predicted for lymphedema on univariate analysis (P=0.007), and sacrifice of a major vein was associated with an increased risk of lymphedema (P=0.02). On multivariate analysis, smoking (P=0.02, odds ratio 0.31) negatively predicted for and sacrifice of a major vein (P=0.03, odds ratio 2.7) positively predicted for lymphedema.

CONCLUSIONS

There may be an association between smoking and decrease post-therapy lymphedema. Also, patients who undergo resection of a major vein seem to be more prone to post-therapy lymphedema.

Radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome in breast cancer patients is associated with age

Background

Radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome is a rarely observed phenomenon characterized by infiltration of the lungs outside of the radiation field, differentiating it from radiation pneumonitis (RP).The risk factors for radiation-induced BOOP (RT-BOOP) remain unclear and controversial. We retrospectively analyzed the incidence and risk factors for RT-BOOP associated with radiation therapy (RT) after breast conserving surgery (BCS) and post-mastectomy radiation therapy (PMRT).

Methods and materials

We analyzed 1,176 breast cancer patients treated with RT after BCS or PMRT between March 2005 and September2008 at the cancer institute hospital of the Japanese foundation for cancer research. Chest radiographs were routinely obtained every three to six months for at least 12 months after surgery, as well as when the patients experienced respiratory symptoms or fever.

Results

RT-BOOP syndrome was diagnosed in 16patients (1.4%), including12BCS patients (1.3%) and four PMRT patients (1.8%). An older age (≥52 years old) was significantly associated with the incidence of RT-BOOP syndrome in a univariate analysis (p =0.023). The type of treatment (BCS or PMRT) and irradiated lung volume at 20 Gy (V20) were not significantly associated with the incidence of RT-BOOP syndrome in the entire patient cohort. In the multivariate analysis, age and smoking were the significant factor associated with RT-induced BOOP syndrome (p =0.044 and 0.049, respectively).

Conclusions

RT-BOOP syndrome was a rarity, and the incidence for BCT cases was similar to that for PMRT cases. The irradiated lung volume was not significantly associated with RT-BOOP syndrome. An older age can predict the incidence of RT-BOOP syndrome.

New approaches to radiation protection

Radioprotectors are compounds that protect against radiation injury when given prior to radiation exposure. Mitigators can protect against radiation injury when given after exposure but before symptoms appear. Radioprotectors and mitigators can potentially improve the outcomes of radiotherapy for cancer treatment by allowing higher doses of radiation and/or reduced damage to normal tissues. Such compounds can also potentially counteract the effects of accidental exposure to radiation or deliberate exposure (e.g., nuclear reactor meltdown, dirty bomb, or nuclear bomb explosion); hence they are called radiation countermeasures. Here, we will review the general principles of radiation injury and protection and describe selected examples of radioprotectors/mitigators ranging from small-molecules to proteins to cell-based treatments. We will emphasize agents that are in more advanced stages of development.

Systematic review of postradiotherapy bronchiolitis obliterans organizing pneumonia in women with breast cancer

BACKGROUND

Radiation therapy for breast cancer has been implicated in the development of bronchiolitis obliterans organizing pneumonia (BOOP). This inflammatory lung disorder was first noted in 1983, and there have been numerous reports of BOOP occurring in women who have had radiation therapy for breast cancer since 1995. This study was undertaken to perform a systematic review of postradiotherapy BOOP to determine the occurrence, presentation, treatment, and outcome.

MATERIALS AND METHODS

A systematic literature review was conducted according to the guidelines provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses report.

RESULTS

The literature search yielded 10 Japanese epidemiological reports with 129 women, 4 case series reports with 36 women, and 24 case reports with 34 women. Common symptoms included fever, cough, and shortness of breath. Most patients received corticosteroid therapy, and duration of treatment ranged from 6 months to 1 year, although some patients received steroids for longer than 1 year because of relapse, which occurred in approximately one half of patients. No deaths have been reported.

CONCLUSION

BOOP is a rare but significant complication from radiation therapy for breast cancer. Chest radiographic studies for women who report new respiratory symptoms during the postradiation period can be beneficial for early diagnosis and for guiding appropriate management.

