|
Table of Contents
|
Matching tangential fields with the Supraclavicular field
A) The superior edge of the tangential beams can be made perfectly vertical by means of the "hanging block" technique
B) The superior edge of the tangential beams can be made perfectly vertical by avoiding rotation with the use of a rotating beam splitter.
PMRT w/o AXILLARY BOOST (based on SWOG 9927)
Supraclavicular Field
| Top | cricothyroid membrane but do not flash the shoulder |
|---|---|
| Inferior | inferior clavicular head |
| Medial | 1 cm contralateral to anterior midline |
| Lateral | bisect coracoid process |
| Gantry | 10-15 degrees to avoid trachea, esophagus and spinal cord. |
Note: this does not treat the "axilla"
1/2 beam block the SC field to avoid divergence to tangent fields
Chest Wall Fields
| Medial | 5 cm into the ipsilateral chest wall from the med-stermun |
|---|---|
| Lateral | Mid-axillary line |
| Superior | Mached to Surpaclavicular field |
| Inferior | 1 cm inferior to inframammary fold |
Technique A (Tangents + IM Fields)
Internal Mammary Electron Field
Medial-lateral
- 1 cm contral-lateral of the midline to tangent field. ||
Superior-inferior
- length of the tangent field
- Interspace 1-3 should be marked and the IMC field can be split into two field so that separate electron energies can be used to cover the depth of the IMN.
Internal Mammary Photon Field
- Anterior photon field can be used up to 5 treatment to spare the skin
- Inferior border is at the tip of the xyphoid otherwise same as IM electron field.
Technique B (Partial Deep Tangents)
Superior Tangents
Cover IMN 1-3
Limit lung to 3.0 cm. If this is not possible use alternate technique.
Inferior Tangents
Eliminate incidental cardiac irradiation
electrons to inferior medial and/or lateral aspect may be needed
Technique C (Electrons)
90% of isodose line should encompass the nodes
6-12 MeV should be used for the IMN
6-9 MeV are sufficient to cover chest wall.
If energies in excess of 12 MeV are needed alternate plan need to be used due to concerns of pneumonitis.
Technique D (IMRT)
Bolus
- Photon field should be bolused every other day with 1 cm or 0.5 cm.
- Reconstructed breasts should also receive bolus.
- Electron field should not require bolus.
Dose
- 50 Gy in 2 Gy fractions
- 50.4 Gy in 1.8 fractions
- 10 Gy boost in 2 Gy fractions
IRRADIATION OF REGIONAL LYMPHATICS
Supraclavicular Lymph Nodes
| Top | cricothyroid membrane but do not flash the shoulder |
|---|---|
| Inferior | inferior clavicular head |
| Medial | 1 cm contralateral to anterior midline, following the medial border of the sternocleidomastoid muscle |
| Lateral | bisect coracoid process Lateral to Humoral Head |
| Gantry | 10-15 degrees to avoid trachea, esophagus and spinal cord. |
Note: this does not treats the "axilla"
1/2 beam block the SC field to avoid divergence to tangent fields
(AP/PA) supraclavicular/axillary fields may be reasonable when the axillary and supraclavicular nodes are deep.
Posterior Axillary Boost
| Top | split the clavicle |
|---|---|
| Inferior | match supraclavicular field |
| Medial | 1.5-2.0 cm of lung |
| Lateral | posterior axillary fold |
| Gantry | 10-15 degrees to avoid trachea, esophagus and spinal cord. |
