Assessment of setup uncertainty in hypofractionated liver radiation therapy with a breath-hold technique using automatic image registration–based image guidance

Autor: Sunil Krishnan, Joseph M. Herman, Eugene J. Koay, Gye Won Choi, Bruce D. Minsky, Sam Beddar, Albert C. Koong, Grace L. Smith, Prajnan Das, Cullen M. Taniguchi, Yelin Suh, Emma B. Holliday
Rok vydání: 2019
Předmět:
lcsh:Medical physics. Medical radiology. Nuclear medicine
Setup uncertainty
Hypofractionated Radiation Therapy
lcsh:R895-920
medicine.medical_treatment
Residual
lcsh:RC254-282
Liver radiotherapy
Breath Holding
Automatic image registration
03 medical and health sciences
0302 clinical medicine
Image Processing
Computer-Assisted
medicine
Humans
PTV margin
Radiology
Nuclear Medicine and imaging
IGRT
Image-guided radiation therapy
business.industry
Radiotherapy Planning
Computer-Assisted
Research
Liver Neoplasms
Uncertainty
Ptv margin
Cone-Beam Computed Tomography
lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens
Prognosis
In-room CT
Radiation therapy
Oncology
030220 oncology & carcinogenesis
Breathing
Measurement uncertainty
Radiation Dose Hypofractionation
Radiotherapy
Intensity-Modulated
Nuclear medicine
business
Radiotherapy
Image-Guided
Zdroj: Radiation Oncology (London, England)
Radiation Oncology, Vol 14, Iss 1, Pp 1-9 (2019)
ISSN: 1748-717X
DOI: 10.1186/s13014-019-1361-6
Popis: Background Target localization in radiation therapy is affected by numerous sources of uncertainty. Despite measures to minimize the breathing motion, the treatment of hypofractionated liver radiation therapy is further challenged by residual uncertainty coming from involuntary organ motion and daily changes in the shape and location of abdominal organs. To address the residual uncertainty, clinics implement image-guided radiation therapy at varying levels of soft-tissue contrast. This study utilized the treatment records from the patients that have received hypofractionated liver radiation therapy using in-room computed tomography (CT) imaging to assess the setup uncertainty and to estimate the appropriate planning treatment volume (PTV) margins in the absence of in-room CT imaging. Methods We collected 917 pre-treatment daily in-room CT images from 69 patients who received hypofractionated radiation therapy to the liver with the inspiration breath-hold technique. For each treatment, the daily CT was initially aligned to the planning CT based on the shape of the liver automatically using a CT-CT alignment software. After the initial alignment, manual shift corrections were determined by visual inspection of the two images, and the corrections were applied to shift the patient to the physician-approved treatment position. Considering the final alignment as the gold-standard setup, systematic and random uncertainties in the automatic alignment were quantified, and the uncertainties were used to calculate the PTV margins. Results The median discrepancy between the final and automatic alignment was 1.1 mm (0–24.3 mm), and 38% of treated fractions required manual corrections of ≥3 mm. The systematic uncertainty was 1.5 mm in the anterior-posterior (AP) direction, 1.1 mm in the left-right (LR) direction, and 2.4 mm in the superior-inferior (SI) direction. The random uncertainty was 2.2 mm in the AP, 1.9 mm in the LR, and 2.2 mm in the SI direction. The PTV margins recommended to be used in the absence of in-room CT imaging were 5.3 mm in the AP, 3.5 mm in the LR, and 5.1 mm in the SI direction. Conclusions Manual shift correction based on soft-tissue alignment is substantial in the treatment of the abdominal region. In-room CT can reduce PTV margin by up to 5 mm, which may be especially beneficial for dose escalation and normal tissue sparing in hypofractionated liver radiation therapy.
Databáze: OpenAIRE
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