Breast Exams:

Mammograms :

• Baseline should be taken at 35 and after 40 regular mammograms each year for a normal female
• Baseline at 30 and regular mammograms at 35 for a woman with familial incidence of breast cancer

Self Breast Exams should be done every month at the SAME TIME of the month.   Should be done on Day 10 of the Menstrual Cycle which should be about 5 days after her period ends.

Day 1 is the first day of menses

Nulliparous – a woman that has never given birth

Tail of Spence – breast that protrudes in the axillary region

If a woman has had a baby before the age of 20 she has ½ the chance of developing breast cancer compared to a woman who has had her first child over the age of 30

RADIATION THERAPY:

Radiation is also used as an adjuvant to surgery when treating breast cancer.  The whole breast will be irradiated to prevent recurrance in the area.

Radiation can also be used as the Primary Treatment when surgery cannot be performed

When used with a Lumpectomy we should consider Radiation as the Primary Treatment

Typical Doses:

For Small and Regular Size breasted Woman : a dose of 5000 cGy would be given to the Tangents and a boost of 1000 cGy would be given with electrons (total dose = 6000 cGy)

For Larger Breasted Woman : a dose of 4500 cGy would be given to the tangents with a dose of 1500 cGy with electrons (total dose = 6000 cGY)

• larger breasted woman would not be given as large a dose as smaller breasted woman because the entrance dose would be too large

Energy is chosen on the basis of patient seperation : for average patients with a separation of 22cm or lower typically 6Mv Photons are used

For patients with a separation of 22cm or greater usually 10 – 16 Mv is used (this is because the 50% line for a 6Mv Photons is about 10cm so with a seperation of 22cm or greater the 50% line would not be midline on the breast and midline would be underdosed)

For All of Radiation Therapy we want the isodose lines to be within 5% of total dose to be given (Not to exceed 5%)

Note About Lung Tolerance:

• Tolerance for the onset up pneumonitis is 2500 cGy to the Lung and usually presents around 1 - 3 months after treatments
• Tolerance for fibrosis is 4500 cGy and usually presents around 7 - 10 months after treatments 9has a longer latent period than pneumonitis
• we usually include 2 cm of lung when treating tangents to the breast and must be careful that we do not exceed this limit.  Patients know that they will recieve some fibrosis on the outer edge of the lung

BREAST SETUPS:

When setting up a breast:

To find the sternum you would palpate the Suprasternal Notch (SSN) and the Zyphoid Notch

For a typical breast field the borders are:

• Medial : 1cm from the Breast Tissue medially, which would fall midline of the sternum
• Laterally : midaxillary (2 cm below the lateral aspect of breast tissue)
• Inferiorly : 2-3 cm below the inframammary fold (for patients post mastctomy the inferior border can be extrapolated from the inframammary fold of the contralateral breast)
• Superiorly : first intercostal space, superior extent of the breast tissue

To reduce match fields with breast setups (3 Field or to match the beams evenly across the lung) coplaner setups would be used.

Coplaner - divergences meet instead of the central axis meeting

*** this is only for Square Field sizes!!! If assymetrical jaws are used the angle will be 180 degrees

Borders for the a SupraClavicular Field Are:

• Medial : SupraSternal Notch (SSN)
• Lateral : 3cm of the humeral head must be included
• Superiorly : 5 cm up from the SupraSternal Notch (SSN)
• Inferiorly : the superior border of the tangent fields

Also with the Supraclavicular Field :

• when matching the Supraclavicular field to the tanget field to reduce the divergence you would close the field down to midline (asymmetrical)
• when treating the Supraclav Field AP whe would angle the beam laterally 10 - 15 degrees to prevent treating the spinal cord
• When treating the tangets to accommodate for the divergence you would kick the couch towards the head of the gantry/collimator to reduce tangential divergence (foot of the couch is angles away from the gantry/collimator)
• Humeral Head is blocked out of the field for 1 of 2 reasons: to protect the blood supply to the humeral head to prevent frozen shoulder or to protect the hematopoetic tissue (bone marrow)
• Also we block the spinal cord, trachea and the larynx with a midline block (externally we can use the sternocleidomastiod muscle to know that all of these structures are out of the field)

For Treating a IMN Field:

• Tangents are used and a electron field might be abutted to the medial aspect of the medial field (MIXED BEAM : electrons and photons)
• Would just keep the gantry at the medial treatment angle and add electrons to that
• Field would be matched with the medial border of the tangent field
• Must be careful not to include to much lung or heart volume into the fields that’s why electrons are preffered to treat the IMN

Electrons Boost:

• 2 cm is used around the scar or surgical clips if they are used. (area where the tumor was located / sometimes the scars are in a different location due to the surgeon  tunneling for cosmetic reason)
• Electron Cut-Out is used
• Electron Energy and Percent lines are chosen to treat to a certain depth in the patient to where the tumor was to include the entire tumor bed.

Physics Review of Electron Beams :

• PDD is much shallower for an electron beam than for X or gamma rays of the same energy
• 6 Mev to over 20 Mev
• treatment is generally prescibed to the 80% or 90% level because electron beams do not penetrate as deeply into tissue

Some Generalities about electron Beams :

• dose to skin can be anywhere from 80% to 90% of the Dmax dose, with the skin dose increasing with an increase in energy (because of exitiation, electons will bounce back and out of patient)
• the depth to the 90% level is approximately equal to Mev/4
• the depth to the 80% level is approximately equal to Mev/3
• the depth to the 10% level is approximately equal to Mev/2 - ½
• the range of electrons is approximately equal to Mev/2

Survival

Not based on the typical 5 year like most other cancers.  Based Upon 10 years because that is how long it will take for the cancer to recur or spread.

• If patients have mets the survival rates drop dramatically