Respiratory Complications After Radiation Therapy

The potential for chronic pulmonary sequelae is related to the radiation dose administered, the volume of lung irradiated, and the fractional radiation therapy doses.[6]

Combined-modality therapy, including radiation therapy and pulmonary toxic chemotherapy or thoracic/chest wall surgery, increases the risk of pulmonary function impairment.[7,8]

Chronic pulmonary complications reported after treatment for pediatric malignancies include restrictive or obstructive chronic pulmonary disease, pulmonary fibrosis, and spontaneous pneumothorax.[9]

After partial lung radiation, acute pulmonary toxicity was uncommon, with grade 2 to 3 incidence of radiation pneumonitis of less than 1%.

Late toxicities, including subclinical/asymptomatic impaired pulmonary function, were more common (<4%) and appeared to increase in incidence and severity over time.

The risk of pulmonary complications was low among children treated with a mean lung dose of lower than 14 Gy and total lung V20Gy less than 30%.

Within the spectrum of doses that could be analyzed, pulmonary toxicity was higher after whole-lung irradiation, but no dose-response relationship was identified.

Bleomycin and other chemotherapeutic agents at current dose regimens did not contribute substantially to adverse pulmonary outcomes after partial lung irradiation. However, this risk increased with whole-lung irradiation.

For survivors of pediatric Hodgkin lymphoma, the prevalence of pulmonary symptoms using contemporary involved-field techniques is reported to be low. However, some patients exhibit substantial subclinical dysfunction.[11]

For survivors of pediatric Hodgkin lymphoma, the prevalence of pulmonary symptoms using contemporary involved-field techniques is reported to be low. However, some patients exhibit substantial subclinical dysfunction.[11]

A study of 54 children who were treated with induction chemotherapy (usually doxorubicin, bleomycin, vincristine, etoposide, prednisone, and cyclophosphamide–based chemotherapy) and 21 Gy of radiation therapy from 2008 through 2016 confirmed these findings.[12]

For survivors of pediatric Hodgkin lymphoma, the prevalence of pulmonary symptoms using contemporary involved-field techniques is reported to be low. However, some patients exhibit substantial subclinical dysfunction.[11] › A study of 54 children who were treated with induction chemotherapy (usually doxorubicin, bleomycin, vincristine, etoposide, prednisone, and cyclophosphamide–based chemotherapy) and 21 Gy of radiation therapy from 2008 through 2016 confirmed these findings.[12]

At a median follow-up of 39.5 months, 3 of 54 patients (5.6%) or 3 of 108 lungs (2.8%) developed radiation pneumonitis (RP); two lungs had grade 1 RP and one lung had grade 2 RP.

For survivors of pediatric Hodgkin lymphoma, the prevalence of pulmonary symptoms using contemporary involved-field techniques is reported to be low. However, some patients exhibit substantial subclinical dysfunction.[11] › A study of 54 children who were treated with induction chemotherapy (usually doxorubicin, bleomycin, vincristine, etoposide, prednisone, and cyclophosphamide–based chemotherapy) and 21 Gy of radiation therapy from 2008 through 2016 confirmed these findings.[12]

RP was seen only in patients with a median lung dose of higher than 12.4 Gy or with an individual mean lung dose higher than 13.8 Gy.

For survivors of pediatric Hodgkin lymphoma, the prevalence of pulmonary symptoms using contemporary involved-field techniques is reported to be low. However, some patients exhibit substantial subclinical dysfunction.[11]

In a study of 109 patients (59% with Hodgkin lymphoma) who were irradiated at a median age of 13.8 years (range, 0.04–20.9 years; median follow-up, 3.4 years), patients were treated with a median prescribed radiation therapy dose of 21 Gy (range, 0.4–64.8 Gy); 58.7% of patients received bleomycin, and 83.5% of patients received cyclophosphamide.[13]

For survivors of pediatric Hodgkin lymphoma, the prevalence of pulmonary symptoms using contemporary involved-field techniques is reported to be low. However, some patients exhibit substantial subclinical dysfunction.[11] › In a study of 109 patients (59% with Hodgkin lymphoma) who were irradiated at a median age of 13.8 years (range, 0.04–20.9 years; median follow-up, 3.4 years), patients were treated with a median prescribed radiation therapy dose of 21 Gy (range, 0.4–64.8 Gy); 58.7% of patients received bleomycin, and 83.5% of patients received cyclophosphamide.[13]

The 5-year cumulative incidence after irradiation was: pneumonitis, 6%; chronic cough, 10%; pneumonia, 35%; dyspnea, 11%; supplemental oxygen requirement, 2%; radiographic interstitial lung disease, 40%; and chest wall deformity, 12%.

