Concurrent end-phase boost high-dose radiation therapy for non-small-cell lung cancer with or without cisplatin chemotherapy

The aim of this study was to audit the results of a high-dose, combined-modality prospective protocol for non-small-cell lung cancer in terms of survival, disease-specific survival and toxicity. One hundred and twenty-one patients with non-small-cell lung cancer were treated with a concurrent, end-phase, boost, high-dose radiotherapy protocol with 65 Gy in 35 fractions for more than 5 weeks. Sixty-six patients received radiotherapy alone (group 1), 29 received concurrent chemoradiation (group 2) and 26 received neoadjuvant and concurrent chemotherapy (group 3). Thirty-four patients had stage I disease, six had stage II and 81 had stage III. Overall median survival was 23 months: 75% at 1 year and 23% at 5 years. Median survivals for patients with stage I and stages II and III disease were 43 and 19 months, respectively. For stages II and III patients by groups 1-3, median survivals were 18, 25 and 18 months, respectively, and 2-year survivals were 36, 52 and 38%, respectively. Toxicity was acceptable. Overall, 9% had symptomatic pneumonitis and 7% had grades 3 and 4 oesophagitis. For those who had the mediastinum included in the volume, grade > or = 3 oesophagitis occurred in 0, 11 and 22% (n = 110, P = 0.001), respectively, for treatment groups 1-3. Overall treatment-related mortality was 3%, consisting of two septic deaths, one pneumonitis and possibly one late cardiac event, all occurring in patients who had chemotherapy (7% of 55 patients). Treatment-related mortality declined over the study period. Accelerated radiotherapy was well tolerated, with only moderate increased acute toxicity when combined with concurrent platinum chemotherapy. Toxicity was enhanced by induction chemotherapy. Overall survival outcomes were excellent for this condition. Continued use of this radiotherapy schedule is recommended as the platform for assessment of other chemotherapy schedules.

Clinical dose-volume histogram analysis in predicting radiation pneumonitis in Hodgkin's lymphoma

PURPOSE

To quantify the incidence of radiation pneumonitis (RP) in a modern Hodgkin's lymphoma (HL) cohort, and to identify any clinically relevant parameters that may influence the risk of RP.

METHODS AND MATERIALS

Between January 2003 and February 2005, 64 consecutive HL patients aged 18 years or older receiving radical mediastinal radiation therapy (RT) were retrospectively reviewed. Symptomatic cases of radiation pneumonitis were identified. Dose-volume histogram parameters, including V(13), V(20), V(30), and mean lung dose (MLD), were quantified.

RESULTS

At a median follow-up of 2.1 years, the actuarial survival for all patients was 91% at 3 years. There were 2 (2/64) cases of Radiation Therapy Oncology Group (RTOG) Grade 2 RP (incidence 3.1%). Both index cases with corresponding V(20) values of 47.0% and 40.7% were located in the upper quartile (2/16 cases), defined by a V(20) value of > or =36%, an incidence of 12.5% (p = 0.03). Similarly for total MLD, both index cases with values of 17.6 Gy and 16.4 Gy, respectively, were located in the upper quartile defined by MLD > or =14.2 Gy, an incidence of 11.8% (2/17 cases, p = 0.02).

CONCLUSIONS

Despite relatively high V(20) values in this study of HL patients, the incidence of RP was only 3%, lower compared with the lung cancer literature. We suggest the following clinically relevant parameters be considered in treatment plan assessment: a V(20) greater than 36% and an MLD greater than 14 Gy, over and above which the risk of RTOG Grade 2 or greater RP would be considered clinically significant.

The Relationship of Radiation Pneumonitis to Treated Lung Volume in Breast Conservation Therapy

Breast conservation therapy has become a common modality for therapy of early stage breast cancer. Most studies of primary lung irradiation correlate the risk of pneumonitis with the volume of lung treated. It is proposed that the lung volume treated during tangential radiation of the intact breast may be calculated from a measurement of the central lung distance. Central lung distance is the distance from the chest wall to the edge of the field at the central axis. This study examines whether the incidence of radiation pneumonitis indeed correlates with the lung volume treated as calculated from a measurement of the central lung distance. From January 1, 1985, through December 31, 1998, 353 patients were treated with breast conservation therapy at the University of Louisville. The charts were reviewed for any evidence of clinically significant radiation pneumonitis. The treatment films were obtained and the central lung distance ascertained. Four cases of radiation pneumonitis were identified. Three of these occurred after tangential radiation and one occurred in a retreatment field after bone marrow transplant. The overall rate of radiation pneumonitis was 1.2%. A central lung distance of less than 3 cm was found in 78.3% of patients and 21.7% had a central lung distance of three or greater. There was no correlation between central lung distance and the risk of radiation pneumonitis. Breast conservation therapy is a well-tolerated modality for treatment of early stage breast cancer. The incidence of radiation pneumonitis is very low and is usually associated with other factors in addition to the tangential field lung volume.

Radiation pneumonitis in breast cancer patients treated with taxanes: does sequential radiation therapy lower the risk?

Taxanes are now routinely used in conjunction with radiation therapy (RT) as adjuvant therapy for breast cancer. Recent publications have reported several cases of radiation pneumonitis (RP) in patients receiving RT and taxane chemotherapy, thus raising concern as to the safety of this combination. To decrease the potential risk of RP, we sequenced RT after taxane chemotherapy with a target interval of 3-4 weeks in two consecutive institutional breast protocols. Forty patients were treated on two adjuvant systemic protocols consisting of modified radical mastectomy (n = 9) or breast-conserving surgery (n = 31), followed by adjuvant doxorubicin, cyclophosphamide, and a sequential taxane (ACT), followed by RT. All patients had either node-positive or high-risk node-negative breast cancer and were treated between October 2000 and September 2002. Postmastectomy, a median dose of 5040 cGy was delivered to the chest wall. After breast-conserving surgery, a median dose of 4680 cGy was delivered to the breast plus a 1400 cGy boost to the surgical cavity. Information regarding RP was gathered retrospectively by reviewing patient records. With a median follow-up of 28 months (range 6-42 months), no cases of clinical RP were identified and no local failures had occurred. The median time interval for all patients between the completion of chemotherapy and the initiation of RT was 34 days (range 5-70 days). At the latest follow-up, 2 patients were diagnosed with metastatic disease and 38 patients were without evidence of disease. Sequencing of RT after taxane therapy with a target interval of 3-4 weeks does not appear to result in increased pulmonary toxicity and is associated with good local control.

