Preauricular Field

  • Inferior border: match the Mantle
  • Posterior: external auditory canal
  • Superior: zygoma
  • Anterior: anterior masseter muscle
  • Treat with 6 – 9 MeV electrons

Waldeyer's Field

  • Above is the large Waldeyer Field
  • Includes: submandibular
  • preauricular
  • occipital
  • high cervical nodes
  • Inferior: match mantle low in the neck

Unilateral neck


If only the involved neck is being considered for treatment on this study, please note that the protocol
specified margins must be followed. In the treatment of children the medial field border nearly always
must cross the midline and include all of the vertebral body in order to have the appropriate margin for
treatment. The superior border should extend from the midpoint of the chin through the mid-tragus. This
should provide at a minimum of 2 cm margin at the tip of the mastoid. The inferior border must be
1.5 cm below the clavicle. Small blocks of the oral cavity and spine are not permitted as they often
impose on areas of involvement and do not provide for an adequate margin. The lateral field border
should be determined by the most lateral extent of disease on the CT study of the neck.

Unilateral axilla


Arms should preferably be positioned akimbo (hands on hips) as the arms-up position may place areas of
involvement into the parallax of the humeral head. The CT image is crucial to the design of these fields
as interpretation of soft -tissue images can vary among institutions. These field borders, accordingly, will
vary based on extent of disease at presentation. Please note that disease in the anterior axillary line
resides medial to the lateral chest wall, therefore there is often more of the superior aspect of the lung in
the axillary treatment field than a traditional mantle field. The humeral head should be shielded if

Mantle Field


Para-aortic-spleen Field

  • if the spleen is intact, the entire spleen is treated.

Pelvic Field


Supra and infradiaphragmatic fields

Separate Surpa- and infradiaphragmatic Fields

  • A 4-week rest may be given between supradiaphragmatic and infradiaphragmatic field.
  • A gap between the portals must be calculated as described in Section 6.37 under Gap Calculation.
  • Posterior "cheater" block should be used.

Gap Calculation

  • 50% lines of the superior and inferior adjacent fields match at the midplane of the patient.
  • Superior and inferior margins of the fields overlapping the spinal axis should be tattooed for possible future reference.

Single Surpa- and infradiaphragmatic Fields

  • Alternatively, when the supradiaphragmatic field includes a full mantle with coverage of the inferior mediastinum, a single "extended" field may be used, avoiding the necessity for a gap.
  • In that case, the inferior border of the para-aortic field should be no lower than the bottom of L2 (see Appendix VII, Figure 13 for composite diagram).
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