Prospective study of long-term pulmonary manifestations of mantle irradiation

Late effects in survivors treated for lymphoma as adolescents and young adults: a population-based analysis

PURPOSE

The study objective is to describe and quantify the incidence of treatment-induced late effects in AYA lymphoma patients.

METHODS

Consecutive patients diagnosed with Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL) at 15-24 years of age were identified. All patients in British Columbia who received radiation therapy (RT) from 1974 to 2014 with ≥ 5-year survival post-RT were included. Late effects' analyses included only survivors who received RT to the relevant anatomical site(s) and/or relevant chemotherapy, and were reported as cumulative incidence (CI) ± standard error.

RESULTS

Three hundred and five patients were identified (74% HL). Median age of diagnosis was 21 years. Median follow-up was 19.1 years for secondary malignancy and 7.2 years for other endpoints. Hypothyroidism was the most prevalent late effect, with a CI of 22.4 ± 2.8% and 35.1 ± 4% at 5 and 10 years, respectively. CI of in-field secondary malignancy was 0.4 ± 0.4% at 10 years and 2.8 ± 1.2% at 20 years. CI of symptomatic pulmonary toxicity was 4.6 ± 1.5% and 6.8 ± 2.0% at 5 and 10 years, respectively, and was higher in patients receiving multiple RT courses (p = 0.009). Esophageal complications occurred at a CI of 1.4 ± 0.8% at 5 years and 2.2 ± 1.1% at 10 years. CI of xerostomia/dental decay was 2.6 ± 1.3% at 5 years and 4.9 ± 2.1% at 10 years. CI of cardiac disease was at 2.3 ± 0.9% at 5 years and 4.4 ± 1.5% at 10 years. CI of infertility was 6.5 ± 1.6% at 5 years and 9.4 ± 2.1% at 10 years.

CONCLUSION

Survivors of AYA lymphoma have a high incidence and diverse presentation of late effects.

IMPLICATIONS FOR CANCER SURVIVORS

AYA lymphoma survivors should be educated about their risks of late effects and offered screening and follow-up when appropriate.

18F-FDG PET/CT in Patients with Parenchymal Changes Attributed to Radiation Pneumonitis

Objectives:

Radiation pneumonitis (RP) can be an adverse complication of radiotherapy (RT) and can limit the application of the already planned radiation dose. It is often associated with RT of lung carcinoma and is occasionally caused by radiation therapy of breast carcinoma and lymphomas located in the mediastinum. Positron emission tomography/computed tomography (PET/CT) emerges lately as a prospective modality for early diagnostics of RP. The aim of this study was to summarize the initial data from diagnostic application of PET/CT in patients suspicious of RP and to derive criteria, which can help differentiate RP from early recurrence of the disease and/or residual tumor.

Methods:

The current study included 23 patients who had metabolic (PET) and anatomical (CT) changes consistent with RP. We additionally defined metabolic activity (SUV_max) in the lung parenchyma of 20 patients without RT.

Results:

All patients had increased metabolic activity in the lung parenchyma involved in the irradiated area with a mean SUV_max 3.45 (ranging between 1 and 7.1). The control group had a physiological background metabolic activity-SUV_max 0.61 +/- 0.11.

Conclusion:

Metabolic changes in patients suspicious of RP involved diffusely increased metabolic activity coinciding with the anatomical changes in the irradiated area. Three out of 23 patients had a proven recurrence of the primary neoplastic process in the irradiated area. The metabolic changes in those patients involved an increase in metabolic activity at follow-up or lack of tendency towards normalization after chemotherapy, which implied the existence of viable tumor cells. Our initial experience in the diagnostic application of ¹⁸F-FDG PET/CT in patients suspicious of RP allows us to summarize the following: PET/CT is a reliable imaging modality in the diagnostics of RP. Through its sequential use, we can differentiate inflammatory changes related to RP from early recurrence of the primary neoplastic process.

To Find a Better Dosimetric Parameter in the Predicting of Radiation-Induced Lung Toxicity Individually: Ventilation, Perfusion or CT based

This study aimed to find a better dosimetric parameter in predicting of radiation-induced lung toxicity (RILT) in patients with non-small cell lung cancer (NSCLC) individually: ventilation(V), perfusion (Q) or computerized tomography (CT) based. V/Q single-photon emission computerized tomography (SPECT) was performed within 1 week prior to radiotherapy (RT). All V/Q imaging data was integrated into RT planning system, generating functional parameters based on V/Q SPECT. Fifty-seven NSCLC patients were enrolled in this prospective study. Fifteen (26.3%) patients underwent grade ≥2 RILT, the remaining forty-two (73.7%) patients didn’t. Q-MLD, Q-V20, V-MLD, V-V20 of functional parameters correlated more significantly with the occurrence of RILT compared to V20, MLD of anatomical parameters (r = 0.630; r = 0.644; r = 0.617; r = 0.651 vs. r = 0.424; r = 0.520 p < 0.05, respectively). In patients with chronic obstructive pulmonary diseases (COPD), V functional parameters reflected significant advantage in predicting RILT; while in patients without COPD, Q functional parameters reflected significant advantage. Analogous results were existed in fractimal analysis of global pulmonary function test (PFT). In patients with central-type NSCLC, V parameters were better than Q parameters; while in patients with peripheral-type NSCLC, the results were inverse. Therefore, this study demonstrated that choosing a suitable dosimetric parameter individually can help us predict RILT accurately.

Pulmonary System

Pulmonary disease is a highly prevalent cause of premature morbidity and mortality in long-term childhood cancer survivors. Pulmonary toxicity is frequently reported in survivors of Hodgkin lymphoma, germ cell tumors, acute lymphoblastic lymphoma and metastatic Wilms tumor survivors, as the chemotherapy, radiation and surgeries used to treat these pediatric cancer (among others) can result in permanent lung damage. This damage can manifest as acute pneumonitis, late onset fibrosis, and structurally induced dysfunction from developmental abnormalities due to impaired growth of the thorax attributable to surgery or radiation. The cumulative incidence of pulmonary problems after childhood cancer increases with time since diagnosis, as with other late-effects, suggesting that survivors are at an elevated risk of developing later-onset pulmonary morbidities as they age.

Pulmonary outcomes in survivors of childhood cancer: a systematic review

BACKGROUND

The purpose of this article is to summarize the literature that documents the long-term impact of cancer treatment modalities on pulmonary function among survivors of cancer and to identify potential areas for further research.

METHODS

Systematic reviews of clinical trials, observational studies, case series, and review articles were conducted. Articles were limited to the studies that discussed pulmonary toxicity or late effects among pediatric cancer survivors and to follow-up investigations that were conducted a minimum of 2 years after completion of cancer-related treatment or 1 year after hematopoietic stem cell transplant.

RESULTS

Sixty publications (51 clinical studies/reports and nine reviews) published from January 1970 to June 2010 in PubMed met the inclusion criteria. Data showed an association between radiotherapy, alkylating agents, bleomycin, hematopoietic stem cell transplant, and thoracic surgery and pulmonary toxicity, as well as possible interactions among these modalities.

CONCLUSIONS

Pulmonary toxicity is a common long-term complication of exposure to certain anticancer therapies in childhood and can vary from subclinical to life threatening. Pulmonary function and associated loss of optimal exercise capacity may have adverse effects on long-term quality of life in survivors. Lung function diminishes as a function of normal aging, and the effects of early lung injury from cancer therapy may compound these changes. The information presented in this review is designed to provide a stimulus to promote both observational and interventional research that expands our knowledge and aids in the design of interventions to prevent or ameliorate pulmonary late effects among survivors of childhood cancer.