Radiation Induced Lung Reactions in Breast Cancer Therapy

BACKGROUND AND PURPOSE

Radiologic reactions in lung, usually subclinical, are a frequent side effect of radiotherapy for breast cancer. This study was initiated to identify effects of age and tamoxifen on radiation pneumonitis and consequent fibrosis.

PATIENTS AND METHODS

Retrospectively, 451 patients irradiated postoperatively between 1992 and 1995 at the Department of Radiotherapy of Carl-Thiem-Klinikum (Cottbus, Germany) were analyzed. The median age was 58 years. After mastectomy (n = 296), 25 x 2.0 Gy were applied; breast-conserving surgery (n = 155) was followed by 30 x 2.0 Gy. In 221 patients, adjuvant tamoxifen was given. Follow-up included thorax radiography after 15 weeks and 1 year. In patients with reversible observations in standard chest radiography from 15 weeks to 1 year, CT or high-resolution (HR-)CT scans were analyzed after 4-7 years.

RESULTS

Clinical symptoms of pneumonitis were seen in 25 patients (5.5%), all with radiologic changes. Early radiologic changes were detected in 134 patients (29.7%). Age (> 58 years; p = 0.0127) and tamoxifen (p = 0.0001) were found as significant parameters of early pneumopathy. Late radiologic changes were seen in 94/425 patients (22.1%), all after a positive early reaction (p = 0.001).

CONCLUSION

A low incidence of clinically symptomatic pneumonitis was observed, while the vast majority of patients presented with early radiologic changes. Higher age and tamoxifen treatment significantly increased the incidence of early pneumopathy. Local fibrotic responses must be expected in all patients with early reactions, indicating a strong consequential component of the late reaction.

Body Mass Index Predicts the Incidence of Radiation Pneumonitis in Breast Cancer Patients

In patients receiving breast radiotherapy, the risk of radiation pneumonitis has been associated with the volume of irradiated lung, and concomitant methotrexate, paclitaxel, and tamoxifen therapy. Many of the studies of radiation pneumonitis are based on estimates of pulmonary risk using central lung distance that is calculated using two-dimensional techniques. With the treatment of internal mammary nodes and three-dimensional treatment planning for breast cancer becoming increasingly more common, there is a need to further consider the impact of dose-volume metrics in assessing radiation pneumonitis risk. We herein present a case control study assessing the impact of clinical and dose-volume metrics on the development of radiation pneumonitis in patients receiving sequential chemotherapy and local-regional radiotherapy.

Is a reduction in radiation lung volume and dose necessary with paclitaxel chemotherapy for node-positive breast cancer?

PURPOSE

To evaluate and quantify the effect of irradiated lung volume, radiation dose, and paclitaxel chemotherapy on the development of radiation pneumonitis (RP) in breast cancer patients with positive lymph nodes.

METHODS AND MATERIALS

We previously reported the incidence of RP among 41 patients with breast cancer treated with radiotherapy (RT) and adjuvant paclitaxel-containing chemotherapy. We recorded the central lung distance, a measure of the extent of lung included in the RT volume, in these patients. We used this measure and the historical and observed rates of RP in our series to model the lung tolerance to RT in patients receiving chemotherapy (CHT) both with and without paclitaxel. To evaluate the risk factors for the development of RP, we performed a case-control study comparing paclitaxel-treated patients who developed RP with those who did not, and a second case-control study comparing patients receiving paclitaxel in addition to standard CHT/RT (n = 41) and controls receiving standard CHT/RT alone (n = 192).

RESULTS

The actuarial rate of RP in the paclitaxel-treated group was 15.4% compared with 0.9% among breast cancer patients treated with RT and non-paclitaxel-containing CHT. Our mathematical model found that the effective lung tolerance for patients treated with paclitaxel was reduced by approximately 24%. No statistically significant difference was found with regard to the dose delivered to specific radiation fields, dose per fraction, central lung distance, or percentage of lung irradiated in the case-control study of paclitaxel-treated patients who developed RP compared with those who did not. In the comparison of 41 patients receiving RT and CHT with paclitaxel and 192 matched controls receiving RT and CHT without paclitaxel, the only significant differences identified were the more frequent use of a supraclavicular radiation field and a decrease in the RT lung dose among the paclitaxel-treated patients. This finding indicates that the major factor associated with development of RP was paclitaxel treatment.

CONCLUSIONS

The use of paclitaxel chemotherapy and RT in the primary treatment of node-positive breast cancer is likely to increase the incidence of RP. In patients treated with paclitaxel, reducing the percentage of lung irradiated by 24% should reduce the risk of RP to 1%, according to our calculations of lung tolerance. Future clinical trials using combination CHT that includes paclitaxel and RT should carefully evaluate the incidence and severity of RP and should also accurately monitor the extent of lung included within the RT volume to develop safe guidelines for the delivery of what is becoming standard therapy for node-positive breast cancer.

Five-Year Results of a Phase II Trial of Hyperfractionated Radiotherapy and Concurrent Daily Cisplatin Chemotherapy for Stage III Non-Small-Cell Lung Cancer

The purpose of this study was to evaluate the 5-year results for a phase II trial of hyperfractionated radiotherapy (RT) and concurrent daily cisplatin chemotherapy. Between August 1994 and December 1999, 63 patients with stage IIIA and stage IIIB non-small-cell lung cancer were treated with RT to a dose of 69.6 Gy at 1.2 Gy twice daily with daily cisplatin at 6 mg/m. Thirty-seven patients elected to receive consolidation carboplatin and paclitaxel chemotherapy. Recurrence and survival outcomes were evaluated by Kaplan-Meier analysis. Acute and late side effects were scored by the Radiation Therapy Oncology Group (RTOG) grading system. Radiographic complete or partial tumor response was achieved in 34 of 63 (54%) of cases. Median absolute survival was 20.1 months. Median time to local recurrence and distant metastases were 10.6 and 8.6 months, respectively. Overall survival rates were 57%, 35%, and 23% at 1, 3, and 5 years, respectively. Survival was significantly greater for patients receiving consolidation chemotherapy (50% versus 20% at 3 years). Only 5 patients (7%) experienced Grade 3 or 4 esophagitis. There were 16 cases of Grade 1 or 2 pneumonitis; steroid therapy resolved symptoms in 9 patients. This regimen of hyperfractionated RT and chemotherapy achieved significant response, and 5-year survival rates with acceptable toxicity.