A polymorphism in the DNA repair domain of APEX1 is associated with the radiation-induced pneumonitis risk among lung cancer patients after radiotherapy

OBJECTIVE

To examine the association of tag single nucleotide polymorphisms (tagSNPs) (rs1130409, rs1760944, rs2307486 and rs3136817) in APEX1 with the risk of severe radiation-induced pneumonitis (RP) after radiotherapy among Han Chinese patients with lung cancer.

METHODS

A total of 168 patients with lung cancer who were receiving radiotherapy were prospectively recruited. RP was evaluated according to the Radiation Therapy Oncology Group. A case-control study was performed. The case group included patients with RP grade of ≥3, while the control group comprised patients with RP grades <3. Four tagSNPs of APEX1 were genotyped in 126 patients with complete follow-up by multi-SNaPshot® (Genesky Biotechnologies Inc., Shanghai, China) genotyping assays. RESULTS were assessed by a logistic regression model for RP risk and Mantal-Cox log-rank test for the cumulative RP probability by the genotypes.

RESULTS

rs1130409 was associated with severe RP. GT genotype of rs1130409 was significantly higher in patients with RP than in those of the control group [68.8% vs 41.8%; p = 0.025; resulting odds ratio (OR), 5.98]. Patients with lung cancer bearing the G allele had a 5.83-fold higher risk of RP than those with the wild TT genotype [OR = 5.83; 95% confidence interval (CI), 1.27-26.90; p = 0.024], and this was further confirmed by the binary regression adjusted by some confounding factors, including Karnofsky performance scale, concurrent chemotherapy-radiotherapy and lung volume receiving >30 Gy (OR = 6.96; 95% CI, 1.36-35.77; p = 0.02). rs1130409 was also associated with the time to occurrence of severe RP (p = 0.04). Three-dimensional model APEX1 protein showed that rs1130409 is located in the random coil structure corresponding to the DNA repair function region.

ADVANCES IN KNOWLEDGE

rs1130409 of APEX1 can be a predictor of RP grades ≥3 among patients with lung cancer.

A clinical score, including biohumoral parameters, is a useful pretest index to discriminate pulmonary infections from radiation damage in chemoradiation-treated lung cancer patients

To obtain an easy and prompt differential diagnosis between lower airways infections and acute radiation pneumonitis in chemoradiation lung cancer patients. From 303 patients treated, only patients with severe pulmonary symptoms were hospitalized. Clinical and radiation scores were calculated evaluating clinical, biohumoral, dosimetric parameters. Out of 36 patients hospitalized, infections and acute radiation pneumonitis were reported in 66.7% and 33.3%, respectively. Patients with clinical score ≥ 2 had an Odds Ratio of 3.4 (1.4-8.3; p = .006) to have infectious pneumonia, while radiation score was not predictive.

Management of normal tissue toxicity associated with chemoradiation (primary skin, esophagus, and lung)

Nearly one quarter of patients with lung cancer present with locally advanced disease where concurrent chemoradiotherapy is the current standard of care for patients with good performance status. Cisplatin-based concurrent chemoradiotherapy consistently showed an improvement in survival compared with sequential chemoradiotherapy, at the expense of an increase in the toxicity profile. Over the past decades, several encouraging biomarkers such as transforming growth factor-beta and radioprotective agents such as amifostine were studied but without reaching approval for patient care. We reviewed the prevalence and risk factors for different adverse effects associated with the combined chemoradiotherapy modality, especially dermatitis, mucositis, esophagitis, and pneumonitis. These adverse effects can further be divided into acute, subacute, and chronic. Dermatitis is usually rare and responds well to topical steroids and usual skin care. Acute esophagitis occurs in 30% of patients and is treated with proton pump inhibitors, promotility agents, local anesthetic, and dietary changes. Radiation pneumonitis is a subacute complication seen in 15% of patients and is usually managed with steroids. Chronic adverse effects such as radiation fibrosis and esophageal stricture occur approximately 6 months after completion of radiation therapy and are usually permanent. In this review, complications of chemoradiotherapy for patients with locally advanced lung cancer are delineated, and approaches to their management are described. Given that treatment interruption is associated with a worse outcome, patients are aggressively treated with a curative intent. Therefore, planning for treatment adverse effects improves patient tolerance, compliance, and outcome.

