The Importance of Head and Neck Lymphoscintigraphy in the Determination of Planning Target Volume for Radiation Therapy of Cephalo-Cervical and Aerodigestive Tumors

Reviewer: William Levin, MD
OncoLink
Last Modified: October 6, 2002

Presenter: F. Campostrini1
Presenter's Affiliation: Department of Radiation Oncology, ASL 21, Legnago, IT
Type of Session: Scientific

Background

Cancers of the head and neck region commonly spread throughout the body via the lymphatic system.
Radiation therapy can be employed to treat such cancers.
Radiation, when used, is typically given to the region of the primary tumor as well as to the neck, where lymph nodes are located.
Lymphoscintigraphy(LS) is a nuclear medicine technique allowing for visualization of lymph nodes.
The current study looks at the use of LS in regards to it's ablity to help locate neck lymph nodes in patients receiving radiation therapy.

Materials and Methods

28 patients with clinically negative lymph nodes were enrolled on this study.
The majority of patients had cancers of the oropharynx, larynx, or oral cavity.
Standard simulation was performed by 3 radiotherapists, at which time the planning treatment volume(PTV) was identified.
Technetium-99 nanocolloids were then injected at four sites (two frontal and two occipital) on the patients' scalp to identify the lymphatic drainage of the neck.
3 hours later, a gammacamera was used to obtain images in the anterior and lateral positions.
The radiotherapists then reviewed the PTV's in relation to the LS images.

Results

LS caused no significant patient discomfort, nor was it related with any significant side-effects.
Information gained by LS resulted in 70% of the original treatment plans being altered.

Author's Conclusions

LS is a safe and effective method of identifying the lymph nodes treated in head and neck cancers.
LS allows for more accurate design of radiation treatment fields and potentially, better results.
By more precisely identifying treatment fields it is posssible to exclude uninvolved critical structures such as the spinal cord.

Clinical/Scientific Implications

LS is a potentially valuable tool for determining radition treatment volumes in head and neck cancer patients.
It is likely, however, that this technique is highly operator dependent, and has a learning curve.
Therefore, clinician experience with this technique is required to ensure accuracy.

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