Classical Hodgkin's lymphoma in adults: guidelines of the Italian Society of Hematology, the Italian Society of Experimental Hematology, and the Italian Group for Bone Marrow Transplantation on initial work-up, management, and follow-up

The Italian Society of Hematology (SIE), the Italian Society of Experimental Haematology (SIES) and the Italian Group for Bone Marrow Transplantation (GITMO) commissioned a project to develop practice guidelines for the initial work-up, therapy and follow-up of classical Hodgkin's lymphoma. Key questions to the clinical evaluation and treatment of this disease were formulated by an Advisory Committee, discussed and approved by an Expert Panel (EP) composed of senior hematologists and one radiotherapist. After a comprehensive and systematic literature review, the EP recommendations were graded according to their supporting evidence. An explicit approach to consensus methodologies was used for evidence interpretation and for producing recommendations in the absence of a strong evidence. The EP decided that the target domain of the guidelines should include only classical Hodgkin's lymphoma, as defined by the WHO classification, and exclude lymphocyte predominant histology. Distinct recommendations were produced for initial work-up, first-line therapy of early and advanced stage disease, monitoring procedures and salvage therapy, including hemopoietic stem cell transplant. Separate recommendations were formulated for elderly patients. Pre-treatment volumetric CT scan of the neck, thorax, abdomen, and pelvis is mandatory, while FDG-PET is recommended. As to the therapy of early stage disease, a combined modality approach is still recommended with ABVD followed by involved-field radiotherapy; the number of courses of ABVD will depend on the patient risk category (favorable or unfavorable). Full-term chemotherapy with ABVD is recommended in advanced stage disease; adjuvant radiotherapy in patients without initial bulk who achieved a complete remission is not recommended. In the elderly, chemotherapy regimens more intensive than ABVD are not recommended. Early evaluation of response with FDG-PET scan is suggested. Relapsed or refractory patients should receive high-dose chemotherapy and autologous hemopoietic stem cells transplant. Allogeneic transplant is recommended in patients relapsing after autologous transplant. All fertile patients should be informed of the possible effects of therapy on gonadal function and fertility preservation measures should be taken before the initiation of therapy.

Long-term pulmonary function in survivors of childhood Hodgkin disease and non-Hodgkin lymphoma

BACKGROUND

The aim of our study was to evaluate the long-term effects of chemotherapy and/or radiotherapy on lung function in 75 childhood Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL) survivors several years after treatment.

PATIENTS AND METHODS

We studied 37 HD and 38 NHL survivors. These patients were divided into two groups according to the treatment protocols applied. Group I consisted of 23 patients who were treated with both chemotherapy and thoracic irradiation and Group II consisted of 52 patients who were treated with chemotherapy and no thoracic irradiation. A detailed history of smoking habits, respiratory symptoms, and diseases was recorded. Complete physical examinations and pulmonary function tests [PFT, including spirometry, lung volume, and diffusion capacity for carbon monoxide (DLCO)] were performed on all subjects.

RESULTS

No patients reported acute or chronic respiratory symptoms or diseases. Pulmonary function abnormality (reduced lung volume and diffusion capacity) was found in 13% of patients at a median 5 years after diagnosis. The percentage of predicted normal value of forced expiratory volume in the 1st sec (FEV(1)), residual volume (RV), and DLCO were significantly lower in Group I than these values for Group II. There were no significant differences in PFT parameters between patients with HD and NHL (P > 0.05). It appears that the risk of reduced lung function was greater the younger the patient in therapy.

CONCLUSION

Chemotherapy or chemo-radiotherapy-induced pulmonary sequalae in childhood may remain asymptomatic for many years.

Long-term Events in Adult Patients with Clinical Stage IA-IIA Nonbulky Hodgkin's Lymphoma Treated with Four Cycles of Doxorubicin, Bleomycin, Vinblastine, and Dacarbazine and Adjuvant Radiotherapy: A Single-Institution 15-Year Follow-up

PURPOSE

To report on long-term events after short doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) chemotherapy and adjuvant radiotherapy in favorable early-stage Hodgkin's lymphoma.

EXPERIMENTAL DESIGN

We monitored late events and causes of death over 15 years (median follow-up, 120 months) in 120 patients with nonbulky stage IA-IIA Hodgkin's lymphoma, treated with four cycles of ABVD and limited radiotherapy. Pulmonary and cardiac function tests were done throughout the follow-up. Outcome measures included cause-specific mortality, standardized mortality ratio, and standardized incidence ratio for secondary neoplasia.

RESULTS

Projected 15-year event-free and overall survival were 78% and 86%, and tumor mortality was 3%. Standardized mortality ratio was significantly higher than 1 for both males (2.8; P=0.029) and females (9.4; P=0.003). The risk of cardiovascular events at 5 and 12 years was 5.5% and 14%, with a median latent time of 67 months (range: 23-179 months) from the end of radiotherapy. Pulmonary toxicity developed in 8% of patients; all had received mediastinal irradiation and the median time from radiotherapy to pulmonary sequelae was 76 weeks (range: 50-123 weeks). The risk of secondary neoplasia at 5 and 12 years was 4% and 8%, respectively, with no cases of leukemia. Fertility was preserved.

CONCLUSIONS

Long-term events were mostly related to radiotherapy; the role of short ABVD chemotherapy was very limited, as documented by fertility preservation and lack of secondary myelodysplasia/leukemia. A proportion of patients died from causes unrelated to disease progression and the excess mortality risk was mostly due to the occurrence of secondary neoplasms and cardiovascular diseases. A moderate dose reduction of radiotherapy from 40-44 Gy to 30-36 Gy did not decrease the risk of late complications; abolishing radiotherapy in nonbulky early-stage Hodgkin's lymphoma is being evaluated.

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.

Prevention of radiation-induced pneumonitis by recombinant adenovirus-mediated transferring of soluble TGF-β type II receptor gene

To investigate whether radiation-induced pneumonitis in the mouse-irradiated lung could be prevented by recombinant adenovirus-mediated soluble transforming growth factor-beta (TGF-beta) type II receptor gene therapy. Radiation fibrosis-prone mice (C57BL/6J) were randomly divided into four groups consisting of a (1) control group (sham-irradiated); (2) radiation (RT)-alone group; (3) RT+AdCMVsTbetaR group and (4) RT+AdCMVluc group. The RT-alone and sham-irradiated mice were killed at several time points after thoracic irradiation with a single dose of 9 Gy, and then the TGF-beta1 concentrations in serum and broncho-alveolar lavage fluid (BALF) were quantified by enzyme-linked immunosorbent assay (ELISA). We used an adenoviral vector expressing a soluble TGF-beta type II receptor (AdCMVsTbetaR), which can bind to TGF-beta and then block the TGF-beta receptor-mediated signal transduction. The C57BL/6J mice were intraperitoneally (i.p.) injected with either 5 x 10(8) plaque-forming units of AdCMVsTbetaR or AdCMVluc, a control adenovirus-expressing luciferase, a week preceding and a week following the X-ray thoracic irradiation. Four weeks after irradiation, the mice were killed and the concentration of TGF-beta1 in the serum and BALF were then measured using ELISA and the lung tissue specimens were examined histopathologically. Following thoracic irradiation with a single dose of 9 Gy, radiation-induced TGF-beta1 release in the serum reached the first peak concentration at 12 h and then declined. It reached a maximal value at 2 weeks after irradiation. In the BALF, the TGF-beta1 concentration was appreciable within the first hour and thereafter declined. It reached a maximal value at 3 days after irradiation. A one-time i.p. injection of AdCMVsTbetaR 1 week before irradiation could not completely suppress the two peaks of the radiation-induced TGF-beta1 increase, whereas an injection a week preceding and a week following thoracic irradiation was able to suppress those two peaks thoroughly. The TGF-beta1 was completely suppressed in the AdCMVsTbetaR-treated mouse serum and BALF; however, no statistical difference was observed in the serum and BALF between the AdCMVluc-infected mice and the control mice at 4 weeks after irradiation (P < 0.05). A histopathological examination showed only mild radiation pneumonitis in the irradiated lungs of AdCMVsTbetaR-treated mice in comparison to the AdCMVluc-infected and RT-alone mice. Our results demonstrated that TGF-beta1 plays an important role in radiation pneumonitis, thus suggesting that the adenovirus-mediated overexpression in soluble TGF-beta type II receptor gene therapy may be a potentially feasible and effective strategy for the prevention of radiation pneumonitis.