Meta-analysis of incidence of early lung toxicity in 3-dimensional conformal irradiation of breast carcinomas

Background

This meta-analysis aims to ascertain the significance of early lung toxicity with 3-Dimensional (3D) conformal irradiation for breast carcinomas and identify the sub-groups of patients with increased risk.

Methods

Electronic databases, reference sections of major oncological textbooks and identified studies were searched for synonyms of breast radiotherapy and radiation pneumonitis (RP). Major studies in thoracic irradiation were reviewed to identify factors frequently associated with RP. Meta-analysis for RP incidence estimation and odds ratio calculation were carried out.

Results

The overall incidence of Clinical and Radiological RP is 14% and 42% respectively. Ten studies were identified. Dose-volume Histogram (DVH) related dosimetric factors (Volume of lung receiving certain dose, V_dose and Mean lung Dose, MLD), supraclavicular fossa (SCF) irradiation and age are significantly associated with RP, but not sequential chemotherapy and concomitant use of Tamoxifen. A poorly powered study in IMN group contributed to the negative finding. Smoking has a trend towards protective effect against RP.

Conclusion

Use of other modalities may be considered when Ipsilateral lung V_20Gy > 30% or MLD > 15 Gy. Extra caution is needed in SCF and IMN irradiation as they are likely to influence these dosimetric parameters.

Radiation pneumonitis and pulmonary function with lung dose-volume constraints in breast cancer irradiation

Purpose

We studied symptomatic radiation pneumonitis (RP) and changes in pulmonary function tests (PFTs) after loco-regional radiotherapy (LRRT) with V₂₀ lung constraints in breast cancer (BC).

Patients and methods

Sixty-four women underwent PFTs before and 5 months after 3D planned LRRT for BC. The incidentally irradiated ipsilateral lung V₂₀ was minimised to <30%. Patients were monitored for symptoms of RP 1, 4 and 7 months after radiotherapy (RT) and data on covariates were collected prospectively. The outcome was compared with previous treatment series.

Results

Pneumonitis was less frequent with the applied constraint, that is, four mild and one moderate case, than in our previous report (p < 0·001). In multivariate analyses, neither dosimetric data nor covariates appeared to influence mean changes in vital capacity [−0·11L, standard error of the mean (SEM) 0·03] or diffusing capacity of the lung for carbon monoxide (DLCO) (−0·20 mmol/kPa/min, SEM 0·01), except for pre-RT chemotherapy, which diminished the change in DLCO 5 months post-RT.

Conclusions

The used constraint and 3D planning lowered the rate of RP and short-term changes in PFTs compared with our previous treatment series. Pre-RT chemotherapy affects DLCO baseline levels. Rates of side effects should be continuously studied when new target definitions or therapies are introduced in LRRT of BC.

A literature-based meta-analysis of clinical risk factors for development of radiation induced pneumonitis

INTRODUCTION

The risk of developing side effects after radiotherapy is not only dependent on radiation dose, but may also be affected by patient-related risk factors. Here we perform a literature-based meta-analysis to estimate the effect of various clinical risk factors on the incidence of symptomatic radiation pneumonitis (RP).

MATERIAL AND METHODS

A systematic review of English language articles in the Pubmed, Embase and Cochrane controlled trials registers. Studies with the mesh term "radiation pneumonitis" or the search term "radiation pneumonitis" were included. Additional studies were identified by manual searching of the references. Studies reporting crude incidence or odds ratios (OR) for radiation pneumonitis vs. age, disease location, smoking status, chemotherapy schedule or comorbidity were included. A systematic overview (meta-analysis) was conducted to synthesize data across multiple studies.

RESULTS

Significant risk factors for RP were: older age (OR = 1.7, p < 0.0001); disease located in mid-lower lung (OR = 1.9, p = 0.002); presence of comorbidity (OR = 2.3, p = 0.007). Ongoing smoking was found to protect against RP (OR = 0.6, p = 0.008). History of smoking tended to protect against RP (OR = 0.7, p = 0.06). Sequential (rather than concomitant) chemotherapy scheduling (OR = 1.6, p = 0.01) increased RP risk, but treatment intensity and patients selection are likely confounders.

CONCLUSION

This systematic overview revealed several clinical risk factors for RP that have not been unambiguously identified in the literature. These risk factors should be considered when defining dose-volume constraints for radiation treatment plan optimization.

