Search Courses

DJR 47-2B: Patient setup accuracy in DIBH radiotherapy of breast cancer with lymph node inclusion using surface tracking and image guidance

Course Details

MDCB Credits: 2.50

ARRT Credits: 1.00

Available Until: 5/31/2023

Non-Member Price: $87.50

Member Price: $50.00

Member PLUS Price: $50.00

Add to My Courses

Once you have exceeded your annual free credit allowance you will be prompted to pay a per-credit fee.

Courses purchased using your credit allowance are non-refundable and need to be completed before their expiration date

View your annual credit allowance here.

Authors: Maija Rossi, PhD,, Marko Laaksomaa, RTT, Antti Aula, PhD,

Department of Medical Physics, Tampere University Hospital, Tampere, 33521, Finland
Department of Oncology, Tampere University Hospital, Tampere, 33521 Finland

Abstract:
Studying setup accuracy in breast cancer patients with axillary lymph node inclusion in deep inspiration breath-hold (DIBH) after patient setup with surface-guided radiotherapy (SGRT) and image-guided radiotherapy (IGRT). Breast cancer patients (N = 51) were treated (50 Gy in 25 fractions) with axillary lymph nodes within the planning target volume (PTV). Patient setup was initiated with tattoos and lasers, and further adjusted with SGRT. The DIBH guidance was based on SGRT. Orthogonal and/or tangential imaging was analyzed for residual position errors of bony landmarks, the breath-hold level (BHL), the skin outline, and the heart; and setup margins were calculated for the PTV. The calculated PTV margins were

4.3 to 6.3 and 2.8 to 4.6 mm before and after orthogonal imaging, respectively. The residual errors of the heart were 3.6 ± 2.2 mm and 2.5 ± 2.4 mm before and 3.0 ± 2.5 and 2.9 ± 2.3 mm after orthogonal imaging in the combined anterior-posterior/lateral and the cranio-caudal directions, respectively, in tangential images. The humeral head did not benefit from daily IGRT, but SGRT guided it to the correct location. We presented a slightly complicated but highly accurate workflow for DIBH treatments. The residual position errors after both SGRT and IGRT were excellent compared to previous literature. With well-planned SGRT, IGRT brings only slight improvements to systematic accuracy. However, with the calculated PTV margins and the number of outliers, imaging cannot be omitted despite SGRT, unless the PTV margins are re-evaluated.

 

As of January 1, 2022, ARRT requires CE Credits for Directed Journal Readings to be based on the word count for each article. So, the number of CE Credits for each DJR article will vary for ARRT. For this article, the ARRT CE Credit will be 1 Credit. The MDCB CE Credits will remain at 2.5 Credits.