# Presentation: 709006

## NCI Workshop

- Advanced Technologies for Breast Cancer

## Radiation of Intact Breast

- Excellent LOCAL CONTROL (95 % at 5 years) achieved with standard dose 50 Gy Whole Breast plus boost to primary site
- NO NEED to Dose Escalate
- OARs: Skin, Lung, Heart (Left sided cases) and “Cosmetic Outcome”

## Intact Breast Phase III Trial

- Vancouver/Toronto Study comparing IMRT to Standard Wedge 2 D Planning
- Presented at ASTRO 2006
- 358 patients entered/331 analyzed for acute toxicity up to 6 weeks
- Results: IMRT plans showed improved dose homogeneity and clinically associated with reduced incidence moist desquamation (31% vs 48%, p=0.0019)

## Prone IMRT at MSKCC

- Minimize radiation to the heart and lungs by utilizing gravity effect on mobile breast
- Specify beam direction (Two tangent fields) before inverse planning process to avoid an increase in integral dose
- Bring dose intensity pattern to field edge to account for minimal edema thru treatment

## Figure 1a. Customized prone breast board with adjustable aperture and wedge for contralateral breast.Figure 1b. Ipsilateral breast and anterior chest wall hang in a dependent fashion away from the thorax while the ipsilateral arm is placed above the head

- 1a

- 1b

- Goodman

## Figure 6.  Left breast irradiation using prone breast IMRT technique can spare left ventricle and coronary arteries.

- Goodman

## IMRT

- Conventional

- Figure 4a. Transverse Dose Distributions

- 113

- 108

- 100

- 90

- 50

- Isodose
-    in %

- 102

- 10

- Goodman

## IMRT

- Conventional

- Figure 4b. Sagittal Dose Distributions

- 117

- 108

- 100

- 90

- 50

- Isodose
-    in %

- 102

- 10

- Goodman

## Figures 3a and 3b. Dose-Volume Histogram (DVH) for prone breast IMRT technique

- Fig 3a. 5mm skin was excluded from the PTV.
- IMRT: Intensity modulated radiation therapy
- CONV: Conventional tangents

- Fig. 3b. Buildup region was included in the PTV.
- IMRT: Intensity modulated radiation therapy
- CONV: Conventional tangents

- IMRT

- CONV

- IMRT

- CONV

- Goodman

## Figure 5.  Maximum Dose as a Function of Breast Depth for Simplified IMRT and Conventional Tangent Plans.

- Figure 5.  Maximum Dose as a Function of Breast Depth for Simplified IMRT and Conventional Tangent Plans.

- Goodman

## Slide 11

## Intensity Map of a Typical Breast IMRT Field

**Intensity Map of a Typical Breast IMRT Field**

- skin flash

- depressed intensity through the lung volume

- ‘wedge-like’ intensity distribution

## Breast IMRT at MSKCC

- Viewed (based on prostate model) as an improved method of dose delivery to primary
- Therefore change in technology simply executed in the department

## Integrated Boost

- Freedman et al (Fox Chase) have demonstrated feasibility of doing concomitant “boost” during whole breast IMRT with “Dose Painting”
- This is under consideration has an RTOG Phase II trial

## Partial Breast RT

- RTOG/NSABP Phase III Trial open since 2005 to compare Standard Whole Breast RT to Partial Breast RT using 10 fx in 5 days
- Accrual well past 2000 of 3000 planned
- In women randomized to “PBI”, over 70% are receiving RT by 3D XRT, 20 % by MammoSite and 5% by Brachy

## MGH PBI/Protons

- 20 Stage I patients in Phase I/II Trial
- Results: (Median F/U 12 months) No local failures
- Side Effects: “Moderate to severe skin color changes in 79 %, moderate to severe moist desquamation in 22 %, skin telangiectasia in 3 patients and rib tenderness in 3 patients

## Slide 17

## Slide 18

## Post-Mastectomy RT/1

- If breast reconstruction present, similar issues to intact breast
- Chest wall: Multiple techniques, including tangent fields, electron beam, and combinations.
- SKIN is part of the target, so “skin-sparing” not an advantage

## Post  Mastectomy RT/2

- Supraclavicular Nodal RT always given
- Internal Mammary Nodal RT highly controversial in standard adjuvant settings (NCCN guidelines Level 3)
- OAR include lung, heart, brachial plexus and esophagus, depending on technique

## Post Mastectomy RT/3

- NCI-funded Phase III trial now ongoing at U. of Michigan
- Will compare IMRT to 3D Conformal in the post-mastectomy setting, including regional nodes
- No IMRT used off study in this clinical situation
- PI: Lori Pierce

## Hypothetic Plan IMRT/Protons

- Lomax et al at PSI
- Target included breast, and regional nodes including IMN chain
- IMRT plan had increased target homogeneity compared to 2D, but with increased dose to critical neighboring organs
- 2 field, energy modulated Proton plan appeared superior to IMRT

## Other Clinical Scenarios

- Inoperable presentations
- Bulky, non-resectable recurrent cancer
- IMRT plans have sometimes looked significantly better than 3D conformal, on a CASE BY CASE basis

## Conclusions/Breast

- One Phase III trial demonstrates superiority of IMRT over standard treatment, for acute side effects in the intact breast
- Modest decrease in late cardiac and lung toxicity likely with IMRT (With 2 field tx)
- Improvement in local control unlikely, since it is already at 95 % at 5 years

## More Conclusions

- Limited single institution center studies on IMRT and Proton use for PBI
- Imaging the PTV daily likely needed, given the tight margins, daily set-up error, organ deformation (edema) and target mobility with breathing