Pulmonary toxicity after radiotherapy in primary breast cancer patients: results from a randomized chemotherapy study

Understanding changes in pulmonary function and functional status in breast cancer patients after systemic chemotherapy and radiotherapy: a prospective study

BACKGROUND

Respiratory complications in breast cancer (BC) patients after chemotherapy (CT) and radiotherapy (RT) have been well acquainted and these complications should be investigated to prevent secondary problems and/or improve BC patients' clinical outcomes. Therefore, this study aimed to assess the potential acute effect of systemic chemotherapy and radiotherapy on respiratory function and functional status of patients with breast cancer.

METHODS

A total of 25 BC patients who were candidates for systemic chemotherapy and radiotherapy were recruited after oncological examination and included in this study. Respiratory function and functional status were assessed with the Pulmonary Function Test (PFT) and the Six-Minute Walk Test (6MWT), respectively. Patients were assessed before CT (c0), after CT (c1), and after RT (r1).

RESULTS

25 BC patients were assessed in c0 and c1 while only 15 out of 25 patients (60%) were assessed in r1. The actual values of Forced vital capacity (FVC) (t = 2.338, p =.028), Forced expiratory volume in 1s (FEV1 (t = 2.708, p =.012), and the forced expiratory flow of between 25% and 75% of vital capacity (FEF25-75%) (t = 2.200, p =.038) were found significantly different after systemic CT. Inspiratory (MIP) and expiratory (MEP) muscle strength also did not show a significant change from c0 to c1. A significant effect of the type of surgery was found (Wilks' lambda, F [1, 19] = 6.561, p =.019, ηp2 = 0.25) between c0 and c1 in actual FVC value. The main effect of time was found significant in FVC (F [2, 28] = 4.840, p =.016, ηp2 = 0.25) from c0 to r1. Pairwise comparisons with Bonferroni correction showed that there was a significant difference between c0 and r1 (p =.037).

DISCUSSION

The present study showed decreased FVC and FEV1 actual values and percent predicted rates from baseline to the completion of treatment. Since the interactional effect of the type of surgery was significant, we suggest that clinical and demographic factors such as age should be considered when interpreting the early changes in PFT. In addition, the significant linear trend of decreasing in some specific outcomes in respiratory function also highlighted the need for continuous monitoring of potential respiratory problems in patients with BC from baseline to the completion of chemotherapy and radiotherapy.

Lung-heart toxicity in a randomized clinical trial of hypofractionated image guided radiation therapy for breast cancer

Background

TomoBreast hypothesized that hypofractionated 15 fractions/3 weeks image-guided radiation therapy (H-IGRT) can reduce lung-heart toxicity, as compared with normofractionated 25-33 fractions/5-7 weeks conventional radiation therapy (CRT).

Methods

In a single center 123 women with stage I-II operated breast cancer were randomized to receive CRT (N=64) or H-IGRT (N=59). The primary endpoint used a composite four-items measure of the time to 10% alteration in any of patient-reported outcomes, physician clinical evaluation, echocardiography or lung function tests, analyzed by intention-to-treat.

Results

At 12 years median follow-up, overall and disease-free survivals between randomized arms were comparable, while survival time free from alteration significantly improved with H-IGRT which showed a gain of restricted mean survival time of 1.46 years over CRT, P=0.041.

Discussion

The finding establishes TomoBreast as a proof-of-concept that hypofractionated image-guided radiation-therapy can improve the sparing of lung-heart function in breast cancer adjuvant therapy without loss in disease-free survival. Hypofractionation is advantageous, conditional on using an advanced radiation technique. Multicenter validation may be warranted.

Trial registration

https://clinicaltrials.gov/ct2/show/NCT00459628. Registered 12 April 2007.

