NCI Workshop

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NCI Workshop

• Advanced Technologies for Breast Cancer

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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

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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,
  p0.0019)

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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

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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
Goodman
1a
1b
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Figure 6. Left breast irradiation using prone
breast IMRT technique can spare left ventricle
and coronary arteries.
Goodman
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Goodman
Figure 4a. Transverse Dose Distributions
IMRT
Conventional
Isodose in
113
108
100
90
50
102
10
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Goodman
Figure 4b. Sagittal Dose Distributions
Conventional
IMRT
Isodose in
117
108
100
90
50
102
10
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Figures 3a and 3b. Dose-Volume Histogram (DVH)
for prone breast IMRT technique
Goodman
IMRT
IMRT
CONV
CONV
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
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Figure 5. Maximum Dose as a Function of Breast
Depth for Simplified IMRT and Conventional
Tangent Plans.
Goodman
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Intensity Map of a Typical Breast IMRT Field
depressed intensity through the lung volume
wedge-like intensity distribution
skin flash
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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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