Breast contouring and planning techniques

Detailed Breast contouring with various atlases and different planning techniques.

1. Breast Contouring Presenter : Dr. Rituraj Dr. Navaudhayam Moderator : Dr. Ritesh 9 August 2017

2. Treatment overview Early Breast Ca (T1 T2 N0 N1) Sx (BCS/MRM) ± CCT ± RT ± HT Locally Advanced MRM + CCT + RT ± HT Neoadjuvant CCT + Sx (MRM/ BCS) + RT ± HT Metastatic (M1) Palliative CCT/ Palliative RT/ ± HT ± Sx MRM (N0) – No RT MRM (N1) – RT to CW + SCF BCS WBRT + Boost APBI N1 – RT to SCF MRM – RT to CW + SCF BCS - WBRT + Boost + SCF

3. Indications of RT Indications of Whole Breast RT All patients after BCS Indications of Chest Wall RT N2-N3 disease High risk patients with N1 disease (1-3 LNs) Locally advanced breast ca

4. Indications of Loco-regional RT Supraclavicular LNs Clinical/Pathological N2 or N3 disease 1–3 +LN with high risk features (N1) Node + sentinel lymph node with no dissection unless risk of additional axillary disease is very small High risk, no dissection Axillary LNs N + with extensive ECE or soft tissue deposits or Heavy nodal burden SN + with no dissection Inadequate axillary dissection High risk with no dissection Internal Mammary: Individualized but consider for: Positive axillary nodes with central and medial lesions + SLN in the IM chain

5. Target Structures CTV Breast and Tumor Bed Axillary Lymph nodes Supraclavicular Lymph Nodes Internal Mammary LNs OARs Contralateral Breast Lung – I/ L and C/L Heart (including LAD) Spinal Cord Brachial Plexus Esophagus Thyroid

6. Available Guidelines RTOG (EBC and LABC) ESTRO (EBC) – Less liberal margins DBCG (EBC) RADCOMP Consortium PROCAB guidelines (Vessel based nodal contouring)

7. Why wires around Breast? Large differences are reported b/w CTV localization using standard anatomic borders, palpation and USG Hurkmans et al* - study in 2001 P alpable breast glandular tissue was marked by lead wire before Planning CT in 6 pts Vs. 4 patients without lead wire CTV was delineated by 4 RO Interobserver variation in volume was decreased by a factor of 4 on scans with lead wire Deviations in PTV extent were greater in Posterior, Cranial and medial directions *IJROBP Vol 50 No5, 2001

8. A word of Caution- Individualization!!! Guidelines serve as base on which CTV can be individually adapted Encompass primary tumor bed adequately , including relevant margins around it In patients with tumours placed too medially / laterally one needs to modify conventional borders Apply wires carefully even on opposite breast as you keep comparing your contours with opposite breast Not applicable for T/t in prone position All Contours are shown- does not mean that all volumes have to be treated

9. CTV Breast

10. Cranial Uppermost level of palpable/ visible Breast tissue Maximally up to inferior edge of sternoclavicular joint (G) Caudal Most Caudal CT slice with visible breast tissue (G) In obese patients, positioned more ventrally in the caudal part of breast due to abdominal wall fatty tissue (G, ESTRO)

11. Dorsal Pectoral muscle or intercostal ms where there is no P Major Include chest wall also in LABC Ventral 5mm under skin (G, ESTRO) I n cases with T4b,c,d cancer where full dose up to skin is advised: bolus may be added (G, ESTRO, RTOG)

12. Medial Clinical Reference / Wire Maximal to edge of sternum Lateral Most difficult to delineate ( varies according to breast ptosis) Traditional: Mid Axillary Line or 1.5-2 cm beyond palpable breast tissue Medial to lateral thoracic A, Breast fold (G, ESTRO, DBCG) Exclude Lats Dorsi ms.

13. CTV Chest Wall Place radio opaque wires around imaginary- original site of breast and also on MRM scar Generally same as breast Dorsal- RTOG guidelines- Rib Pleural interface (including ribs, IC ms and pectoralis ms ) ESTRO- Unless invasion was demonstrated (tumor stage T4 a-c ), no reason to routinely include major pectoral muscle and ribs - Impacts Lung and Heart Doses!