Breast cancer survivors with preserved or rescued cardiorespiratory fitness have similar cardiac, pulmonary and muscle function compared to controls

Breast cancer survivors (BCS) have a high prevalence of cardiovascular disease and low cardiorespiratory fitness (CRF). CRF is an important predictor of survival in BCS. However, the physiological factors that contribute to low CRF in BCS have not been completely elucidated. To assess differences in physiological factors (cardiac, pulmonary, muscle function) related to CRF between BCS and controls. Twenty-three BCS and 23 age-body mass index (BMI) matched controls underwent a peak cycling exercise test to determine CRF, with physiological factors measured at resting and at peak exercise. Cardiac hemodynamics (stroke volume [SV], SVindex, heart rate [HR], cardiac output [Formula: see text], and [Formula: see text]index) were evaluated using ultrasonography. Pulmonary function was evaluated using the oxygen uptake efficiency slope (OUES), ventilation to carbon dioxide production slope [Formula: see text] and breathing reserve at peak exercise (BR). Muscle oxygenation variables (oxygenated [HbO₂] deoxygenated [HHb] and total hemoglobin [Hb], and tissue oxygenation index [TSI]) were measured with near-infrared spectroscopy (NIRS). Both groups had similar CRF and similarly increased all hemodynamic variables (HR, SV, SVindex, [Formula: see text] and [Formula: see text]index) at peak exercise compared to resting (p < 0.001). BCS had higher overall HR and lower SVindex (group effect, p < 0.05). BCS had similar OUES, [Formula: see text] and BR compared to the controls. Both groups decreased TSI, and increased Hb and HHb similarly at peak exercise compared to resting (p < 0.001). Our data suggest BCS do not exhibit differences in cardiac, pulmonary, or muscle function at peak exercise compared to controls, when both groups have similar CRF and physical activity.

Impact of thoracic radiotherapy on respiratory function and exercise capacity in patients with breast cancer

Objective:

To evaluate the impact of thoracic radiotherapy on respiratory function and exercise capacity in patients with breast cancer.

Methods:

Breast cancer patients in whom thoracic radiotherapy was indicated after surgical treatment and chemotherapy were submitted to HRCT, respiratory evaluation, and exercise capacity evaluation before radiotherapy and at three months after treatment completion. Respiratory muscle strength testing, measurement of chest wall mobility, and complete pulmonary function testing were performed for respiratory evaluation; cardiopulmonary exercise testing was performed to evaluate exercise capacity. The total radiotherapy dose was 50.4 Gy (1.8 Gy/fraction) to the breast or chest wall, including supraclavicular lymph nodes (SCLN) or not. Dose-volume histograms were calculated for each patient with special attention to the ipsilateral lung volume receiving 25 Gy (V₂₅), in absolute and relative values, and mean lung dose.

Results:

The study comprised 37 patients. After radiotherapy, significant decreases were observed in respiratory muscle strength, chest wall mobility, exercise capacity, and pulmonary function test results (p < 0.05). DLCO was unchanged. HRCT showed changes related to radiotherapy in 87% of the patients, which was more evident in the patients submitted to SCLN irradiation. V₂₅% significantly correlated with radiation pneumonitis.

Conclusions:

In our sample of patients with breast cancer, thoracic radiotherapy seemed to have caused significant losses in respiratory and exercise capacity, probably due to chest wall restriction; SCLN irradiation represented an additional risk factor for the development of radiation pneumonitis.

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.

Analysis of Irradiated Lung and Heart Volumes using Virtual Simulation in Postoperative Treatment of Stage I Breast Carcinoma

Aims and Background

The aim of the study was to assess the usefulness of virtual simulation in postoperative radiotherapy treatment planning of early-stage breast cancer and to evaluate its potential to reduce the volume of critical structures exposed compared to treatment plans produced by a conventional 2D system.

Methods and Study Design

Eighteen patients undergoing breast radiotherapy following conservative surgery for small breast carcinomas were studied. Scans from spiral CT equipment (with the patient in the treatment position) were transferred to a virtual simulator. From the screen images the operator contoured breast, lung and heart. Calculations were made of the extent to which the heart and lung were included in the irradiation fields (50% isodose line of tangential fields).

Results

Manual contouring was time-consuming, but when virtual simulation was used, the mean volume of the lung included in the radiation fields was significantly reduced compared to the 2D treatment plan (4.5% vs 5.4%, P = 0.034); in addition, a slight reduction was observed for the heart (0.5% to 1.2%), but this was not statistically significant.