Postmastectomy Chest Wall Radiation with Electron-Beam Therapy

PURPOSE

Postmastectomy chest wall radiation therapy using electron-beam therapy has been reported to increase lung radiation dose and the potential for pneumonitis. These reports describe treatment with varying energy electron beams prescribed to the breast/chest wall junction. Because the tissue at risk includes dermal lymphatics and subcutaneous tissues, low-energy electron beams may reduce lung radiation dose and the incidence of pneumonitis yet preserve good local control. At the University of Louisville, patients who have undergone mastectomy are treated with 6-MeV electron beam and bolus.

PATIENTS AND METHODS

From 1985 through 1998, 273 patients underwent postmastectomy radiation therapy at the University of Louisville. The chest wall was treated using 6-MeV electron beam with 5-mm bolus prescribed to the 90% isodose-line, ensuring adequate dermal lymphatic dose. Internal mammary nodes were treated with electron-beam energy sufficient to treat to depth (approximately 15 MeV). Supraclavicular nodes were treated using 6-MV photon beam. Patients' charts were reviewed with respect to complications and outcome.

RESULTS

Radiation pneumonitis was confirmed in one case (0.4%). The pneumonitis resolved with prednisone treatment. Twenty patients experienced locoregional failure (7.3%), 14 of whom failed in the chest wall (5.1%).

DISCUSSION

Local control in our study is excellent and comparable to results expected for postmastectomy radiation therapy as reported in the literature. We conclude that postmastectomy patients can be treated with low-energy electron beam radiation therapy, protecting underlying lung without sacrificing local disease control.

An artificial neural network for predicting the incidence of radiation pneumonitis

A method to predict radiation-induced pneumonitis (RP) using an artificial neural network (ANN) was investigated. A retrospective study was applied to the clinical data from 142 patients who have been treated with three-dimensional conformal radiotherapy for tumors in the thoracic region. These data were classified, based on their treatment outcome, into two patient clusters: with RP (Np=26) and without RP (Np= 116). An ANN was designed as a classifier. To perform the classification, a patient-treatment outcome with RP was assigned a value of 1, and a patient treatment outcome without RP was assigned a value of -1. The input of the ANN was limited to the patient lung dose-volume data only. A volume vector (VD) that describes patient lung subvolumes receiving more than a set of threshold doses was used as the network input variable. A zero value was used as the threshold to set the output value into -1 or 1. Three ANNs (ANN_1, ANN_2, and ANN_3), each with three layers, were trained to perform this classification function and to show the effect of training data on the ANN performance. Radial basis function was applied as the hidden layer neuron activation function and a sigmoid function was selected as the output layer neuron function. Backpropagation with a conjugate gradient algorithm was used to train the network. ANN_1 was trained and tested by using the leave-one-out method. ANN_2 was trained by randomly selecting 2/3 of the patient data, and tested by the remaining 1/3 of the data. ANN_3 was trained by a user selecting 2/3 of the patient data, and tested by the remaining 1/3 of the data. The predictive accuracy was verified as the area under a receiver operator characteristic (ROC) curve. The correct classification rates of 73% for RP cases, and 99% for non-RP cases were obtained from ANN_1. The corresponding correct classification rates of 44% for RP cases, and 89% for non-RP cases were obtained from ANN_2. From the ANN_3 test phase, the corresponding correct classification rates of 55% for RP cases, and 95% non-RP cases were achieved. The area under ROC curve was 0.85+/-0.05, 0.68+/-0.10, and 0.81+/-0.09 for ANN_1, ANN _2, and ANN_3, respectively, within its asymmetric 95% confidence interval. The sensitivity was 95%, 57%, and 71%, and the specificity was 94%, 88%, and 90% for ANN_1, ANN_2, and ANN_3, respectively. Preliminary results suggest that the ANN approach provides a useful tool for the prediction of radiation-induced lung pneumonitis, using the patient lung dose-volume information.

A prospective study on radiation pneumonitis following conformal radiation therapy in non-small-cell lung cancer: clinical and dosimetric factors analysis

BACKGROUND AND PURPOSE

Clinical and dosimetric prognostic factors for radiation pneumonitis (RP) have been reported after three-dimensional conformal radiotherapy (3D-CRT) in patients with non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Ninety-six patients who received 3D-CRT for stage IA to IIIB NSCLC were evaluated prospectively. Surgery was performed before radiation in 51% of the patients (n = 49). RP was diagnosed six-eight weeks after 3D-CRT using the Lent-Soma classification. Factors evaluated included treatment factors such as total mean lung dose (MLD), and dose-volume histogram (DVH) thresholds for several radiation dose steps. These thresholds were originally determined from the median of the irradiated lung volume at each step.

RESULTS

Six patients could not be evaluated for RP six weeks after 3D-CRT. Of the 90 remaining patients, 40 (44%) had RP (i.e. grade > or =1) at 6 weeks, including 7 patients (7.8%) with severe RP (grade > or =2). Regarding the whole toxicity (grade > or =1), age (> or =60 years), MLD, V20 and V30 were significantly related to RP. DVH thresholds determined for radiation doses from 20 to 40 Gy were also predictive of RP. Considering only severe RP (grade > or =2), only MLD, V20 and V30 remained associated with increased acute pulmonary toxicity.