Cigarette smoke and bleomycin-induced pulmonary oxidative stress in rats

Bleomycin causes pulmonary fibrosis by increasing free oxygen radicals. Cigarette smoke is a strong oxidant which adversely affects pulmonary tissue. We evaluated the effects of cigarette smoke administered with intratracheal bleomycin on pulmonary tissue. We studied 3 groups of rats (n=10): one group received intratracheal saline and served as a control; one received intratracheal bleomycin (IT) (0.5 U/100 g body weight, single dose on the first day), and one group received intratracheal bleomycin (single dose on first day) and tobacco smoke (two times per day) (IT-S). After 4 weeks, the levels of malondialdehyde (MDA) and nitric oxide (NO) and the activities of superoxide dismutase (SOD) and xanthine oxidase (XO) were assayed in the homogenate of the lung tissue samples. The severity of interstitial fibrosis was assessed using the grading system described by Ashcroft. There was more intensive fibrosis in the IT and IT-S than in the control samples (P<0.001). The levels of MDA, NO and activity of XO were significantly increased (P<0.001, <0.002 and <0.002, respectively), and SOD activity (P<0.001) was significantly decreased in the IT group when compared to these values in the control group. The concentration of NO was significantly decreased (P<0.002), and SOD activity was significantly increased (P<0.05) in the lung tissue samples of the IT-S group. Theoretically, the combination of cigarette smoke and bleomycin may have a synergistic effect on oxidative lung injury. In conclusion, we showed that inhalation of cigarette smoke provides protection against oxidative stress in the lung tissue of rats with bleomycin-induced pulmonary fibrosis.

Radiation-related treatment effects across the age spectrum: differences and similarities or what the old and young can learn from each other

Radiation related effects in children and adults limit the delivery of effective radiation doses and result in long-term morbidity affecting function and quality of life. Improvements in our understanding of the etiology and biology of these effects, including the influence of clinical variables, dosimetric factors, and the underlying biological processes have made treatment safer and more efficacious. However, the approach to studying and understanding these effects differs between children and adults. Using the pulmonary and skeletal organ systems as examples, comparisons are made across the age spectrum for radiation related effects, including pneumonitis, pulmonary fibrosis, osteonecrosis, and fracture. Methods for dosimetric analysis, incorporation of imaging and biology as well a length of follow-up are compared, contrasted, and discussed for both organ systems in children and adults. Better understanding of each age specific approach and how it differs may improve our ability to study late effects of radiation across the ages.

A genetic algorithm for variable selection in logistic regression analysis of radiotherapy treatment outcomes

A given outcome of radiotherapy treatment can be modeled by analyzing its correlation with a combination of dosimetric, physiological, biological, and clinical factors, through a logistic regression fit of a large patient population. The quality of the fit is measured by the combination of the predictive power of this particular set of factors and the statistical significance of the individual factors in the model. We developed a genetic algorithm (GA), in which a small sample of all the possible combinations of variables are fitted to the patient data. New models are derived from the best models, through crossover and mutation operations, and are in turn fitted. The process is repeated until the sample converges to the combination of factors that best predicts the outcome. The GA was tested on a data set that investigated the incidence of lung injury in NSCLC patients treated with 3DCRT. The GA identified a model with two variables as the best predictor of radiation pneumonitis: the V30 (p=0.048) and the ongoing use of tobacco at the time of referral (p=0.074). This two-variable model was confirmed as the best model by analyzing all possible combinations of factors. In conclusion, genetic algorithms provide a reliable and fast way to select significant factors in logistic regression analysis of large clinical studies.

Analysis of radiation pneumonitis risk using a generalized Lyman model

PURPOSE

To introduce a version of the Lyman normal-tissue complication probability (NTCP) model adapted to incorporate censored time-to-toxicity data and clinical risk factors and to apply the generalized model to analysis of radiation pneumonitis (RP) risk.

METHODS AND MATERIALS

Medical records and radiation treatment plans were reviewed retrospectively for 576 patients with non-small cell lung cancer treated with radiotherapy. The time to severe (Grade >/=3) RP was computed, with event times censored at last follow-up for patients not experiencing this endpoint. The censored time-to-toxicity data were analyzed using the standard and generalized Lyman models with patient smoking status taken into account.