Interstitial lung disease in lung cancer: separating disease progression from treatment effects

Lung cancer often develops in individuals with pre-existing pulmonary and cardiac pathology. Many of these individuals with pre-existing pathology are also at risk of occupational lung disease. New and worsening symptoms can be secondary to pre-existing pathology, progressive cancer or treatment. Pulmonary toxicity, including interstitial lung disease, following radiotherapy and conventional cytotoxic chemotherapy (e.g. cyclophosphamide, bleomycin), has been recognised for many years. Pulmonary toxicity also occurs with the newer classes of cytotoxic agents, including the deoxycytidine analogue gemcitabine. A small percentage (0.88%) of patients treated with the epidermal growth factor receptor tyrosine kinase inhibitor gefitinib have developed interstitial lung disease. This complication has been reported at a higher frequency in Japanese patients than in US patients (1.9% vs 0.34%, respectively) and in those with pre-existing pulmonary fibrosis. This review discusses the difficulties in both recognition and treatment of gefitinib-associated interstitial lung disease. Symptoms are vague, such as dyspnoea, cough and fever and can be difficult to differentiate from progressive disease, co-existing morbidity and new pulmonary pathology. Diagnosis is, therefore, by rigorous investigation to exclude all other differential diagnoses. Treatment, at present, is supportive and includes discontinuation of gefitinib, oxygen supplementation, high-dose corticosteroids and antibacterials.

Pentoxifylline in prevention of radiation-induced lung toxicity in patients with breast and lung cancer: a double-blind randomized trial

PURPOSE

Pentoxifylline (Ptx) is thought to be helpful in preventing radiotoxicity by inhibiting platelet aggregation and tumor necrosis factor. We assessed whether prophylactic use of Ptx could prevent early and late normal lung tissue damage due to radiotherapy in a double-blind, randomized trial.

METHODS AND MATERIALS

A total of 40 patients with lung or breast cancer were randomized to receive Ptx (400 mg) or a placebo, 3 times daily, during the entire period of radiotherapy. We used the late effects normal tissue-subjective, objective, management, and analytic (LENT-SOMA) scale to evaluate and compare toxicity, including the findings of pulmonary function tests and radiologic and scintigraphic evaluations performed before and at 3 and 6 months of follow-up.

RESULTS

According to the LENT score, a statistically significant difference was found between the two groups in favor of Ptx (p = 0.016). The difference in diffusing capacity of the lung for carbon monoxide and regional perfusion scan results were found to be statistically significant between the groups at 3 and 6 months (p <0.05). The use of Ptx resulted in a noticeable reduction in the higher degrees of lung injury detected radiologically.

CONCLUSION

Our study showed a significant protective effect of Ptx for both early and late lung radiotoxicity. We recommend the prophylactic use of Ptx, finding it to be safe and effective.

Can 99mTc-DTPA aerosol scanning predict radiation pneumonitis?

PURPOSE

To investigate whether changes in diethylenetriamine pentaacetic acid (DTPA) aerosol clearance lung scans predict the development of radiation pneumonitis.

METHODS AND MATERIALS

Thirty-three patients with advanced non-small-cell lung cancer were treated with palliative radiation therapy to thorax. All patients were subjected to pretreatment and post-treatment DTPA aerosol clearance lung scans. The clearance t1/2 values were compared using the paired t test. Changes in percentage aerosol deposition were also compared. The patients were serially assessed clinically and radiologically for development of radiation pneumonitis.

RESULTS

For the whole group, the mean DTPA clearance t1/2 for the diseased lung fell from 36.33 to 28.85 min (p = 0.17). Twelve patients developed radiation pneumonitis, 8 Grade 1, 2 Grade 2, 1 Grade 3, and 1 Grade 4. In patients who developed radiation pneumonitis, the clearance t1/2 for the diseased lung decreased from 37.50 min to 29.00 min after treatment (p = 0.50). Other subgroups analyzed, including smokers, nonsmokers, those with and without endobronchial disease, as well as those free from radiation pneumonitis, also showed no significant change in the clearance of the aerosol. The difference between the percentage aerosol deposition of the diseased lung (37.92%) and that of the opposite lung (62.08%) for the entire sample was significantly different both before and after treatment (p < 0.01). Delivery of radiation did not significantly change the aerosol deposition in either lung.

CONCLUSIONS

We conclude that, in patients with advanced non-small-cell lung cancer, significant change in the pulmonary clearance of 99mTc-DTPA aerosol could not be demonstrated after radiation therapy. In such patients, clearance of the aerosol does not predict the development of radiation pneumonitis.

Effect of concurrent radiation therapy and chemotherapy on pulmonary function in patients with esophageal cancer: dose-volume histogram analysis

PURPOSE

The pulmonary effects of concurrent radiation therapy and chemotherapy were studied in patients enrolled in a phase I trial for esophageal cancer.

MATERIALS AND METHODS

Pulmonary function tests were performed prospectively before and after combined-modality therapy (oxaliplatin, 5-fluorouracil, and radiation therapy) in 20 patients with esophageal cancer. Cumulative and differential lung DVH analysis from 0 to 5400 cGy in 25-cGy intervals was performed for the last 15 patients. Correlation between radiation exposure in various dose ranges and percent reduction in pulmonary function tests was calculated as an exploratory analysis.

RESULTS

Significant reductions in carbon monoxide diffusion capacity corrected for hemoglobin (12.3%) and total lung capacity (2.5%) were evident at a median of 15.5 days after radiation therapy. DVH analysis revealed that the single dose of maximum correlation between lung volume radiation exposure and lung function reduction was less than 1000 cGy for all pulmonary functions. The percent lung volume that received a total dose between 700 and 1000 cGy maximally correlated with the percent reductions in total lung capacity and vital capacity, and the absolute lung volume that received a total dose between 700 and 1000 cGy maximally correlated with the percent reductions in total lung capacity, vital capacity, and carbon monoxide diffusion capacity.

DISCUSSION

Significant declines in carbon monoxide diffusion capacity and total lung capacity are evident immediately after the administration of conformal radiation therapy, oxaliplatin, and 5-fluorouracil for esophageal cancer. Other lung functions remain statistically unchanged. The percent or absolute lung volume that received a total dose between 700 and 1000 cGy may be significantly correlated with the percent decline of carbon monoxide diffusion capacity, total lung capacity, and vital capacity. These associations will be evaluated further in a follow-up study.

A report on serious pulmonary toxicity associated with gemcitabine-based therapy

BACKGROUND

Serious pulmonary toxicity (SPT) has recently been noted with gemcitabine-based therapy (G). However, the incidence of SPT has not been fully evaluated. This retrospective review estimates the incidence of, and the factors influencing, SPT with G.

