Have you ever faced a situation where getting a patient into the correct position for their radiotherapy has been challenging? Do you ever worry that monitoring your patients’ every move by visually watching a camera is erroneous? Would you like to be able to offer patients radiotherapy treatment without always having to use a permanent mark? If you can relate to this, then learn how surface guided radiotherapy (SGRT) integrated on the Radixact® System can enhance your clinics’ efficiency and accuracy as well as the patient experience.
SGRT is rapidly becoming a game-changer in the field of radiotherapy, with data showing it can potentially reduce up to 21% of errors associated with radiation treatments [1]. In recent years, SGRT has primarily been used with C-arm linacs, but now it is possible to provide SGRT on the helical ring gantry linac known as the Radixact System [2].
Integrating an SGRT system with the Radixact System is fundamental to performing optical patient setup, monitoring, and breath-hold gating deliveries.
SGRT Integration with the Radixact System
In collaboration with C-RAD, the VitalHold™ package incorporates three high definition Catalyst+ HD™ cameras that project optical imaging onto the patient’s surface, offering three critical functionalities on the Radixact System:
1. Surface-Guided Daily Patient Setup
Using optical setup, the user can align the patient’s external surface to their reference surface in real-time. The reference surface is typically established during CT simulation and determines the coordinates to shift the patient to align the external surface to the reference surface. The user can view the coordinate information displayed on the treatment delivery console and accept the shifts and proceed to register and treat the patient. Optical setup can make patient positioning faster and more efficient compared to manually setting up the patient. Additionally, it can potentially allow clinics to go tattoo-free, reducing anxiety to patients. Having a permanent mark for radiotherapy localization purposes can cause stress to patients, acting as a constant reminder of their treatment.
2. Breath-hold Gating using TomoDirectTM
For deep inspiration breath hold (DIBH) treatments, VitalHold utilizes the central camera to synchronize beam delivery with the patient’s breathing pattern. The SGRT system determines when to gate the megavoltage (MV) beam based on the patient’s breathing amplitude. The MV beam can pause in less than 100 milliseconds and resume in less than one second. In contrast with other linacs, the Radixact System treatment beam is truly shut off and not simply blocked by a closed MLC. This method of true beam off helps to ensure the patient is not exposed to any leakage radiation. DIBH is particularly beneficial for patients with left sided-breast cancer, increasing the distance between the heart and the chest wall. It minimizes radiation doses to the heart and ipsilateral lung, helping to reduce the risk of coronary and pulmonary complications [2].
3. In-Bore Position Gating
Position gated deliveries behave similarly to that of breath hold gated deliveries, but instead of gating the treatment beam due to breath hold, the beam is gated when the patient moves outside of predetermined position threshold. Positional changes including postural movement such as an arm or shoulder moving out of position are monitored in real-time. Position gating thresholds can be determined at CT simulation or at the delivery bunker. The central camera captures subtle movements that might be missed by the console cameras. The beam will pause in less than 100 milliseconds and the user can resume treatment when ready. In this use case SGRT acts as an additional layer of precision providing real-time visibility throughout the entire radiotherapy process, giving users and patients the confidence in accurate treatment delivery.
Enhancing Patient Precision and Throughput with VitalHold
The VitalHold package is designed to optimize patient setup, aid monitoring during treatment and facilitate DIBH treatments with seamless integration.
Beyond its technical advantages, VitalHold is designed for simplicity and efficiency in clinical settings. Its seamless integration with the Radixact System workflow enables healthcare providers to optimize treatment delivery. This not only enhances patient throughput but also reduces overall treatment times. For instance, average treatment sessions on the Radixact System can be completed in just 10 minutes door-to-door.
Feasibility of SGRT and the Radixact System in the Clinic
A recent study demonstrated the compatibility, feasibility, and benefits of combining DIBH, SGRT and fixed-angle beams (TomoDirect) on the Radixact System for breast cancer patients. The DIBH plans significantly (p<0.001) lowered the mean radiation doses to the heart and left anterior descending artery (LAD) compared to free breathing plans, demonstrating the dosimetric advantages of combining these modalities. In addition, it was noted that the integration of high-resolution imaging, such as ClearRT® kVCT, can significantly reduce positioning uncertainty and allow for detailed inspection of anatomical changes in the treatment area. Unlike conventional C-arm linacs, which require multiple breath holds, the kVCT scans on the Radixact System were acquired in a single breath-hold, enabling quick and reliable verification of patient anatomy and positioning before treatment. Furthermore, it was found that SGRT can facilitate patient positioning, reducing on-couch time [2].
Image courtesy of: Kadhim M et al. Surface guided ring gantry radiotherapy in deep inspiration breath hold for breast cancer patients. J Appl Clin Med Phys. 2024 Aug 13:e14463. doi: 10.1002/acm2.14463. Epub ahead of print. PMID: 39138877.
SGRT technology on the Radixact System is not restricted to a single treatment case – it has been utilized in various clinical applications since its implementation, including total marrow irradiation (TMI), total skin irradiation (TSI) and total body irradiation (TBI). You can read the full paper HERE.
Clinical Example of DIBH with VitalHold in a Left-sided Breast Cancer Patient
Clinic: Sahyadri Superspeciality Hospital, Hadapsar, Pune, Maharashtra, India
Patient Profile:
A 45-year-old woman was diagnosed with pT2N1M0 invasive ductal carcinoma of the left breast. She underwent breast conservation surgery with axillary dissection, followed by chemotherapy and radiation therapy.
Radiation Therapy Details:
Radiation therapy was administered using the Radixact System with VitalHold, enabling DIBH.
- Dose: 40 Gy in 15 fractions to the left breast and supraclavicular fossa (SFC)
- Treatment Plan: VOLO™ Ultra Optimizer with Accuray Precision® Treatment Planning System
- Delivery Mode: DIBH with TomoDirect
- Treatment Time: 4.5 minutes per session
Outcome:
The patient tolerated the treatment well, maintaining a consistent breath hold throughout the sessions with no complications. The combination of VOLO Ultra and VitalHold was effective in helping minimize the radiation dose to the heart, contributing to a successful treatment experience.
“The Radixact System not only improves accuracy and safety but also prioritizes patient comfort and experience. This makes it a compelling choice for DIBH treatment, setting higher standards in radiation therapy.”
Conclusion
By integrating SGRT with the Radixact System, VitalHold helps empower healthcare providers to deliver precise, personalized and efficient treatments across a broad spectrum of patient cases. This innovation represents a significant step forward in enhancing the quality and efficiency of radiotherapy treatments.
Learn More About VitalHold on the Radixact System
References:
- Al-Hallaq HA, Batista V, Kügele H, Ford E, Viscariello N, Meyer J The role of surface-guided radiation therapy for improving patient safety. Radiotherapy and Oncology 2021;163:229–236. https://doi.org/10.1016/j.radonc.2021.08.008
- Kadhim M, Haraldsson A, Kügele M, Enocson H, Bäck S, Ceberg S. Surface guided ring gantry radiotherapy in deep inspiration breath hold for breast cancer patients. J Appl Clin Med Phys. 2024 Aug 13:e14463. doi: 10.1002/acm2.14463. Epub ahead of print. PMID: 39138877. https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.14463