RESULTS

The generalized Lyman model with patient smoking status taken into account produced NTCP estimates up to 27 percentage points different from the model based on dose-volume factors alone. The generalized model also predicted that 8% of the expected cases of severe RP were unobserved because of censoring. The estimated volume parameter for lung was not significantly different from n = 1, corresponding to mean lung dose.

CONCLUSIONS

NTCP models historically have been based solely on dose-volume effects and binary (yes/no) toxicity data. Our results demonstrate that inclusion of nondosimetric risk factors and censored time-to-event data can markedly affect outcome predictions made using NTCP models.

Association between systemic chemotherapy before chemoradiation and increased risk of treatment-related pneumonitis in esophageal cancer patients treated with definitive chemoradiotherapy

BACKGROUND

There is limited information on risk factors for treatment-related pneumonitis in esophageal cancer patients.

AIM OF THE STUDY

To determine factors associated with treatment-related pneumonitis in esophageal cancer patients treated with definitive chemoradiotherapy.

MATERIALS AND METHODS

We retrospectively reviewed clinical data from esophageal cancer patients treated with definitive chemoradiotherapy from 2000 to 2003. Demographic, clinical, and treatment-related data were collected for all patients. The time to occurrence of grade > or =2 pneumonitis was calculated from the end of radiotherapy. Univariate analyses were performed to determine the existence of any association between patient demographic, clinical, or treatment characteristics and pneumonitis.

RESULTS

In total, 96 patients were included in the study with a median follow-up of 8 months (range, <1-48 months). Among them, 23 patients also received an average of two cycles of systemic chemotherapy before the initiation of concurrent chemoradiation. The incidence of grade > or =2 pneumonitis was 22% at 1 year. Systemic chemotherapy before concurrent chemoradiation was significantly associated with an increased risk of grade > or =2 pneumonitis (p = 0.003), with the 1-year incidence of grade > or =2 pneumonitis for patients with and without systemic chemotherapy being 49 and 14%, respectively. No other clinical or dosimetric factors investigated were associated with the risk of grade > or =2 pneumonitis.

CONCLUSIONS

Systemic chemotherapy before concurrent chemoradiation was significantly associated with an increased risk of grade > or =2 pneumonitis, suggesting that induction chemotherapy may have sensitized the lung tissue to radiation damage in esophageal cancer patients.

Pulmonary changes after radiotherapy for conservative treatment of breast cancer: a prospective study

PURPOSE

Radiotherapy (RT) after conservative surgery for breast cancer involves part of the pulmonary parenchyma with a potential detrimental effect of reducing the normal functional reserve. Such an effect deserves to be studied in depth, considering the given long life expectancy of these women. We prospectively analyzed high-resolution computed tomography (HRCT) and pulmonary function tests (PFTs) with correlation with dosimetric data from RT.

METHODS AND MATERIALS

Lung HRCT and PFTs were performed in 41 women who had undergone conservative surgery for breast cancer before and 3 and 9 months after postoperative RT. The PFTs included forced vital capacity, forced expiratory volume in 1 s, total lung capacity, maximal expiratory flow at 50% and 25% of vital capacity, and the diffusion capacity of carbon monoxide. HRCT was matched with the RT treatment plan images to analyze the dosimetric correlation.

RESULTS

At 3 months after RT, the lung alterations were classified at HRCT as follows: 46.3% were Grade 1, 24.4% Grade 2, and 7.3% Grade 3, and at 9 months, 58.5% were Grade 1, 19.5% Grade 2, and 0% Grade 3. The PFTs showed a significant decrease at 3 months, with only partial recovery at 9 months. Chemotherapy, but not hormonal therapy, was associated with PFT changes. The grade of fibrosis increased with increasing lung volume treated to a dose > or = 25 Gy.

CONCLUSION

Lung changes, mainly related to damage to the alveolar-capillary barrier and smallest airway ramifications, were observed at 3 months, with only partial recovery at 9 months after RT. Minimizing the lung volume receiving > or = 25 Gy could reduce pulmonary toxicity.

Challenges in pulmonary fibrosis . 4: smoking-induced diffuse interstitial lung diseases

Smoking-induced diffuse interstitial lung processes include respiratory bronchiolitis, respiratory bronchiolitis-associated interstitial lung disease (RBILD), desquamative interstitial pneumonia (DIP) and Langerhans' cell histiocytosis. The histological, radiological and clinical features of respiratory bronchiolitis, RBILD and DIP are reviewed, with particular reference to management issues; Langerhans' cell histiocytosis is covered elsewhere in this series of articles. Possible relationships between smoking and other diffuse lung diseases are explored briefly.