CONCLUSIONS

In this study, dosimetric factors (MLD, V20, V30) and age (> or =60 years) were predictive of RP regarding the whole pulmonary toxicity (grade > or =1). In addition, thresholds from 20 to 40 Gy, based on a stratification according to the median of the percentage of irradiated lung volume, were also predictive factors. They may, therefore, help discriminate patients at high and low risk for RP. However, only MLD, V20 and V30 remained associated with severe RP (grade > or =2), probably due to the small number of severe events in our series.

Total body irradiation and pneumonitis risk: a review of outcomes

A review was undertaken of all patients treated at Royal Adelaide Hospital, South Australia with total body irradiation (TBI) for the purpose of assessing the incidence of interstitial pneumonitis (IP) and possible prognostic factors for its development. The aim was also to assess the impact of IP and other prognostic factors on long-term survival outcome following bone marrow transplantation. A total of 84 patients received TBI, with 12 Gy in six fractions delivered using two different instantaneous dose rates of 7.5 and 15 cGy min⁻¹. This series included 26 cases of acute lymphoblastic leukaemia, 26 of multiple myeloma and 15 of acute myelogenous leukaemia. On multivariate analysis, a higher dose rate was independently significant for an increased risk of IP.

Comparing different NTCP models that predict the incidence of radiation pneumonitis. Normal tissue complication probability

PURPOSE

To compare different normal tissue complication probability (NTCP) models to predict the incidence of radiation pneumonitis on the basis of the dose distribution in the lung.

METHODS AND MATERIALS

The data from 382 breast cancer, malignant lymphoma, and inoperable non-small-cell lung cancer patients from two centers were studied. Radiation pneumonitis was scored using the Southwestern Oncology Group criteria. Dose-volume histograms of the lungs were calculated from the dose distributions that were corrected for dose per fraction effects. The dose-volume histogram of each patient was reduced to a single parameter using different local dose-effect relationships. Examples of single parameters were the mean lung dose (MLD) and the volume of lung receiving more than a threshold dose (V(Dth)). The parameters for the different NTCP models were fit to patient data using a maximum likelihood analysis.

RESULTS

The best fit resulted in a linear local dose-effect relationship, with the MLD as the resulting single parameter. The relationship between the MLD and NTCP could be described with a median toxic dose (TD(50)) of 30.8 Gy and a steepness parameter m of 0.37. The best fit for the relationship between the V(Dth) and the NTCP was obtained with a D(th) of 13 Gy. The MLD model was found to be significantly better than the V(Dth) model (p <0.03). However, for 85% of the studied patients, the difference in NTCP calculated with both models was <10%, because of the high correlation between the two parameters. For dose distributions outside the range of the studied dose-volume histograms, the difference in NTCP, using the two models could be >35%. For arbitrary dose distributions, an estimate of the uncertainty in the NTCP could be determined using the probability distribution of the parameter values of the Lyman-Kutcher-Burman model.

CONCLUSION

The maximum likelihood method revealed that the underlying local dose-effect relation for radiation pneumonitis was linear (the MLD model), rather than a step function (the V(Dth) model). Thus, for the studied patient population, the MLD was the most accurate predictor for the incidence of radiation pneumonitis.

Predictive value of dose-volume histogram parameters for predicting radiation pneumonitis after concurrent chemoradiation for lung cancer

PURPOSE

To clarify whether the percentage of pulmonary volume irradiated to >20 Gy (V20) is related to the incidence and grade of radiation pneumonitis (RP) in cases of lung cancer treated with concurrent chemoradiation.

METHODS AND MATERIALS

The subjects comprised 71 patients with lung cancer who were treated with conventionally fractionated definitive concurrent chemoradiation. The chemotherapy agents were carboplatin or cisplatin combined with taxane for most patients. Radiotherapy was delivered at 1.8-2.0 Gy fractions once daily to a total of 48-66 Gy (median 60). We analyzed the relation between RP grade and V20. Univariate and multivariate analyses were performed to assess patient- and treatment-related factors, including age, gender, smoking history, pulmonary function (forced expiratory volume in 1 s), tumor location (upper lobe vs. middle/lower lobe), chemotherapy regimen (platinum + taxane vs. other), total dose, overall radiation periods in addition to V20.

RESULTS

With a median follow-up of 7.5 months, an RP grade of 0, 1, 2, 3, and 5 was observed in 16, 35, 17, 1, and 2 patients, respectively; the corresponding mean V20 values were 20.1%, 22.0%, 26.3%, 27.0%, and 34.5%. The 6-month cumulative incidence of RP greater than Grade 2 was 8.7%, 18.3%, 51%, and 85% in patients with a V20 of <or=20%, 21-25%, 26-30%, and >or=31%, respectively (p <0.0001). According to both univariate and multivariate analyses, V20 was the only factor associated with RP of Grade 2 or greater.

CONCLUSION

The incidence and grade of RP are significantly related to the V20 value. Thus, V20 appears to be a factor that can be used to predict RP after concurrent chemoradiation for lung cancer.

Technical factors associated with radiation pneumonitis after local +/- regional radiation therapy for breast cancer

PURPOSE

To assess the incidence of, and clinical factors associated with, symptomatic radiation pneumonitis (RP) after tangential breast/chest wall irradiation with or without regional lymph node treatment.

METHODS AND MATERIALS

The records of 613 patients irradiated with tangential photon fields for breast cancer with >6 months follow-up were reviewed. Clinically significant RP was defined as the presence of new pulmonary symptoms requiring steroids. Data on clinical factors previously reported to be associated with RP were collected, e.g., tamoxifen or chemotherapy exposure and age. The central lung distance (CLD) and the average of the superior and inferior mid lung distance (ALD) in the lateral tangential field were measured on simulator films as a surrogate for irradiated lung volume. Many patients were treated with partly wide tangential fields that included a heart block shielding a part of the lower lung.

