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Oral Cavity Cancer
51
Primary tumor (T)
TX Primary tumor cannot be assessed
T0 No evidence of primary tumor
Tis Carcinoma in situ
T1 Tumor 2 cm or less in greatest dimension
T2 Tumor more than 2 cm but not more than 4 cm in greatest dimension
T3 Tumor more than 4 cm in greatest dimension or extension to lingual surface of epiglottis
T4a Tumor invades the larynx, extrinsic muscle of tongue, medial pterygoid, hard palate, or mandible*
T4b Tumor invades lateral pterygoid muscle, pterygoid plates, lateral nasopharynx, or skull base or encases carotid
artery
Regional lymph nodes (N)
NX Regional lymph nodes cannot be assessed
N0 No regional lymph node metastasis
N1 Metastasis in a single ipsilateral lymph node, 3 cm or less in greatest dimension
N2 Metastasis in a single ipsilateral lymph node, more than 3 cm but not more than 6 cm in greatest dimension, or
in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimension, or in bilateral or contralateral
lymph nodes, none more than 6 cm in greatest dimension
N3 Metastasis in a lymph node more than 6 cm in greatest dimension
Distant metastasis (M)
M0 No distant metastasis
M1 Distant metastasis
Factor
Description
Lymph node
status
Nodal status is the most important prognostic factor related with survival and local
control.
Vascular and
lymphatic
invasion
Both Vascular and perineural invasion seems to predict increased risk of local
recurrence and diminished likelihood of survival.
Location
lesions that originate more anteriorly have a better prognosis than lesions that arise
more posteriorly
Treatment
Local control is directly related to the total dose of radiation delivered and inversely
related to the duration of treatment.
Table 3. TNM staging system for oral cavity cancer
Reference
American Joint Committee on Cancer Staging Manual, 7th, Edge SB, Byrd DR, Compton
CC, et al (Eds), Springer, New York 2010.
9. Prognostic Factors
The probability of tumor control and survival is related with various tumor and patients
factors, as described in table-4.
Table 4. Prognostic factors for local control and survival of oral cavity cancer
Gustavo Arruda Viani
52
Study
Description
Zitsch
A retrospective review of 323 patients treated with either surgical excision and/or
radiotherapy, evaluated disease recurrence, cause-specific mortality, and the
incidence of metachronous lesions.
Recurrence-free survival at 10 years was estimated to be 92.5%, and cause-specific
survival at 10 years was estimated to be 98.0%. Equivalent rates of local control
were obtained with surgery and radiotherapy.
Mc Combe
Retrospective review of 1252 patients with lip cancer treated by resection were
analyzed to identify prognostic variables.
Large tumor size, high tumor grade, the presence of adenopathy, a subsite other
than the lower lip, and inadequate surgical margins were found to have a negative
impact on determinate survival of patients with lip carcinoma.
Recurrence developed in 15.1% of the patients reviewed and was strongly
associated with large tumor size and poor differentiation.
Local recurrence was associated with a determinate survival of 78%, whereas
patients having regional recurrences had a survival rate of 52%.
References
Mishra RC, Parida G, Mishra TK, et al. Tumour thickness and relationship to locoregional
failure in cancer of the buccal mucosa. Eur J Surg Oncol 1999;25:186-189.
Bentzen SM, Johansen LV, Overgaard J, et al. Clinical radiobiology of squamous cell
carcinoma of the oropharynx. Int J Radiat Oncol Biol Phys 1991;20:1197-1206.
Sobel S, Rubin P, Keller B, et al. Tumor persistence as a predictor of outcome after radiation
therapy of head and neck cancers. Int J Radiat Oncol Biol Phys 1976;1:873-880.
10. Treatment by Site
10.1. Early Stage
Lip
• The majority of lesions can be treated with either surgery or radiation alone. Surgery
is preferred for small lesions without significant functional deficits.
• Lesions involving the lip commissure or which would result in severe functional
deficits after resection should be evaluated for radiation therapy.
• Surgery is generally preferred T1 lesions (up to 2 cm in diameter) that do not involve
the oral commissure. Excision of such lesions is simple (V or W excision with
primary closure or flap reconstruction), and the functional and cosmetic outcome is
satisfactory.
• Radiation is a good option for lesions larger than 2 cm or those involving the
commissure, in which surgical resection results in microstomia or oral incontinence.