PATIENTS AND METHODS

Pulmonary toxicity was defined as dyspnea, interstitial pneumonitis, lung disorder, lung edema, lung fibrosis, pneumonia, respiratory disorder, and respiratory distress syndrome. Patients were identified from 2 worldwide Lilly databases--the clinical trial database (CTD) and the safety database (SD). Events designated as serious and possibly/probably related to therapy by the primary physician were independently evaluated and confirmed. Serious pulmonary toxicity events were categorized as dyspnea or other SPT events.

RESULTS

Of the 91 patients identified by the investigator in the CTD as having G-related SPT, 32 had G-related SPT per the independent reviewers. Based on the 4448 patients treated with G in the CTD, the incidences of dyspnea and other SPT events were 0.45% and 0.27%, respectively. Of the 295 patients identified by the investigator in the SD as having G-related SPT, 167 had G-related SPT per the independent reviewers. Based on an estimated 217,400 patients treated with commercial G worldwide, the crude incidences of dyspnea and other SPT events were 0.02% and 0.06%, respectively.

CONCLUSIONS

SPT associated with G is uncommon. Incidences from the CTD for dyspnea and other SPT are 0.45% and 0.27%, respectively. Incidences from the SD for dyspnea and other SPT are 0.02% and 0.06%, respectively. The influence of other factors, such as anticancer therapies, on these incidences needs to be better understood.

The time course of radiation therapy-induced reductions in regional perfusion: a prospective study with >5 years of follow-up

PURPOSE

To assess the time-dependence of radiation therapy (RT)-induced reductions in regional lung perfusion, as measured by single photon emission computed tomography (SPECT) lung perfusion scans.

METHODS AND MATERIALS

Between 1991 and 1999, 79 patients had SPECT lung perfusion scans before and serially after RT. Changes in regional perfusion were correlated with regional dose using 3D planning tools and image fusion (PLUNC-Plan UNC). Multiple post-RT follow-up scans were evaluated to determine the temporal nature of RT-induced regional perfusion changes. To facilitate the comparison of dose-response curves (DRCs) at different post-RT intervals, each DRC was fit to a linear model and thus described by its slope.

RESULTS

There was a dose-dependent reduction in regional perfusion at nearly all time points post-RT (p = 0.0001). The slope of the DRCs for RT-induced reductions in regional perfusion became steeper at essentially each successive follow-up interval (p = 0.0001). However, the increases in slope became progressively smaller at later follow-up intervals. Overall, about 80% of the long-term RT-induced regional perfusion injury was manifest within 12 months post-RT.

CONCLUSION

There is a progression of RT-induced reductions in regional perfusion, with most of this injury manifest within 12 months post-RT. Additional regional injury appears to evolve for years.

Pulmonary sequelae after electron spinal irradiation

We measured pulmonary function in 21 patients, after craniospinal irradiation with a posterior spinal electron beam. The median age at treatment was 7.5 years. Nine patients (43%) demonstrated abnormal pulmonary function tests, five with restrictive changes, one with isolated diminished diffusion capacity, and three with obstructive disease. These changes were mild and predominantly asymptomatic.

Comparison of three rat strains for development of radiation-induced lung injury after hemithoracic irradiation

The purpose of this study is to define differences in radiation sensitivity among rat strains using breathing frequency and lung perfusion as end points of radiation-induced lung injury. The results have confirmed previous findings in mice showing that under stringently controlled iso-dose/volume irradiation conditions, substantial differences can be found in susceptibility to functional lung damage after radiation.

Can we predict radiation-induced changes in pulmonary function based on the sum of predicted regional dysfunction?

PURPOSE

To determine whether changes in whole-lung pulmonary function test (PFT) values are related to the sum of predicted radiation therapy (RT)-induced changes in regional lung perfusion.

PATIENTS AND METHODS

Between 1991 and 1998, 96 patients (61% with lung cancer) who were receiving incidental partial lung irradiation were studied prospectively. The patients were assessed with pre- and post-RT PFTs (forced expiratory volume in one second [FEV1] and diffusion capacity for carbon monoxide [DLCO]) for at least a 6-month follow-up period, and patients were excluded if it was determined that intrathoracic recurrence had an impact on lung function. The maximal declines in PFT values were noted. A dose-response model based on RT-induced reduction in regional perfusion (function) was used to predict regional dysfunction. The predicted decline in pulmonary function was calculated as the weighted sum of the predicted regional injuries: equation [see text] where Vd is the volume of lung irradiated to dose d, and Rd is the reduction in regional perfusion anticipated at dose d.

RESULTS

The relationship between the predicted and measured reduction in PFT values was significant for uncorrected DLCO (P = .005) and borderline significant for DLCO (P = .06) and FEV1 (P = .08). However, the correlation coefficients were small (range,.18 to.30). In patients with lung cancer, the correlation coefficients improved as the number of follow-up evaluations increased (range,.43 to.60), especially when patients with hypoperfusion in the lung adjacent to a central mediastinal/hilar thoracic mass were excluded (range,.59 to.91).

CONCLUSION

The sum of predicted RT-induced changes in regional perfusion is related to RT-induced changes in pulmonary function. In many patients, however, the percentage of variation explained is small, which renders accurate predictions difficult.

Radiation dose selection in Hodgkin's disease patients with large mediastinal adenopathy treated with combined modality therapy

PURPOSE

To determine the effective dose of consolidation radiation in Hodgkin's disease (HD) patients with large mediastinal adenopathy (LMA) treated with combined modality therapy (CMT).

METHODS AND MATERIALS

Eighty-three HD patients with LMA receiving CMT between 1983 and 1997 at Duke University and Yale University were identified. Patients underwent complete clinical staging. The staging breakdown was: IA, 4 patients; IB, 1 patient; IIA, 25 patients; IIB, 33 patients; IIIA, 3 patients; IIIB-6 patients; IVA, 2 patients; and IVB, 9 patients. All patients received induction chemotherapy (CT) as follows: MOPP/ABV(D), 31 patients; BCVPP, 15 patients; ABVD, 24 patients; MOPP, 3 patients; and other regimens, 10 patients. Following 6 cycles of CT, patients were restaged and classified as having either complete response (CR) or induction failure (IF). Post-CT gallium scans were obtained in 52 patients. Patients with residual radiographic abnormalities were classified as having CR if they were gallium-negative and clinically well otherwise. Following induction CT, 78 patients had a CR. There were 5 IFs. Consolidation irradiation was administered to all sites of initial involvement in patients who had achieved CR. RT dose varied. Patients were grouped into the following dose ranges: < or = 20 Gy, 12 patients; 20-25 Gy, 24 patients; 25-30 Gy, 30 patients; > or = 30 Gy, 12 patients.

RESULTS

Overall survival and failure-free survival were both 76% at 10 years. Of the 78 CR patients, 15 failed. Patterns of failure were in-field alone, 8 patients; out of field alone, 2 patients; and combined, 5 patients. Failure patterns by RT dose were: < or = 20 Gy, 0/12; 20-25 Gy, 7/24; 25-30 Gy, 5/30; > or = 30 Gy, 3/11. There was no apparent correlation between RT dose and subsequent failure. Post chemotherapy gallium scans were helpful in predicting for failure. Of 48 patients in whom the gallium was negative after chemotherapy, there were 6 failures, compared with 9 failures among 30 patients in whom gallium was not done after chemotherapy (p = 0.066). Additionally, patients receiving adriamycin-based chemotherapy regimens had improved outcomes compared to those not receiving adriamycin (p = 0.03.)