RESULTS

RP developed in 15/613 (2.4%) patients. In the univariate analysis, there was an increased incidence of RP among patients treated with local-regional radiotherapy (RT) (4.1%) vs. those receiving local RT only (0.9%) (p = 0.02), and among patients receiving chemotherapy (3.9%) vs. those not treated with chemotherapy (1.4%) (p = 0.06). According to multivariate analysis, only the use of nodal RT remained independently associated with RP (p = 0.03). There was no statistically significant association between ranked CLD or ALD measurements and RP among patients treated with nodal irradiation with tangential beams. However, there was a statistically nonsignificant trend for increasing rates of RP with grouped ALD values: below 2 cm (4% RP rate), between 2 and 3 cm (6%), and above 3 cm (14%).

CONCLUSIONS

RP was an uncommon complication, both with local and local-regional RT. The addition of regional lymph node irradiation slightly increased the incidence of RP among patients treated with the partly wide tangential field technique. Concern for RP should, however, not deter patients with node-positive breast cancer from receiving local-regional RT.

The influence of age on the delivery, tolerance, and efficacy of thoracic irradiation in the combined modality treatment of limited stage small cell lung cancer

PURPOSE

To assess the impact of age on the delivery, tolerance, and efficacy of thoracic irradiation (TI) for limited small cell lung cancer (L-SCLC).

METHODS AND MATERIALS

This is a retrospective review of data from 608 patients 80 years or less with L-SCLC, who participated in two previously reported randomized trials (BR3 and BR.6) of the National Cancer Institute of Canada. All patients received the same chemotherapy, consisting of cyclophosphamide, doxorubicin, vincristine (CAV), and etoposide cisplatin (EP) delivered either in sequential or alternating sequence. In BR.3, TI was given after chemotherapy with randomization to 25 Gy in 10 fractions or 37.5 Gy in 15 fractions. In BR.6, TI (40 Gy in 15 fractions) was given concurrently with EP with randomization to either the early (with cycle 2, week 4) or late (with cycle 6, week 16) arm.

RESULTS

A total of 665 patients entered these two trials. Of these, 608 patients were eligible for analysis, 300 in BR.3 and 308 in BR.6. Five hundred and twenty patients were under age 70 and 88 patients were 70 years or older. Baseline characteristics between the two groups were comparable. In BR3, 179 patients (60%) participated in radiotherapy randomization (61% young, 52% elderly), and 176 patients actually received TI. In BR.6, randomization occurred at study entry for all patients, and 282 (91.6%) patients received TI (92% young, 88% elderly). More patients of both age groups randomized to receive late TI did not receive TI (13% and 14%) than those randomized to the early TI arm (3%) of BR.6. We could identify no tendency to reduce field sizes to minimize toxicity in either age group at higher doses of TI. Once TI was started, there was no difference between the two age groups with regards to the proportion of patients who completed TI, although elderly patients were less likely to complete high dose TI. Of those who completed TI, there was no difference in the time to complete TI, mean dose delivered or in the incidence of acute and late TI-related toxicities. No statistical difference in response rate, local relapse rate, or overall survival was seen between young and older age groups.

CONCLUSION

In summary, in the dose range examined, age does not appear to impact on the delivery, tolerance or efficacy of TI in the combined modality management of L-SCLC. Potentially curative combined modality treatment should not be withheld on the basis of age.

Radiation pneumonitis as a function of mean lung dose: an analysis of pooled data of 540 patients

PURPOSE

To determine the relation between the incidence of radiation pneumonitis and the three-dimensional dose distribution in the lung.

METHODS AND MATERIALS

In five institutions, the incidence of radiation pneumonitis was evaluated in 540 patients. The patients were divided into two groups: a Lung group, consisting of 399 patients with lung cancer and 1 esophagus cancer patient and a Lymph./Breast group with 78 patients treated for malignant lymphoma, 59 for breast cancer, and 3 for other tumor types. The dose per fraction varied between 1.0 and 2.7 Gy and the prescribed total dose between 20 and 92 Gy. Three-dimensional dose calculations were performed with tissue density inhomogeneity correction. The physical dose distribution was converted into the biologically equivalent dose distribution given in fractions of 2 Gy, the normalized total dose (NTD) distribution, by using the linear quadratic model with an alpha/beta ratio of 2.5 and 3.0 Gy. Dose-volume histograms (DVHs) were calculated considering both lungs as one organ and from these DVHs the mean (biological) lung dose, NTDmean, was obtained. Radiation pneumonitis was scored as a complication when the pneumonitis grade was grade 2 (steroids needed for medical treatment) or higher. For statistical analysis the conventional normal tissue complication probability (NTCP) model of Lyman (with n=1) was applied along with an institutional-dependent offset parameter to account for systematic differences in scoring patients at different institutions.

RESULTS

The mean lung dose, NTDmean, ranged from 0 to 34 Gy and 73 of the 540 patients experienced pneumonitis, grade 2 or higher. In all centers, an increasing pneumonitis rate was observed with increasing NTDmean. The data were fitted to the Lyman model with NTD50=31.8 Gy and m=0.43, assuming that for all patients the same parameter values could be used. However, in the low dose range at an NTDmean between 4 and 16 Gy, the observed pneumonitis incidence in the Lung group (10%) was significantly (p=0.02) higher than in the Lymph./Breast group (1.4%). Moreover, between the Lung groups of different institutions, also significant (p=0.04) differences were present: for centers 2, 3, and 4, the pneumonitis incidence was about 13%, whereas for center 5 only 3%. Explicitly accounting for these differences by adding center-dependent offset values for the Lung group, improved the data fit significantly (p < 10(-5)) with NTD50=30.5+/-1.4 Gy and m=0.30+/-0.02 (+/-1 SE) for all patients, and an offset of 0-11% for the Lung group, depending on the center.

CONCLUSIONS

The mean lung dose, NTDmean, is relatively easy to calculate, and is a useful predictor of the risk of radiation pneumonitis. The observed dose-effect relation between the NTDmean and the incidence of radiation pneumonitis, based on a large clinical data set, might be of value in dose-escalating studies for lung cancer. The validity of the obtained dose-effect relation will have to be tested in future studies, regarding the influence of confounding factors and dose distributions different from the ones in this study.

Clinical radiation pneumonitis and radiographic changes after thoracic radiation therapy for lung carcinoma

BACKGROUND

The authors attempted to determine the incidence of and risk factors for clinical radiation pneumonitis in patients treated for lung carcinoma. They also sought to describe the corresponding posttreatment radiographic changes.