Predicting Risk of Radiation-Induced Lung Injury

Radiation-induced lung injury (RILI) is the most common, dose-limiting complication of thoracic radio- and radiochemotherapy. Unfortunately, predicting which patients will suffer from this complication is extremely difficult. Ideally, individual phenotype- and genotype-based risk profiles should be able to identify patients who are resistant to RILI and who could benefit from dose escalation in chemoradiotherapy. This could result in better local control and overall survival. We review the risk predictors that are currently in clinical use--dosimetric parameters of radiotherapy such as normal tissue complication probability, mean lung dose, V20 and V30--as well as biomarkers that might individualize risk profiles. These biomarkers comprise a variety of proinflammatory and profibrotic cytokines and molecules including transforming growth factor beta1 that are implicated in development and persistence of RILI. Dosimetric parameters of radiotherapy show a low negative predictive value of 60% to 80%. Depending on the studied molecule, negative predictive value of biomarkers is approximately 50%. The predictive power of biomarkers might be increased if they are coupled with radiogenomics, e.g., genotyping analysis of single nucleotide polymorphisms in transforming growth factor beta1, transforming growth factor beta1 pathway genes, and other cytokines. Genetic variability and the complexity of RILI and its underlying molecular mechanisms make identification of biological risk predictors challenging. Further investigations are needed to develop more effective risk predictors of RILI.

Quantitative assessment of lung density changes after 3-D radiotherapy for breast cancer

Our aim was to reduce the rates of clinical and radiological pneumonitis in local-regional radiotherapy (RT) for breast cancer compared to a previous treatment series by applying a pre-planned lung dose volume constraint. 3-D dose planning was performed in 66 women with the aim of not exceeding an ipsilateral V20 of 30%. The patients were followed for short-term signs/symptoms of post-RT pneumonitis and radiological changes on chest CT 4 months after RT. Radiological abnormalities were scored with a CT-adapted modification of a semi-quantitative classification system originally proposed by Arriagada which accounts for severity and affected lung regions. The abnormal subvolumes were contoured and the mean doses were calculated. Three cases of mild and one case of moderate symptomatic pneumonitis were diagnosed. The mean V20 was higher in symptomatic than in unaffected patients, 29% vs. 24% (p =0.04). Mild/moderate radiological changes were frequently observed on CT in regions with average doses >30 Gy. According to multivariate modeling, a trend for association was found between the studied dosimetric factors V13, V20, V30 and mean lung dose, and moderate-severe changes on CT but not with patient specific covariates, e.g. chemotherapy or tamoxifen exposure. 3-D planned local-regional RT with a preplanned lung dose volume constraint of V20 <30% resulted in few cases of moderate symptomatic pneumonitis. Mild/moderate radiological changes were still detectable on CT in subvolumes receiving doses >30 Gy. Long-term follow-up for evaluation of possible late morbidity is warranted.

Morbidity after breast cancer treatment and physiotherapeutic performance

Breast cancer (BC) accounts for >30% of all new cancer patients among women but with increased early detection rates and improved adjuvant therapy, the 5-year survival rate presently reaches >85%. As the number of BC survivors increases, research into the sequelae of the cancer and its treatment on quality of life is a priority. Understanding the potential complications of treatment and developing effective rehabilitation techniques can reduce the impact of such effects on activities of daily life. The aim of this review is to discuss the major sequelae of treatment for BC, and the physiotherapist's role in the prevention and treatment of such complications. Breast cancer treatment can result in pulmonary and upper extremity morbidities that may manifest either early or late. Prevention and treatment of lymphoedema, scar adherence and pulmonary complications can be achieved. Additionally pain reduction and maintenance of range of movement, muscle strength and adequate posture are parts of physiotherapy, which is an important component in the rehabilitation of women with BC.

The risk of early and late lung sequelae after conformal radiotherapy in breast cancer patients

PURPOSE

To study the risks of early and late radiogenic lung damage in breast cancer patients after conformal radiotherapy.