CONCLUSIONS

These retrospective data suggest that low-dose radiotherapy following CR achieved with induction chemotherapy (particularly when documented with gallium scanning) may be as effective as higher doses for bulky HD at presentation. Phase III trials are necessary for confirmation of this hypothesis.

The physical parameters and molecular events associated with radiation-induced lung toxicity

Radiation therapy (RT) is frequently used to treat patients with tumors in and around the thorax. Clinical radiation pneumonitis is a common side effect, occurring in 5% to 20% of patients. Efforts to identify patients at risk for pneumonitis have focused on physical factors, such as dose and volume. Recently, the underlying molecular biological mechanisms behind RT-induced lung injury have come under study. Improved knowledge of the molecular events associated with RT-induced lung injury may translate into a better ability to individualized therapy. This review discusses our current understanding of the physical and molecular factors contributing to RT-induced pulmonary injury.

Multivariate analysis of pulmonary fibrosis after electron beam irradiation for postmastectomy chest wall and regional lymphatics: evidence for non-dosimetric factors

BACKGROUND AND PURPOSE

To evaluate the factors associated with pulmonary fibrosis after postmastectomy electron beam irradiation of chest wall and regional lymphatics in patients with breast cancer.

MATERIALS AND METHODS

From July 1987 through July 1994, 109 women with stage II and III breast cancer receiving modified radical mastectomies were managed by postoperative electron beam irradiation. Doses of 46 to 50.4 Gy were delivered to the chest wall covered with bolus, internal mammary nodes, supraclavicular nodes and axillary lymph nodes via 12 or 15 MeV single portal electron beam. Seventeen patients received additional 10-16 Gy surgical scar boost via 9 MeV electron beam. Comparison of pre-treatment and post-treatment chest X-ray films were used to monitor the development of pulmonary fibrosis.

RESULTS

Only Grade 1 radiation-induced late pulmonary toxicity was noted in 33 patients (29%). Twenty-six patients (24%) developed pulmonary fibrosis under unbolused chest wall. Lung fibrosis under bolused chest wall was noted in 11 patients (10%). Statistical difference (P<0.01) was noted between the incidence of fibrosis in these two sites. In multivariate analysis of lung fibrosis under unbolus-covered chest wall, the independent prognostic factors are low body mass index (BMI) (P<0.01), tamoxifen taking (P=0.03), and no treatment interruption (P=0.03). No independent factor was associated with lung fibrosis under bolus-covered chest wall in multivariate analysis.

CONCLUSIONS

In the analysis of pulmonary fibrosis induced by unbolused electron beam, BMI rather than body weight and body height is a strong prognostic factor. Tamoxifen and short overall time can predispose the development of lung fibrosis.

Active breathing control (ABC) for Hodgkin's disease: reduction in normal tissue irradiation with deep inspiration and implications for treatment

PURPOSE

Active breathing control (ABC) temporarily immobilizes breathing. This may allow a reduction in treatment margins. This planning study assesses normal tissue irradiation and reproducibility using ABC for Hodgkin's disease.

METHODS AND MATERIALS

Five patients underwent CT scans using ABC obtained at the end of normal inspiration (NI), normal expiration (NE), and deep inspiration (DI). DI scans were repeated within the same session and 1-2 weeks later. To simulate mantle radiotherapy, a CTV1 was contoured encompassing the supraclavicular region, mediastinum, hila, and part of the heart. CTV2 was the same as CTV1 but included the whole heart. CTV3 encompassed the spleen and para-aortic lymph nodes. The planning target volume (PTV) was defined as CTV + 9 mm. PTVs were determined at NI, NE, and DI. A composite PTV (comp-PTV) based on the range of NI and NE PTVs was determined to represent the margin necessary for free breathing. Lung dose-mass histograms (DMH) for PTV1 and PTV2 and cardiac dose-volume histograms (DVH) for PTV3 were compared at the three different respiratory phases.

RESULTS

ABC was well-tolerated by all patients. DI breath-holds ranged from 34 to 45 s. DMHs determined for PTV1 revealed a median reduction in lung mass irradiated at DI of 12% (range, 9-24%; n = 5) compared with simulated free-breathing. PTV2 comparisons also showed a median reduction of 12% lung mass irradiated (range, 8-28%; n = 5). PTV3 analyses revealed the mean volume of heart irradiated decreased from 26% to 5% with deep inspiration (n = 5). Lung volume comparisons between intrasession and intersession DI studies revealed mean variations of 4%.

CONCLUSION

ABC is well tolerated and reproducible. Radiotherapy delivered at deep inspiration with ABC may decrease normal tissue irradiation in Hodgkin's disease patients.

Time course of radiological lung density changes after postmastectomy radiotherapy

The purpose of this study was to quantify the time course of radiological lung changes in patients after postmastectomy radiotherapy assessed from routine follow-up chest x-rays. Radiological density changes in the apex of the irradiated lung were quantified by a recent lung densitometry assay. Lung changes were expressed as the so-called Relative change in Equivalent Absorber Thickness (REAT). The clinical series comprised 329 patients treated with postmastectomy radiotherapy between 1978 and 1982. Of these patients 100 were treated with chemotherapy (CTX or CMF) and 41 were given tamoxifen as an additional adjuvant treatment; 290 patients (88.2%) had pretreatment x-rays and at least one x-ray after completion of radiotherapy and these were included in the study. A total of 2,209 chest x-rays was taken during follow-up, and among these 1921 x-rays (86.9%) were judged to be assessable. Late changes were defined as changes occurring more than a year after radiotherapy. A total of 280 patients had at least one chest x-ray taken more than one year after radiotherapy and these were evaluable with respect to late changes. There were 1,390 follow-up x-rays in these patients and 207 patients (73.9%) had three or more follow-up x-rays. Linear regression of REAT vs. observation time was used to identify three patterns of time changes: progressive, regressive, and stable. The results were as follows. Two phases of lung changes were observed. The early phase peaks around 6 months and the density changes may subsequently resolve, completely or in part. In most cases (173 patients or 84%), the lung density changes reached a stable level 12 months after irradiation. Yet, in 16 patients (7.7%) the lung changes progressed for five or more years. Regression of the density changes was seen in 18 patients (8.7%), and in some cases there were signs that this apparent regression was caused by contraction of the fibrotic tissue. We conclude that two phases of lung response can be distinguished and can be graded according to severity using this assay. Early lung changes reach a maximum around 6 months after RT. Late reactions reach a plateau in most patients after one year, but progress in some cases for five or more years.

The effect of patient-specific factors on radiation-induced regional lung injury

PURPOSE

To assess the impact of patient-specific factors on radiation (RT)-induced reductions in regional lung perfusion.

METHODS

Fifty patients (32 lung carcinoma, 7 Hodgkin's disease, 9 breast carcinoma and 2 other thoracic tumors) had pre-RT and > or = 24-week post-RT single photon emission computed tomography (SPECT) perfusion images to assess the dose dependence of RT-induced reductions in regional lung perfusion. The SPECT data were analyzed using a normalized and non-normalized approach. Furthermore, two different mathematical methods were used to assess the impact of patient-specific factors on the dose-response curve (DRC). First, DRCs for different patient subgroups were generated and compared. Second, in a more formal statistical approach, individual DRCs for regional lung injury for each patient were fit to a linear-quadratic model (reduction = coefficient 1 x dose + coefficient 2 x dose2). Multiple patient-specific factors including tobacco history, pre-RT diffusion capacity to carbon monoxide (DLCO), transforming growth factor-beta (TGF-beta), chemotherapy exposure, disease type, and mean lung dose were explored in a multivariate analysis to assess their impact on the coefficients.

