Bronchoalveolar lavage fluid findings following radiotherapy for non-small cell lung cancer

Acute and Late Pulmonary Effects After Radiation Therapy in Childhood Cancer Survivors: A PENTEC Comprehensive Review

OBJECTIVES

The Pediatric Normal Tissue Effects in the Clinic (PENTEC) pulmonary task force reviewed dosimetric and clinical factors associated with radiation therapy (RT)-associated pulmonary toxicity in children.

METHODS

Comprehensive search of PubMed (1965-2020) was conducted to assess available evidence and predictive models of RT-induced lung injury in pediatric cancer patients (<21 years old). Lung dose for radiation pneumonitis (RP) was obtained from dose-volume histogram (DVH) data. RP grade was obtained from standard criteria. Clinical pulmonary outcomes were evaluated using pulmonary function tests (PFTs), clinical assessment, and questionnaires.

RESULTS

More than 2,400 abstracts were identified; 460 articles had detailed treatment and toxicity data; and 11 articles with both detailed DVH and toxicity data were formally reviewed. Pooled cohorts treated during 1999 to 2016 included 277 and 507 patients age 0.04 to 22.7 years who were evaluable for acute and late RP analysis, respectively. After partial lung RT, there were 0.4% acute and 2.8% late grade 2, 0.4% acute and 0.8% late grade 3, and no grade 4 to 5 RP. RP risk after partial thoracic RT with mean lung dose (MLD) <14 Gy and total lung V20Gy <30% is low. Clinical and self-reported pulmonary outcomes data included 8,628 patients treated during 1970 to 2013, age 0 to 21.9 years. At a median 2.9- to 21.9-year follow-up, patients were often asymptomatic; abnormal PFTs were common and severity correlated with lung dose. At ≥10-year follow-up, multi-institutional studies suggested associations between total or ipsilateral lung doses >10 Gy and pulmonary complications and deaths. After whole lung irradiation (WLI), pulmonary toxicity is higher; no dose response relationship was identified. Bleomycin and other chemotherapeutics at current dose regimens do not contribute substantially to adverse pulmonary outcomes after partial lung irradiation but increase risk with WLI.

CONCLUSIONS

After partial lung RT, acute pulmonary toxicity is uncommon; grade 2 to 3 RP incidences are <1%. Late toxicities, including subclinical/asymptomatic impaired pulmonary function, are more common (<4%). Incidence and severity appear to increase over time. Upon review of available literature, there appears to be low risk of pulmonary complications in children with MLD < 14 Gy and V20Gy <30% using standard fractionated RT to partial lung volumes. A lack of robust data limit guidance on lung dose/volume constraints, highlighting the need for additional work to define factors associated with RT-induced lung injury.

Pulmonary Effects of Antineoplastic Therapy

Pulmonary toxicity is common after cancer therapy and can result from all therapeutic modalities. The consequential decrease in lung function ranges in severity from subclinical to life-threatening or even fatal and can manifest in the acute setting or many years after completion of therapy. Radiation effects are due to direct insult to the pulmonary parenchyma and, for younger children, impaired thoracic musculoskeletal development. Radiation pneumonitis can occur in the acute/subacute setting, as well as fibrosis with comprised gas exchange as a late effect of direct lung irradiation; thoracic wall malformation can cause restriction of function as a chronic sequela. The pulmonary effects of cytotoxic drugs usually present as acute effects, but there is the potential for significant late morbidity and mortality. Of course, surgical interventions can also cause both acute and/or late pulmonary effects as well, depending on the specific procedure. Although treatment approaches for the management of pediatric cancers are continually adapted to provide optimal therapy while minimizing toxicities, to a varying degree all therapies have the potential for both acute and late pulmonary toxicity. Of note, the cumulative incidence of pulmonary complications rises with increasing time since diagnosis, which suggests that adult survivors of childhood cancer require lifelong monitoring and management of potential new-onset pulmonary morbidity as they age. Knowledge of cytotoxic therapies and an understanding of lung physiology and how it may be altered by therapy facilitate appropriate clinical care and monitoring of long-term survivors.

