Postoperative Radiation for Oral Postoperative Radiation for Oral Cavity Squamous Cell Carcinoma: Cavity Squamous Cell Carcinoma:

The EPThe EP

The Difference?The Difference?

Album EP

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Squamous Cell CarcinomaSquamous Cell Carcinoma

• Oral Cavity Cancer is a Surgical Disease

• Use Radiation Postoperatively for Appropriate Patients

• RT can be used as primary therapy for small (T1, T2) tumors of the oral cavity.

• Oral tongue

• Floor of Mouth

• Lip

• Best results are with a combination of external beam radiation and brachytherapy

Difficult getting enough dose to primary with brachytherapy while still delivering adequate dose to the regional nodes IJROBP 1990; 18:1287-92.

Brachytherapy complications: soft tissue necrosis, osteonecrosis

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Squamous Cell CancerSquamous Cell Cancer

• Who needs postop RT?

• Definite Indications:

• 1) Positive Margins

• 2) Multiple Nodes

• 3) Extracapsular Extension

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Squamous Cell CancerSquamous Cell Cancer

• Who needs postop RT?

• Less certain indications:

• 1) Lymphovascular space invasion

• 2) Perineural spread

• 3) Single encapsulated node +• 4) Thick tumors (Tumors 3-9 mm: 44% node+, 7% local

recurrence; >9 mm: 53% subclinical node+, 24% local recurrence Head Neck

2002: 24:513-20)

• 5) Surgeon Vibe

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Squamous Cell CancerSquamous Cell Cancer

• Why give radiation after surgery?

• RTOG 73-03: locally advanced H&N cancers: supraglottic larynx, hypopharynx, oral cavity and oropharynx

• Preop (50 Gy) vs Postop (60 Gy)• Oral Cavity/oropharynx also had definitive RT

arm (65-70 Gy) followed by surgery if residual cancer

• Head Neck Surg 1987;10:19-30

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Squamous Cell CancerSquamous Cell Cancer

• RTOG 73-03 • 277 patients• Ten year follow-up• Improved locoregional control in postoperative

RT arm (65%) vs. preop RT (48%, p=0.04)• Trend toward improved survival: 38% vs 33%,

p=0.10)• Surgical and radiation therapy complications

“similar”. IJROBP 1991;20:21-8.

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Cancer: Radiation DoseCancer: Radiation Dose

• RTOG 7303 established 60 Gy as postop RT dose

• MD Anderson performed prospective randomized trial evaluating RT dose for 240 patients with resected stage III/IV cancers of oral cavity, oropharynx, hypopharynx, larynx

• 180 cGy fractions• Dose ranged from 52.2 Gy to 68.4 Gy• IJROBP 1993; 26:3-11.

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Cancer: Radiation DoseCancer: Radiation Dose

• Patients receiving <54 Gy had significantly higher failure rate.• No dose response beyond 57.6 Gy except for patients with

extracapsular nodal spread.

• +ECE needed at least 63 Gy

• “Clusters” of two or more of the following also predicted increased risk of failure and need for 63 Gy: oral cavity primary, positive/close margins, nerve invasion, >2 positive nodes, largest node >3 cm, treatment delay >6weeks, Zubrod performance status>2

• Moderate to severe complications seen in 7.1%; more if RT dose >63 Gy

• Dose escalation above 63 Gy “does not appear to improve the therapeutic ratio”.

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Cancer: RT + ChemotherapyCancer: RT + Chemotherapy

• Two large randomized trials evaluating RT with or without cisplatin chemotherapy in high-risk resected head and neck squamous cell cancers.

• EORTC• RTOG• NEJM 2004; 350:1945-1952• NEJM 2004: 350:1937-1944

• High risk features: >2 + nodes, +ECE, + margins (EORTC also included perineural spread and vascular tumor embolism)

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Cancer: RT + ChemotherapyCancer: RT + Chemotherapy

• Radiation dose: 60 Gy RTOG; 66 Gy EORTC• Cisplatin 100 mg/m2 days 1, 22, 43 both • 334 EORTC + 459 RTOG patients (793 total)• 26-27% oral cavity primaries

• In combined analysis, only patients with +ECE and/or + margins benefited from addition of cisplatin Head Neck 2005; 27: 843-850

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Cancer: RT + ChemotherapyCancer: RT + Chemotherapy

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Cancer: RT + ChemotherapyCancer: RT + Chemotherapy

Postoperative Radiation for Oral Cavity Postoperative Radiation for Oral Cavity Cancer: RT + ChemotherapyCancer: RT + Chemotherapy

• What’s Next?

• RTOG 0234 evaluated postop chemoRT (cisplatin or docetaxel) + EGFR inhibitor cetuximab (Erbitux)

• This phase II study completed but results are pending

Get to Work!!Get to Work!!

Three-Way Tie for Last