Comparison Between Weight-Based Variable-Voltage and Fixed Volume-Voltage Protocols in Cancer Surveillance Computed...

Area of Science:

• Radiology
• Medical Imaging
• Oncology

Background:

• CT scans are crucial for cancer surveillance.
• Contrast media administration impacts scan quality and patient safety.
• Optimizing contrast protocols is essential for efficient cancer patient care.

Purpose of the Study:

• To evaluate a weight-based, variable tube voltage (SMART) protocol against a fixed contrast, fixed tube voltage (OLD) protocol for CT chest, abdomen, and pelvis (CAP) scans.
• To determine if the SMART protocol can reduce contrast dose without compromising contrast enhancement in oncology patients.
• To assess the impact on radiation dose (DLP and CTDIvol) with the SMART protocol.

Main Methods:

• 149 oncology patients underwent two surveillance CT CAP scans, one with the OLD protocol and one with the SMART protocol.
• Contrast volume, CT attenuation (Hounsfield units) at key anatomical sites, dose-length product (DLP), and CT Dose Index volume (CTDIvol) were recorded for both protocols.
• Statistical analysis focused on comparing contrast volume, enhancement levels, and radiation dose between the two protocols.

Main Results:

• The SMART protocol utilized a median contrast volume of 80 mL, a 20% absolute reduction compared to the OLD protocol's 100 mL.
• Non-inferior Hounsfield unit (HU) values, indicating comparable contrast enhancement, were observed with the SMART protocol across all measured sites.
• The SMART protocol resulted in a 19% decrease in DLP and a 9% decrease in CTDIvol, signifying reduced radiation exposure.

Conclusions:

• The weight-based contrast, variable tube voltage (SMART) protocol effectively reduces contrast volume in CT CAP scans for cancer patients.
• This protocol achieves significant contrast dose reduction without compromising diagnostic image quality or contrast enhancement.
• The SMART protocol also leads to a reduction in radiation exposure, offering a safer and more efficient imaging option.