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
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Last Modified: October 6, 2002

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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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