1. Radiation Oncology
Demystified

2. Patient Populations We Treat
Early Breast Cancer (incl. DCIS): post-lumpectomy
Locally Advanced Breast Cancer: post-Mastectomy
Recurrent Breast Cancer: chest wall nodules
Metastatic Breast Cancer: bone mets, brain mets
Not LCIS
Not DCIS if s/p Mastectomy

3. Think Twice Connective Tissue Disorder, esp. Scleroderma Really young
Really old
Previous Radiation Therapy to same site
History of Radiation Induced Malignancies

4. Special Cases Reconstruction Bilateral (Ca and/or Reconstruction)
Comorbidities (such as diabetes, CTDs, CVD, asthma, lymphedema, port, genetic predisposition to malig)
Tight Arm after Axillary Lymph Node Dissection
Previous Radiation Therapy Tx, or Rad Exposures
On systemic treatments that may affect healing or scarring (antiangiogenic; taxoxifen)
On herbals and/or high dose vitamins

5. Targets Breast Chest Wall Supraclavicular/Axillary Apex Partial Breast
Operative Bed
Recurrent Chest Wall Nodules
Bone Mets
Brain Mets

6. Beams Photons Electrons (boost, intraop) Orthovoltage (TARGIT)
Additional Devices
Bolus
Tattoos
Custom Bra
Hyperthermia
Port films

7. Skin Care Moisturizers Antifungal/Antinflammatory Astringent Soaks
Mepilex
Mesh “Bra”
Avoid Underwire
Moisturize Irradiated Skin Forever!
Follow Up

8. Simulation

9. CT-based Treatment Planning

10. E- Beams

11. Photon Beams: Single 6 or 18 MV
cobalt
flounder posted this in Radiation Therapy on August 17th, 2009
If we were to treat this patient with a single beam of radiation with an energy of 6 MV, the resulting dose distribution would look like the red curve in Figure 1. You can see that while the tumor is receiving the correct dose (100 cGy), the shallower normal tissue is receiving a much higher dose. If we were to use a higher energy, such as 18 MV, the dose distribution would look like the blue curve. Since the beam penetrates farther, the dose to shallower tissue is less, but still more than the tumor receives. In some cases this might be ok, but others will need a better plan.

12. Photon Beams: Parallel Opposed
flounder posted this in Radiation Therapy on August 17th, 2009
To improve the distribution we can add a second beam on the other side of the patient. This arrangement is called parallel opposed fields and is shown in Figure 2. The yellow lines are the edges of the treatment beam, and the red circle is the location of the tumor.
Figure 3 shows the dose distribution along the axes of the beam for a 6 MV beam. We can see that the dose to normal tissue is lower than with a single beam, but still slightly higher than the tumor dose. In addition, there are now two spots with a high dose. Figure 4. Using higher energy beams will lower the dose to the normal tissue.
Figure 4 shows the difference in maximum dose for a 6 MV and an 18 MV pair of beams. Again, increasing the beam energy helps reduce the ratio of normal tissue dose to tumor dose.

13. Photon Beams: 6 vs. 18 MV parallel opposed
flounder posted this in Radiation Therapy on August 17th, 2009
This Figure shows the difference in maximum dose for a 6 MV and an 18 MV pair of beams. Again, increasing the beam energy helps reduce the ratio of normal tissue dose to tumor dose. But also less dose superficially.

14. Tangents

15. Dose Cloud Technique (IMRT)
Successive Cone Downs on Medial and Lateral Tangential Fields, For example:
65 cGy
10 cGy
15 cGy
= 90 cGy +
Medial Field 1
Medial Field 2
Medial Field 3
Heart Block
Dynamic Leaves Computerized

16. CT based Treatment Planning

17. Direct AP Photon Field For IMC
What might the plan look like if we treated the internal mammary nodes?
Direct AP Photon Field For IMC
Too Much Heart
Hockey-stick
OLD DAYS

18. What might the plan look like if we treated the internal mammary nodes?
Co-60 e-
50% e-
10 % e-
0 % e-
50% Co-60
10 % Co-60

19. What might the plan look like if we treated the low internal mammary nodes with tangential fields?
3 cm

20. So what is our target? After BCS
Traditionally
Whole breast +/- boost to operative bed & scar
Most agree
At least: Operative bed + 1 cm
Some would say
Operative bed cm
Whole breast
Chest wall

21. Histologic evidence of tumor in IMC Extended Radical Mastectomyho r P a t ie n t s O u t e r Q ua d ra n t I n n e
r Q u ad r an t A
ny Q u ad r an t U r b an
341 42 %
53 % B u ca l
ossi
553 29 %
. . . So we treat the IMCs, tho as you can see from previous slide, the rates of actual IMC recurrence are fairly low . . . Ha n dl e y
535 21 %
48 % L i
635 25 %
35%
As high as 53%

22. What about after Mastectomy? Patterns of Locoregional Failure
No. of Patients
Chest Wall
Clavicular
Internal Mammary
Axilla
Univ. Hospital of Cleveland*
209
59%
25% NS 7%
M. D. Anderson*
148
60%
13% 3% 7%
Malinckrodt
129
77%
33%
11%
18%
Univ. of Pennsylvania
128
83%
25% 3%
11%
Institute Jules Bordet
128
77%
25% NS
10%
Mt. Sinai - Miami
124
77%
11% 8%
21%
ECOG * 70
53%
24% NS
11%
DBCG
214
64%
17% NS
34% %
0 – 11%
*Details about multiple sites not provided

23. Risks: IMC Failure An IMC failure is difficult to salvage.
Reirradiation of this area would be morbid.
There is no proven survival advantage to treating the IMC region
In select patients we do treat the upper IMC region
Luckily, it is clear that the IMC region can be safely excluded for patients with DCIS, so we can even better spare the heart and lung in those patients.

24. Risks: Local Recurrence
Some patients who wished for breast conservation will require a mastectomy.
Reirradiation can cause tissue and chest wall necrosis and severe fibrosis. We treat with 400 cGy x 8 with hyperthermia.
Without reirradiation, the salvage surgery will need to be a larger procedure (wide margins) and the patient may yet fail again.
It’s not a pretty picture.

25. Chest Wall Failure This is not where we want to be.
This is not salvagable.

26. Important Questions . . . Pandora’s Box
Physician philosophy on IMN treatment
Risks
Benefits
Physician philosophy on partial breast irradiation
Will leave some breast out of field to spare heart?
Use of mammosite or other brachytherapy device?
Physician philosophy on margin status
Caveat: No national consensus on above, and the actual treatment plan greatly depends on
the patient’s anatomy in treatment position
institutional standard of care
Clinical judgment
informed patient choice

27. TARGIT

28. Hyperthermia

29. Mammosite Mammosite pic

30. IMRT Breast