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
Last Modified: October 6, 2002
Presenter: F. Campostrini1
Presenter's Affiliation: Department of Radiation Oncology, ASL 21, Legnago, IT
Type of Session: Scientific
- 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.
- 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.
- 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.
- 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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