From GTV to CTV: A Critical Step Towards Cure. Kenneth Hu, MD Associate Professor New York University Langone Medical Center June 21, 2017

Transcription

1 From GTV to CTV: A Critical Step Towards Cure Kenneth Hu, MD Associate Professor New York University Langone Medical Center June 21, 2017

2 Head and Neck Cancer Model for Understanding CTV Expansion Radiation therapy is key to successful definitive and adjuvant treatment Complex patterns of failure Local tumor spread Regional nodes Perineural invasion Distant Metastasis Multidisciplinary treatment options allow individualized treatment Serious and life-threatening acute toxicities Long-term impact on function/organ preservation and quality of life

3 Defining GTV Physical examination Extent of local spread and relationship to adjacent organs Appropriate Anatomic and Functional Imaging CT, PET, MRI Multidisciplinary Evaluation Radiologist Pathologist Medical oncology plans Surgical op notes/planned vs salvage Implications for simulation: IV contrast, Radiographic markers (wiring/bb s)

4 Importance of Physical Exam to Define Primary GTV: Example 1 76yo Male non-smoker who presents with Base of Tongue carcinoma PET/CT on 3/18/15 showed a FDG avid enhancing mass in the left base of tongue measuring 2.8 x 2.2 cm in maximum area in the axial plane (SUV 7.4) and 2.9 cm in maximum craniocaudad dimension. Inferiorly, the mass extends into the left vallecula; Surgery agrees with imaging findings Biopsy: squamous cell carcinoma

5 Physical exam: Inspection of oral cavity/oropharynx: Trismus, Tongue mobility, Tonsil/oral tongue involvement Palpation of primary site/neck nodes Endoscopy: L bot lesion into larynx

6 Example 2: Importance of Physical Exam to Determine Unilateral vs Bilateral Treatment in Oropharynx 69yo M with 35pk-yr Tob who presents with bulky left neck nodes II- V. FNA showed p16+ SCC. PET/CT showed:

7 Physical Exam showed L tonsil lesion lateralized away from midline Stage T2N2b Decision: Unilateral radiation concurrent with chemotherapy

8 Unilateral treatment safe in lateralized T1-2 Tonsil cancer with N0-1

9 Defining CTV Clinical Target Volume defines areas of potential microscopic tumor spread High Risk 66-70Gy, Intermediate Risk 60-63Gy, Low Risk (50-56Gy) Based on patterns of failure for a tumor Tailored to histology, tumor location, stage Impact on acute-and chronic toxicity to adjacent normal organs

10 Basics of Contouring CTV CTV High= GTV + 3-5mm trim based on skin, air and bone along with compartments CTV Intermediate=Areas of potential spread locally and regional nodes CTV Low=Areas at risk further away from GTV, second echelon nodes

11 Define CTV High & Intermediate

12 Draw Organs at Risk (OAR)

13 CTV Primary Site Cover partial vs whole organ of tumor origin e.g. oral tongue/laryngopharynx Nasopharynx: Parapharyngeal space, paranasal sinus

14 Nodal Management

15 Nodal Management Lymph nodes involving in majority of cases Predictable patterns of spread Unilateral vs Bilateral Selective nodal level coverage if clinically negative Comprehensive nodal coverage if clinically positive

16 Incidence of Positive Lymph Nodes Unilateral versus Contralateral node positive Oral Cavity : 30% 5% Oropharynx: 60-75% 20-30% Larynx: 55% 20% Hypopharynx: 75% 10% Nasopharynx: 90% 50% Nasal Cavity/PNS: 10% <5%

17 Percentage Incidence and Distribution of Pathologically Involved Nodes in a Clinical Node Negative Neck After Elective Radical Neck Dissection Oropharynx n=48 Hypopharynx n=24 Larynx n=79 Oral Cavity N=192 I II III IV V Shah, J.P et al. The patterns of cervical lymph node metastases from squamous carcinoma of the oral cavity. Cancer, (1): p

18 Percentage Incidence and Distribution of Pathologically Involved Nodes in a Clinical Node Positive after Therapeutic Radical Neck Dissection Oropharynx n=165 I II III IV V Larynx n= Hypopharynx n=104 Oral Cavity n= Shah, J.P., Patterns of cervical lymph node metastasis from squamous carcinomas of the upper aerodigestive tract. Am J Surg, (4): p

19 NPC: 29-89% Post Pharynx % SP 0-56% BOT 0-13% Tonsil 12-20% HPX 0-50%

20 2D Allowed Comprehensive Nodal Coverage

21 CT-Based Neck Node Level Classification: Selective Nodal Radiation Som et al, AJR, 2000

22 References for Lymph Node Delineation CT-Based Delineation of Lymph Node Levels and Related CTV in Node Negative Neck Dahanca, EORTC, GORTEC,NCIC,RTOG Gregoire, et al. Radiotherapy and Oncology, , Proposal for the delineation of the nodal CTV in Nodepositve and the post-operative neck Gregoire, et al. Radiotherapy and Oncology, , update: Delineation of neck nodal levels: Gregoire, et al, Radiotherapy and Oncology, ,

