Radiation Oncology Demystified

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

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

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

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

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

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

Simulation http://www.google.com/imgres?imgurl=http://www.riversideonline.com/source/images/image_popup/mcdc7_breast_radiation.jpg&imgrefurl=http://www.riversideonline.com/health_reference/Womens-Health/DS00328.cfm&usg=__tN02CqIN8rIzmHecVjUYx3M8j_c=&h=326&w=400&sz=48&hl=en&start=0&zoom=1&tbnid=gFE2LyR8B3-UfM:&tbnh=146&tbnw=179&prev=/images%3Fq%3Dbreast%2Bradiation%2Bplan%26hl%3Den%26biw%3D2848%26bih%3D1460%26gbv%3D2%26tbs%3Disch:1&itbs=1&iact=hc&vpx=1734&vpy=79&dur=125&hovh=203&hovw=249&tx=132&ty=74&ei=skjLTIPcM8iQjAfv6NixDQ&oei=skjLTIPcM8iQjAfv6NixDQ&esq=1&page=1&ndsp=140&ved=1t:429,r:9,s:0

CT-based Treatment Planning

E- Beams

Photon Beams: Single 6 or 18 MV cobalt http://www.drflounder.com/archives/440 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.

Photon Beams: Parallel Opposed http://www.drflounder.com/archives/440 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.

Photon Beams: 6 vs. 18 MV parallel opposed http://www.drflounder.com/archives/440 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.

Tangents http://linac96.web.cern.ch/Linac96/Proceedings/Thursday/TH202/Paper.html http://www.google.com/imgres?imgurl=http://www.varian.com/media/oncology/products/clinac/images/Halberg_Axial_View_01.png&imgrefurl=http://www.varian.com/us/oncology/radiation_oncology/clinac/success_stories/marin_cancer_institute.html&usg=__XqdWtTUWkw08wx3ulCCNhHh4s_I=&h=431&w=600&sz=79&hl=en&start=0&zoom=1&tbnid=dZdFXUBK2yqqqM:&tbnh=109&tbnw=144&prev=/images%3Fq%3Dtangents%2Bbreast%2Bcancer%26hl%3Den%26biw%3D2848%26bih%3D1460%26gbv%3D2%26tbs%3Disch:1&itbs=1&iact=hc&vpx=111&vpy=171&dur=969&hovh=190&hovw=265&tx=202&ty=77&ei=LkfLTO7ULdW6jAe_89HHDw&oei=LkfLTO7ULdW6jAe_89HHDw&esq=1&page=1&ndsp=158&ved=1t:429,r:0,s:0

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

CT based Treatment Planning

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

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

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

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 + 2-3-4 cm Whole breast Chest wall

Histologic evidence of tumor in IMC Extended Radical Mastectomy ho 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%

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% 53 - 83% 0 – 11% *Details about multiple sites not provided

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.

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.

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

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

TARGIT http://www.google.com/imgres?imgurl=http://www.targittrial.org/TARGIT/intrabeam.jpg&imgrefurl=http://www.targittrial.org/TARGIT/ctg_targit_open_intrabeam.shtm&usg=__gBmMlzv1nPa7-f5QAcy1Xbs3Pmw=&h=394&w=236&sz=24&hl=en&start=0&zoom=1&tbnid=BWr09Vxq8WhdnM:&tbnh=145&tbnw=87&prev=/images%3Fq%3Dintrabeam%26um%3D1%26hl%3Den%26biw%3D2848%26bih%3D1460%26tbs%3Disch:1&um=1&itbs=1&iact=rc&dur=688&ei=DE_LTN_HNoi6jAfBvt3NDw&oei=DE_LTN_HNoi6jAfBvt3NDw&esq=1&page=1&ndsp=143&ved=1t:429,r:0,s:0&tx=38&ty=63

Hyperthermia http://www.google.com/imgres?imgurl=http://www.vci.org/images/breast-cancer-treatment-hyperthermia.jpg&imgrefurl=http://www.vci.org/breastcancer.htm&usg=__23qotqho6W7oiHqiLXAr-oWYlmo=&h=307&w=407&sz=21&hl=en&start=0&zoom=1&tbnid=WpJDfJiBQubCiM:&tbnh=137&tbnw=182&prev=/images%3Fq%3Dhyperthermia%26um%3D1%26hl%3Den%26biw%3D2848%26bih%3D1460%26tbs%3Disch:1&um=1&itbs=1&iact=rc&dur=453&ei=3k_LTM6oLtvPjAeLzMzHDw&oei=3k_LTM6oLtvPjAeLzMzHDw&esq=1&page=1&ndsp=148&ved=1t:429,r:0,s:0&tx=91&ty=60

Mammosite Mammosite pic http://www.google.com/imgres?imgurl=http://www.radiation-treatment.com/images/column/mammosite-CT.jpg&imgrefurl=http://www.radiation-treatment.com/specialties/brachy.html&usg=__3t0F-FKKeIGGosJw-yWyFPCOc1U=&h=234&w=396&sz=16&hl=en&start=0&zoom=1&tbnid=1KFOjdSXgYbOPM:&tbnh=111&tbnw=188&prev=/images%3Fq%3Dmammosite%26hl%3Den%26sa%3DG%26biw%3D2848%26bih%3D1460%26gbv%3D2%26tbs%3Disch:1&itbs=1&iact=hc&vpx=337&vpy=408&dur=6816&hovh=172&hovw=292&tx=74&ty=197&ei=nlDLTOWtFJG7jAfu-u3IDw&oei=nlDLTOWtFJG7jAfu-u3IDw&esq=1&page=1&ndsp=137&ved=1t:429,r:31,s:0 http://www.google.com/imgres?imgurl=http://imaging.cmpmedica.com/cancernetwork/journals/oncology/200704/ONCApr1507p454f2.jpg&imgrefurl=http://www.psychiatrictimes.com/display/article/10165/60968%3FpageNumber%3D3&usg=__BqjS6tk3X0DtJy67vNHohT_fnIs=&h=281&w=426&sz=38&hl=en&start=0&zoom=1&tbnid=jw-qiogU9OhYeM:&tbnh=117&tbnw=177&prev=/images%3Fq%3Dmammosite%26hl%3Den%26sa%3DG%26biw%3D2848%26bih%3D1460%26gbv%3D2%26tbs%3Disch:10%2C561&itbs=1&iact=rc&dur=408&ei=QlLLTJeiHY_QsAOtz_HoDg&oei=KFLLTIrnMpO7jAfozbXSDw&esq=4&page=1&ndsp=137&ved=1t:429,r:45,s:0&tx=148&ty=53&biw=2848&bih=1460

IMRT Breast http://www.google.com/imgres?imgurl=http://www.medizin.uni-tuebingen.de/medphys/forschung/jelen/tol3_1.gif&imgrefurl=http://www.medizin.uni-tuebingen.de/medphys/research.html&usg=__BWeTg610GyM3aoJXF7APW7O8eM0=&h=325&w=498&sz=33&hl=en&start=0&zoom=1&tbnid=u8d8oD_x3hEnhM:&tbnh=144&tbnw=207&prev=/images%3Fq%3DIMRT%2Bbreast%26um%3D1%26hl%3Den%26sa%3DN%26biw%3D2848%26bih%3D1460%26tbs%3Disch:1&um=1&itbs=1&iact=hc&vpx=132&vpy=89&dur=395&hovh=181&hovw=278&tx=218&ty=76&ei=BlPLTKu0B5O7jAemhL3ADw&oei=BlPLTKu0B5O7jAemhL3ADw&esq=1&page=1&ndsp=143&ved=1t:429,r:0,s:0