14. Ventral RTOG- Skin ESTRO- 5 mm under skin surface Skin Bolus of 3-5mm may be applied for very thin CW (ESTRO is only for EBC) Inflammatory breast cancer- Up to skin Bolus for all fractions

15. Borders Cranial Caudal Anterior Posterior Lateral Medial Breast ( EBC ) -Uppermost palpable/visible breast tissue -Max: till head of clavicle Clinical reference + 1-2 cm below breast tissue Skin Excludes pectoralis muscles , Chest wall muscles, ribs Clinical Reference + Mid axillary line typically, excludes latissimus dorsi Sternal-rib Junction , Shouldn’t cross midline Breast + Chest wall (LABC, Post NACT) Same Same Same Includes pectoralis muscles, Chest wall muscles, ribs Same Same Chest Wall After mastectomy Caudal border of the clavicle head Clinical reference+ loss of CT apparent contralateral breast Same Rib-pleural interface. (Includes pectoralis muscles, chestwall muscles, ribs) Clinical Reference/ mid axillary line typically, excludes lattismus dorsi Sternal rib junction Medial extent of mastectomy scar should typically be included

16. Lumpectomy GTV Include seroma cavity Include all surgical clips when present Use pre-operative imaging Pre-operative and per-operative clinical findings Architectural changes in planning CT

17. PLANNING TARGET VOLUME Isotropic PTV Margin of 1-1.5 cm (depending on institutional protocol) Adequate margin in air is required for field shaping and to define edges of MLCs Breast PTV Eval A substantial part of the Breast PTV often extends outside the patient, and is not a part of dosimetric calculations Anteriorly exclude the part outside the patient and the first 3-5 mm of tissue under the skin (in order to remove most of the build up region for the DVH analysis) Posteriorly no deeper to the anterior surface of the ribs (excludes bony thorax and lung). It is used for DVH constraints analysis. Breast PTV Eval cannot be used for beam aperture generation.

18. NODAL CONTOURING

19. Supraclavicular LNs Cranial RTOG -Caudal Edge Cricoid Cartilage PROCAB -Cranial Edge of Subclavian A Arch Caudal RTOG-caudal edge of Medial head of Clavicle Junction of Brachiocephalic V and Axillary V Medial Exclude thyroid and trachea Medial Edge of Int carotid A and IJV Lateral RTOG- Cranially- Scalene ms Caudally- Junction of first rib and clavicle DBCG- Medial edge of P Minor and Clavicle Ventral SCM, Clavicle, 5 mm below skin Dorsal Cranially- Posterior to ICA and Anterior to scalene medius ms Caudally- Lung

20. Axilla Can be contoured as a single structure, as contouring each level separately can be time consuming and often can’t be demarcated clearly from each other. Cranial P. Minor inserts into coracoid Caudal P. Major inserts into ribs – 4-5 th Intercostal space Ventral Laterally: Anterior surface of P. major Medially: Posterior surface of P. major/ Ant surface of P. minor Dorsal Ribs/Intercostal muscles/Subscapularis Medial Thoracic Inlet Lateral Medial border of Latissimus dorsi

21. Borders Cranial Caudal Anterior Posterior Lateral Medial Supraclavicular Below Cricoid cartilage Caudal edge of clavicle head, Should connect to IMN SCM/Strap Muscles/ Clavicle Anterior aspect of the scalene, Post edge of SCM/vascular bundle Cranial: lateral edge of SCM Caudal: 1st rib-clavicle junction Medial edge of carotid a., Excludes thyroid and trachea Axilla Level I Axillary vessels cross lateral edge of Pec. Minor Pectoralis (Pec.) major muscle insert into ribs (base of ant ax line) Plane defined by: anterior surface of Pec. Maj. m. and Lat. Dorsi Anterior surface of subscapularis m. Medial border of lat. dorsi m. Lateral border of Pec. minor m. Axilla Level II Axillary vessels cross medial edge of Pec. Minor Axillary vessels cross lateral edge of Pec. Minor Anterior surface Pec. Minor Ribs and intercostal muscles Lateral border of Pec. Minor Medial border of Pec. Minor Axilla Level III Pec. Minor insert on cricoid Axillary vessels cross medial edge of Pec. Minor Posterior surface Pec. Major Ribs and intercostal muscles Medial border of Pec. Minor Thoracic inlet IMN LN Superior aspect of the medial 1st rib. Cranial aspect of the 4th rib encompass the internal mammary/ thoracic vessels

22. OARS Heart Contoured below pulmonary trunk bifurcation All mediastinal tissue below this level should be contoured including great vessels Coronaries: Left anterior descending artery P roximal 1/5th of the vessel, from the end of the left main coronary artery passing anteriorly behind the pulmonary artery M id 2/5th of the vessel descending anterolaterally in the anterior interventricular groove D istal 2/5th of the vessel running in the interventricular groove and extending to the apex Brachial Plexus

23. 1. Identify and contour C5, T1, and T2. 2. Identify and contour the subclavian and axillary neurovascular bundle . 3. Identify and contour anterior and middle scalene muscles from C5 to insertion onto the first rib. 4. To contour the brachial plexus OAR use a 5-mm diameter paint tool . 5. Start at the neural foramina from C5 to T1; this should extend from the lateral aspect of the spinal canal to the small space between the anterior and middle scalene muscles. 6. For CT slices, where no neural foramen is present, contour only the space between the anterior and middle scalene muscles. 7. Continue to contour the space between the anterior and middle scalene muscles; eventually the middle scalene will end in the region of the subclavian neurovascular bundle. 8. Contour the brachial plexus as the posterior aspect of the neurovascular bundle inferiorly and laterally to one to two CT slices below the clavicular head. 9. The first and second ribs serve as the medial limit of the OAR contour .