METHODS

Between 1989-1993, 83 patients received curative radiation therapy for lung carcinoma. Of these, 39 patients were treated with definitive radiation therapy, and 44 patients were treated with adjuvant radiation therapy after surgical resection. The median radiation therapy dose was 54 gray (Gy), and the median treatment area was 182 cm2. Chest radiographs obtained after radiation therapy were reviewed and scored for margin definition, volume loss, and texture quality.

RESULTS

A total of 17 patients (20%) developed clinical radiation pneumonitis (CRP). The median radiation therapy dose for the CRP cohort was 54 Gy, and the median treatment volume was 193 cm2. The median time to onset of symptoms was 3 weeks after radiation therapy, and the median duration of symptoms was 10 weeks. Of the 15 evaluable patients, symptoms resolved for 9 patients, improved but persisted for 4 patients, and CRP was fatal for 2 patients. The incidence of CRP was increased for patients with low performance status, comorbid lung disease, smoking history, low pulmonary function tests, and for those patients who did not undergo a surgical resection. Posttreatment radiographic changes were common and progressed with time. Radiographic changes were more pronounced in the CRP cohort, and extended outside the radiation therapy treatment field in the majority of patients (67%).

CONCLUSIONS

Clinical radiation pneumonitis developed in 20% of lung carcinoma patients. Risk factors included low performance status, comorbid lung disease, smoking history, low pulmonary function tests, and the absence of a surgical resection. Posttreatment radiograph changes were common and progressed with time, and typically were not confined to the radiation therapy treatment field.

[Pneumonitis after radiotherapy of bronchial carcinoma: incidence and influencing factors]

BACKGROUND

The most important side effect in radiotherapy of lung cancer is pneumonitis. The incidence of pneumonitis was evaluated in a retrospective study in the patient collective of the University of Heidelberg. Therapy related and therapy independent factors have been evaluated.

PATIENTS AND METHODS

In 348 of 392 cases with lung cancer who were treated by local irradiation between January 1989 and January 1992 the patient's records were evaluable for response and toxicity. All patients were treated by megavolt equipment with a conventional fractionation in most cases. Standard target volumes were irradiated including the lymphatic drainage. From a dose of above 30 Gy a technique sparing the spinal cord was chosen. Retrospectively pneumonitis was classified into 4 grades starting from slight symptoms to respiratory insufficiency requiring O2. Grade I and II were summarized to slight, grade III and IV to severe pneumonitis.

RESULTS

Regarding the treatment prior to irradiation patients with primary irradiation were affected in 26.5% (17% slight, 9.5% severe), with postoperative irradiation in 14% (9.3% slight, 4.7% severe), with radiochemotherapy of small cell lung cancer (SCLC) in 15.4% (12% slight, 3.4% severe) by this side effect. These differences were not significant (p = 0.32). The median onset of pneumonitis was 31 days after end of irradiation (severe 23 days, slight 44 days, p = 0.026). By a univariate analysis the total dose at the prescription point was the most important factor (30 to 50.5 Gy 11%, 52 to 59 Gy 15%, 60 to 74 Gy 26%, p = 0.007). High single doses (2.5 Gy) were only applied within a study of radiochemotherapy with a randomised sequential and alternating schedule. So that the increased rate of pneumonitis (42%) is not clearly separable from other influencing variables. A correlation between the applied techniques and the irradiated volume (measured by planimetric methods) was not demonstrable. Regarding the independent factors a high age, female sex and a low FeV1 were unfavourable. However, age and sex corrected FeV1 was not predictive.

CONCLUSIONS

The observed incidence is within the range of literature. By a clinical point of view the total dose is an obvious factor. Also single doses above 2 Gy have to be seen critically (a total dose of 50 Gy). The results confirm the fact that patients with a low FeV1 are not suitable to a high dose irradiation of the chest. In this connection old patients and women also should be seen as patients at risk.

[Influence of reduction of radiation dosage on the incidence of radiation-induced pneumonitis, pulmonary fibrosis and pericarditis after mediastinal irradiation in the treatment of lymphogranulomatosis]

BACKGROUND

The amount of radiation dose applied in the treatment of Hodgkin's disease is associated with the incidence of complications including radiation-induced pneumonitis, lung fibrosis and pericarditis. Therefore, from the beginning of 1986, we have started to apply a radiation therapy approach with reduced doses in order to minimize complications while maintaining effective treatment.

PATIENTS AND METHOD

From 1983 through 1992 141 patients suffering from Hodgkin's disease were included in the present study. All of them were treated by radiation of mediastinum. In 126 cases polychemotherapy was applied before radiation. From 1986 we used a reduced radiation dose in cases that were treated by radiation alone (affected nodal regions with 40 Gy instead of 45 Gy and unaffected nodal regions with 36 Gy instead of 40 Gy) as well as after application of chemotherapy (affected nodal regions 36 Gy instead of 40 Gy and unaffected nodal regions with 30 Gy instead of 36 Gy). Ninety-five patients were treated according to the new therapy protocol. Forty-six patients had been treated with the higher dosages and served as the historical control group. Radiation therapy included Co-60, 15-MV and 9-MV photons, and 15-MeV and 9-MeV electrons. Serial thoracic X-ray controls were performed. CT scans, echocardiographic and electrocardiographic investigations were added in selected cases.

RESULTS

During the period from 1983 to 1992, we diagnosed radiation-induced pneumonitis in 31% of the patients who underwent radiation therapy of the mediastinum. In addition, 16% demonstrated lung fibrosis and 10% pericarditis. After implementation of the reduced radiation dosages, the incidence of pneumonitis decreased from 35% to 24% (nearly significant in the 5% range), lung fibrosis from 24% to 12% (p < 0.05) and pericarditis from 26% to 2% (p < 0.01). The efficacy of treatment remained unaffected by the new therapy approach as has been demonstrated for cumulative survival data and recurrence-free intervals.

CONCLUSIONS

Reduction of radiation dose in patients with Hodgkin's disease who undergo mediastinal radiation leads to a decrease in the incidence of radiation-induced complications (pneumonitis, lung fibrosis, pericarditis) whereas treatment efficacy remains unchanged.