• Radiotherapy can be delivered by external beam irradiation, brachytherapy, or a
combination of both, depending on the location and size of the lesion. A combination
of surgery and radiotherapy is frequently required for advanced destructive lesions,
that is those invading the bone or nerve, or with nodal involvement (table-5).
Table 5. Clinical evidence for surgery and radiotherapy in early lip cancer
Oral Cavity Cancer
53
Study
Description
Rodgers et al
(1993)
194 patients with previously untreated squamous cell carcinoma of the floor of mouth
were managed by surgery and radition alone.
A retrospective analysis was undertaken in order to evaluate the treatment results and
associated complication rates.
Surgery or irradiation alone was found to result in similar local control rates for stage I
and II lesions, whereas more advanced tumors had better local control rates with a
combination of surgery and irradiation.
Radiotherapy had a higher incidence of minor and moderate complications, whereas a
greater number of severe complications occurred after surgery.
Matsumoto et
al (1996)
A retrospective analysis of 90 patients with T1 and T2 SCCs of the floor of the mouth
who underwent brachytherapy were performed.
The radiotherapy mainly consisted of 198Au grain implants with or without external
irradiation.
Stage I (T1N0), 21 cases; Stage II (T2N0), 55 cases; and Stage III-IV (T1-2N1-2), 14
cases. The minimum follow-up time was 3 years.
The local control rates based on tumor size, were 89% for T1 lesions, 76% for T2a (<or
= 3 cm) lesions, and 56% for T2b (>3 cm) lesions.
The 5-year, cause-specific survival rates by staging were 95% for T1N0, 79% for T2N0,
and 54% for T1-2N1-2. Severe complications requiring surgery was low (5%).
Reference
Zitsch RP 3rd, Park CW, Renner GJ, Rea JL. Outcome analysis for lip carcinoma.
Otolaryngol Head Neck Surg. 1995;113(5):589.
Floor of Mouth
• Surgery is the preferred approach for early stage lesions due to the risk of severe
radiation adverse effects, mainly, radionecrosis of mandibule, associated with
definitive RT.
• The majority of early stage floor of mouth lesions be managed by a via transoral
excision.
• Large defects are best repaired can needed of a surgical reconstruction to optimize
functional outcomes including radial forearm free flap reconstruction.
• Definitive radiotherapy produces similar results to surgery in terms of local control
and survival, but with a increase in adverse late effects. Table-6 describes the results
of radiation therapy for floor of mouth lesions.
Table 6. Clinical evidence for surgery and/or radiotherapy in early floor mouth cancer
References
Rodgers LW Jr, Stringer SP, Mendenhall WM, Parsons JT, Cassisi NJ, Million RR. Manage-
ment of squamous cell carcinoma of the floor of mouth. Head Neck. 1993;15(1):16.
Matsumoto S, Takeda M, Shibuya H, Suzuki S. T1 and T2 squamous cell carcinomas of the
floor of the mouth: results of brachytherapy mainly using 198Au grains. Int J Radiat
Oncol Biol Phys. 1996;34(4):833.
Gustavo Arruda Viani
54
Study
Description
Wendt et al
(1990)
103 patients with Stage T1N0 and T2N0 squamous cell carcinomas of the oral tongue
were treated with definitive radiotherapy.
The primary was Stage T1 in 18 patients and T2 in 85 patients. Median follow-up was
159 months.
The 2-year local control rate was 92% for patients treated with external therapy to doses
of less than 40 Gy combined with a moderately high dose of brachytherapy, compared
with 65% for patients who received external therapy to doses of greater than or equal to
40 Gy with lower brachytherapy doses (p = .01).
Nair et al
(1988)
Retrospective study of 234 patients with oral tongue treated with radiotherapy in a single
institution from India.
Radiotherapy was used as the first line of management in this series and surgery was
reserved for failures even though very few patients opted for salvage surgery.
Of the 234 evaluable patients, 42% survived disease-free at the end of 3 years with
radiotherapy alone. By stage, DFS was 85% for Stage I, 63% for Stage II, 41% for Stage
III, and 15% for Stage IV at 3 years.
Oral Tongue
• Surgery can be offered for early oral tongue cancer, since a good functional result
can be achieved.
• Based on a good functional result, a partial glossectomy with negative margins
preserving speech and swallowing should be offered for stage I and II lesions.
• Evaluating surgical resection margins is difficult, mainly, because deep tongue
muscle margins are not found in a single plane, in contrast to the radial mucosal
margins. Therefore, close deep surgical margins should be interpreted with caution
and more aggressive treatment may be indicated in this context.
