A Scintigraphic Method for Quantitation of Lymphatic Function in Arm Lymphedema

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Physiology

Background:

• Lymphoscintigraphy is a standard tool for evaluating breast cancer-related lymphedema.
• Current methods lack reliable quantitative measures to distinguish normal lymphatic function from lymphedema.
• There is a need for precise quantitative assessment of lymphatic function in the arm.

Purpose of the Study:

• To develop and validate a quantitative method for assessing arm lymphedema.
• To utilize the physiological mean transit time (MTT) of lymph fluid for quantitative analysis.
• To differentiate lymphatic function in lymphedema-affected arms versus normal arms.

Main Methods:

• Simultaneous bilateral lymphoscintigraphy was performed on 11 patients with unilateral arm lymphedema.
• ^99mTc-labeled human serum albumin (HSA) was injected intradermally.
• A quantitative model based on convolution of input and retention functions was used to calculate MTT from time-activity curves.

Main Results:

• The proposed model accurately described measured time-activity curves.
• Mean transit time (MTT) in the lymphedema arm (mean 60.1 min) was significantly longer than in the normal arm (mean 5.4 min) (p < 0.0001).
• The MTT measure effectively distinguished between normal and lymphedematous lymphatic function.

Conclusions:

• The developed quantitative model shows high fidelity with measured data.
• Calculated MTT provides a reliable method to quantitatively assess lymphatic function in the arm.
• This approach successfully differentiates lymphedema from normal lymphatic function, aiding in clinical assessment.