Clinical evaluation of the partition model for estimating radiation doses from yttrium-90 microspheres in the treatment of hepatic cancer

Radiation doses to the tumour and non-tumorous liver compartments from yttrium-90 microspheres in the treatment of hepatic cancer, as estimated by a partition model, have been verified by correlation with the actual doses measured with a beta probe at open surgery. The validity of the doses to the lungs, the tumour and non-tumorous liver compartment as estimated by the partition model was further evaluated in clinical settings. On the basis of the observation that one of three patients who received more than 30 Gy from a single treatment and one of two patients who received more than 50 Gy from multiple treatments developed radiation pneumonitis, it was deduced that an estimated lung dose < 30 Gy from a single treatment and a cumulative lung dose < 50 Gy from multiple treatments were probably the tolerance limits of the lungs. Three of five patients who received lung doses > 30 Gy as estimated by the partition model and were predicted to develop radiation pneumonitis, did so despite the use of partial hepatic embolization to reduce the degree of lung shunting. Furthermore, a higher radiological response rate and prolonged survival were found in the group of patients who received higher tumour doses, as estimated by the partition model, than in the group with lower estimated tumour doses. Thus the radiation doses estimated by the partition model can be used to predict (a) complication rate, (b) response rate and (c) duration of survival in the same manner as the actual radiation doses measured with a beta probe at open surgery. The partition model has made selective internal radiation therapy using 90Y microspheres safe and repeatable without laparotomy.

Efficacy and toxicity of radiation in preparative regimens for pediatric stem cell transplantation. II: Deleterious consequences

There has been a dramatic improvement in the treatment of both allogeneic and autologous stem cell transplants, especially in children and young adults. However, attempts to apply more intensive conditioning treatments to the more refractory pediatric malignancies have also increased the risks of deleterious consequences. This review examines the risks, and reports important variations in the toxic effects of using different conditioning techniques.

Radiation pneumonitis following combined modality therapy for lung cancer: analysis of prognostic factors

PURPOSE

To identify factors associated with radiation pneumonitis (RP) resulting from combined modality therapy (CMT) for lung cancer.

MATERIALS AND METHODS

Series published before 1994 that used CMT for the treatment of lung cancer and explicitly reported the incidence of RP are the basis for this analysis. Factors evaluated included the radiation dose per fraction (Fx), total radiation dose, fractionation scheme (split v continuous), type of chemotherapy and intended dose-intensity, overall treatment time, histology (small-cell lung cancer [SCLC] v non-small-cell lung cancer [NSCLC]), and treatment schedule (concurrent v induction, sequential, or alternating CMT).

RESULTS

Twenty-four series, including 27 treatment groups and 1,911 assessable patients, met our criteria for inclusion in this analysis. The median total dose of radiation used in the trials analyzed was 50 Gy (range, 25 to 63 Gy). The median daily Fx used was 2.0 Gy (range, 1.5 to 4.0 Gy). Nineteen series included 22 treatment groups and 1,745 patients treated with single daily fractions. Among these patients, 136 received a daily Fx greater than 2.67 Gy. Five series used twice-daily radiotherapy and included 166 patients (Fx, 1.5 to 1.7 Gy). The incidence of RP was 7.8%. In a multivariate analysis, only daily Fx, number of daily fractions, and total dose were associated with the risk of RP (P < .0001, P < .018, and P < .003, respectively).

CONCLUSION

In this analysis, the use of Fx greater than 2.67 Gy was the most significant factor associated with an increased risk of RP. High total dose also appears to be associated with an increased risk, but twice-daily irradiation seems to reduce the risk expected if the same total daily dose is given as a single fraction. High-Fx radiotherapy should be avoided in patients who receive CMT with curative intent.

Radiation and the lung: a reevaluation of the mechanisms mediating pulmonary injury

Recent data from several investigators, including our unit, have provided additional information on the etiology of radiation-induced lung damage. These data suggest that there are two quite separate and distinct mechanisms involved: (a) classical radiation pneumonitis, which ultimately leads to pulmonary fibrosis is primarily due to radiation-induced local cytokine production confined to the field of irradiation; and (b) sporadic radiation pneumonitis, which is an immunologically mediated process resulting in a bilateral lymphocytic alveolitis that results in an "out-of-field" response to localized pulmonary irradiation. Both animal experiments and human studies show that classical radiation pneumonitis has a threshold dose and a narrow sigmoid dose-response curve with increasing morbidity and mortality over a very small dose range. Clinical pneumonitis rarely causes death, whereas in the animal and human studies of classical radiation pneumonitis, all subjects will eventually suffer irreversible pulmonary damage and death. The description of classical radiation pneumonitis is that of an acute inflammatory response to lung irradiation, which is confined to the area of irradiation. Recent studies have also shown that irradiation induces gene transcription and results in the induction and release of proinflammatory cytokines and fibroblast mitogens in a similar fashion to other chronic inflammatory states, and which ultimately results in pulmonary fibrosis. The description of classical radiation pneumonitis does not adequately explain the following observed clinical characteristics: (a) the unpredictable and sporadic onset; (b) the occurrence in only a minority of patients; (c) the dyspnoea experienced, which is out of proportion to the volume of lung irradiated; and (d) the resolution of symptoms without sequelae in the majority of patients. We have demonstrated a bilateral lymphocytic alveolitis of activated T lymphocytes and a diffuse increase in gallium lung scan uptake in patients studied before and 4 to 6 weeks after strictly unilateral lung irradiation. This is suggestive of a hypersensitivity pneumonitis, which gives rise to an "out-of-field" response to localized lung irradiation and hence more accurately describes the clinical picture of radiation pneumonitis. Reevaluation of the mechanisms of pulmonary injury from irradiation suggest that (a) a new term, sporadic radiation pneumonitis, should be introduced to describe the clinical picture of radiation pneumonitis, which is not adequately explained by the classical description and is quite clearly an entirely different process; and (b) that the chronic response to localized lung irradiation that leads to pulmonary fibrosis is largely mediated through the induction and release of tissues cytokines.