23 Dose Constraints OAR

24 IMRT Improved Xerostomia: PASSPORT Trial 94 pts with OP/HP cancer randomized to IMRT vs 3DRT Whole contralateral parotid < 24Gy Lent SOMA Score EORTC Dry Mouth Subscale Nutting CM et al, Lancet Oncol 2011, 12:127

25 Submandibular Gland Sparing 36 pts OPX (n=28) NPX treated with RT Case matched 18pts with SMG sparing and 18 without. SMG spared had lower N stage (no N2b-3) vs SMG non-spared group (59% N2b-3) Saarilahti et al Radiotherapy and Oncology78 (2006)

26 Pharyngeal Constrictors Superior Mid Inferior Werbrouch J et al, IJROBP 2009, 73:1187 Courtesy Dr. Eisbruch/Le

27 Probability Swallowing Problems Cyberknife (3x + 4x) Brachytherapy implant No BT / No Cyberknife 4x 3x Dose superior constrictor muscle (Gy) Levendag PC, et al. Radiother Oncol. 2007

28 Contouring in the Elective and Node Positive Neck

29 CTV of LN+ J foramen ICA, IJV Sparing of parotid in LN- Sup constrictor spared on L L Lat RP LN Upper Ib,II,Va C1 TVP

30 Ib,IIa/b Submandib gl IIa/b Ia LN spared Lx, SMG, mid constrictors

31 L III/Va LN, Lx, inf constrictors

32 L IV,Vb LN, Lx, cricopharyngeus L IV,SCL LN, trachea, cervical esoph

33 Contouring in the Elective and Node Positive Neck Implications for Salivary and Swallowing Function

34 Washington University 748 pts opx/hpx/lx/unk primary IMRT 3 generations of elective coverage ( )in contralateral node neg neck A) Bilateral RS/RP, 260pts B)Sparing CL RS 205 pts C) Spared CL RS/RP 283 pts Median Followup 37mo s MDADI Dysphagia QOL and POF

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36 Swallowing Better in Group C vs A MDADI at >30mo in group A vs group C Differences >18points are significant NO FAILURES IN SPARED RS/RP LN S

37 Pathologic Factors Important for CTV Coverage Extracapsular /soft tissue extension 5-10mm margins Post-operative-Treat scar/surgical bed Perineural Invasion

38 Perineural Invasion: Radiation Most Effective Modality

39 Perineural Invasion Pathologic and Clinical Definitions Pathologic Focal small nerve Extensive Multifocal, Intraneural, >0.1mm, named branch of nerve Clinical Radiographic evidence of nerve involvement Symptomatic

40 Recommended Elective Neural Coverage Focal PNI Consider larger margin 2cm at tumor bed Extensive PNI Involved nerve to skull base Clinical PNI Involved nerve peripheral to skull base and intracranial extension Communicating nerve Histologies with PNI Parotid (Salivary Duct, Adenoid Cystic Cancer) Recurrent skin cancers, Squamous cell carcinoma of nasopharynx, Lymphoma

41 Extensive PNI + RT Extensive PNI + RT Extensive PNI- RT Extensive PNI - RT

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43 CN V & VII: Most Common Pathways at Risk Extracranial Path Gross Disease: Extra- and Intracranial Pathways Anastamotic Communication Between V and VII

44 PNI V1 SOF Cavernous Sinus Meckel s Cave Barker, Target Volume Delineation for Conformal and Intensity- Modulated Radiation Therapy, 129 Medical Radiology. Radiation Oncology, DOI: /174_2014_975, Springer International Publishing Switzerland 2014 Gluck, et al.

45 PNI: V2--> PPF Foramen Rotundum Cav Sinus Meckel s Target Volume Delineation for Conformal and Intensity-Modulated Radiation Therapy, 167 Medical Radiology. Radiation Oncology, Gluck, et al.

46 PNI V3 Parapharyngeal Space Foramen Ovale Meckel s Pre-pontine Cistern Target Volume Delineation for Conformal and Intensity-Modulated Radiation Therapy, 167 Medical Radiology. Radiation Oncology,

47 CN VII Stylomastoid Foramen Mastoid Tympanic IAC Pre-Pontine Cistern Target Volume Delineation for Conformal and Intensity-Modulated Radiation Therapy, 167 Medical Radiology. Radiation Oncology,

48 Common Pathways of PNI spread between Auriculotemporal Nerve (V3 + VII) Target Volume Delineation for Conformal and Intensity-Modulated Radiation Therapy, 167 Medical Radiology. Radiation Oncology, Gluck, et al.

49 Greater Superficial Petrosal Nerve (GSPN) Connects V2 + VII Gluck, et al.

50 Conclusions Multidisciplinary evaluation of imaging, pathology, surgery, exam CTV expansion based on radiation oncologist understanding of patterns of failure Importance of understanding CTV dosing impact on adjacent normal organs function and quality of life