• Definitive RT of oral tongue cancer typically combines external beam RT with either
an intraoral cone (for tumors less than 2 cm thick) or interstitial brachytherapy for the
boost. Small (less than or equal to 10 mm) and superficial lesions can be treated with
either an intraoral cone or interstitial brachytherapy alone (table-7).
Table 7. Clinical evidence for surgery and/or radiotherapy
in early oral tongue cancer
References
Wendt CD, Peters LJ, Delclos L, Ang KK, Morrison WH, Maor MH, Robbins KT, Byers
RM, Carlson LS, Oswald MJ. Primary radiotherapy in the treatment of stage I and II oral
tongue cancers: importance of the proportion of therapy delivered with interstitial
therapy. Int J Radiat Oncol Biol Phys. 1990;18(6):1287.
Nair MK, Sankaranarayanan R, Padmanabhan TK. Evaluation of the role of radiotherapy in
the management of carcinoma of the buccal mucosa. Cancer. 1988;61(7):1326.
Retromolar Trigone and Lower Alveolar Ridge
• Early tumors of the retromolar trigone have a high local recurrence rate due to
microscopic extension into the mandible and a high probability of occult regional
lymph node metastases.
Oral Cavity Cancer
55
Study
Description
Hao et al
(1990)
50 patients with retromolar trigone squamous cell carcinoma were treated with
surgery and/or radiation or chemoradiation therapy
Patients were followed up for 36 months (mean). There were 6 stage I, 13 stage II, 4
stage II, and 27 stage N patients.
The 5-year actuarial survival rate for stage I to N and all stages were 100%, 74.1%,
75%, 43.6%, and 60.6%, respectively.
Multivariate analysis revealed that masticator space involvement, neck recurrence,
and cervical metastasis were poor prognosticators of survival by order.
Lo et al
(1987)
159 patients with previously untreated squamous cell carcinomas of the anterior
faucial pillar or retromolar trigone received definitive radiation therapy with doses
ranging from 60 Gy to 75 Gy.
The 5-year survival rate for the overall group was 83%. The cumulative recurrence
rate showed that 92% of the patients had recurrence by 2 years.
The failure rate for the evaluable patients was 29% for T1 lesions, 30% for T2 lesions,
24% for T3 lesions, and 40% for T4 lesions. Whereas stage was a poor indicator for
treatment outcome, there was a significantly higher failure rate for infiltrative and/or
ulcerated lesions (35%) than for exophytic or superficial lesions (15%).
After radiotherapy, 30% of the patients developed some degree of bone exposure but
only 5.6% (9 patients) required a segmental mandibular resection.
• Surgical procedure include wide local excision, however, the surgical resection can
be sometimes technically difficult. Thus, even for small tumors a lip-splitting cheek
flap or a marginal mandibulectomy may be required to achieve negative margins.
• To achieve negative margins a mucosal resection margin >1 cm is suggested, for this,
the degree of tumor invasion should be evaluated before surgery as well as possible
(table-8).
Table 8. Clinical evidence for surgery and/or radiotherapy
in early retromolar trigone cancer
References
Hao SP, Tsang NM, Chang KP, Chen CK, Huang SS. Treatment of squamous cell carcinoma
of the retromolar trigone. Laryngoscope. 2006;116(6):916.
Lo K, Fletcher GH, Byers RM, Fields RS, Peters LJ, Oswald MJ. Results of irradiation in the
squamous cell carcinomas of the anterior faucial pillar-retromolar trigone. Int J Radiat
Oncol Biol Phys. 1987;13(7):969.
Buccal Mucosa
• Surgery is typically preferred for buccal mucosa cancers, despite high local
recurrence rates and technical challenges. Exposure of the cancer can be difficult via
a transoral approach, which makes it difficult to obtain clear radial margins in an en
bloc resection. Furthermore, the short distance between the buccal mucosa and the
buccal space permits early invasion to deep structures or to the skin of the anterior
cheek. The surgeon must choose between taking a thin deep margin and risking
recurrence versus removing skin and reconstructing both the inner and outer cheek
surfaces. Although more aggressive surgery, including exenteration of the buccal
Gustavo Arruda Viani
56
Study
Description
Dixit et al.
(1998)
176 patients with buccal mucosa SCC were treated with surgery alone (Group 1), and
61 patients were treated with a combination of surgery and postoperative radiotherapy
(Group 2).