Interleukin (IL)-1A and IL-6: applications to the predictive diagnostic testing of radiation pneumonitis

PURPOSE

To explore the application of interleukin (IL)-1alpha and IL-6 measurements in the predictive diagnostic testing for symptomatic radiation pneumonitis (RP).

METHODS AND MATERIALS

In a prospective protocol investigating RP and cytokines, IL-1alpha and IL-6 values were analyzed by enzyme-linked immunosorbent assay from serial weekly blood samples of patients receiving chest radiation. We analyzed sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) over selected threshold values for both cytokines in the application to diagnostic testing.

RESULTS

The average coefficient of variation was 51% of the weekly mean IL-1alpha level and 39% of the weekly mean IL-6 value. Interleukin 1alpha and IL-6 became positively correlated with time. Specificity for both cytokines was better than sensitivity. IL-6 globally outperformed IL-1alpha in predicting RP, with higher PPV and NPV.

CONCLUSIONS

Our data demonstrate the feasibility of applying IL-1alpha and IL-6 measurements of blood specimens to predict RP. Interleukin-6 measurements offer stronger positive predictive value than IL-1alpha. This application might be further explored in a larger sample of patients.

Increased plasma levels of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in lung and breast cancer are altered during chest radiotherapy

PURPOSE

Does the release of plasma matrix metalloproteinase-9 (MMP-9) by radiation-activated airway epithelial cells and infiltrating inflammatory cells play a role in the radiation damage or repair process in the lungs? We evaluated lung damage by ionizing radiation using plasma levels of MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), and MMP-3 as biologic markers of tissue damage, and also their relationship to changes in pulmonary epithelial permeability, clinical signs and symptoms, and lung structural changes.

METHODS AND MATERIALS

Seven serial studies were conducted in each of 8 patients undergoing chest radiotherapy (RT) for lung or breast cancer, beginning before the first treatment (baseline) and then biweekly to approximately 100 days during and after RT. Chest radiographs were monitored for each patient. Sandwich enzyme-linked immunoassays (ELISA) were used to measure plasma MMP-3, MMP-9, and TIMP-1 levels. Lung permeability was evaluated by measuring the rate of epithelial clearance of approximately 150 microCi ( approximately 5.6 MBq) inhaled (99m)Tc diethylenetriamine pentaacetate aerosol (DTPA).

RESULTS

Lung and breast cancer resulted in very high plasma levels of MMP-9 (126-893 ng/mL) and TIMP-1 (496-8985 ng/mL) in all subjects studied before initiation of RT. This compares with plasma MMP-9 and TIMP-1 values in healthy volunteers of 29 +/- 11 ng/mL and 436 +/- 86 ng/mL, respectively. RT was followed by a sharp decrease in plasma MMP-9 within the first 2 weeks, but without a corresponding change in TIMP-1. In contrast, plasma MMP-3 levels, which are generally increased with inflammation, were elevated in only 1 of 5 subjects.

CONCLUSION

Lung and breast cancer are associated with high plasma levels of MMP-9 and TIMP-1. These high baseline plasma levels of MMP-9 were reduced in the first 2 weeks of RT in 7 of 8 subjects, and TIMP-1 plasma levels remained high in all subjects. The decrease in plasma MMP-9 after initiation of chest RT appears to reflect a suppressive effect on cancer-induced cellular responses rather than a primary role for MMP-9 in radiation-induced lung damage. Likewise, the lack of a rise in plasma MMP-3 levels does not support a role for MMP-3 in tissue injury or repair in the lung. It remains to be determined whether plasma MMP-9 measurements will serve as a useful parameter in predicting cancer relapse.