[Radiation pneumonitis and pulmonary fibrosis after the CT-planned radiotherapy of bronchial carcinoma]

PURPOSE

Examination of the influence of total tumor dose, additional therapy and age on the development of radiation pneumonitis and lung fibrosis.

PATIENTS AND METHODS

Two hundred and sixteen patients with squamous cell carcinoma of the lung were examined retrospectively. Hundred and eighty-three of them received a percutaneous radiation therapy of the primary tumor and the mediastinal and ipsilateral hilar lymph nodes. The majority of 130 patients was given radiotherapy as only treatment, 27 were irradiated after resection and 26 received chemo- and radiotherapy. Treatment volume was determined by three-dimensional planning using chest CT-scan. The irradiation was administered in a first series of 56 Gy and a following boost to the primary and involved lymph nodes to a total dose of 70 Gy. There was one daily irradiation with 2 Gy 5 days a week. Post-resectional radiation encompassed the bronchus stump and the mediastinum with a total dose of about 60 Gy.

RESULTS

Sixty-eight of the 183 irradiated patients developed a pneumonitis (37.2%) and 60 a lung fibrosis (32.8%). The most important factor was the administered total irradiation dose (p < 0.001). There was no pneumonitis documented below 36 Gy and no fibrosis below 40 Gy. An additional chemotherapy did not increase the incidence (pneumonitis after radiotherapy 35.4%, after radio- and chemotherapy 34.6%; fibrosis after radiotherapy 33.9%, after radio- and chemotherapy 38.5%). Particularly high was the incidence of pneumonitis when radiotherapy followed resection (48.2%) while the rate of fibrosis in this group of patients was relatively low (22.2%). Age of patients did not affect the frequency of pneumonitis while fibrosis significantly occurred more often with increasing age (p = 0.037).

CONCLUSION

The total dose affecting the normal lung tissue is the most important factor for the development of radiation pneumonitis and lung fibrosis. It is recommended to keep the treatment volume appropriate to the individual extend of tumor. Good results are achieved with a computer supported CT-planning which helps to gain minimal burdening of normal tissue.

Dose-volume histogram and 3-D treatment planning evaluation of patients with pneumonitis

PURPOSE

Tolerance of normal lung to inhomogeneous irradiation of partial volumes is not well understood. This retrospective study analyzes three-dimensional (3-D) dose distributions and dose-volume histograms for 63 patients who have had normal lung irradiated in two types of treatment situations.

METHODS AND MATERIALS

3-D treatment plans were examined for 21 patients with Hodgkin's disease and 42 patients with nonsmall-cell lung cancer. All patients were treated with conventional fractionation, with a dose of 67 Gy (corrected) or higher for the lung cancer patients. A normal tissue complication probability description and a dose-volume histogram reduction scheme were used to assess the data. Mean dose to lung was also calculated.

RESULTS

Five Hodgkin's disease patients and nine lung cancer patients developed pneumonitis. Data were analyzed for each individual independent lung and for the total lung tissue (lung as a paired organ). Comparisons of averages of mean lung dose and normal tissue complication probabilities show a difference between patients with and without complications. Averages of calculated normal tissue complication probabilities for groups of patients show that empirical model parameters correlate with actual complication rates for the Hodgkin's patients, but not as well for the individual lungs of the lung cancer patients treated to larger volumes of normal lung and high doses.

CONCLUSION

This retrospective study of the 3-D dose distributions for normal lung for two types of treatment situations for patients with irradiated normal lung gives useful data for the characterization of the dose-volume relationship and the development of pneumonitis. These data can be used to help set up a dose escalation protocol for the treatment of nonsmall-cell lung cancer.

Quantitative effect of combined chemotherapy and fractionated radiotherapy on the incidence of radiation-induced lung damage: a prospective clinical study

PURPOSE

The objective of this work was to assess the incidence of radiological changes compatible with radiation-induced lung damage as determined by computed tomography (CT), and subsequently calculate the dose effect factors (DEF) for specified chemotherapeutic regimens.

METHODS AND MATERIALS

A prospective, clinical study was conducted to determine the response of normal lung tissue to combined chemotherapy and radiotherapy. Radiation treatments were administered once daily, 5 days-per-week. Six clinical protocols were evaluated: ABVD (adriamycin, bleomycin, vincristine, and DTIC) followed by 35 Gy in 20 fractions; MOPP (nitrogen mustard, vincristine, procarbazine, and prednisone) followed by 35 Gy in 20; MOPP/ABVD followed by 35 Gy in 20; CAV (cyclophosphamide, adriamycin, and vincristine) followed by 25 Gy in 10; and 5-FU (5-fluorouracil) concurrent with either 50-52 Gy in 20-21 or 30-36 Gy in 10-15 fractions. CT examinations were taken before and at predetermined intervals following radiotherapy. CT evidence for the development of radiation-induced damage was defined as an increase in lung density within the irradiated volume. The radiation dose to lung was calculated using a CT-based algorithm to account for tissue inhomogeneities. Different fractionation schedules were converted using two isoeffect models, the estimated single dose (ED) and the normalized total dose (NTD).

RESULTS

A total of 102 patients were entered and 70 completed the study. Forty-two patients developed CT changes compatible with lung damage. The actuarial incidence of radiological pneumonitis was 71% for the ABVD, 49% for MOPP, 52% for MOPP/ABVD, 67% for CAV, 73% for 5-FU radical, and 58% for 5-FU palliative protocols. Depending on the isoeffect model selected and the method of analysis, the DEF was 1.11-1.14 for the ABVD, 0.96-0.97 for the MOPP, 0.96-1.02 for the MOPP/ABVD, 1.03-1.10 for the CAV, 0.74-0.79 for the 5-FU radical, and 0.94 for the 5-FU palliative protocols.

CONCLUSION

Quantitative dose effect factors (DEF) were measured by comparing the incidences of CT-observed lung damage in patients receiving chemotherapy and radiotherapy to those receiving radiotherapy alone. The addition of ABVD or CAV appeared to reduce the tolerance of lung to radiation.