The 3-year locoregional control in Groups 1 and 2 was 11% and 48% for patients with
stage III + IV cancer (P = .001) and 71% and 75% for patients with stage I + II cancer
(P = .74), respectively.
On multivariate analysis for locoregional failure, surgical margin, bone invasion, high
grade, and node involvement were significant factors in Group 1, whereas in Group 2
only tumor thickness was a significant factor.
Iyer et al
(2004)
A total of 147 consecutive patients were retrospectively analyzed.
108 patients (73.5%) had no recurrence, whereas 18 (12.2%) had a local recurrence, 11
(7.5%) had regional metastasis, and 10 (6.8%) had locoregional recurrence over a
median follow-up of 46 months.
Most patients with local recurrences (15 patients, 83.3%) and regional metastases (eight
patients, 72%) could be salvaged with treatment.
Most of the recurrences in this study group occurred within 2 years of primary
treatment (74%).
Three-year actuarial overall survival rate and disease-free survival rates were 91% and
77%, respectively.
space and parotidectomy, may improve oncologic results, the disfigurement and
morbidity associated with these procedures is considerable.
• The buccal mucosal surface must be aggressively reconstructed regardless of the
depth of resection; inadequate soft tissue coverage will result in severe, irreversible
trismus. Thus, free tissue transfer reconstruction (eg, radial forearm flap) is
recommended for all but the smallest buccal cancers. Even with adequate
reconstruction, aggressive rehabilitation is required for the best functional outcome
(table-9).
Table 9. Clinical evidence for surgery and/or radiotherapy
in early buccal mucosa cancer
References
Dixit S, Vyas RK, Toparani RB, Baboo HA, Patel DD. Surgery versus surgery and
postoperative radiotherapy in squamous cell carcinoma of the buccal mucosa: a
comparative study. Ann Surg Oncol. 1998;5(6):502.
Iyer SG, Pradhan SA, Pai PS, Patil S. Surgical treatment outcomes of localized squamous
carcinoma of buccal mucosa. Head Neck. 2004;26(10):897.
• Adjuvant postoperative radiation, with or without concurrent chemotherapy, is
indicated for patients who have positive or close resection margins, bone invasion,
pathologically positive lymph nodes, lymphovascular or perineural invasion in the
primary tumor (table-10).
Oral Cavity Cancer
57
Study
Decription
EORTC 22931 (Bernier
et al. 2004)
334 patients with operable stage III/IV oral cavity, oropharynx, larynx, and
hypopharnx cancer randomized to post-op RT (2/66 Gy) vs. post-op chemoRT (2/66 Gy and cisplatin 100 mg/m2 on days 1, 22, 43).
All patients received 54 Gy to the low-risk neck. Eligible stages included
pT3–4N0/+, T1–2N2–3, and T1–2N0–1with extra capsular extension,
+margin,or perineural invasion.
Chemo-RT improved 5-year DFS (59 vs 47%), 5-year OS (65 and 53%), and
5-year LRC (82%), but increased grade 3–4 toxicity (21 and 41%).
RTOG 95–01 (Cooper
et al. 2004)
459 patients with operable cancer of the oral cavity, oropharynx, larynx, or
hypopharynx who had 2 or more involved lymph nodes, nodal extracapsular
extension, or a + margin were randomized to post-op RT (2/60–66 Gy) vs.
post-op chemo-RT (2/60–66 Gy and cisplatin ×3 c).
Chemo-RT improved 2-year DFS (43 vs 54%), LRC (72 vs 82%), and had a
trend for improved OS (57 and 63%), with increased grade 3–4 toxicity (34
and 77%).
Pooled RTOG/EORTC
analysis (Bernier 2005)
Chemo-RT improved OS, DFS, and LRC for ECE and/or + margins, but
provided only trend for improvements (p > 0.06) for stage III–IV, PNI,
LVSI, and/or enlarged LN in levels IV–V.
Table 10. Clinical evidence for adjuvant radiotherapy combined or not with
chemothrapy in oral cavity cancer
References
Bernier J, Cooper JS, Pajak TF, et al. Defining risk levels in locally advanced head and neck
cancers: a comparative analysis of concurrent postoperative radiation plus chemotherapy
trials of the EORTC (#22931) and RTOG (# 9501). Head Neck. 2005;27(10):843-50.
Cooper JS, Pajak TF, Forastiere AA, et al. Postoperative concurrent radiotherapy and
chemotherapy for high-risk squamous-cell carcinoma of the head and neck. N Engl J Med
2004;350:1937-1944.