Conclusions

With a 3D system we obtained optimal target coverage and a reduction of the dose to critical structures (statistically significant only for the lung). From a clinical point of view, this 0.9% reduction in the mean irradiated lung volume is probably not significant, as the percentage irradiated with a 2D system is considerably below the recommended value. Furthermore, our analysis was performed in a relatively small group of patients; for a reliable estimate larger series would be required. Consequently, the 3D system should not be considered in routine treatment after breast conserving surgery for early stage carcinomas; for the time being it should be reserved for selected cases.

Occurrence of pneumonitis following radiotherapy of breast cancer - A prospective study

AIM

of this study is to determine the temporal resolution of therapy-induced pneumonitis, and to assess promoting factors in adjuvant treated patients with unilateral mammacarcinoma.

PATIENTS AND METHODS

A total of 100 post-surgery patients were recruited. The cohort was treated by 2 field radiotherapy (2FRT; breast and chest wall, N = 75), 3 field radiotherapy (3FRT; + supraclavicular lymphatic region, N = 8), or with 4 field radiotherapy (4FRT; + parasternal lymphatic region, N = 17). Ninety-one patients received various systemic treatments prior to irradiation. Following an initial screening visit post-RT, two additional visits after 12 and 25 weeks were conducted including radiographic examination. In addition, general anamnesis and the co-medication were recorded. The endpoint was reached as soon as a pneumonitis was developed or at maximum of six months post-treatment.

RESULTS

A pneumonitis incidence of 13% was determined. Of 91 patients with prior systemic therapy, 11 patients developed pneumonitis. Smoking history and chronic obstructive pulmonary disease (COPD) appeared to be positive predictors, whereas past pneumonia clearly promoted pneumonitis. Further pneumonitis-promoting predictors are represented by the applied field extensions (2 field radiotherapy [2FRT] < 3 field radiotherapy [3FRT] < 4 field radiotherapy [4FRT]) and the type of combined initial systemic therapies. As a consequence, all of the three patients in the study cohort treated with 4FRT and initial chemotherapy combined with anti-hormone and antibody protocols developed pneumonitis. A combination of the hormone antagonists tamoxifen and goserelin might enhance the risk for pneumonitis. Remarkably, none of the 11 patients co-medicated with statins suffered from pneumonitis.

CONCLUSIONS

The rapidly increasing use of novel systemic therapy schedules combined with radiotherapy (RT) needs more prospective studies with larger cohorts. Our results indicate that contribution to pneumonitis occurrence of various (neo)adjuvant therapy approaches followed by RT is of minor relevance, whereas mean total lung doses of >10 Gy escalate the risk of lung tissue complications. The validity of potential inhibitors of therapy-induced pneumonitis as observed for statin co-medication should further be investigated in future trials.

Respiratory Factors Contributing to Exercise Intolerance in Breast Cancer Survivors: A Case-Control Study

CONTEXT

Breast cancer survivors often experience activity-related dyspnea and exercise intolerance, but the underlying mechanisms remain unknown.

OBJECTIVES

We evaluated physiological contributors to reduced peak oxygen uptake (VO2), with particular attention to the role of respiratory impairment.

METHODS

We compared symptom assessments, respiratory and peripheral muscle strength, pulmonary function, and ventilatory responses to symptom-limited incremental treadmill exercise in 29 women who had survived breast cancer and 29 age-matched healthy controls.

RESULTS

Peak VO2 was reduced more than 20%, on average, in the cancer group compared with controls (P < 0.001). Slopes of dyspnea intensity ratings over ventilation or VO2 were >50% greater in the cancer group compared to controls (P < 0.05). Women with breast cancer had lower lung diffusing capacity for carbon monoxide (DLCO), respiratory and limb muscle strength, and ventilatory thresholds during exercise compared with controls (all P < 0.05). During exercise, indices of ventilatory efficiency were similar to controls, but inspiratory capacity (IC) was lower and breathing pattern was more rapid and shallow in the cancer group (P < 0.05). The lower peak VO2 in the cancer group was associated with greater dyspnea intensity, and lower DLCO, IC and ventilatory threshold (all P < 0.05).