METHODS AND MATERIALS

Radiogenic lung sequelae were assessed prospectively in 119 patients by means of clinical signs, radiologic abnormalities, and the mean density change (MDC) of the irradiated lung on CT.

RESULTS

Significant positive associations were detected between the development of lung abnormalities 3 months or 1 year after the radiotherapy and the age of the patient, the ipsilateral mean lung dose (MLD), the radiation dose to 25% of the ipsilateral lung (D(25%)) and the volume of the ipsilateral lung receiving 20 Gy (V(20 Gy)). The irradiation of the axillary and supraclavicular lymph nodes favored the development of pneumonitis but not that of fibrosis. No relation was found between the preradiotherapy plasma TGF-beta level and the presence of radiogenic lung damage. At both time points, MDC was strongly related to age. Significant positive associations were demonstrated between the risks of pneumonitis or fibrosis and the age of the patient, MLD, D(25%), and V(20 Gy). A synergistic effect of MLD, D(25%), and V(20 Gy) with age in patients older than 59 years is suggested.

CONCLUSION

Our analyses indicate that the risks of early and late radiogenic lung sequelae are strongly related to the age of the patient, the volume of the irradiated lung, and the dose to it.

Initial evaluation of treatment-related pneumonitis in advanced-stage non-small-cell lung cancer patients treated with concurrent chemotherapy and intensity-modulated radiotherapy

PURPOSE

To investigate the rate of high-grade treatment-related pneumonitis (TRP) in patients with advanced non-small-cell lung cancer (NSCLC) treated with concurrent chemotherapy and intensity-modulated radiotherapy (IMRT).

METHODS AND MATERIALS

From August 2002 to August 2005, 151 NSCLC patients were treated with IMRT. We excluded patients who did not receive concurrent chemotherapy or who had early-stage cancers, a history of major lung surgery, prior chest RT, a dose <50 Gy, or IMRT combined with three-dimensional conformal RT (3D-CRT). Toxicities were graded by Common Terminology Criteria for Adverse Events version 3.0. Grade > or = 3 TRP for 68 eligible IMRT patients was compared with TRP among 222 similar patients treated with 3D-CRT.

RESULTS

The median follow-up durations for the IMRT and 3D-CRT patients were 8 months (range, 0-27 months) and 9 months (range, 0-56 months), respectively. The median IMRT and 3D-CRT doses were 63 Gy. The median gross tumor volume was 194 mL (range, 21-911 mL) for IMRT, compared with 142 mL (range, 1.5-1,186 mL) for 3D-CRT (p = 0.002). Despite the IMRT group's larger gross tumor volume, the rate of Grade > or = 3 TRP at 12 months was 8% (95% confidence interval 4%-19%), compared with 32% (95% confidence interval 26%-40%) for 3D-CRT (p = 0.002).

CONCLUSIONS

In advanced NSCLC patients treated with chemoradiation, IMRT resulted in significantly lower levels of Grade > or = 3 TRP compared with 3D-CRT. Clinical, dosimetric, and patient selection factors that may have influenced rates of TRP require continuing investigation. A randomized trial comparing IMRT with 3D-CRT has been initiated.

The impact of induction chemotherapy and the associated tumor response on subsequent radiation-related changes in lung function and tumor response

PURPOSE

To assess the impact of induction chemotherapy, and associated tumor shrinkage, on the subsequent radiation-related changes in pulmonary function and tumor response.

METHODS AND MATERIALS

As part of a prospective institutional review board-approved study, 91 evaluable patients treated definitively with thoracic radiation therapy (RT) for unresectable lung cancer were analyzed. The rates of RT-associated pulmonary toxicity and tumor response were compared in the patients with and without pre-RT chemotherapy. In the patients receiving induction chemotherapy, the rates of RT-associated pulmonary toxicity and tumor response were compared in the patients with and without a response (modified Response Evaluation Criteria in Solid Tumor criteria) to the pre-RT chemotherapy. Comparisons of the rates of improvements in pulmonary function tests (PFTs) post-RT, dyspnea requiring steroids, and percent declines in PFTs post-RT were compared in patient subgroups using Fisher's exact test, analysis of variance, and linear or logistic regression.

RESULTS

The use of pre-RT chemotherapy appears to increase the rate of radiation-induced pneumonitis (p = 0.009-0.07), but has no consistent impact on changes in PFTs. The degree of induction chemotherapy-associated tumor shrinkage is not associated with the rate of subsequent RT-associated pulmonary toxicity. The degree of tumor response to chemotherapy is not related to the degree of tumor response to RT.