Secretory activity and cell cycle alteration of alveolar type II cells in the early and late phase after irradiation

PURPOSE

Type II cells and the surfactant system have been proposed to play a central role in pathogenesis of radiation pneumonitis. We analyzed the secretory function and proliferation parameters of alveolar type II cells in the early (until 24 h) and late phase (1-5 weeks) after irradiation (RT) in vitro and in vivo.

METHODS AND MATERIALS

Type II cells were isolated from rats according to the method of Dobbs. Stimulation of secretion was induced with terbutaline, adenosine triphosphate (ATP), and 12-O-tetradecanoylphorbol-13-acetate (TPA) for a 2-h period. Determination of secretion was performed using (3)H-labeled phosphatidylcholine. For the early-phase analysis, freshly isolated and adherent type II cells were irradiated in vitro with 9-21 Gy (stepwise increase of 3 Gy). Secretion stimulation was initiated 1, 6, 24, and 48 h after RT. For late-phase analysis, type II cells were isolated 1-5 weeks after 18 Gy whole lung or sham RT. Each experiment was repeated at least fivefold. Flow cytometry was used to determine cell cycle distribution and proliferating cell nuclear antigen index.

RESULTS

During the early-phase (in vitro) analysis, we found a normal stimulation of surfactant secretion in irradiated, as well as unirradiated, cells. No change in basal secretion and no dose effect were seen. During the late phase, 1-5 weeks after whole lung RT, we observed enhanced secretory activity for all secretagogues and a small increase in basal secretion in Weeks 3 and 4 (pneumonitis phase) compared with controls. The total number of isolated type II cells, as well as the rate of viable cells, decreased after the second post-RT week. Cell cycle alterations suggesting an irreversible G(2)/M block occurred in the second post-RT week and did not resolve during the observation period. The proliferating cell nuclear antigen index of type II cells from irradiated rats did not differ from that of controls.

CONCLUSION

In contrast to literature data, we observed no direct effect of radiation on secretory activity in the early phase after RT. In our study of isolated type II cells, as well as in intact animals, RT did not result in an impaired surfactant secretion up to 5 weeks after RT. Our in vivo experiments even showed an increased response of phosphatidylcholine secretion to all known secretagogues at Weeks 3 and 4 after whole lung RT, possibly due to inflammatory cytokines. Cell cycle alterations with G(2)/M block and cell loss in the late post-RT period may contribute more to the manifestation of radiation-induced lung damage than functional impairment in type II cells.

Role of CD13/aminopeptidase N in rat lymphocytic alveolitis caused by thoracic irradiation

CD13/aminopeptidase N is a cell surface glycoprotein that is widely distributed in a variety of mammalian cells. It was recently shown to have chemotactic activity for T lymphocytes. This study examined the role of CD13/aminopeptidase N in lymphocytic alveolitis in radiation-induced lung injury caused by a single-dose thoracic irradiation (15 Gy) in rats. Significantly increased aminopeptidase activity was detected in bronchoalveolar lavage fluid obtained from irradiated rats at 4 weeks after irradiation compared to the activity in unirradiated rats. Significantly higher aminopeptidase activity was detected on alveolar macrophages from irradiated rats at 2 and 4 weeks than on those from unirradiated rats. Western blot analysis showed an increased expression of CD13/aminopeptidase N protein in alveolar macrophages from irradiated rats at 4 weeks. Chemotactic activity for normal rat lymphocytes was detected in bronchoalveolar lavage fluid from irradiated rats at 4 weeks, and approximately 60% of the activity was inhibited by pretreatment of bronchoalveolar lavage fluid with bestatin, a specific aminopeptidase inhibitor. This study suggests that CD13/aminopeptidase N may play an important role as a lymphocyte chemoattractant in lymphocyte-mediated alveolitis in experimental radiation-induced lung injury.