CONCLUSION

Breast cancer survivors had greater peripheral and respiratory muscle weakness, greater reduction of IC, impaired lung diffusion, and evidence of deconditioning compared with controls. Exercise intolerance was multifactorial and correlated well with the combination of these factors as well as with exertional dyspnea. Individualized physiological testing in breast cancer survivors can identify important contributors to exercise intolerance which can be targeted for treatment.

Inhalative steroids as an individual treatment in symptomatic lung cancer patients with radiation pneumonitis grade II after radiotherapy - a single-centre experience

Purpose

To assess efficacy of our single-centre experience with inhalative steroids (IS) in lung cancer patients with symptomatic radiation pneumonitis (RP) grade II.

Material and methods

Between 05/09 and 07/10, 24 patients (female, n = 8; male, n = 16) with lung cancer (non-small cell lung carcinoma [NSCLC]: n = 19; small cell lung cancer [SCLC]: n = 3; unknown histology: n = 2) and good performance status (ECOG ≤1) received definitive radiotherapy to the primary tumour site and involved lymph nodes with concurrent chemotherapy (n = 18), sequential chemotherapy (n = 2) or radiation only (n = 4) and developed symptomatic RP grade II during follow-up. No patient presented with oxygen requiring RP grade III. The mean age at diagnosis was 66 years (range: 50–82 years). Nine patients suffered from chronic obstructive pulmonary disease (COPD) before treatment, and 18 patients had a smoking history (median pack years: 48). The mean lung dose was 15.5 Gy (range: 3.0–23.1 Gy). All patients were treated with IS. If a patient’s clinical symptoms did not significantly improve within two weeks of IS therapy initiation, their treatment was switched to oral prednisolone.

Results

All 24 patients were initially treated with a high dose IS (budesonide 800 μg 1-0-1) for 14 days. Of the patients, 18 showed a significant improvement of clinical symptoms and 6 patients did not show significant improvement of clinical symptoms and were classified as non-responders to IS. Their treatment was switched to oral steroids after two weeks (starting with oral prednisolone, 0.5 mg/kg bodyweight; at least 50 mg per day). All of these patients responded to the prednisolone. None of non-responders presented with increased symptoms of RP and required oxygen and / or hospitalization (RP grade III). The median follow-up after IS treatment initiation was 18 months (range: 4–66 months). The median duration of IS treatment and prednisolone treatment was 8.2 months (range: 3.0–48.3 months) and 11.4 months (range: 5.0–44.0 months), respectively. Of the 18 IS treatment responders, 2 (11.1 %) patients with pre-existing grade 2 COPD still required IS (400 μg twice a day) 45.0 and 48.3 months after radiotherapy, respectively. For the remaining 16 responders (88.9 %), IS therapy was stopped after 7.7 months (range: 3.0–18.2 months). None of the patients treated with IS developed any specific IS-related side effects such as oral candidiasis.

Conclusion

This single-centre experience shows that high-dose IS is an individual treatment option for radiation-induced pneumonitis grade II in patients with a good performance status.

Radiation Pneumonitis After Conventional Radiotherapy For Breast Cancer: A Prospective Study

BACKGROUND

Loco-regional radiotherapy is an important treatment modality in breast cancer and radiation pneumonitis (RP) is one of the early toxicities.

AIM

To study the occurrence, correlation of RP with patient and radiotherapy related factors and the effects on pulmonary function following conventional radiotherapy in breast cancer.

SETTINGS AND DESIGN

Prospective study, from a tertiary hospital in a developing country.

MATERIALS AND METHODS

Prospective analysis of clinical symptoms, pulmonary function and radiologic changes was done prior to and 12 weeks after adjuvant radiotherapy (n=46). Statistical analysis was done using SPSS version 10 software.

RESULTS

Radiological and clinical RP was seen in 45.65% (n=21) and 19.56% (n=9) respectively. RP was significantly higher with age >50 years (OR 4.4), chest wall irradiation with electrons, (electrons 83.3% vs cobalt60 32.4%, p=0.02) and supraclavicular field treatment with 6 MV photons (p= 0.011). There was significant relationship between Inferior Lung Distance (ILD) and RP (p=0.013). The fall in Total Lung Capacity (TLC) was significantly more in those with RP (p=0.02).

