Principles of Radiation Therapy A Bapsi Chakravarthy, MD Associate e P rofessor Professor Radiation Oncology

Transcription

1 Principles of Radiation Therapy A Bapsi Chakravarthy, MD Associate Professor Radiation Oncology

2 Disclosure Information I have no financial relationships to disclose relevant to the conten of this presentation.

3 RT FOLLOWING NEOADJUVANT CHEMOTHERAPY Multidisciplinary evalu uation prior to starting chemotherapy Determining who is a candidate for BCT? Determine who needs post mastectomy radiation? How to integrate recon nstruction?

4 NSABP B18 >1500 patients Mean tumor size 3.5cm 26% clinically node positive Complete CR to preop p chemo 36% Complete pathologic response 13%

5 Breast conservation rates NSABP B-18 68% 60% 22% 8% Fisher JCO 1998

6 NSABP B27 >2400 patients Mean tumor size 4.4cm 30% clinically node positive Complete CR to preopchemo(ac-t)63% Complete pathologic response 26% 62% BCS (preop) vs. 64% in post op Taxane

7 NSABP-27 OPERABLE BREAST CA N=2411 AC AC TXT AC SURGERY SURGERY SURGERY Tamoxifen for all pts s. TXT

8 LR FOLLOWING NEOADJUVANT CT PRE POST B % 10% B27 7% 5% Rastogi JCO 26:778, 2008

9 PRE VS POST CT SENTINEL NODE BIOPSY PRE Role of nodal RT SN more sensitive POST Single surgical procedure pocedue Nodal pcr rates?alnd

10 BCT FOLLOWING NEOADJVUANT CHEMOTHERAPAY BCT: Neoadjuvant CT increa ases rates of BCT Reasonable if margin negative resection can be achieved. Can be considered for T4N1 patients Clip placed pre treatme ent CONTRAINDICATIONS Diffuse microcalcifications Inflammatory breast cancer

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12 BCT following NCT Multidisciplinary Coordination -careful serial imagingi -careful pathology -margin assessment BCT after neoadjuvant chemotherapy -effective and safe treatm ment -affords many option of BCT

13 PMRT FOLLOWING NEOADJVUANT CHEMOTHERAPAY Pre treatment clinical stage Post treatment pathologic stage Crude LR by pathologic nodal stage post CT 0 nodes: 10% 1-3 LN: 17% 4-9 LN: 47%

14 Clinical Stage III Disease: pcr Buchholz JCO 2002

15 PMRT FOLLOWING NEOADJVUANT CT All Stage III patients (based on pre chemo clinical stage) Stage I/II with 1-2 LN+ less clear All patients with inflammatory breast cancer

16 PREDICTORS OF LR FOLLOWING NCT Clinical tumor size at presentation Clinical nodal status s at presentation Pathologic nodal status Pathologic response in the breast Young age Margins < 2mm High grade LVI

17 SIDE EFFECTS OF RT ON RECONSTRUCTION Skin: hyperpigmentatio on, telengiectasia Flap: fibrosis, contractu ure, necrosis Implant: capsule contra acture, malposition, pain, infection, implant loss 40% risk of needing a second surgery

18 CT Treatment Planning IMN Field

19 IMRT Static multileaf collimator IMRT technique Int J Radiat Oncol Biol Phys 2000; 48:

20 Varian Trilogy with On-Board Imager (OBI) Multi-leaf leaf Collimation

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22 COLON CANCER VS. RECTAL CANCER Similar histology Rectal cancers are pro one to local recurrence as surgically less accessible Randomized trials hav ve established the role of concurrent chemort in rectal cancers

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24 Neoadjuvant Chemoradiation Less toxic Downstages primary and LNs Improves sphincter preservation Improves local l control No change in survival Potential overtreatment:t2 vs. T3, N0 vs. N1 Increase in surgical mo orbidity

25 Rates of Sphincter-Sparing Surgery in 194 Patients Determined by the Surgeon before Randomization to Require Abdominoperineal Resection, According to Actual Treatment Given Sauer, R. et al. N Engl J Med 2004;351:

26 Preoperative vs. Postoperative ChemoRT Local recurrence Distant recurrence Sauer, R. et al. N Engl J Med 2004;351:

27 Conclusions Preoperative chemoradiotherapy improved local control reduced toxicity did not improve overall survival May over treat patients

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29 Preoperative RT vs. TME alone

30 Can we omit radiation for T3N0 disease? MSKMC 188 patients ut3n0 rectal cancer Preop chemort (FU based Gy) 50G pcr20% Mesorectal nodes 22% Conclude: can not safe ely omit RT» Guil llem et al JCO 26: ,2008

31 Radiation Ports

32 Radiation Ports

33 Isodose

34 Isodose

35 Translation of FLT PET to trials

36 Thank You