HEAD AND NECK CANCER: READ WITH THE EXPERTS

Marc Seltzer, MD

Associate Professor of Radiology Geisel School of Medicine at Dartmouth

Director, PET-CT Course American College of Radiology

A. Initial treatment evaluation of all stages I through IV B. Only for initial treatment evaluation of stages III and IV C. Post treatment surveillance D. All of the above

In patients with head and neck cancer, in which situation(s) is PET/CT recommended by the National Comprehensive Cancer Network (NCCN)?

A. Initial treatment evaluation of all stages I through IV B. Only for initial treatment evaluation of stages III and IV C. Post treatment surveillance D. All of the above

In patients with head and neck cancer, in which situation(s) is PET/CT recommended by the National Comprehensive Cancer Network (NCCN)?

CASE 1

• 58 yo woman with 40 P-Y history presented with sore throat, then enlarging bilateral neck nodes + R otalgia

• FNA neck node: nondiagnostic • Exam: R tongue base lesion; Bx: basaloid SCCa, p16 (-) • Staging PET/CT

CASE 1

• Treated with definitive chemoradiation • Escalating throat pain, palpable bilateral neck nodes 1

month after completion • Exam: ulceration in tongue base; Bx: adenosquamous

Ca • Plan: restage with PET-CT, consider salvage surgery

(glossectomy, bilat neck dissections)

CASE 1

• Pleural Bx: confirmed metastatic disease • Palliative chemotherapy given; disease progression • Hospice care

CASE 1: TAKE HOME POINTS:

• H/N cancers persisting through chemoradiation have high risk of metastases

• Thorough restaging needed before embarking on surgical salvage

A. 1–2 weeks B. 2–3 weeks C. 4–6 weeks D. 8–12 weeks E. At least 24 weeks

What is the accepted optimal time interval to wait after completing chemoradiation before performing PET-CT to assess response to therapy?

A. 1–2 weeks B. 2–3 weeks C. 4–6 weeks D. 8–12 weeks E. At least 24 weeks

What is the accepted optimal time interval to wait after completing chemoradiation before performing PET-CT to assess response to therapy?

A. Mediastinal nodes B. Bone C. Lung D. Liver

In locally advanced head and neck cancer, which of the following is the MOST COMMON site of distant metastases?

A. Mediastinal nodes B. Bone C. Lung D. Liver

In locally advanced head and neck cancer, which of the following is the MOST COMMON site of distant metastases?

CASE 2

• 55 yo male with 51 P-Y smoking history • Painless L neck mass noted 2012; sought medical

attention when it grew by late 2014 • Initial exam (-) in mouth and throat; 3 cm L zone II

mass • Node FNA: basaloid SCCa, p63 (+), p16 (+) • F/U exam: tiny L tonsil lesion

CASE 2

• Staging PET/CT

CASE 2: TAKE HOME POINTS

• PET/CT useful in initial staging • Biopsy confirmation of metastasis warranted if a priori

risk was low and change in Rx goals would be major • Tobacco-associated H/N cancers are more aggressive

even if p16 (+)

CASE 3

• 68 yo woman, 20 P-Y smoking history, long history of psoriatic arthritis on oral methotrexate

• Neck mass noted by Rheumatologist • Clinical exam and CT informative only in neck node • Excisional node Bx: nonkeratinizing SCCa, EBV (+)

CASE 3

• PET/CT obtained to search for site of primary malignancy and to complete staging

A. Nasopharynx B. Oropharynx C. Hypopharynx D. None of the above, primary site

not identified

Based on the PET-CT findings shown, the most likely site of primary malignancy is:

A. Nasopharynx B. Oropharynx C. Hypopharynx D. None of the above, primary site

not identified

Based on the PET-CT findings shown, the most likely site of primary malignancy is:

TAKE HOME POINTS

• PET/CT can help find occult primary H/N cancers that may be difficult to access by clinical exam (endoscopy)

• Immunocompromised patients who develop new adenopathy may have something other than lymphoma or infection as the cause.

CASE 4

• 64 yo with 40 P-Y smoking history presented with progressive odynophagia and dysphagia, R>L neck nodes

• Exam: large base of tongue tumor; neck: 5 cm node mass L, several 2 cm nodes R

• Bx: nonkeratinizing SCCa, p16 (+) • Staging PET/CT

A. Assume nodes are positive and proceed with palliative chemotherapy

B. Assume nodes are negative and proceed with curative chemoradiation

C. Bronchoscopic biopsy of hilar/mediastinal nodes

D. Repeat PET-CT after 6 weeks of antibiotics

Based on PET-CT findings of FDG avid hilar and mediastinal adenopathy, the next BEST step in clinical management is:

A. Assume nodes are positive and proceed with palliative chemotherapy

B. Assume nodes are negative and proceed with curative chemoradiation

C. Bronchoscopic biopsy of hilar/mediastinal nodes

D. Repeat PET-CT after 6 weeks of antibiotics

Based on PET-CT findings of FDG avid hilar and mediastinal adenopathy, the next BEST step in clinical management is:

CASE 4

• Bronchoscopy with endobronchial ultrasound-guided biopsies:

• 3 samples with lymphocytes and histiocytes only, consistent with granulomatous disease.