For survivors of pediatric Hodgkin lymphoma, the prevalence of pulmonary symptoms using contemporary involved-field techniques is reported to be low. However, some patients exhibit substantial subclinical dysfunction.[11] › In a study of 109 patients (59% with Hodgkin lymphoma) who were irradiated at a median age of 13.8 years (range, 0.04–20.9 years; median follow-up, 3.4 years), patients were treated with a median prescribed radiation therapy dose of 21 Gy (range, 0.4–64.8 Gy); 58.7% of patients received bleomycin, and 83.5% of patients received cyclophosphamide.[13]

One patient died of progressive respiratory failure.

For survivors of pediatric Hodgkin lymphoma, the prevalence of pulmonary symptoms using contemporary involved-field techniques is reported to be low. However, some patients exhibit substantial subclinical dysfunction.[11] › In a study of 109 patients (59% with Hodgkin lymphoma) who were irradiated at a median age of 13.8 years (range, 0.04–20.9 years; median follow-up, 3.4 years), patients were treated with a median prescribed radiation therapy dose of 21 Gy (range, 0.4–64.8 Gy); 58.7% of patients received bleomycin, and 83.5% of patients received cyclophosphamide.[13]

Postirradiation pulmonary function tests available from 44 patients showed evidence of obstructive lung disease (25%), restrictive disease (11%), hyperinflation (32%), and abnormal diffusion capacity (12%).

For survivors of pediatric Hodgkin lymphoma, the prevalence of pulmonary symptoms using contemporary involved-field techniques is reported to be low. However, some patients exhibit substantial subclinical dysfunction.[11] › In a study of 109 patients (59% with Hodgkin lymphoma) who were irradiated at a median age of 13.8 years (range, 0.04–20.9 years; median follow-up, 3.4 years), patients were treated with a median prescribed radiation therapy dose of 21 Gy (range, 0.4–64.8 Gy); 58.7% of patients received bleomycin, and 83.5% of patients received cyclophosphamide.[13]

Thoracic surgery, bleomycin, age, maximum lung irradiation dose V30 (volume of lung exposed to a radiation dose >30 Gy), and volume of lung exposed to a radiation dose of greater than 25 Gy were significant risk factors for the development of adverse pulmonary outcomes on univariate analysis.

For survivors of pediatric Hodgkin lymphoma, the prevalence of pulmonary symptoms using contemporary involved-field techniques is reported to be low. However, some patients exhibit substantial subclinical dysfunction.[11] › In a study of 109 patients (59% with Hodgkin lymphoma) who were irradiated at a median age of 13.8 years (range, 0.04–20.9 years; median follow-up, 3.4 years), patients were treated with a median prescribed radiation therapy dose of 21 Gy (range, 0.4–64.8 Gy); 58.7% of patients received bleomycin, and 83.5% of patients received cyclophosphamide.[13]

Mean lung irradiation dose, maximum lung dose, and Vdose (percentage of volume of lung receiving the threshold dose or greater) were highly correlated. On multivariate analysis, mean lung irradiation dose was the sole significant predictor of adverse pulmonary outcome (P = .01).

Changes in lung function have been reported in children treated with whole-lung radiation therapy for metastatic Wilms tumor.[14,15]

Changes in lung function have been reported in children treated with whole-lung radiation therapy for metastatic Wilms tumor.[14,15]

A dose of 12 Gy to 14 Gy reduced TLC and vital capacity to about 70% of predicted values, and even lower if the patient had undergone thoracotomy.

Administration of bleomycin alone can produce pulmonary toxicity and, when combined with radiation therapy, can heighten radiation reactions. Chemotherapeutic agents such as doxorubicin, dactinomycin, and busulfan are radiomimetic agents and can reactivate underlying radiation damage.[14,15]