RESULTS

None of the variables tested had a consistent impact on the radiation sensitivity of regional lung (i.e., the slope of the DRC). In the formal statistical analysis, there was a suggestion of a slight increase in radiation sensitivity in the dose range >40 Gy for nonsmokers (vs. smokers) and in those receiving chemotherapy (vs. no chemotherapy). However, this finding was very dependent on the specific statistical and normalization method used.

CONCLUSION

Patient-specific factors do not have a dramatic effect on RT-induced reduction in regional lung perfusion. Additional studies are underway to better clarify this issue. We continue to postulate that patient-specific factors will impact on how the summation of regional injury translates into whole organ injury. Refinements in our methods to generate and compare SPECT scans are needed.

Risk factors for severe radiation pneumonitis in lung cancer

BACKGROUND

Risk factors for severe radiation pneumonitis, which often spreads beyond treatment portals and may even be bilateral, have not been fully investigated. The purpose of this study was to identify important factors associated with severe radiation pneumonitis.

METHODS

111 cases of primary lung cancer, treated with radiotherapy or chemoradiotherapy, were retrospectively analyzed.

RESULTS

Severe radiation pneumonitis occurred in 17 cases (15.3%). The ratio of interstitial change in lungs before radiotherapy and radiotherapy to the contralateral mediastinum with > 40 Gy in the radiation pneumonitis group (RP group) was significantly higher than in patients without radiation pneumonitis (control group) (47.1% vs 5.3%; P < 0.001 and 58.8% vs 27.7%; P = 0.037, respectively). Using logistic regression analysis, interstitial changes before radiotherapy and radiotherapy to the contralateral mediastinum of > 40 Gy were significant risk factors associated with severe radiation pneumonitis.

CONCLUSIONS

These data suggest that pre-existing interstitial changes detected by chest radiography or computed tomography and radiotherapy to the contralateral mediastinum (> 40 Gy) may predict the development of severe radiation pneumonitis.

Nonsegmental ventilation-perfusion scintigraphy mismatch after radiation therapy

PURPOSE

This report illustrates the utility of ventilation-perfusion scintigraphy in differentiating radiation pneumonitis from other causes of dyspnea, including pulmonary embolism, heart failure, obstructive tumor, and chronic obstructive pulmonary disease.

METHODS AND RESULTS

A nonsegmental mismatched perfusion abnormality, which exactly conformed to a radiation port, was diagnostic of radiation pneumonitis.

CONCLUSION

In patients with lung tumors presenting with dyspnea, ventilation-perfusion scintigraphy may be useful in diagnosing radiation pneumonitis and effectively excluding other causes of dyspnea.

Radiation therapy for tracheobronchial amyloidosis

A 67-year-old man presented with localized tracheobronchial amyloidosis involving the distal trachea and the right-sided airways. The disease caused right middle lobe collapse and threatened the right upper and lower lobes. A variety of bronchoscopic methods, including Nd:YAG laser resection, dilation, and stenting, were used as temporizing methods. External beam radiation therapy, considered because of disease progression, caused a measurable local response. Radiation therapy should be considered as a treatment option for localized tracheobronchial amyloidosis causing airway obstruction.

[Pulmonary and cardiac late effects of ionizing radiations alone or combined with chemotherapy]

High doses of ionizing radiation (> 40 Gy) cause severe lung fibrosis in approximately 5% of the cases. There is a twofold increase when chemotherapy is added to ionizing radiation. Lung fibrosis is due to the destruction of lung tissue by ionizing radiation but also to various cytokine effects (PDGF-beta, TGF-beta). Only a minority of patients (approximately 10%) with abnormal X-rays will experience clinical symptoms. The most important radiobiological parameters which accounts for pulmonary tolerance is the fraction size. Irradiation of the heart begets multifarious late sequelae which are often left unrecognized. Chronic pericarditis affects approximately 5% of the patients when the irradiation dose exceeds 40 Gy. Coronary artery disease can be diagnosed in 5 to 10% of the patients. This late complication is more likely to occur if the patient was young at the time of the irradiation or if other risk factors are associated. Valvular defects can be found in 15 to 30% of the patients. However, the mortality rate is very low (0.5%). Finally, conduction defects can also be seen in approximately 5% of the patients. It is very likely that the radiation dose given to the heart should not exceed 30 Gy if late sequelae are to be avoided.

Risk factors for reduced pulmonary function after malignant lymphoma in childhood

The aim was to study pulmonary function after Hodgkin disease or non-Hodgkin Lymphoma in childhood and to evaluate if younger age at diagnosis and therapy is a risk factor for reduced pulmonary function. We studied a population-based sample of survivors of Hodgkin disease (n = 22) or non-Hodgkin lymphoma (n = 19) in childhood. Pulmonary function test results were compared with reference values for our laboratory, generated by adjusting published reference values fit 348 healthy never-smokers from a local population study. Data were analyses as standardised residuals, which are [observed minus predicted value] divided by the residual standard deviation of the reference equations. At a median of 11 years after diagnosis (range 2 to 24), the participants had significantly reduced lung volumes and transfer factor, unrelated to the few pulmonary symptoms. On average, the total lung capacity was reduced to -0.9 standardised residual and the transfer factor was reduced to -1.3 standardised residual. Young age at therapy seemed to be a risk factor for reduced lung function, especially when treatment included thoracic irradiation. No significant toxic synergism was observed between smoking and previous cancer therapy. Therapy without thoracic irradiation but with doxorubicin and cyclophosphamide was almost as toxic to lung function as therapy with thoracic irradiation but without doxorubicin and cyclophosphamide. In conclusion, lung volumes and transfer factor were reduced several years after childhood Hodgkin disease of non-Hodgkin lymphoma, with young age at therapy as a risk factor, especially when combined with thoracic irradiation.

Physical and biological predictors of changes in whole-lung function following thoracic irradiation

PURPOSE

To develop methods of predicting the pulmonary consequences of thoracic irradiation (RT) by prospectively studying changes in pulmonary function following RT.

METHODS AND MATERIALS

100 patients receiving incidental partial-lung irradiation during treatment of tumors in or adjacent to the thorax had whole-lung function assessed via symptoms and pulmonary function tests (PFTs: FEV1-forced expiratory volume 1 s; DLCO-diffusion capacity) before and repeatedly 6-48 months following RT. All had computed tomography-based three-dimensional (3D) dose calculations with lung density heterogeneity corrections for dose-volume histogram (DVH) and normal tissue complication probability (NTCP) calculations. Functional DVHs (DVfH) based on SPECT (single photon emission computed tomography) lung perfusion scans, and serial transforming growth factor-beta (TGF-beta1) levels were available in 50 and 48 patients, respectively. The incidence and severity of changes in whole-lung function were correlated with clinical, physical, and biological factors. Exploratory statistical analyses were performed using chi-square, Pearson correlations, logistic regression, and multiple linear regression.

RESULTS

RT-induced symptoms developed in 21 patients. In the overall group, the single best predictor for the development of symptoms was the NTCP (p < 0.05). Pre-RT PFTs alone were less predictive (p = 0.1 for FEV1, p = 0.08 for DLCO). A multivariate model based on pre-RT DLCO and CT-based NTCP was strongly predictive for the development of symptoms (p < 0.001). NTCPs based on SPECT-derived DVf Hs and TGF-beta1 levels did not appear to provide additional predictive value. The presence or absence of pulmonary symptoms was correlated with the decline in PFT 6 months following RT (p < 0.05). In the overall group, the degree of decline in PFTs was not well correlated with any of the dose-volume variables considered. In patients with "good" pre-RT PFTs, there was a relationship between the percent reduction in PFT and dose-volume parameters such as the percent of lung volume receiving > 30 Gy (p < 0.05).

