Oropharynx

Question 1

Unilateral tonsil

Answer 1

ACR Appropriateness criteria: T1-2N0-1 oropharynx, less than 1 cm extension to soft palate, and no BOT involvement Many will also treat unilateral for up to N2a”

“Some now recommended TORS first to avoid toxicity from RT. But TORS usually has close margin. Many will avoid RT in this circumstance.

On PE make sure to note BOT or soft palate extension, trismus (pterygoid involvement), inability to protrude tongue (T4 deep tongue muscles)”

“definitive
70/63/56 (2/1.8/1.6) 35 fx DAHANCA, 6 fractions per week, with a BID fraction one day a week
70/56 with DAHANCA fx

RTOG 0022 regimen: 66/2.2 Gy and 54/1.8 in 30 fx SIB to ipsilateral neck, no chemo. Though some believe over 2 Gy per fx increases risk of necrosis

Can consider doing ipsilateral RT for up to T2N2b per O’Sullivan”

“CTV neck: levels II-IV. Include V if ≥2 nodes positive. Add RP for posterior pharyngeal wall.

5 mm CTV-P1 and 10 mm CTV-P2 per standard.

Consider chemoRT or RT alone for T2N1 per NCCN. Otherwise no chemo.

If gross nodes were treated, perform PET at 3 months for HPV- and 4 months for HPV+. If disease is still active, recommend neck dissection

“LC>90%T1, >80%T2 (T3 50%)
2-yr OS 95%

Contralateral neck failure<5%”

Question 2

Oropharynx advanced

Answer 2

Test for P16. If negative but still suspicious, check HPV PCR

At this time treatment regimens for HPV positive and negative are identical”

“Three volume: 6996/5940/5412 (2.12/1.8/1.64) 33 fx with chemo
Two volume: 7000/5600

PET at 3 months then elective neck dissection if incomplete response. HPV+ tumors may continue to regress up to 4 months. “

“CTV neck: levels II-IV. Include V if more than one node positive. Add RP for posterior pharyngeal wall.

5 mm CTV-P1 and 10 mm CTV-P2 per standard.

If gross nodes were treated, perform PET at 3 months for HPV- and 4 months for HPV+. If disease is still active, recommend neck dissection

"RPA risk groups:
Low:p16+ with <10 py any, or p16+ with >10 py and N0-2a
Int: p16+ and >10py and N2b-3
   or p16- and <10py and T2-3
High: p16- with >10py, or p16- with <10 py and T4
3-yr OS:
Low risk: 93%
Int risk: 71%
High risk: 46%

3-yr OS HPV+ vs. HPV-: 82% vs. 57%
3-yr DM HPV+ vs. HPV-: 9% vs. 15%
3-yr LRC HPV+ vs. HPV-: 86% vs. 65%”