Predictors of Radiation Pneumonitis in Patients Receiving Intensity Modulated Radiation Therapy for Hodgkin and Non Hodgkin Lymphoma

Abstract

Purpose-Few studies to date have evaluated factors associated with the development of radiation pneumonitis (RP) in patients with Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL), especially in patients treated with contemporary radiation techniques. These patients represent a unique group owing to the often large radiation target volumes within the mediastinum and to the potential to receive several lines of chemotherapy that add to pulmonary toxicity for relapsed or refractory disease. Our objective was to determine the incidence and clinical and dosimetric risk factors associated with RP in lymphoma patients treated with intensity modulated radiation therapy (IMRT) at a single institution. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Methods-We Conflicts of Interest: None HHS Public Access Author Manuscript Author ManuscriptAuthor ManuscriptAuthor Manuscript acute toxicity criteria were identified in univariate analysis using the Pearson χ 2 test and logistic multivariate regression.Results-Mediastinal radiation was administered as consolidation therapy in 110 patients with newly diagnosed HL or NHL and in 40 patients with relapsed or refractory disease. The overall incidence of RP (RTOG grade 1-3) was 14% in the entire cohort. Risk of RP was increased for patients who received radiation for relapsed or refractory disease (25%) versus those who received consolidation (10%, P=0.019). Several dosimetric parameters predicted RP, including mean lung dose (MLD) >13.5 Gy, V 20 >30%, V15 >35%, V 10 >40% and V 5 >55%. The likelihood ratio (LR) χ 2 value was highest for V 5 < 55% (LR χ 2 =19.37).Conclusions-In using IMRT to treat mediastinal lymphoma, all dosimetric parameters predicted RP, although small doses to large volumes of lung had the greatest influence. Patients with relapsed or refractory lymphoma who received salvage chemotherapy and hematopoietic stem cell transplantation were at higher risk for symptomatic RP.

Modeling the risk of radiation-induced lung fibrosis: Irradiated heart tissue is as important as irradiated lung

“…The incidence of symptomatic RILF (RTOG G2-3) is in agreement with the low incidence (5-10%) of clinically significant symptomatic pneumonitis in HL cohorts reported in the literature [11]. Limited data are available on dosimetric predictors for RILF and specific studies on pulmonary complication in HL patients [13,14,33] are focused on acute radiation pneumonitis. However, bleomycin-containing CHT along with lower radiation doses inherent to HL treatments may be responsible for late-phase subclinical RT-induced injury such as fibrosis.…”

“…Recent data [14] suggest that relatively low doses (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) to large volumes of lung are more predictive for acute radiation pneumonitis than the traditionally considered volumes receiving more than 20 or 30 Gy.…”

Superior sulcus non-small cell lung carcinoma: A comparison of IMRT and 3D-RT dosimetry

“…Some have argued that these low doses are associated with a higher risk of causing radio-induced pneumopathy in IMRT-treated patients than higher doses. 40 However, the differences between the results of the current series and the previously published articles are probably related to the location of the tumors because SS-NSCLC has less neighboring lung parenchyma. However, the high level of V 5 Gy retrieved in both series with 3D-RT is surprising and may explain the absence of a significant difference compared with IMRT, and may be related on the number of 3D-RT beams used.…”

Proton pencil beam scanning for mediastinal lymphoma: treatment planning and robustness assessment

“…Mean lung doses (MLD) below 13.5 Gy and V 5 Gy below 55% are associated with a low incidence of clinically significant pneumonitis; however, the risk is higher in patients with relapsed/refractory disease [20]. The incrementally decreased lung dose with PBS Table 2.…”