CONCLUSION

Clinical RP occurs in almost one-fifth of breast cancer patients treated with conventional radiotherapy. Chest wall irradiation with electrons, supraclavicular field irradiation with 6 MV photons, higher ILD and age >50 years was associated with increased RP. The pulmonary function parameter most affected was TLC. The factors associated with increased RP should be considered when adjuvant radiotherapy is planned to minimize its likelihood and intervene appropriately.

After the bomb drops: a new look at radiation-induced multiple organ dysfunction syndrome (MODS)

PURPOSE

There is increasing concern that, since the Cold War era, there has been little progress regarding the availability of medical countermeasures in the event of either a radiological or nuclear incident. Fortunately, since much is known about the acute consequences that are likely to be experienced by an exposed population, the probability of survival from the immediate hematological crises after total body irradiation (TBI) has improved in recent years. Therefore focus has begun to shift towards later down-stream effects, seen in such organs as the gastrointestinal tract (GI), skin, and lung. However, the mechanisms underlying therapy-related normal tissue late effects, resulting from localised irradiation, have remained somewhat elusive and even less is known about the development of the delayed syndrome seen in the context of whole body exposures, when it is likely that systemic perturbations may alter tissue microenvironments and homeostasis.

CONCLUSIONS

The sequence of organ failures observed after near-lethal TBI doses are similar in many ways to that of multiple organ dysfunction syndrome (MODS), leading to multiple organ failure (MOF). In this review, we compare the mechanistic pathways that underlie both MODS and delayed normal tissue effects since these may impact on strategies to identify radiation countermeasures.

Inhibition of the tumor necrosis factor-alpha pathway is radioprotective for the lung

PURPOSE

Radiation-induced lung toxicity limits the delivery of high-dose radiation to thoracic tumors. Here, we investigated the potential of inhibiting the tumor necrosis factor-alpha (TNF-alpha) pathway as a novel radioprotection strategy.

EXPERIMENTAL DESIGN

Mouse lungs were irradiated with various doses and assessed at varying times for TNF-alpha production. Lung toxicity was measured by apoptosis and pulmonary function testing. TNF receptor 1 (TNFR1) inhibition, achieved by genetic knockout or antisense oligonucleotide (ASO) silencing, was tested for selective lung protection in a mouse lung metastasis model of colon cancer.

RESULTS

Lung radiation induced local production of TNF-alpha by macrophages in BALB/c mice 3 to 24 hours after radiation (15 Gy). A similar maximal induction was found 1 week after the start of radiation when 15 Gy was divided into five daily fractions. Cell apoptosis in the lung, measured by terminal deoxyribonucleotide transferase-mediated nick-end labeling staining (mostly epithelial cells) and Western blot for caspase-3, was induced by radiation in a dose- and time-dependent manner. Specific ASO inhibited lung TNFR1 expression and reduced radiation-induced apoptosis. Radiation decreased lung function in BALB/c and C57BL mice 4 to 8 weeks after completion of fractionated radiation (40 Gy). Inhibition of TNFR1 by genetic deficiency (C57BL mice) or therapeutic silencing with ASO (BALB/c mice) tended to preserve lung function without compromising lung tumor sensitivity to radiation.

CONCLUSION

Radiation-induced lung TNF-alpha production correlates with early cell apoptosis and latent lung function damage. Inhibition of lung TNFR1 is selectively radioprotective for the lung without compromising tumor response. These findings support the development of a novel radioprotection strategy using inhibition of the TNF-alpha pathway.

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.

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.

Radiological pulmonary findings after breast cancer irradiation: A prospective study

The aim of this study was to evaluate radiation-induced pulmonary abnormalities of breast cancer patients. Altogether 202 consecutive patients receiving postoperative radiotherapy entered the study. Plain chest radiographs taken at entry and 3, 6 and 12 months after radiotherapy were evaluated according to modified Arriagada classification. In addition, pulmonary symptoms were recorded. Supplementary high-resolution computed tomography (HRCT) was employed in a subgroup of patients (n?=?15). Plain radiographs were interpreted by a radiologist, and uncertain findings were re-evaluated by a radiologist together with a radiation oncologist. Grade 2 pneumonitis was the most common abnormality. The proportion of patients yielding a grade 2 finding was 22.5%, 28.1%, and 16.0% at three, six, and twelve months, respectively. There were 2 normal findings in HRCTscans, and 8 in plain radiographs of the same patients. Radiological lung abnormalities are common after radiotherapy, but they are usually reversible, and their significance for the patient's well-being is minor. No correlation between symptoms and lung or pleural reactions was seen.