CONCLUSION

The extent of alteration in whole-lung function (symptoms or PFT changes) appears to be related to both dose-volume and pre-RT PFT parameters. The data suggest that no one variable is likely to be an adequate predictor and that multivariate predictive models will be needed. Additional studies are underway to develop better predictive models that consider physical factors such as the DVH and regional perfusion, as well as biological/clinical factors such as pre-RT PFTs and TGF-beta1.

Quantification of radiation-induced regional lung injury with perfusion imaging

PURPOSE

To better understand the dose and time dependence of radiation therapy (RT)-induced regional lung dysfunction as assessed by changes in regional lung perfusion.

METHODS AND MATERIALS

Patients who were to receive RT for tumors in and around the thorax, wherein portions of healthy lung would be incidentally irradiated, were prospectively studied. Regional function was assessed pre- and post-RT with single photon emission computed tomography (SPECT) lung perfusion scans, obtained following the intravenous administration of approximately 4 mCi of technetium-99m macroaggregated albumin. Pre-RT computed tomography (CT) scans were used to calculate the three-dimensional (3D) dose distribution, reflecting tissue density inhomogeneity corrections. Each SPECT scan was correlated with the pre-RT CT scan, and the 3D dose distribution. Changes in regional lung perfusion were correlated with regional RT dose, at various time intervals following radiation.

RESULTS

The data from 20 patients (7 breast cancer, 5 lymphoma, 1 esophagus, 1 sarcoma, and 6 lung cancer) have been analyzed. Patients with gross intrathoracic lung cancers causing obstruction of regional pulmonary arteries were not included. For most patients, there is a statistically significant dose-dependent reduction in regional blood flow at all time points following radiation. While a time dependence is suggested in the high dose range, the limited amount of data prevents meaningful statistical evaluation.

CONCLUSIONS

Radiation therapy-induced regional lung dysfunction occurs in a dose-dependent manner and develops within 3-6 months following radiation. In contrast to classical "sigmoid" dose-response curves, described mainly for changes following whole lung irradiation, these data suggest a more gradual relationship between regional dysfunction and RT dose. Retraction of irradiated lung with secondary movement of unirradiated lung into the "3D-defined irradiated volume" may have introduced inaccuracies into this analysis. Additional studies are currently underway to assess this possibility and better refine this dose-response curve. Studies are underway to determine if changes in assessments of whole lung function, such as pulmonary function tests, can be predicted by summing the regional changes observed.

The role of three dimensional functional lung imaging in radiation treatment planning: the functional dose-volume histogram

PURPOSE

During thoracic irradiation (XRT), treatment fields are usually designed to minimize the volume of nontumor-containing lung included. Generally, functional heterogeneities within the lung are not considered. The three dimensional (3D) functional information provided by single photon emission computed tomography (SPECT) lung perfusion scans might be useful in designing beams that minimize incidental irradiation of functioning lung tissue. We herein review the pretreatment SPECT scans in 86 patients (56 with lung cancer) to determine which are likely to benefit from this technology.

METHODS AND MATERIALS

Prior to thoracic XRT, SPECT lung perfusion scans were obtained following the intravenous injection of approximately 4 mCi of 99mcTc-labeled macro-aggregated albumin. The presence of areas of decreased perfusion, their location relative to the tumor, and the potential clinical usefulness of their recognition, were scored. Patients were grouped and compared (two-tailed chi-square) based on clinical factors. Conventional dose-volume histograms (DVHs) (DVFHs) are calculated based on the dose distribution throughout the computed tomography (CT)-defined lung and SPECT-defined perfused lung, respectively.

RESULTS

Among 56 lung cancer patients, decreases in perfusion were observed at the tumor, adjacent to the tumor, and separate from the tumor in 94%, 74%, and 42% of patients, respectively. Perfusion defects adjacent to the tumor were often large with centrally placed tumors. Hypoperfusion in regions separate from the tumor were statistically most common in patients with relatively poor pulmonary function and chronic obstructive pulmonary disease (COPD). Considering all SPECT defects adjacent to and separate from the tumor, corresponding CT abnormalities were seen in only approximately 50% and 20% of patients, respectively, and were generally not as impressive. Following XRT, hypoperfusion at and separate from the tumor persisted, while defects adjacent to the tumor improved in several patients. In four patients who achieved a complete response scored by CT with chemotherapy prior to XRT, persistent hypoperfusion was present at and adjacent to the tumor site in three. Among 30 patients with cancers not arising in the lung (14 breast, 12 lymphoma, 4 others), perfusion defects were seen in only 4 (2 adjacent and 2 apart). Recognition of decreases in perfusion mainly impacted on treatment planning for a few patients with poor pulmonary function and limited target volumes. DVFHs have been useful in beam selection for patients with marked perfusion heterogeneities.

CONCLUSIONS

Lung perfusion scans provide functional information not provided by CT scans that can be useful in designing radiation treatment beams that minimize incidental irradiation of the function regions of the lung. This approach appears to be most helpful in patients with gross intrathoracic lung cancer, especially those with small targets and relatively poor pulmonary function. One limitation of this approach is that some of the defects adjacent to the tumor site reperfuse following treatment, indicating that these scans identify perfusion rather than potential perfusion. Three dimensional functional data can be used to generate DVFHs that may be more predictive of the physiological consequences of the radiation than conventional DVHs. Additional work is currently underway to test this hypothesis.

Injury to the lung from cancer therapy: clinical syndromes, measurable endpoints, and potential scoring systems

Toxicity of the respiratory system is a common side effect and complication of anticancer therapy that can result in significant morbidity. The range of respiratory compromise can extend from acute lethal events to degrees of chronic pulmonary decompensation, manifesting years after the initial cancer therapy. This review examines the anatomic-histologic background of the lung and the normal functional anatomic unit. The pathophysiology of radiation and chemotherapy induced lung injury is discussed as well as the associated clinical syndromes. Radiation tolerance doses and volumes are assessed in addition to chemotherapy tolerance and risk factors and radiation-chemotherapy interactions. There are a variety of measurable endpoints for detection and screening. Because of the wide range of available quantitative tests, it would seem that the measurement of impaired lung function is possible. The development of staging systems for acute and late toxicity is discussed and a new staging system for Late Effects in Normal Tissues (LENT) is proposed.

Late therapy-induced cardiac and pulmonary complications in cured patients with Hodgkin's disease treated with conventional combination chemo-radiotherapy

In recent years, with the advent of modern therapeutic approaches, patients with advanced Hodgkin's disease achieve high cure rates. Accordingly, more attention is now focused upon the late complications of chemotherapy and irradiation, occurring in cured patients many years after successful therapy for HD. In this report, we review the incidence and presentation of some of the cardiovascular and pulmonary complications which may appear in cured patients up to 20 years after therapy.

Pneumothorax following thoracic radiation therapy for Hodgkin's disease

Radiation therapy alone to the nodal drainage sites above the diaphragm, namely a "mantle" field, is often standard treatment for early stage Hodgkin's disease and may be used in combination with chemotherapy in more advance disease. Localised pneumonitis and fibrosis are recognised treatment related sequelae; however, other pulmonary complications, including pneumothorax, have been described. Two cases of spontaneous pneumothorax following mantle radiation therapy are presented.

