Page 22 - ARNM-2-1

Advances in Radiotherapy &

Nuclear Medicine

ORIGINAL RESEARCH ARTICLE
Assessing the adequacy of a 5-mm planning

target volume margin for 4D-CT scan-based
image-guided radiotherapy for locally advanced

carcinoma of the lung

1
1
Animesh Saha *, Aditi Mishra , Shreya Manna , Ajay Banik ,
1
1
1
1
1
Suchanda Goswami , Jibak Bhattacharya , Tanmoy Mukhopadhay ,
2
2
Prosenjit Soren , Sayantan Mondal , Saptaswa Chattopadhyay , Biplab Sarkar ,
2
2
Suvra Biswal , Kiruba George , Mousin Gazi , and Sandipan Roy Chowdhury 2
2
2
2
1 Department of Radiation Oncology, Apollo Multispeciality Hospitals, Kolkata, West Bengal, India
2 Department of Medical Physics, Apollo Multispeciality Hospitals, Kolkata, West Bengal, India
Abstract
In developed nations, 4D-computed tomography (4D-CT)-based image-guided
radiotherapy (IGRT) has become the standard for treating lung carcinoma
patients, with the primary goal of achieving disease cure. However, its usage in
India remains limited. Here, we compared target volume delineation for radical
radiation planning in patients with locally advanced lung carcinoma using helical
*Corresponding author: free-breathing CT (FBCT) and 4D-CT. In addition, we assessed the adequacy of a
Animesh Saha
(720292@apollohospitals.com) 5-mm planning target volume (PTV) margin with 4D-CT planning. Fifty patients
with locally advanced lung cancer were enrolled in the study. Each patient
Citation: Saha A, Mishra A,
Manna S, et al. Assessing the underwent contouring based on 4D-CT to generate an internal target volume,
adequacy of a 5-mm planning target and a 5-mm PTV margin (PTV_4D) was added for radical radiation. Subsequently,
volume margin for 4D-CT scan- each patient underwent two intensity-modulated radiation therapy (IMRT) plans
based image-guided radiotherapy
for locally advanced carcinoma of with comparable planning and optimization parameters. One plan was based on
the lung. Adv Radiother Nucl Med. the FBCT-based volume (PTV_3D), while the other was based on the 4D-CT-based
2024;2(1):2784. volume (PTV_4D). PTV, organ at risk (OAR) dose, and PTV coverage by 95% of the
https://doi.org/10.36922/arnm.2784 prescribed dose (PTVD 95_3D vs. PTVD 95_4D) were compared between the two
Received: January 19, 2024 schemes. Results revealed that 4D-CT-based planning reduced PTV (mean PTV
Accepted: March 12, 2024 volume: 539 cc vs. 782 cc) and lowered OAR doses (mean lung dose: 13 Gy vs.
15 Gy; mean esophagus dose: 18.5 Gy vs. 21.15 Gy; mean spinal cord max dose:
Published Online: March 27, 2024 35.59 Gy vs. 37.39 Gy). At 3 months after treatment imaging, 40% of the patients
Copyright: © 2024 Author(s). showed a complete response, 48% showed a partial response, 4% showed stable
This is an Open-Access article disease, and 8% showed progressive disease. In conclusion, 4D-CT-based radiation
distributed under the terms of the
Creative Commons Attribution planning for locally advanced lung carcinoma with a reduced PTV margin of 5 mm
License, permitting distribution, can dramatically decrease the PTV and OAR doses without sacrificing PTV coverage
and reproduction in any medium, compared to FBCT-based planning. However, daily online image guidance or at
provided the original work is
properly cited. least a well-defined offline image guidance protocol is recommended when
employing such a small PTV margin.
Publisher’s Note: AccScience
Publishing remains neutral with
regard to jurisdictional claims in
published maps and institutional Keywords: Lung cancer; 4D-CT; Image-guided radiotherapy; Planning target volume
affiliations.

Volume 2 Issue 1 (2024) 1 https://doi.org/10.36922/arnm.2784