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.

Proton therapy of cancer: potential clinical advantages and cost-effectiveness

Proton therapy may offer potential clinical advantages compared with conventional radiation therapy for many cancer patients. Due to the large investment costs for building a proton therapy facility, however, the treatment cost with proton radiation is higher than with conventional radiation. It is therefore important to evaluate whether the medical benefits of proton therapy are large enough to motivate the higher costs. We assessed the cost-effectiveness of proton therapy in the treatment of four different cancers: left-sided breast cancer, prostate cancer, head and neck cancer, and childhood medulloblastoma. A Markov cohort simulation model was created for each cancer type and used to simulate the life of patients treated with radiation. Cost and quality adjusted life years (QALYs) were used as primary outcome measures. The results indicated that proton therapy was cost-effective if appropriate risk groups were chosen. The average cost per QALY gained for the four types of cancer assessed was about pounds 10,130. If the value of a QALY was set to pounds 55,000, the total yearly net benefit of treating 925 cancer patients with the four types of cancer was about pounds 20.8 million. Investment in a proton facility may thus be cost-effective. The results must be interpreted with caution, since there is a lack of data, and consequently large uncertainties in the assumptions used.

Economic evaluation of proton radiation therapy in the treatment of breast cancer

BACKGROUND AND PURPOSE

Proton beam therapy offers potential clinical advantages compared with conventional radiation therapy for many cancer patients. The benefits are mainly a result of a more favourable dose distribution. The treatment cost with proton radiation is higher than for conventional radiation, mainly due to the large investment cost of building a proton therapy facility. It is therefore important to evaluate whether the medical benefits of proton therapy are large enough to justify the higher treatment costs, compared with conventional radiation therapy.

PATIENTS AND METHODS

The cost-effectiveness of proton therapy in the treatment of 55-year old women with left-sided breast cancer was assessed. A Markov cohort simulation model was used to simulate the life of patients diagnosed with breast cancers and treated with radiation. Cost and quality adjusted life years (QALYs) were the primary outcome measures.

RESULTS

The study found a cost per QALY gained of 67,000 Euro for the base case analysis of an average breast cancer patient. The cost per QALY gained would, however, be considerably lower if a population with high-risk of developing cardiac disease was treated. Sensitivity analyses showed that the results were stable and that the risk of cardiac disease was the most important parameter.

CONCLUSIONS

The results indicate that proton therapy for breast cancer can be cost-effective if appropriate risk groups are chosen as targets for the therapy.

Inhalation delivery of manganese superoxide dismutase-plasmid/liposomes protects the murine lung from irradiation damage

Intratracheal injection of manganese superoxide dismutase-plasmid/liposome (MnSOD-PL) complexes has been demonstrated to delay the onset and reduce the extent of ionizing irradiation-induced murine pulmonary organizing alveolitis/fibrosis. To facilitate translation of this modality to clinical fractionated radiotherapy, inhalation delivery of MnSOD-PL was developed using an ultrasonic nebulizer. Transgene product was quantitated by immunohistochemical quantitation and pulmonary tissue levels of MnSOD biochemical activity. C57BL/6NHsd female mice demonstrated a plasmid dose-dependent increased expression of MnSOD transgene product over the range of 250 microg-2.5 mg of MnSOD-PL administered over a constant 5 min interval. Delivery of a constant concentration of 500 microg of MnSOD-PL with varying times of administration ranging from 0.5 to 10 min demonstrated optimal MnSOD expression at 5 min. Mice pretreated by inhalation delivery of MnSOD-PL demonstrated significantly improved survival after 20 Gy single fraction irradiation to both lungs compared to LacZ-PL inhalation-treated or irradiated control mice. Mice receiving 10 fractions of 3.5 cGy demonstrated increased pulmonary MnSOD transgene product activity by a protocol of every Monday-Wednesday or daily inhalation of MnSOD-PL. Thus, inhalation radioprotective gene therapy using MnSOD-PL provides a practical and effective method for delivery of lung-specific radioprotection during fractionated radiotherapy protocols in a mouse model.

