Treatment/Prognosis

Question 1

In general, what is the Tx paradigm for OCC?

Answer 1

OCC Tx paradigm: Sg +/- PORT (+/- chemo)

Question 2

What pathologic features of the OCC primary lesion call for prophylactic/elective neck management?

Answer 2

Tumor thickness >2 mm, grade III Dz, +LVI, lower alveolar ridge and RMT, and a recurrent lesion are features that increase the need for prophylactic neck management.

Question 3

What are the indications for PORT?

Answer 3

N2 or N3, low neck nodes or >2 LN levels, T3/T4, +/close margins, no neck dissection in high-risk pts, and LVI, PNI are indications for PORT.

Question 4

In what circumstances should chemo be added to PORT?

Answer 4

Chemo should be administered with RT if there is a +margin, +ECE (per Bernier and Cooper adj RCT of PORT vs. PORT + chemo). (Bernier J et al., NEJM 2004; Bernier J et al., J Head Neck 2005; Cooper JS et al., IJROBP 2012)

Question 5

When is bilat neck dissection recommended for lesions of the OC?

Answer 5

Bilat neck dissection is recommended with ≥N2c Dz (bilat or bulky LNs).

Question 6

For what OC sites is definitive RT preferred?

Answer 6

Definitive RT is preferred (over Sg) for lip commissure and RMT lesions with tonsillar pillar involvement.

Question 7

What is generally considered a close margin?

Answer 7

<5 mm

Question 8

What are the indications for PORT to the primary site for OC lesions?

Answer 8

+ or close margin, PNI/perivascular invasion, and T3–T4 Dz are indications for PORT.

Question 9

What RT doses are typically used in OCC?

Answer 9

PORT: 60 Gy (–margins) to 66 Gy (+margins) in 2 Gy/fx

Definitive RT: 70 Gy to gross Dz +/– chemo

Question 10

When is brachytherapy indicated for OCC?

Answer 10

Definitive: early (T1–T2) lip/early oral tongue/FOM lesions—LDR to 66–70 Gy in 1 Gy/hr

As a supplement: T4 tongue/FOM lesions, 40% of total dose or ∼30 Gy

Question 11

For oral tongue lesions, which modality is associated with better LC: LDR or HDR?

Answer 11

Both modalities yield similar results. 5-yr LC was 76%–77% for both HDR and LDR techniques in a phase III comparison. (Inoue T et al., IJROBP 2001)

Question 12

What are the common LDR and HDR doses used with an interstitial implant for OCC?

Answer 12

LDR: 60–70 Gy (0.4–0.6 Gy/hr)

HDR: 60 Gy (5 Gy bid × 12 fx)

Question 13

What alternate teletherapy modalities can be employed for superficial OC lesions?

Answer 13

An intraoral cone can be employed for superficial OC lesions: orthovoltage (100–250 keV) or electrons (6–12 MeV).

Question 14

Why is a tongue depressor/bite block used when irradiating the OC?

Answer 14

A tongue depressor is used to spare the sup OC/palate and to surround the lat oral tongue lesion with other mucosa to minimize air tissue interfaces and maximize dose buildup.

Question 15

What kind of surgical resection is typically performed for leukoplakia or CIS of the lip?

Answer 15

Vermilionectomy with advancement of the mucosal flap (“lip shave”), which involves simple excision from the vermilion to the orbicularis muscle.

Question 16

When is Sg an option for cancers of the lip?

Answer 16

Sg is an option if the lesion involves <30% of the lip, if it is a T1 lesion, or the lesion does not involve the oral commissure; otherwise, use RT. Sg is typically WLE with primary closure (W-shaped excision) and with a 0.5-cm gross margin.

Question 17

When is definitive RT used for cancers of the lip?

Answer 17

Definitive RT is used for lip tumors >2 cm, large lesions (>50% of the lip), upper lip lesions, or if the lesion involves the oral commissure.

Question 18

Is elective nodal RT of the neck required for T1–T2 cancers of the lip?

Answer 18

No. Elective nodal RT is not needed b/c the occult nodal positivity rate is only ∼5%.

Question 19

What are the doses used for the Tx of T1–T2 cancers of the lip?

Answer 19

T1: 50 Gy (2.5 Gy × 20)

T2: 60 Gy (2.5 Gy × 24) with 100–250 keV photons or 6–9 MeV electrons + 1-cm bolus

Question 20

When is PORT indicated for lip cancers?

Answer 20

PORT is indicated for lip cancers in case of T4 Dz (bone invasion), +margin, extensive PNI, +ECE, ≥2 nodes+, or T3–T4 Dz without dissection of the neck.

Question 21

What randomized evidence supports PORT over Sg alone for stages III–IV SCC of the buccal mucosa?

Answer 21

Indian data. Mishra RC et al. showed improved 3-yr DFS with PORT (68% vs. 38%). (Eur J Surg Oncol 1996)

Question 22

Is bilat neck RT required for stage III–IV buccal mucosa lesions?

Answer 22

PORT fields for gingival lesions with PNI must include the entire hemimandible (from the mental foramen to the temporomandibular joint).

Question 23

What randomized data support the need for PORT for OC lesions based on specific risk factors?

Answer 23

MDACC series (Ang KK et al., IJROBP 2001): pts with a +margin, PNI, and ECE had higher failure rates.

Question 24

For RMT/alveolar ridge tumors, in what circumstances is RT preferred over Sg and vice versa?

Answer 24

Definitive RT preferred if there is no bone erosion or if the lesion extends to the ant tonsillar pillar, soft palate, or buccal mucosa. If there is bone erosion, then Sg is preferred → PORT.

Question 25

What is the preferred management approach for hard palate lesions?

Answer 25

Generally, initial Sg is preferred for all cases, except if there is extension to the soft palate or RMT, in which case definitive RT can be considered.

Question 26

Per NCCN guidelines, what is the recommended time interval b/t Sg and PORT for OCC?

Answer 26

Per NCCN guidelines, the recommended time interval b/t Sg and PORT for OCC is 6 wks.