Lung toxicity following chest irradiation in patients with lung cancer

Classical radiation pneumonitis has been described after single dose whole lung irradiation in experimental animals where above a threshold dose of irradiation, there is a sigmoid dose response curve with increasing morbidity and mortality. After clinical fractionated irradiation, however, acute radiation pneumonitis consisting of cough shortness of breath and patchy radiological changes, occurs in <10% of patients, has dyspnoea out of proportion to the volume of lung irradiated and usually resolves completely without long-term effects. There is increasing evidence that this represents a bilateral lymphocytic alveolitis or hypersensitivity pneumonitis and has been termed sporadic pneumonitis. Late radiation toxicity results in pulmonary fibrosis. This is a consequence of repair, which is initiated by tissue injury within the radiation portal. It follows release of chemotactic factors for fibroblasts including transforming growth factor-beta, fibronectin and platelet derived growth factor. Radiation fibrosis is the clinically more significant syndrome for patients. It may result in progressive dyspnoea and mortality in patients. The most predictable change in laboratory lung function tests is a decrease in transfer factor due to damage at the capillary-alveolar level. It also results in decreased lung compliance, which will affect the total lung capacity and the forced vital capacity. The forced expiratory volume in 1 s is less affected, although this seems to depend on the volume of lung irradiated. There is also a decrease in perfusion in the irradiated lung. Radiation fibrosis seems to depend, amongst other factors, on the volume of lung, which is irradiated above a threshold of 20-30 Gy. The morbidity of radiation fibrosis may therefore be minimized by the use of dose volume histogram to minimize the volume of normal lung irradiated in patients at high risk, e.g., patients with who present with poor lung function. The importance of the baseline perfusion in the irradiated areas continues to be studied.

Radiation pneumonitis and early circulatory cytokine markers

Radiation pneumonitis is a distinct clinical entity that differs from other pulmonary symptoms such as allergic pneumonitis, chemical pneumonitis, or pneumonia by various infectious agents. Recent research has supported the mechanism of cellular interaction between lung parenchymal cells and circulating immune cells mediated through a variety of cytokines including proinflammatory cytokines, chemokines, adhesion molecules, and profibrotic cytokines. Identifying reliable biomarkers for radiation pneumonitis will allow us to identify individuals at risk for pneumonitis before or during the early stage of therapy. Prospective blood sampling, scoring of respiratory symptoms, and chest imaging were conducted for patients receiving thoracic radiotherapy for malignancy. Serial plasma specimens were analyzed for circulating cytokine changes before, during, and up to 12 weeks after radiation. Radiation pneumonitis was diagnosed using National Cancer Institute (NCI) common toxicity criteria. Cytokine analysis was assayed for interleukin 1alpha (IL-1alpha), interleukin 6 (IL-6), monocyte chemotactic protein 1 (MCP-1), E-selectin, L-selectin, transforming growth factor beta1 (TGF-beta1), and basic fibroblast growth factor (bFGF) using enzyme linked immmunosorbant assay (ELISA). Twenty-four patients had clinical follow-up longer than 12 months after radiotherapy. Thirteen had symptomatic pneumonitis (NCI grade 2). The peak incidence of symptoms was between 6 and 13 weeks after radiotherapy. Six patients had only radiographic infiltrates (NCI grade 1). Five patients did not have clinical or radiographic pneumonitis. Both IL-1alpha and IL-6 levels were significantly higher before, during, and after radiotherapy for those who had pneumonitis. The pattern of changes of MCP-1, E-selectin, L-selectin, TGF-beta1, and bFGF varied, but none of these cytokines correlated with radiation pneumonitis. Analysis of a panel of circulating cytokines with different putative functions in radiation pulmonary injury identified IL-1alpha and IL-6 as early circulating cytokine markers for radiation pneumonitis.

Radiation-induced pneumonitis in the "nonirradiated" lung

OBJECTIVE

To describe six cases of radiation-induced organizing pneumonitis occurring outside the direct radiation field and to review clinical, radiologic, and histologic aspects of this entity.

