Exceptionally high incidence of symptomatic grade 2-5 radiation pneumonitis after stereotactic radiation therapy for lung tumors.

Hideomi Yamashita,Naoki Nakamura,Hiroki Koyanagi,Masao Tago,Hiroshi Igaki,Kenshiro Shiraishi,Kuni Ohtomo,Nakashi Sasano,Keiichi Nakagawa

doi:10.1186/1748-717x-2-21

Hideomi Yamashita, Naoki Nakamura + Show 7 more

Open Access

https://doi.org/10.1186/1748-717x-2-21

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Abstract

BackgroundTo determine the usefulness of dose volume histogram (DVH) factors for predicting the occurrence of radiation pneumonitis (RP) after application of stereotactic radiation therapy (SRT) for lung tumors, DVH factors were measured before irradiation.MethodsFrom May 2004 to April 2006, 25 patients were treated with SRT at the University of Tokyo Hospital. Eighteen patients had primary lung cancer and seven had metastatic lung cancer. SRT was given in 6–7 fields with an isocenter dose of 48 Gy in four fractions over 5–8 days by linear accelerator.ResultsSeven of the 25 patients suffered from RP of symptomatic grade 2–5 according to the NCI-CTC version 3.0. The overall incidence rate of RP grade2 or more was 29% at 18 months after completing SRT and three patients died from RP. RP occurred at significantly increased frequencies in patients with higher conformity index (CI) (p = 0.0394). Mean lung dose (MLD) showed a significant correlation with V5–V20 (irradiated lung volume) (p < 0.001) but showed no correlation with CI. RP did not statistically correlate with MLD. MLD had the strongest correlation with V5.ConclusionEven in SRT, when large volumes of lung parenchyma are irradiated to such high doses as the minimum dose within planning target volume, the incidence of lung toxicity can become high.

Highlights

To determine the usefulness of dose volume histogram (DVH) factors for predicting the occurrence of radiation pneumonitis (RP) after application of stereotactic radiation therapy (SRT) for lung tumors, DVH factors were measured before irradiation
All patients enrolled in this study satisfied the following eligibility criteria: 1) solitary or double lung tumors; 2) tumor diameter < 40 mm; 3) no evidence of regional lymph node metastasis; 4) Karnofsky performance status scale м 80% ; and 5) tumor not located adjacent to major bronchus, esophagus, spinal cord, or great vessels
This paper describes the experience of treating 25 patients with small (< 4 cm) lung tumors with four fractions of 12Gy

Summary

Introduction

To determine the usefulness of dose volume histogram (DVH) factors for predicting the occurrence of radiation pneumonitis (RP) after application of stereotactic radiation therapy (SRT) for lung tumors, DVH factors were measured before irradiation. Since 1990, stereotactic radiotherapy (SRT) has been widely available for the treatment of intracranial lesions. The use of SRT has gradually been expanded to include the treatment of extra-cranial lesions. SRT has been demonstrated as a safe and effective modality in the treatment of primary and metastatic lung tumors [1]. Initial clinical results were favorable, and local control rates around 90% have been reported [1,2,3,4,5,6,7,8,9]. Few cases with severe toxicity have been reported [10]

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