Bernier J, Domenge C, Ozsahin M, et al. Postoperative irradiation with or without
concomitant chemotherapy for locally advanced head and neck cancer. N Engl J Med
2004;350:1945-1952.
Locally Advanced Disease
• Patients with locally advanced (stage III or IV) oral cavity cancer, should be
submitted to a functional organ preservation strategy rather than surgical resection.
• In the clinical practice both concurrent chemoradiotherapy and sequential
chemoradiotherapy are used as a functional organ preservation strategy.
• Chemoradiation is preferred mainly for patients with negative or N1 lymph nodes.
On the other hand, sequential therapy is reserved mainly for patients with high risk of
distant metastases (N3 lymph nodes), as described in table-11.
References
Lefebvre JL, Chevalier D, Luboinski B, et al. Larynx preservation in pyriform sinus cancer:
preliminary results of a European Organization for Research and Treatment of Cancer
Gustavo Arruda Viani
58
Study
Description
RTOG 90–03
(Fu et al. 2000):
268 patients with locally advanced cancer ( oral cavity, oropharynx, supraglottic
larynx, or hypopharynx) randomized to 70/2 Gy vs. 81.6 /b.i.d. 1.2 Gy vs. splitcourse 67.2 Gy/ 1.6 b.i.d. (with 2-week break) vs. concomitant boost RT to 72 Gy
(1.8 Gy/fraction with a 1.5 Gy boost on the last 12 treatment days).
Concomitant boost and continuous b.i.d. hyperfractionation improved the 2-year
LRC (54%), DFS (38–39%), and OS (51–54%) vs. standard or split-course b.i.d.
RT. Altered fractionation increased acute side effects.
Posner et al.
(2007)
Randomized 501 patients with unresectable stage II–IV head and neck cancer (14%
oral cavity) to TPF (docetaxel/cisplatin/5-FU) vs. PF (cisplatin/5-FU) induction
chemotherapy followed by carboplatin chemo-RT (70–74 Gy).
Induction TPF improved LRC and 3-year OS (48→62%), but not DM. 21–25% of
patients did not receive concurrent chemo- RT due to progressive disease, adverse
events, death, or withdrawal of consent.
MACH-NC
metaanalysis
(2009):
87 phase III trials and 16,485 patients. 4.5% OS benefit at 5 years when
chemotherapy was added to RT, with greater benefit for concurrent chemo-RT vs.
induction chemo followed by RT (6.5% OS benefit with concurrent chemo-RT).
Similar results in trials with post-op RT, conventional, and altered fractionation.
No difference between mono or polychemotherapy regimens, but increased benefit
with platinum-based compounds.
phase III trial. EORTC Head and Neck Cancer Cooperative Group. J Natl Cancer Inst
1996;88:890-899.
Forastiere AA, Goepfert H, Maor M, et al. Concurrent chemotherapy and radiotherapy for
organ preservation in advanced laryngeal cancer. N Engl J Med 2003;349:2091-2098.
Pointreau Y, Garaud P, Chapet S, et al. Randomized trial of induction chemotherapy with
cisplatin and 5-fluorouracil with or without docetaxel for larynx preservation. J Natl
Cancer Inst 2009;101(7):498-506.
Bonner JA, Harari PM, Giralt J, et al. Radiotherapy plus cetuximab for squamous-cell
carcinoma of the head and neck. N Engl J Med 2006; 354: 567-578.
Lefebvre JL, Rolland F, Tesselaar M et al. Phase 3 randomized trial on larynx preservation
comparing sequential vs alternating chemotherapy and radiotherapy. J Natl Cancer Inst.
2009;101(3):142-52.
Table 11. Clinical evidence for chemoradiation in locally advanced
head and neck cancer
11. Radiotherapy Technique
Patients should lie supine with a straight spine, immobilized with a thermoplastic shell. A
custom-made mouth bite may help to push the tongue inferiorly when irradiating the hard
palate or upper alveolus or to separate the roof of the mouth from the inferior oral cavity
when irradiating the tongue (figure-5).
