Pulmonary changes induced by radiotherapy. HRCT findings

Transcription

1 Pulmonary changes induced by radiotherapy. HRCT findings Poster No.: C-2299 Congress: ECR 2015 Type: Educational Exhibit Authors: R. E. Correa Soto, M. Albert Antequera, K. Müller Campos, D S. Palominos Pose, J. D. Albillo Labarra, M. J. Martín Sánchez ; Salamanca/ES, Valencia/ES, Santiago/CL, Barcelona/ES Keywords: Radiotherapy techniques, Drugs / Reactions, Treatment effects, Image compression, Education, CT-High Resolution, Radioprotection / Radiation dose, Lung, Thorax DOI: /ecr2015/C-2299 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 15

2 Learning objectives To review the clinical diagnosis and risk factors of pulmonary changes induced by radiotherapy treatment. Describe the radiographic findings at high resolution computered tomography (HRCT) of pulmonary parenchyma in patients who have received radiotherapy. Set the differential diagnosis of secondary changes to radiotherapy treatments and other entities with similar radiological findings. Page 2 of 15

3 Background Radiation-induced lung injury is a pulmonary inflammatory process occurred after ionizing radiation exposure. It is observed today in patients who have undergone thoracic or neck irradiation for the treatment of malignancy (eg. lung, breast, laryngeal or hematologic). The diagnosis of this entity is based on the correlation between clinical events with the timing of irradiation and radiographic changes. Nevertheless, the clinical diagnosis or radiation-induced lung injury is complicated by the presence of other conditions, including malignancy, thromboembolic disease, drug-induced pneumonitis, infection or cardiogenic pulmonary edema. Page 3 of 15

4 Findings and procedure details From July 2009 to July 2014, we reviewed patients who underwent lung damage after radiotherapy treatment. We describe associated risk factors in table 1 and clinical presentation and radiological findings at HRCT in table 2. The HRCT scan appearance of radiation pneumonitis correlates with the phase of lung injury, although a given patient may present at any one of the phases. Acute lung injury, from 3 to 6 months after radiation therapy, typically shows ground-glass attenuation within the area of radiated lung. We also can observe patchy areas of consolidation that coalesce to form a relatively sharp edge that conforms to the radiation therapy portals rather than anatomic structures, corresponding to the organizing phase. These areas sometimes appear nodular. Chronic lung injury, from 6 months after radiotherapy treatment and can progress over years. The opacities with the organizing phase may resolve with minimal scarring or may evolve into fibrotic phase. This phase is characterized on HRCT by linear opacities or an area of dense consolidation and volume loss. This area tipically corresponds closely to the radiation port, yielding a nonanatomic straight edge effect. The radiographic pattern is influenced by the specific radiation therapy technique used, such as limited tangencial beams (eg, for breast cancer), conformal therapy (eg, for bronchogenic cancer), or complex portal arrangements (eg, margins around the tumor or regional lymph nodes). Page 4 of 15

5 Images for this section: Fig. 1 Page 5 of 15

6 Fig. 2 Page 6 of 15

7 Fig. 3: Axial HRCT of a patient with radiation pneumonitis shows ground-glass (green arrow), parenchymal consolidation (red arrow). Linear lesions. Page 7 of 15

8 Fig. 4: Sagittal HRCT of a patient with radiation fibrosis shows: consolidation with air bronchograms (red arrow), loss of volume and tensile bronchiectasis (yellow arrow). Page 8 of 15

9 Fig. 5: Axial HRCT of a patient with radiation pneumonitis shows a consolidation with air bronchograms (red arrow), loss of volume and tensile bronchiectasis (yellow arrow). Linear lesions. Page 9 of 15

10 Fig. 6: Axial HRCT of a patient with radiation pneumonitis shows ground-glass, parenchymal consolidation. Subpleural airspaces. Linear lesions. Page 10 of 15

11 Fig. 7: Coronal HRTC of a patient with radiation pneumonitis shows ground-glass, parenchymal consolidation, loss of volume and tensile bronchiectasis. Linear lesions. Page 11 of 15

12 Fig. 8: Axial HRTC of a patient with radiation pneumonitis shows ground-glass, parenchymal consolidation, loss of volume and tensile bronchiectasis. Linear lesions. Page 12 of 15

13 Fig. 9: Axial HRCT of a patient with radiation pneumonitis shows ground-glass, parenchymal consolidation with air bronchograms. Linear lesions. Page 13 of 15

14 Conclusion Lung tissue is particularly radiosensitive. Patients in a higher risk of lung injury are those who undergo thoracic or neck irradiation. Many factors affect the risk for radiation pneumonitis including the method of irradiation, the volume of irradiated lung, the total dosage and frequency of irradiation, associated chemotherapy, and possibly the genetic background of the patient. Most patients who exhibit radiation pneumonitis are asymptomatic, and the diagnosis is incidental by radiological post-treatment control tests. Frequent changes of acute radiation pneumonitis are the presence of consolidations. Radiation fibrosis phase is dominated by the presence of pseudomass pattern. Page 14 of 15

15 References Choi YW et al: Effects of radiation therapy on the lung: radiologic appearances and differential diagnosis. Radiographics. 24(4):985-97; discussion 998, Miwa S et al: The incidence and clinical characteristics of bronchiolitis obliterans organizing pneumonia syndrome after radiation therapy for breast cancer. Sarcoidosis Vasc Diffuse Lung Dis. 21(3):212-8, Takeda T et al: Radiation injury after hypofractionated stereotactic radiotherapy for peripheral small lung tumors: serial changes on CT. AJR Am J Roentgenol. 182(5):1123-8, Koenig TR et al: Radiation injury of the lung after three-dimensional conformal radiation therapy. AJR Am J Roentgenol. 178(6):1383-8, Ogasawara N et al: Perfusion characteristics of radiation-injured lung on Gd-DTPA-enhanced dynamic magnetic resonance imaging. Invest Radiol. 37(8):448-57, Libshitz HI et al: Filling in of radiation therapy-induced bronchiectatic change: a reliable sign of locally recurrent lung cancer. Radiology. 210(1):25-7, Frank A et al: Decision logic for retreatment of asymptomatic lung cancer recurrence based on positron emission tomography findings. Int J Radiat Oncol Biol Phys. 32(5): , Roberts CM et al: Radiation pneumonitis: a possible lymphocyte-mediated hypersensitivity reaction. Ann Intern Med. 118(9): , 1993 Page 15 of 15