1. Duel Acquisition Neck CTA/ CT for Pre-TLM H&N Ca Patient Evaluation Steven M. Weindling, M.D. Mayo Clinic Florida weindling.steven@mayo.edu XIX Symposium Neuroradiologicum

2. TLM Surgery: Background Transoral Laser Microsurgery (TLM) Since 1996 TLM utilized increasing for resection of primary H&N cancers @ Mayo Clinic CO 2 Laser via transoral approach allows piecemeal tumor resection & “following the tumor” w/ frozen sections May be performed in conjunction w/ standard neck nodal resection # 1

3. TLM Advantages: Excellent oncologic results: Local recurrence is uncommon w/ TLM TLM can be repeated for local tumor recurrence Organ preservation: Improved functional outcome & faster recovery Socioeconomics: Shortened hospital stay (3 days vs 7-8d for oropharynx T2 SCC) Single intervention for 75% of H&N Cancer patients If second primary tumor occurs – All Tx options are available # 2 TLM Surgery: Background

4. TLM Disadvantages (Relative): Lesion resection limited by line of site Postoperative bleeding from arterial branch along inner margins of deeply invasive tumors –701 TLM patients @ Mayo Clinic from 1996-2006 (Salassa, JR, Hinni ML, et al Otolaryngol Head Neck Surg; 2008; 139: 453-459) –1.4% had post-op bleeding from TLM site –3 Catastrophic bleeds (death or life threatening) # 3 TLM Surgery: Background

5. Improve visualization of peritumoral arterial branches on pre-TLM patient imaging Facilitate TLM patient selection Assist surgeon w/ surgical planning → lower bleeding risk Study Objective

6. Subjects: Patients being considered for Transoral Laser Microsurgery (TLM) resection of primary H&N tumors Extracranial CTA & enhanced ST Neck CT performed sequentially 64 slice CT Scanner (Somatom Sensation; Siemans) Duel Acquisition CTA/ CT: Technique

7. Combined CTA/ CT: Contrast 100 ml of Omnipaque 300 mg% (50 ml x 2) sec #1: 50 ml contrast followed by 30 ml NS @ 4cc/ sec #2: 50 ml contrast followed by 50 ml NS @ 4cc/ sec 40 # 1 # 2 Begin CTA bolus tracking 060 CTA 80 Neck CT(+C) 90

8. Duel Acquisition CTA/ CT: Technique CTACT(+C) Scan directionCaudo-cranialCranio-caudal kVp120 mAs240 Collimation0.6 x 64 Rotation time0.37 FOV22 cm

9. Enhanced Neck CT: Soft Tissue Axial 2 q 2 mm CTA : Soft Tissue Axial 2 q 2 mm Volume Rendered 3D – “Endoscopic Views”: Tumor & adjacent vessels (4cm slab) Duel Acquisition CTA/ CT: Images

10. 20 patients w/ 1˚ H&N cancer in whom TLM resection was being considered by ENT surgeon Primary Tumors: 19 SCC; 1 Adenoid Cystic Ca (oropharynx) Primary Tumor Location & Stage: Oropharynx 12 (T2-8, T3-4) Oral tongue 3 (T3-3) Hypopharynx 3 (T2-3) Supraglottic Larynx 2 (T2-1, T3-1) Patient Population

11. Neck CTA vs. CT(+C) studies compared for: –Tumor & vessel enhancement (Ax. 2D images) –Tumor/ vessel relationships (Ax. 2D & 3D endoscopic images) Clinical notes & operative reports reviewed to identify: –Patients in whom TLM surgical approach was altered or changed to conventional open surgery as a result of pre- surgical CTA-CT findings –TLM patients with perioperative bleeding Study Evaluation

12. Peritumoral vessel enhancement: Superior on CTA in all but 1 patient (19/20) Tumor enhancement (HU): CT(+C) > CTA: 12 patients CTA ≥ CT(+C): 8 patients In 30% (6/20 patients) CTA-CT information led to a change in surgical approach: 4 - Neck dissection pre-TLM to ligate peritumoral artery 1 - Allowed surgeon to avoid aberrant thyroidal artery 1 - TLM ∆ to open surgery Study Results

13. CT(+C)CTA T2 SCC Hypopharynx – # 1 Aberrant Thyroidal artery along anterior tumor 3D Endoscopic View Lt.

14. T3 SCC Tongue Base– # 9 CT(+C)CTACTA Cor. Recon. Tumor encased Lingual Artery ligated pre-TLM

15. T3 SCC Tongue Base– # 9 Tumor encased Lingual Artery ligated pre-TLM 3D Endoscopic Views

16. T3 SCC Oral Tongue – # 17 CT(+C)CTA Tumor encased Lingual Artery ligated pre-TLM 3D Endoscopic View

17. T3 SCC Oropharynx – # 19 CTA ECA & ICA Proximity → ∆ Open Surgery 3D Endoscopic Views T

18. Duel Acquisition Neck CTA/ CT for Pre-TLM H&N Ca Patient Evaluation Conclusions: 1. No instances perioperative bleeding among our TLM patients 2. Our TLM ENT surgeons like it: a. Facilitated TLM planning in all cases (esp. 3D images) b. Changed surgical approach in 30% of patients c. May also be used to facilitate Transoral Robotic Surgical (TORS) resection of H&N cancers 3. Benefits to Radiologist: a. Improved visualization of peritumoral vasculature (19/20) b. Tumor enhancement often best on CTA source images

19. The End Thanks for your attention

21. T3 SCC Oral Tongue – # 17 CT(+C)CTACTA Cor. Recon. Tumor encased Lingual Artery ligated pre-TLM

22. 3D Endoscopic Views Rt. Lingual Artery Encasement T3 SCC Oral Tongue – # 17

23. Critical Arterial Anatomy: Rt. Endoscopic ViewsLat.

24. T3 SCC Supraglottic Larynx – # 4 CT wCTACTA Cor. Recon.

25. T2 SCC Oropharynx – # 8 CT wCTACTA Cor. Recon.

26. Rt. 3D Endoscopic View T2 SCC Oropharynx – # 8

27. CTA Cor. Recon.CTA Sag. Recon.Endoscopic view. Lt. Lingual Artery Encasement T3 SCC Oral Tongue – # 9