MATERIAL AND METHODS

We present detailed case reports of six women, with a mean age of 62.8 years (range, 50 to 75), who had received radiation therapy (mean dose, 6,560 cGy) for breast cancer.

RESULTS

From 6 to 17 months (mean, 8.8) after the completion of radiotherapy, recurrent and migrating lung infiltrates were detected outside the radiation field in the six study patients. Three patients had pronounced respiratory symptoms, whereas the rest were minimally symptomatic or asymptomatic. Thoracic computed tomography showed dense alveolar infiltrates. Bronchoalveolar lavage in two patients revealed lymphocytosis (25% and 19%), and lung biopsy in five patients demonstrated a histologic pattern consistent with bronchiolitis obliterans organizing pneumonia. Even though the symptomatic patients showed prompt resolution of their symptoms and roentgenographic abnormalities after systemic corticosteroid therapy, the lung infiltrates recurred after corticosteroid therapy was discontinued.

CONCLUSION

These six cases, including their prompt response to corticosteroid therapy, provide additional evidence that irradiation damages lung tissue outside of the direct treatment field and suggest that an immunologically mediated lymphocytic alveolitis may be responsible for the recurrent migratory organizing pneumonitis.

Tumour response and radiation-induced lung injury in patients with recurrent small cell lung cancer treated with radiotherapy and concomitant interferon-alpha

The aim of this study was to determine whether either natural or recombinant interferon (IFN)-alpha can improve the response to radiotherapy (RT) in patients with small cell lung cancer (SCLC), and to assess the role of IFN in radiation-induced lung injury. All patients had previously participated in a randomised trial of chemotherapy alone or in combination with IFN-alpha in three arms (arm O: no IFN, arm I: natural IFN-alpha, arm II: recombinant IFN-alpha). Patients with locally progressive disease in the lungs following chemotherapy were treated with RT and they continued with their concomitant IFN-alpha. The RT dose was 50 Gy. Radiation-induced lung injury was assessed by lung function tests, computed tomography and bronchoalveolar lavage fluid (BALF) analysis which included cell findings, Interleukin (IL)-1 alpha/-1 beta expression by alveolar macrophages and surfactant components. Seventeen patients were entered in the study, 16 of whom were evaluable. Response rates in Arms O, I and II were 50, 67 and 50%, respectively. Median survival was 18.5, 7 and 23 months respectively, and 1-year survival was 67, 29 and 75% respectively. Long-term survival as assessed by 2- and 3-year survival rates was 29% in patients receiving natural IFN-alpha as compared to 17% in patients not receiving IFN (not statistically significant findings). Every patient had abnormal results when assessed for radiation-induced lung injury. No statistically significant difference was found in toxicity between the treatment arms. A high surfactant protein (SP)-A/phospholipid ratio and a high level of SP-A in BALF before RT was associated with a high degree of radiation-induced lung injury measured by lung function tests and computed tomography in all arms of the study. Thus, we could not show that the combination of IFN-alpha and RT induced more lung toxicity than RT alone as we did in our previous study. The role of high SP-A/phospholipid ratios and high SP-A levels in BALF before RT as predictors of the development of lung injury after RT needs to be determined in the future.

Management of Toxicities of Combined Modality Therapy for Intrathoracic Malignancies

BACKGROUND: Combined radiation and chemotherapy for intrathoracic tumors can produce appreciable morbidity. Apprehension about the severity of these toxicities may inhibit optimal patient care. METHODS: The literature on recognition, diagnosis, prophylaxis, and management of these toxicities is reviewed and combined with the experiences of the authors to produce management recommendations. RESULTS: Toxicities include acute and chronic esophagitis, early and late pneumonitis with fibrosis, myelosuppression, and neurologic deficits. Measures are available to minimize their severity and to reduce their impact on the patient. CONCLUSIONS: The morbidity of combined radiation and chemotherapy patients with intrathoracic tumors can be minimized by recognizing potential toxicities and by applying appropriate prophylactic and management measures.