A new method to determine dose-effect relations for local lung-function changes using correlated SPECT and CT data

PURPOSE

To determine dose-effect relations for regional lung-function changes after radiotherapy.

METHODS

Single Photon Emission Computed Tomography (SPECT) was performed to quantify regional ventilation and perfusion. CT scans were used to calculate the three-dimensional (3-D) dose distribution. Both SPECT and CT scans were performed prior to radiotherapy and 5 months after the start of the treatment. To obtain combined 3-D information on ventilation, perfusion and dose, the SPECT data were correlated with the corresponding CT data. The relative changes in ventilation and perfusion were calculated in each SPECT voxel (voxel size about 6 x 6 x 6 mm) and related to the dose in that voxel. The average relative changes were determined per dose interval of 4 Gy. This procedure was evaluated using the data from five patients treated for Hodgkin's disease with mantle field irradiation with a prescribed total dose of 40-42 Gy.

RESULTS

Dose-effect relations for perfusion were observed in all patients, while in four of the five patients, a dose-effect relation was found for ventilation. The maximal uncertainty of the calculated radiation dose was 11%: a difference between the position of the patient during treatment and during CT scanning caused a maximal dose uncertainty of 6%, while the accuracy of the dose calculation algorithm itself was estimated to be within 5%.

CONCLUSION

The results indicate that the combined use of SPECT and CT information is an effective method for determining dose-effect relations for regional lung function parameters in each individual patient.

The utility of SPECT lung perfusion scans in minimizing and assessing the physiologic consequences of thoracic irradiation

PURPOSE

Three-dimensional single photon emission computed tomography lung perfusion scans (SPECT) provide a unique quantitative 3-dimensional map of the distribution of functioning pulmonary vascular/alveolar subunits, information not provided by other imaging modalities. This report describes our initial experience utilizing these scans to assist in the design of radiation treatment beams and to assess changes in regional lung function following irradiation.

METHODS AND MATERIALS

Patients were immobilized and scanned in the treatment position with appropriate fiducial markers. Four millicuries of technetium 99M microaggregated albumin were injected and SPECT images of the lung were generated. Pre-treatment SPECT images were used to help design radiation beams to minimize irradiation of functioning lung. Pre- and post-treatment scans were compared to assess changes in regional function. These changes in function were then correlated with the regional radiation dose.

RESULTS

Pre-radiotherapy SPECT scans were obtained in 18 patients (11 with lung cancer). Marked variations in regional function were frequently noted. In patients with primary lung tumors, these variations were not necessarily immediately adjacent to the tumor volume. In general, patients with poor pulmonary function pre-treatment, in whom one would like to spare as much normal lung as possible, had the most non-uniform distribution throughout the lung of functioning vascular/alveolar subunits. In these cases, pre-treatment scans were most useful in designing radiation portals to minimize irradiation of functioning lung. SPECT scans were also used to detect changes in regional lung function secondary to radiotherapy in four patients. With doses in excess of 40 Gy, reductions in regional function were noted 1-6 months following completion of radiotherapy. These reductions were not necessarily accompanied by reductions in conventional pulmonary function tests, which are assessments of whole lung function and may not reflect regional lung injury if the volume affected is small.

CONCLUSIONS

SPECT lung scans provide an excellent means of assessing regional lung function, superior to that obtainable with planar images. The functional data provided by the SPECT images is useful in designing "optimal" radiation treatment beams and in assessing the effect of radiotherapy on regional lung functions. Efforts are continuing in our laboratory to develop a dose response curve for regional lung damage using the tools of SPECT scanning and 3-dimensional dose calculations.

Pulmonary morbidity 10-18 years after irradiation for Hodgkin's disease

Pulmonary function tests were performed in 78 patients who had been curatively treated for Hodgkin's disease with mantle field irradiation 10-18 years ago. Mean values of the total lung capacity (95.2%), vital capacity (VC) (95.9%), forced expiratory volume in 1 s (FEV1) (90.6%), and carbon monoxide diffusing capacity per unit alveolar volume (82.7%) showed significant deviations from the predicted normal values, standardised for age, sex, race and height. In a multiple regression analysis the normalised total dose of irradiation, the field of irradiation, and the interval since irradiation had independent negative effects on the test results. Patients reported more coughing, wheezing and dyspnoea on exertion in comparison with hospital-visitors. Their smoking habits and reported pulmonary disease were not different. It is concluded that small, but significant impairment of pulmonary function exists after a follow-up of 14 (2) years [mean (S.D.)]. The clinical impact of these findings seems, however, minimal. Further avoidance of pulmonary toxicity requires a careful quantitative study of the effects of the radiation dose and irradiated volume.

Long-term effects on pulmonary function of mantle radiotherapy in patients with Hodgkin's disease

Twenty-five patients (21-45 years old) treated for Hodgkin's disease with mantle radiotherapy but no chemotherapy underwent chest radiography and pulmonary testing with spirometry, pulmonary mechanics and exercise test combined with arterial blood gas analysis, lung scintigraphy, assessment of pulmonary artery pressure with Doppler cardiography and vector ECG 10-20 years after treatment. The doses to mediastinum ranged from 35-43 (mean 40) Gy given in 26 fractions with the split-course technique. Radiographic signs of slight to moderate pulmonary fibrosis were seen in 18 patients. Minor restrictive ventilatory defects were found with decreased VC, TLC and lung compliance and increased maximal elastic recoil. Little evidence of airflow obstruction was found. Exercise capacity was decreased in three individuals but the mean value for the study group as a whole was normal. Arterial PO2 at maximum exercise was reduced but no patient had diminished hemoglobin saturation. Lung scintigraphy showed defects in 21 patients, mostly consisting of slight abnormalities at the lung periphery and apices. The perfusion seemed to be more affected than the ventilation, suggesting primary vascular lesions. Twelve patients showed signs of right ventricular hypertrophy in vector ECG and four of these had systolic pulmonary artery pressure greater than or equal to 30 mm Hg. The observed abnormalities were mostly of a minor degree and few clinically significant long-term effects of mantle radiotherapy on pulmonary function were observed.

Late cardiovascular and pulmonary complications of therapy in Hodgkin's disease: report of three unusual cases, with a review of relevant literature

With the advent of modern therapeutic approaches, even patients with advanced Hodgkin's disease have high cure rates today. Therefore, more attention is gradually being focused upon the late complications of chemotherapy and irradiation, appearing long after the patient is in remission and thought to be cured. In this report, we review the incidence and presentation of some of the cardiovascular and pulmonary complications which may appear later in the course of the disease. Cardiovascular mishaps reviewed include pericardial manifestations, conduction abnormalities, cardiomyopathy, and premature coronary artery disease. Pulmonary complications discussed are lung fibrosis, spontaneous pneumothorax, pulmonary veno-occlusive disease, and hyperlucent lung. Three instructive cases from our recent experience, are also presented. One fatal case was due to cardiac failure because of radiation-induced pericarditis and coronary artery disease. Another patient with an almost fatal complication required lung transplantation because of severe bilateral radiation fibrosis of the lung and pulmonary veno-occlusive disease. The third instance was also life-threatening in nature, with radiation-induced arterial changes in the major arteries of the chest and neck, resulting in recurrent cerebral and ophthalmic thromboembolic disease. It is suggested that potentially severe cardiopulmonary complications be considered during the planning of the initial and subsequent management of patients with Hodgkin's disease, particularly in an era employing autologous and allogeneic bone marrow transplantation as part of therapy in some cases.