• Proceeded to definitive chemoradation • Clinical CR in neck and at primary

CASE 4

• Restaging PET/CT 12 weeks after completing chemoradiation

CASE 4: TAKE HOME POINTS

• FDG avid intrathoracic adenopathy should NOT be assumed metastatic

• Tissue sampling is required • In this case, persistent FDG avid adenopathy in the

chest after chemotherapy is reassuring that it all represents granulomatous disease

CASE 5

• 47 yo nonsmoker presented with growing R neck mass • Exam: tiny R tonsil lesion; 5 cm R neck mass • Tonsil Bx (-); incisional neck mass Bx: nonkeratinizing

SCCa, p16(+) • Staging PET/CT

CASE 5

• PET-CT did not identify primary site of cancer • Robotic tonsillectomy: SCCa in right tonsil, clear

margins • Definitive chemoradiation to neck • Slow, near-complete resolution of R neck mass • 3 month restaging PET/CT

A. Take no further action and observe B. Proceed with neck dissection C. Give additional chemoradiation treatment D. Perform image-guided biopsy of the residual

lymph nodes

Based on the PET-CT findings after 12 weeks of chemoradiation, the clinical team is most likely going to:

A. Take no further action and observe B. Proceed with neck dissection C. Give additional chemoradiation treatment D. Perform image-guided biopsy of the residual

lymph nodes

Based on the PET-CT findings after 12 weeks of chemoradiation, the clinical team is most likely going to:

CASE 5

• Clinicians and patient anxious despite negative PET/CT report interpretation

• A “surveillance” repeat PET/CT 1 year post-treatment was ordered due to high risk of recurrence

• Surveillance PET-CT was negative

CASE 5: TAKE HOME POINTS

• Bulky nodal disease is ominous: high risk of persistent disease and of metastasis

• Anxious clinician and patient may need reassurance with a “surveillance” PET-CT in spite of negative clinical exam (no signs or symptoms of recurrence)

NCCN Guidelines 2015 Follow-up Imaging Recommendations

After Definitive Treatment

• “Clinical exam is primary method of follow-up” • “Further reimaging as indicated based on

worrisome or equivocal signs/symptoms, smoking history, and areas inaccessible to clinical examination”

• CT chest commonly ordered to screen for lung metastasis vs second primary lung cancer

• PET-CT not specifically mentioned for surveillance

BONUS CASES:

INTERPRETATION PITFALLS

History

65-year-old woman with right base of tongue squamous cell carcinoma

Pre-treatment PET/CT for right base of tongue tumor and right level II adenopathy

12 months after chemoradiation for right base of tongue tumor and right level II adenopathy

A. Dental related inflammatory change

B. Local recurrence at the lateral margin of the right tongue

C. New primary tumor in the right tongue

D. Osteoradionecrosis of the right mandible

The most likely explanation for the PET finding shown is:

A. Dental related inflammatory change

B. Local recurrence at the lateral margin of the right tongue

C. New primary tumor in the right tongue

D. Osteoradionecrosis of the right mandible

The most likely explanation for the PET finding shown is:

• Osteoradionecrosis is a relatively common complication of radiation therapy in head and neck cancer

• When a post treatment scan shows increased FDG uptake in a location different than the original primary tumor, the activity cannot be due to local tumor recurrence

Teaching Points

• Benign dental related inflammatory foci are commonly seen as an incidental finding on FDG PET/CT

• If there is concern for a new site of malignancy versus focal inflammation, direct visualization and biopsy should be considered

Teaching Points

Baseline PET-CT

Osteoradionecrosis of the mandible (12 months post chemoradiation)

PET-CT 12 months post chemorad for left BOT tumor

Functioning tongue muscle 12m s/p chemoradiation

PET-CT 12 months post hemiglossectomy and chemorad

Functioning tongue s/p hemiglossectomy with flap recon

56 year old man with left hilar mass on CXR CT showed left hilar mass and supraclavicular adenopathy

?

• Benign adenopathy due to old infection

• Non-FDG avid nodal metastasis from FDG avid lung cancer

• Non-FDG avid lymphoma such as small lymphocytic lymphoma

• Non-FDG avid malignancy other than lymphoma

Which of the following best explains the non-FDG avid neck adenopathy:

• Benign adenopathy due to old infection

• Non-FDG avid nodal metastasis from FDG avid lung cancer

• Non-FDG avid lymphoma such as small lymphocytic lymphoma

• Non-FDG avid malignancy other than lymphoma

Which of the following best explains the non-FDG avid neck adenopathy:

?

Post PET-CT Follow-up • Lung biopsy: squamous cell carcinoma • Neck ultrasound: dominant mass in right

lobe of thyroid and bilateral neck nodes • Neck node biopsy: papillary carcinoma

consistent with thyroid primary • Serum Thyroglobulin: 1240 mg/ml (nl:

<55) Tg Ab <20

PET-CT Diagnostic I-131 scan 1 wk after PET-CT

PET Negative, I-131 Positive Thyroid CA

… now, the “flip-flop”

65 yoM T3N1 papillary thyroid ca, 2 months s/p thyroidectomy

Negative I-131 scan 7 days after 120 mCi I-131 ablation

Serum thryoglobulin: <0.4; Tg Ab: 2685 (nl <40) Restaging PET-CT 1 week post I-131 scan

Lung Bx: Papillary Thyroid Cancer

PET Positive, I-131 Negative Thyroid CA

• Differentiated thyroid cancers that lose ability to trap iodine have increased rates of glucose metabolism

• In patients with a high serum thyroglobulin level and negative I-131 scan, the sensitivity and specificity of FDG PET-CT is high (80-90%)

FDG-PET in Thyroid Cancer

Now

Two months from now…

Thank you