CONCLUSIONS

Additional study is needed to better clarify the impact of chemotherapy on radiation-associated disfunction.

Changes in pulmonary function after incidental lung irradiation for breast cancer: A prospective study

PURPOSE

The aim of this study was to analyze changes in pulmonary function after radiation therapy (RT) for breast cancer.

METHODS AND MATERIALS

A total of 39 consecutive eligible women, who underwent postoperative irradiation for breast cancer, were entered in the study. Spirometry consisting of forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), carbon monoxide diffusing capacity (DLCO), and gammagraphic (ventilation and perfusion) pulmonary function tests (PFT) were performed before RT and 6, 12, and 36 months afterwards. Dose-volume and perfusion-weighted parameters were obtained from 3D dose planning: Percentage of lung volume receiving more than a threshold dose (Vi) and between 2 dose levels (V(i-j)). The impact of clinical and dosimetric parameters on PFT changes (Delta PFT) after RT was evaluated by Pearson correlation coefficients and stepwise lineal regression analysis.

RESULTS

No significant differences on mean PFT basal values (before RT) with respect to age, smoking, or previous chemotherapy (CT) were found. All the PFT decreased at 6 to 12 months. Furthermore FVC, FEV(1), and ventilation recovered almost to their previous values, whereas DLCO and perfusion continued to decrease until 36 months (-3.3% and -6.6%, respectively). Perfusion-weighted and interval-scaled dose-volume parameters (pV(i-j)) showed better correlation with Delta PFT (only Delta perfusion reached statistically significance at 36 months). Multivariate analysis showed a significant relation between pV(10-20) and Delta perfusion at 3 years, with a multiple correlation coefficient of 0.48. There were no significant differences related to age, previous chemotherapy, concurrent tamoxifen and smoking, although a tendency toward more perfusion reduction in older and nonsmoker patients was seen.

CONCLUSIONS

Changes in FVC, FEV1 and ventilation were reversible, but not the perfusion and DLCO. We have not found a conclusive mathematical predictive model, provided that the best model only explained 48% of the variability. We suggest the use of dose-perfused volume and interval-scaled parameters (i.e., pV(10-20)) for further studies.

Complications of Breast-cancer Radiotherapy

Although the beneficial effect of postoperative radiotherapy for breast cancer is well documented, this treatment may be related to a number of complications, which may affect patient quality of life and possibly survival. Among significant long-term irradiation sequelae are cardiac and lung damage, lymphoedema, brachial plexopathy, impaired shoulder mobility and second malignancies. The risk of these complications, particularly high with old, suboptimal irradiation techniques, has decreased with the introduction of modern technologies. In this paper, we review the contemporary knowledge on the toxicity of breast-cancer radiotherapy and discuss possible preventive measures.

The effects of tangential radiotherapy on lung clearance in breast cancer patients

PURPOSE

The aim of this study was to investigate the effects of tangential radiotherapy (RT) on lung clearance in the patients with breast cancer by using (99m)Tc-DTPA aerosol scintigraphy.

MATERIAL AND METHODS

Thirty-three female patients [non-smoker: 20, ex-smoker: 13] performed surgery and systemic chemotherapy for breast carcinoma [47+/-13 years] were included in the study. All patients underwent (99m)Tc-DTPA aerosol scintigraphy prior to RT (pre RT), midway through RT (mid RT) and after RT (post RT). Total dose was 50 Gy in modified radical mastectomy and 60 Gy in lumpectomy (2 Gy/fraction). Posterior dynamic images of lungs were obtained immediately after the inhalation of (99m)Tc-DTPA aerosol.

RESULTS

Pulmonary function tests were normal in three measurements for all cases. In the ex-smokers, there was no significant difference among pre RT, mid RT and post RT clearance values in both lungs. Pre RT lung clearance in non-smoker group did not differ from that in ex-smokers. However, the lung clearance for non-smoker group showed significantly increase following RT.

CONCLUSION

In this study, we observed that tangential radiotherapy caused an increase in the lung clearance in the cases of non-smokers even in non-irradiated lung, and that the effect of RT on lung clearance was closely depended on smoking habit before RT.