Epidemiology
General
Risk Factors
Presentation and Evaluation
Anatomy
- The oropharynx is a cubic cavity with following borders
- Superior: superior surface of the soft plate
- Inferior: superior surface of the hyoid bone (or floor of the vallecular)
- Includes following structures:
- base of tongue
- inferior/anterior surface of the soft palate and uvulla
- anterior and posterior tonsillar pillars
- glossotonsillar sulci
- pharyngeal tonsils
- lateral and posterior pharyngeal walls
Pathology
Clinical Presentation
Pattern of Spread
Oropharyngeal Primary
- upper and mid-jugular lymph nodes
- submental/submandibular nodes (less common)
Tonsil
T1-T2, N0-N2b SCCA confined to the tonsillar fossa has less than 5% contralateral LN recurrence following ipsilateral only RT.
Base of Tongue Primary
- Superficial lymphatics
- Continuous with the superficial plexus that covers the oral tongue -> levels II and III
- Deep Muscular lymphatics
- Ipsilaterally or have direct branches that drain to the contralateral neck
- 78% of patients will have either unilateral or bilateral cervical metastases at initial presentation. (Lindberg 1972)
Treatment
Early Stage (T1-2, N0-1)
- Definitive RT (preferred)
- Concurrent Chemoradiation for T1-2, N1
- Excision of primary ± unilateral or bilateral neck dissection
- Choice of therapy depends on functional issues.
Advanced (T3-4a, any N or any T, N2-3)
- Concurrent chemoradiation with cispatin [6] (preferred)
- Surgery ± post-operative radiation or chemoradation
Unresectable
Outcome
Prognostic Factors
Worse DSF[4]
- age > 60
- male gender
- total radiation dose < 70 Gy
- duration of radiotherapy > 50 days.
Better DFS
- HPV+ (improves by 50%)[5]
Altered Fractionation
Altered fractionation is preferred when radiotherapy is used definitively for selected T1, N1 or T2, N0-1 tumors. For patients not receiving concurrent chemoradiation, altered fractionation is preferred.
The recommended schedules are:
(1) concomitant boost accelerated radiotherapy consisting of 72 Gy delivered over 6 weeks
using 1.8 Gy/fractions to the large volume and 1.5 Gy boost as the
second daily fraction 6 hours later during the last 12 treatments to a
smaller volume; or
(2) hyperfractionation consisting of 81.6 Gy given in 7 weeks with 1.2 Gy/fractions twice daily 6 hours apart.
This change from standard radiotherapy for large lesions was made on
the basis of the results of the RTOG 9003 protocol, which detected a local control advantage for patients who were treated with hyperfractionation and concomitant boost versus those treated with standard fractionation or accelerated fractionation with a break in
the treatment schedule.
Increased acute toxicity was demonstrated in both altered fractionation schedules when compared with standard radiotherapy. The concomitant boost schedule resulted in prolongation of acute symptoms 6 to 24 months after the initiation of treatment, but no significant difference was demonstrated in the frequency of late effects among schedules. In addition to the RTOG trial, four other randomized trials have demonstrated improved
outcomes with hyperfractionation.
Studies
GORTEC French H&N Oncology and RT Group 94-01[6]
Patients
- 226 patients
- Stage III or IV oropharynx carcinoma
Results
| Arms | RT | CRT | p-value |
|---|---|---|---|
| Locoregional control-5 | 24.7% | 47.6% | < .01 |
| DFS-5 | 14.6% | 26.6 | .01 |
ORO 93-01
Design
192 patients with Stage III, IV oropharyngeal CA excluding T1 N1 and T2 N1. F/U = 24 months.
Arm A: 66-70 Gy in 2 Gy fx to Tumor and Nodes
Arm B: 64-67.2 in 1.6 BID with 2 week split after 38.4 Gy
Arm C: Concurrent Chemo (Carbo + 5-FU) with RT as in A.
