XIX Symposium Neuroradiologicum
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
TLM Surgery: Background
#1
• Transoral Laser Microsurgery (TLM)
• Since 1996 TLM utilized increasing for resection of primary
H&N cancers @ Mayo Clinic
• CO2 Laser via transoral approach allows piecemeal
tumor resection & “following the tumor” w/ frozen sections
• May be performed in conjunction w/ standard neck nodal
resection
TLM Surgery: Background
#2
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
TLM Surgery: Background
#3
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)
Study Objective
• Improve visualization of peritumoral arterial branches on
pre-TLM patient imaging
• Facilitate TLM patient selection
• Assist surgeon w/ surgical planning → lower bleeding risk
Duel Acquisition CTA/ CT:
Technique
• 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)
Combined CTA/ CT: Contrast
• 100 ml of Omnipaque 300 mg% (50 ml x 2)
#1
#2
CTA
Neck CT(+C)
Begin CTA
bolus tracking
0 sec
40
60
80
#1: 50 ml contrast followed by 30 ml NS @ 4cc/ sec
#2: 50 ml contrast followed by 50 ml NS @ 4cc/ sec
90
Duel Acquisition CTA/ CT: Technique
CTA
Scan direction
Caudo-cranial
CT(+C)
Cranio-caudal
kVp
120
120
mAs
240
240
0.6 x 64
0.6 x 64
0.37
0.37
22 cm
22 cm
Collimation
Rotation time
FOV
Duel Acquisition CTA/ CT: Images
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)
Patient Population
• 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)
Study Evaluation
• 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 presurgical CTA-CT findings
– TLM patients with perioperative bleeding
Study Results
• 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
T2 SCC Hypopharynx – # 1
Aberrant Thyroidal artery along anterior tumor
Lt.
CT(+C)
CTA
3D Endoscopic
View
T3 SCC Tongue Base– # 9
Tumor encased Lingual Artery ligated pre-TLM
CT(+C)
CTA
CTA Cor. Recon.
T3 SCC Tongue Base– # 9
Tumor encased Lingual Artery ligated pre-TLM
3D Endoscopic Views
T3 SCC Oral Tongue – # 17
Tumor encased Lingual Artery ligated pre-TLM
CT(+C)
CTA
3D Endoscopic View
T3 SCC Oropharynx – # 19
ECA & ICA Proximity → ∆ Open Surgery
T
CTA
3D Endoscopic Views
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
Thanks for your attention
The End
T3 SCC Oral Tongue – # 17
Tumor encased Lingual Artery ligated pre-TLM
CT(+C)
CTA
CTA Cor. Recon.
T3 SCC Oral Tongue – # 17
Lingual Artery Encasement
Rt.
3D Endoscopic Views
Critical Arterial Anatomy:
Rt.
Lat.
Endoscopic Views
Rt.
T3 SCC Supraglottic Larynx – # 4
CT w
CTA
CTA Cor.
Recon.
T2 SCC Oropharynx – # 8
CT w
CTA
CTA Cor. Recon.
T2 SCC Oropharynx – # 8
Rt.
3D Endoscopic View
T3 SCC Oral Tongue – # 9
Lingual Artery Encasement
Lt.
CTA Sag. Recon.
CTA Cor. Recon.
Endoscopic view.