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

TLM Surgery: Background Transoral Laser Microsurgery (TLM) Since 1996 TLM utilized increasing for resection of primary H&N 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The End Thanks for your attention

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

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

Critical Arterial Anatomy: Rt. Endoscopic ViewsLat.

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

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

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

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