4D CT scan visualization for lung cancer treatment.

Breathe Easier: How 4D Imaging is Revolutionizing Lung Cancer Treatment

Lena Voss in Health & Wellness November 2025 • 5 min read.

"Discover how 4D computed tomography (4D CT) is transforming stereotactic body radiotherapy (SBRT) for non-small cell lung cancer, offering personalized and precise treatment strategies."

The landscape of cancer treatment is constantly evolving, with technological advancements paving the way for more precise and effective therapies. Radiotherapy, a cornerstone in cancer care, has particularly benefited from these innovations. The goal is always accuracy, precision, and conformity—delivering the right dose to the right place, minimizing harm to surrounding healthy tissues. Modern medical electron linear accelerators have made it possible to treat even small, irregularly shaped lesions with remarkable accuracy, using advanced techniques like intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT).

Among these advancements, Stereotactic Body Radiotherapy (SBRT) has emerged as a powerful tool, especially for early-stage non-small cell lung cancer (NSCLC). SBRT involves delivering high doses of radiation to a precisely targeted tumor in just a few sessions. However, its success hinges on accurately accounting for tumor motion, which can be significant in the lungs due to breathing. This is where four-dimensional computed tomography (4D CT) comes into play, offering a way to capture and manage this motion.

The challenge? Not all patients require the same level of motion management. Some tumors exhibit minimal movement, while others move considerably with each breath. Understanding this variability is crucial for tailoring treatment plans and avoiding unnecessary interventions. This article delves into how 4D CT imaging is used to select the right patients for gated SBRT, ensuring that motion management strategies are applied judiciously and effectively, optimizing treatment outcomes while minimizing patient burden.

4D CT: A Game Changer in Lung Cancer Radiotherapy

4D CT scan visualization for lung cancer treatment.

Conventional CT scans provide a snapshot in time, a static image of the tumor. However, tumors in the lungs are far from static; they move with respiration, cardiac activity, and even digestion. This movement can blur the target, leading to inaccurate treatment delivery and potential damage to healthy tissue. 4D CT addresses this by capturing a series of images over the entire breathing cycle, creating a dynamic view of the tumor's motion. This allows clinicians to:

Define the Internal Target Volume (ITV): The ITV represents the area the tumor occupies throughout the breathing cycle. By delineating the tumor in each phase of the 4D CT scan and combining these outlines, clinicians can create a comprehensive target that accounts for motion.

Accurately assess tumor motion during respiration.
Create personalized treatment plans that account for individual breathing patterns.
Minimize the risk of missing the target due to movement.
Reduce the amount of healthy tissue exposed to radiation.

Manage motion effectively: With 4D CT, doctors can now determine best plan to reduce chances of the cancer cells surviving after the treatment. By understanding how much and in what manner the tumor moves, they can select appropriate motion management techniques, such as gating (delivering radiation only during certain phases of the breathing cycle) or tumor tracking (adjusting the radiation beam in real-time to follow the tumor's movement).

Personalized Radiotherapy: The Future of Lung Cancer Treatment

4D CT imaging is more than just a technological advancement; it's a paradigm shift in how we approach lung cancer radiotherapy. By providing a dynamic and personalized view of tumor motion, 4D CT allows clinicians to tailor treatment plans to each patient's unique needs, maximizing the chances of success while minimizing the risk of side effects. This personalized approach is the future of lung cancer treatment, ensuring that every patient receives the most effective and appropriate therapy for their specific situation. With continued advancements in imaging and treatment techniques, the outlook for individuals with lung cancer is brighter than ever before.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1017/s1460396918000614, Alternate LINK

Title: Selection Of Patient For Gated Treatment Based On The Information From 4Dct Imaging In Stereotactic Body Radiotherapy Of Non-Small Cell Lung Cancer

Subject: Oncology

Journal: Journal of Radiotherapy in Practice

Publisher: Cambridge University Press (CUP)

Authors: N. V. N. Madhusudhana Sresty, A. Krishnam Raju, S. D. Sharma, T. Anil Kumar, Shabbir Ahamed, Harjot Kaur Bajwa

Published: 2018-11-14

Everything You Need To Know

How does 4D CT improve lung cancer radiotherapy compared to traditional CT scans?

4D CT, or four-dimensional computed tomography, captures a series of images throughout the entire breathing cycle, providing a dynamic view of the tumor's motion. This contrasts with conventional CT scans, which offer only a static snapshot in time. This dynamic view allows clinicians to define the Internal Target Volume (ITV) more accurately and to understand how the tumor moves, which is critical for precise and personalized treatment planning in Stereotactic Body Radiotherapy (SBRT).

Why is accounting for tumor motion so important in Stereotactic Body Radiotherapy (SBRT) for non-small cell lung cancer (NSCLC), and how does 4D CT help with this?

Stereotactic Body Radiotherapy (SBRT) delivers high doses of radiation to a precisely targeted tumor in a few sessions. The success of SBRT for early-stage non-small cell lung cancer (NSCLC) depends on accurately accounting for tumor motion due to breathing. Without accounting for this motion, the radiation may not effectively target the tumor or may damage surrounding healthy tissue. 4D CT helps manage this by allowing clinicians to define the Internal Target Volume (ITV) and adjust the treatment plan accordingly, potentially using techniques such as gating or tumor tracking.

In what ways does 4D CT imaging contribute to personalized radiotherapy for lung cancer patients?

4D CT imaging enables personalized radiotherapy by providing clinicians with a detailed understanding of a tumor's movement during respiration. This allows for treatment plans tailored to each patient's unique breathing patterns and tumor characteristics. By using the information from 4D CT to define the Internal Target Volume (ITV), clinicians can select appropriate motion management techniques like gating or tumor tracking, ensuring the radiation is accurately delivered and minimizing harm to healthy tissue. This level of personalization optimizes treatment outcomes for non-small cell lung cancer (NSCLC).

How does 4D CT assist in determining the suitability of patients for gated SBRT, and why is this selection process important?

Gated SBRT is a radiation delivery technique where radiation is administered only during specific phases of the breathing cycle. 4D CT imaging helps determine which patients are suitable for gated SBRT by assessing the extent and pattern of their tumor's motion. If a tumor exhibits significant movement, gating ensures that radiation is delivered when the tumor is within the planned target area, improving precision and reducing the exposure of healthy tissue. The use of 4D CT in this selection process avoids unnecessary interventions and optimizes treatment outcomes. Tumour Tracking is another motion management technique that can be used instead.

What is the Internal Target Volume (ITV), and why is it so important in 4D CT-guided lung cancer treatment?

The Internal Target Volume (ITV) is a crucial concept in 4D CT-guided radiotherapy. It represents the entire area that a tumor occupies throughout the breathing cycle. By delineating the tumor in each phase of the 4D CT scan and combining these outlines, clinicians can create a comprehensive target volume that accounts for tumor motion. Accurate determination of the ITV ensures that the radiation plan covers the tumor throughout its range of motion, improving treatment efficacy and minimizing the risk of missing the target due to respiratory movement during Stereotactic Body Radiotherapy (SBRT).