Sequential pulmonary effects of radiotherapy detected by functional and radiological end points in women with breast cancer

AIMS

To determine the pulmonary effects of locoregional irradiation on clinical and sub-clinical radiographic and functional end points in women with breast cancer, and whether the course of these end points is affected by laterality.

MATERIALS AND METHODS

Twenty patients (10 irradiated on the left side and 10 irradiated on the right side) were prospectively evaluated for changes in pulmonary function tests, Tc-99m DTPA (diethylenetriamine pentaacetic acid) lung clearance scintigraphy and high-resolution computed tomography (HRCT) at 6, 16 and 52 weeks after radiotherapy. Tc-99m DTPA clearance, expressed as the biological half-time, T(1/2), was computed from the time-activity curves for 10 min for each lung. The irradiated lung volume was calculated for each patient.

RESULTS

The mean irradiated lung volume was 6.4% +/- 2 (range 3-11%) for the entire population. In the whole study population, two (10%) patients, who were irradiated on the left side, had mild symptomatic radiation pneumonitis in the follow-up period. There was a statistically significant gradual reduction in all pulmonary function test values during the follow-up period. For patients irradiated on the left side, Tc-99m DTPA clearance T(1/2) values were statistically significantly decreased during the follow-up period (P = 0.03), but the decrease was not statistically significant for patients irradiated on the right side (P = 0.62). Tc-99m DTPA clearance T(1/2) values were statistically significantly decreased in the irradiated lung compared with the opposite lung, and no improvement was seen at week 52 after radiotherapy. The number of patients with changes on HRCT scans increased after radiotherapy, reaching a maximum at 16 weeks, when 80% of patients had changes. There was subsequent partial recovery 52 weeks after radiotherapy.

CONCLUSION

Locoregional irradiation for breast cancer may cause sub-clinical irreversible impairment of radiological and functional pulmonary parameters. The increase in clearance rate of Tc-99m DTPA may be more prominent for patients with left-sided breast cancer.

Long-term radiation sequelae after breast-conserving therapy in women with early-stage breast cancer: an observational study using the LENT-SOMA scoring system

PURPOSE

To evaluate the long-term toxicity after breast-conserving therapy in women with early-stage breast cancer.

METHODS AND MATERIALS

Late toxicity according to the late effects of normal tissue-subjective, objective, management, and analytic (LENT-SOMA) criteria and cosmetic outcome (graded by physicians) were evaluated in 590 of 2943 women with early-stage breast cancer who were irradiated between 1983 and 1995 using the following fractionation schedules: group A, 1983-1987, 2.5 Gy 4x/wk to 60 Gy; group B, 1988-1993, 2.5 Gy 4x/wk to 55 Gy, group C, 1994-1995, 2.0 Gy 5x/wk to 55 Gy.

RESULTS

LENT-SOMA Grade 3-4 toxicity was observed as follows: group A (median follow-up 171 months; range 154-222 months), fibrosis 16% (7 of 45), telangiectasia 18% (8 of 45), and atrophy 4% (2 of 45); group B (median follow-up 113 months; range 78-164 months), pain 2% (8 of 345), fibrosis 10% (34 of 345), telangiectasia 10% (33 of 345), arm edema 1% (2 of 345), and atrophy 8% (27 of 345); and group C (median follow-up 75 months, range 51-96 months, n = 200), occurrence of Grade 3-4 late morbidity <or=2%. The cosmetic outcome was very good to acceptable in 78% (35 of 45) of patients in group A, 83% (286 of 345) in group B, and 94% (187 of 200) in group C.

CONCLUSION

In our population, the long-term side effects after breast-conserving therapy were not rare, but were mainly asymptomatic. The LENT-SOMA breast module is a practical tool to assess radiation-induced long-term toxicity.