24. Dose Volume Histogram Evaluate both CTV and PTV PTV Coverage D95 Dmax Desirable 95% 107% Acceptable 90% 115%

25. OARs Tolerance End Point Ipsilateral Lung Dmean < 7-13 Gy V20 < 20-25 % (or <30-35% if SCF included) V5 < 50 % 10% Symptomatic pneumonitis 20% Symptomatic pneumonitis Contralateral Lung Dmean < 7 Gy V5 < 10-15% 5% Symptomatic pneumonitis Contralateral Breast Dmean < 2 Gy Dermatitis Heart Dmean < 26 Gy V25 < 10%, V20 < 10% (DBCG) <15% Pericarditis <1% Mortality LAD V20 = 0% -- Spinal Cord Dmax < 45 Gy <0.2% Myelopathy Brachial Plexus Dmax < 54 Gy <5% Brachial plexopathy Liver Dmean < 30 Gy <5% Classic RILD Esophagus Dmean < 34 Gy V35 < 50 % Grade 3+ esophagitis Thyroid V45 < 100% 8% Clinical hypothyroidism

26. Hypofractionation Conventional Hypofractionated Ipsilateral Lung V20 V16 V10 V8 V5 V4 Heart V25 V20 V20 V16

27. Plan Generation

28. Conventional tangents with simple or customized shielding Photon based 3DCRT : wedges, MLCs for shielding heart, overdose volume Forward plan IMRT (Field in Field) TomoTherapy TopoTherapy ( TomoDirect ) Arc therapy (VMAT) Flattening filter free planning Inverse plan IMRT Electron based IMRT (prevents low dose exposure of C/L lung & breast) Electronic compensation (lowest no of MUs & planning time) Proton IMRT

29. Tangents

30. ENHANCED DYNAMIC WEDGE ( 15˚) Dmax – 108.8% PHYSICAL WEDGE (15˚) Dmax - 110 %

31. Field-in-field technique: Forward IMRT Modified bi-tangential portals Medial and lateral tangents are first planned and dose distribution noted. Use of multiple segments inside each tangential portal Areas of high dose are then delineated . A new field is created within the existing tangential field with an appropriate MLC configuration so as to reduce the inhomogeneity in these areas. These fields are finally fused by the treatment planning system. ?? Possible improvement in the cosmetic outcome

32. VMAT Novel extension of IMRT: modulation of dose rate, gantry angle and MLC s Optimized three-dimensional (3D) dose distribution may be delivered in a single gantry rotation Reduction in treatment MUs (30 %) and delivery time (55%) due to high dose rates (as compared to cIMRT )

33. VMAT Novel extension of IMRT: modulation of dose rate, gantry angle and MLC s Optimized three-dimensional (3D) dose distribution may be delivered in a single gantry rotation Reduction in treatment MUs (30 %) and delivery time (55%) due to high dose rates (as compared to cIMRT ) Arc treatment: Larger low dose scatter-Contralateral breast, lungs , heart It is becoming evident that even small doses to the heart and contralateral breast during radiotherapy course are important in the long term outcomes of breast cancer patients 1 Dosimetric advantages of VMAT not confirmed for patients requiring adjuvant RT to breast only 2 1 Darby et al. Risk of ischemic heart disease in women after radiotherapy for breast cancer. N Engl J Med 2013 2 Badakhshi et al, BJR 2013

34. Is IMRT really the answer?????

35. VMAT based plan with Short tangential arcs Anusheel   Munshi et al. Short tangential arcs in VMAT based breast and chest wall radiotherapy lead to conformity of the breast dose with lesser cardiac and lung doses: a prospective study of breast conservation and mastectomy patients (n=153)

36. T ried to gain from both the worlds: using classical tangential field arrangement and at the same time using VMAT fields albeit with arc length limited to 30°. Even though the VMAT technique required more MUs as compared with the other two techniques, it is still preferable as the treatment delivery time is very short.

37. VMAT technique consistently scored lower values for all the evaluated parameters for the heart (D2cc, V20Gy, V30Gy and V40Gy) except for its mean dose. VMAT plans were preferable over other plans in terms of PTV highest conformity and lowest heterogeneity. Both FIMRT and VMAT techniques produced comparable plans in terms of PTV coverage and OAR doses except for the heart. However , FIMRT is a labour-intensive technique requiring longer treatment planning time. Besides, the outcome of FIMRT plan strongly depends on the personal expertise of the planning physicist or the planning dosimetrist. On the other hand, VMAT plans were relatively simpler to generate facilitated by readily available standard templates from plan library, requiring only minimal changes during the optimisation depending on the individual patient anatomy.