Mouth bites can distort the anatomy and make volumes on CT more difficult to define
accurately. CT slices are obtained from the base of skull to the arch of the aorta with the
patient immobilized in the treatment position. Treatment planning CT with contrast using 3mm slice thickness should be performed over the primary and regional nodes. IV contrast is
recommended. Fusion with PET and MRI should be considered. The GTV is outlined on a
planning computer with window settings adjusted to show soft tissues. The nodal stations at
Oral Cavity Cancer
59
Stage
Ipsilateral
Contralateral
N0/N1 with
well-lateralized primary
Ib, II, III; include Ia for tumours involving tip
of tongue, floor of mouth or anterior mandible;
include IV for tumours of the anterior tongue
or involving the oropharynx
None
N0/N1 with tumor
across midline
Ib, II, III; include Ia for tumours involving tip
of tongue, floor of mouth or anterior mandible;
include IV for tumours of the anterior tongue
or involving the oropharynx
Similar ipsilateral nodes.
N2/N3 with
well-lateralized primary
Ib, II, III; include Ia for tumours involving tip
of tongue, floor of mouth or anterior mandible;
include IV for tumours of the anterior tongue
or involving the oropharynx, include V if level
IV involved
Ib, II, III; include IV for
tumours of the anterior
tongue or involving the
oropharynx
N2/N3 with tumor
across midline
Ib, II, III; include Ia for tumours involving tip
of tongue, floor of mouth or anterior mandible;
include IV for tumours of the anterior tongue
or involving the oropharynx, include V if level
IV involved
Ib, II, III; include IV for
tumours of the anterior
tongue or involving the
oropharynx.
risk and patterns of primary spread should be determined, as well as treatment to unilateral or
bilateral neck. An extended field treating the primary and all regional nodes should be
considered for patients with extensive lymphadenopathy involving multiple nodal levels.
CTV encompassing gross tumor volume, microscopic disease, and potential for tumor
spread should be outlined and stratified according to burden of disease – high risk: gross
disease; intermediate risk: areas with high likelihood of nodal disease or tumor spread; and
low risk: elective nodal treatment. Expansion from CTV to PTV is typically 5–10 mm.
Recommendations for designing the CTV 44-50 is described in table 12. The CTV 70 should
include the gross tumor volume and any lymphadenopathy.
Figure 5. Thermoplastic mask with custom made mouth bite in patients with oral cavity cancer.
Table 12. Recommendations for designing CTV 44-50 Gy in oral cavity cancer
Gustavo Arruda Viani
60
In the adjuvant setting, the CTV60 should include the sites at risk of microscopic residual
disease. Postoperative oral cavity CTVs can be difficult to define because oral mucosa is not
well defined on CT, dental artifact can obscure the oral anatomy and reconstructive soft tissue
flaps can be confused with normal anatomical structures. If there has been reconstructive
surgery, the whole flap does not need to be included in the CTV60 but the mucosa adjacent to
the primary site should be included with a 10 mm isotropic margin to account for microscopic
spread. A CTV66 should be delineated in the case of positive excision margins. The CTVPTV margin should be individualized, in the majority of services expand CTV-PTV with
margins of 5 mm in each direction (figure-6).
Figure 6. Isodose lines for CTV 60 in the adjuvant setting.
For standard fractionation a total dose of 70 Gy at 2 Gy per daily fraction (in 35 fractions
over 7 weeks) to gross disease is indicated. The prescribed dose to subclinical disease is 4450 Gy at 2 Gy per daily fraction.
For concomitant boost radiotherapy therapy a total dose of 72.0 Gy is given in 42
fractions over 6 weeks as 32.4 Gy in 18 fractions in 3 weeks (1.8 Gy/fraction/day) to a large
field including subclinical disease followed by another 21.6 Gy in 12 fractions (1.8
Gy/fraction) to the same field, and a second daily fraction at least 6 h later consisting of 18.0
Gy in 12 fractions (1.5 Gy/fraction) to a small “boost field”. For adjuvant irradiation a
Standard fractionation is recommended with a total dose of 60– 66 Gy at 2 Gy per fraction (in
30–33 fractions over 6–6. weeks), as used in the RTOG randomized trial. Cisplatin-based
chemotherapy (100 mg/m2 IV on days 1, 22, 43) or cisplatin 30 mg/m2 IV weekly with
concurrent radiation therapy is the regimen best supported by the available literature. Doselimitation guidelines in radiation therapy of oropharyngeal malignancies are described in
table-13.
Intensity-modulated radiotherapy (IMRT) is a new technology from conformal
radiotherapy that by combining several beams of varying intensity achieves improved dose
homogeneity with highly conformal dose distributions.
The main advantages of IMRT are more conformal and homogeneous dose distributions
and sparing of normal tissues (figure-7).