38. PRONE position Dosimetric advantages--- More homogenous dose Less lung dose Disadvantages--- Setup reproducibility poor Pt. tolerance of prone position Retrospective reviews have shown excellent long term disease control as standard supine tangents Particularly useful in Hypofractionated WBI ( Preferred in MSKCC )

39. What is the Optimal Beam Arrangement for IMRT ? TANGENTS !!! Less low dose: Lung, Heart, Contralateral Breast Adequate coverage of Target volume Early Breast Cancer women: Do survive long… to see the long tem effects of scatter dose

40. Hybrid IMRT Add Bilateral open Tangential fields Add Bilateral IMRT Tangential Fields to reduce dose inhomogeneity and reduce high doses to ipsilateral lung and heart

41. THANK YOU

42. Thank You IRCH Practice

43. Whole Breast RT Tangents with Wedges Tangents with Field-in-field technique IMRT/ VMAT : Not preferred

44. Tangent with wedges

45. Tangent with wedges: Dose Colorwash

46. Tangents with Field-in-field

47. Tangents with Field-in-field: Dose colorwash

48. VMAT

49. VMAT: Dose Colorwash

50. VMAT: low dose fall-off

51. Nodal RT ( SCF +/- Axilla) Direct Anterior Field High Tangents VMAT

52. Direct anterior field

53. High tangents to cover SCF

54. VMAT

55. Prescription dose : 42.5 Gy /16#/3wks 1 day PTV Coverage: 95% PTV receiving 95% 0f dose D95 = 40.37 Gy (95% of prescribed dose) Dmax = 48.04 Gy VPTV107% = 8.3% (<10%) VPTV115% = 0 HI = 1.180 CI = 1.027

56. OARs Dose Constraint Achieved Right Lung Dmean < 20 Gy V20 < 30 % Dmean = 13.66 Gy V20 = 26.3% Left Lung Dmean < 7 Gy Dmean = 2.66 Gy Contralateral Breast Dmean < 1.5 Gy Dmean = 3.1 Gy Heart Dmean < 8 Gy V30< 5 % Dm = 6.26 Gy V30 = 0 % Spinal Cord Dmax < 45 Gy Dmax = 25.62 Gy Liver Dmean < 30 Gy Dmean = 8.16 Gy Esophagus Dmean < 34 Gy V35 < 50 % Dmean = 12.97 Gy V35 = 13.2% Thyroid V45< 100% V45 = 18.7% LAD Dmax < 3 Gy Dmax = 2.1 Gy

57. Field Matching In 2-dimensional planning Single Isocentric Technique VMAT

58. Angulation By inferior angulation of the tangential fields. Half beam block technique Blocking the supraclav field’s inferior half, eliminating its divergence inferiorly . Hanging block technique Superior edge of tangential beam made vertical by vertical hanging block.

59. Single Isocentric planning: Beam Arrangement

60. Single Isocentric planning: Dose colorwash

61. Boost Planning Electrons 3 D-CRT using Tangents/Multiple oblique fields Brachytherapy

62. Interstitial Brachytherapy Electrons Photons

63. Boost by tangents

64. Boost by 3D-CRT

65. Boost by brachytherapy

66. Case 48/F Postmenopausal C/O Lump in Right Breast x 6 months Baseline exam : cT2N0M0 , Upper outer quadrant lesion Bx : IDC, ER/PR+ , Her2/ neu equivocal Metastatic workup negative Underwent WLE with ALND HPE: 2.8 cm tumor with negative margins, LNs – 0/11 Received Adjuvant chemo, 4 cycles CEF and 4 cycles Doce q3wkly Planned for Adj RT 42.50 Gy/16#/ 3 wks to Whole Breast f/b boost to tumor bed

67. Carcinoma Rt Breast, HR+ , cT2N0M0 , Post BCS pT 2 N

68. PTV Coverage: D95 : 40.50 Gy (95.4% of prescribed dose) Dmax : 4 6.9 Gy (109%) OARs Tolerable Dose Achieved Esophagus Dmean < 32 Gy V30 < 60 % Dmean = 4.23 Gy V30 = 0% Spinal Cord Dmax < 50 Gy Dmax = 2.91 Gy Right Lung Dmean < 20 Gy V20 < 30% Dmean = 13.00 Gy V20 = 29.4% Left Lung Dmean < 20 Gy Dmean = 0.6 Gy C/L Breast Dmean < 3 Gy Dmean = 1.5 Gy Heart Dmean < 26 Gy V30<46% Dm = 4.41 Gy V30 = 0%