This document discusses indications, evidence, and radiation therapy techniques for oral cavity and oropharyngeal cancers. It covers: - Anatomy of the oral cavity and oropharynx. - Staging principles and indications for surgery vs systemic therapy. - Principles of surgery including adequate resection margins and neck management. - Use of adjuvant radiation therapy or chemoradiation to improve local control, especially for high-risk features like positive margins or extracapsular extension. - Radiation techniques for oral cavity cancers including field design, dose recommendations, and advantages of IMRT for sparing parotid glands.

1. INDICATIONS , EVIDENCES & R.T. TECHNIQUES IN
ORAL CAVITY & OROPHARYNX
Dr. Amrita Rakesh
D.N.B. resident
BHAGWAN MAHAVEER CANCER HOSPITAL AND RESEARCH CENTRE,
JAIPUR

2. ANATOMY OF ORAL CAVITY
• Oral cavity consists of the lips, oral tongue, floor of the mouth,
retromolar trigone, alveolar ridge, buccal mucosa, and hard palate.

4. ANATOMY OF OROPHARYNX
• Boundaries:
• Anteriorly: Oral cavity
• Post.inferiorly: larynx & hypopharynx
• Superiorly: Nasopharynx
• Oropharynx consists of :
- Base of the tongue (lingual tonsil)
- Tonsillar region (anterior & posterior
tonsillar pillar, palatine tonsil),
- Soft palate
- Lateral & posterior oropharyngeal walls

5. STAGING

8. PRINCIPLES OF SURGERY
• En block resection should be attempted wherever feasible
• In continuity neck dissection is necessary when there is direct
extension of the primary tumor into the neck.
• Perineural invasion should be suspected when tumors are adjacent
to motor or sensory nerves.
• Partial or segmental mandibular resection for adequate tumor free
margins.

9. • Adequate resection is defined as clear resection margins with at least
enough clearance from the gross tumor to obtain clear frozen section
and permanent margins (often 1.5 to 2.0 cm of visible and palpable
normal mucosa).
• For glottis cancers – 1 to 2 mm margin is considered adequate.
• Clear margin – distance from the invasive tumor front 5mm
• Close margin – <5mm
• Positive margin – ca in situ or invasive ca at the margin of resection.

10. NECK MANAGEMENT
• N0 - selective neck dissection
* oral cavity at least levels I-III
* oropharynx at least levels II-IV
* hypopharynx levels II-IV & VI when appropriate
• N1 – N2a-c – selective or comprehensive neck dissection
• N3 – comprehensive neck dissection

11. INDICATIONS FOR SYSTEMIC THERAPY
• Unresectable disease or residual disease
• DOI - >/= 4 mm
• LVI +
• PNI +
• T 3 / 4
• Node > 3cm

12. RADIATION THERAPY IN ORAL
CAVITY
GENERAL PRINCIPLES

13. • NCCN recommend only single modality treatment for T1 / T2 lesions ;
primary surgical approach preferred.
• Advanced lesions – adjuvant radiation or chemoradiation
• Adjuvant RT can be delivered pre or post operatively.

14. ADJUVANT RADIATION
• Enhancing the likelihood of locoregional tumor control.
• Robertson et al. – phase III study .
• N = 350 pt.
• T 2 – 4 , N 0 – 2 oral cavity or oropharyngeal cancers.
• Comparing surgery and post op radiation versus radiation alone.
• Study closed early due to difference in survival but better results were
seen in surgery + post op RT ARM.

15. A phase III study at M.D. Anderson Cancer Centre – established relative
prognostic significance of cluster of two or more clinicopathological
features :
1. Close or positive margins
2. Nerve involvement
3. Two or more positive lymph nodes
4. Largest node > 3 cm
5. Treatment delay > 6 weeks
6. Zubord performance status >/= 2.
7. ECE – independent predictive factor of LRR.
Escalation of dose beyond 63 Gy to sites of increased risk does not
improve LRC.

16. Ang et al. – multi-institutional prospective study
• Total treatment time from completion of surgery to the completion of
radiation may affect the likelihood of ultimate disease control.
• Impact of overall treatment time on 5 year LRC.
OVERALL TREATMENT TIME LRC
< 11 WEEKS 76 %
11-13 WEEKS 62 %
> 13 WEEKS 38 %

17. ADJUVANT CHEMORADIOTHERAPY FOR
OROPHARYNGEAL CANCER
• Cisplatin based chemotherapy + PORT versus PORT alone in medically
fit H & N cancer patients of any site – several randomized studies.
• Statistically significant trend to better LRC with chemo + PORT.

18. • The landmark studies of the Radiation Therapy Oncology Group
(RTOG) 9501 and the European Organisation for Research and
Treatment of Cancer (EORTC) 22931, followed by the comparative
analysis of Bernier and colleagues, demonstrated that all patients
with resected head and neck cancer receiving standard fractionated
postoperative radiation who are found to have positive margins or
extranodal extension should be assigned to a combined
chemoradiation approach using concurrent cisplatin (100 mg/m2 on
days 1, 22, and 43).

19. • More recently, the German Cancer Society 95-06 trialdemonstrated
that even with hyperfractionated accelerated treatment regimens,
patients that received concurrent 5-FU and mitomycin experienced an
improvement in locoregional control and overall survival
• A study by Garden and colleagues examined patients with stage III and
IV disease who received a concomitant boost treatment regimen and
cisplatin on days 1 and 22, and found that 4-year locoregional
progression-free survival was 74% and that 4-year overall survival was
54%—results which are quite promising.

20. RTOG 0234
• High risk post operative patients
• Cetuximab – 400 mg/m2 loading followed by
250 mg/m2 weekly
• Docetaxel – 15 mg/m2
• Cisplatin – 30 mg/m2
• Results were found better with cisplatin
PORT +CETUXIMAB +
WEEKLY DOCETAXEL
PORT + CETUXIMAB +
WEEKLY CISPLATIN
High risk features :
Positive margin
ENE
>/= 2 pathologically involved lymph nodes

21. ADJUVANT RADIOTHERAPY DOSE
• 60 to 66 Gy in 2 Gy daily fractions to high risk areas.
• 50 to 54 Gy in 2 Gy per fraction to areas at risk of microscopic
involvement.
POSTOPERATIVE RADIOTHERAPY TREATMENT VOLUME
• Primary tumor site + bilateral neck

22. DEFINITIVE RADIOTHERAPY
• Early stage oropharyngeal cancers – radiotherapy as single modality
associated with good outcome and better functional preservation.
HYPERFRACTIONATED RADIOTHERAPY
EORTC 22791
• T2-3
• N0-1
• Non-base of tongue oropharyngeal cancers

23. Randomized to
associated with statistically significant improvement in LRC (5 YR –
59% vs 40 % ).
CONVENTIONALLY
FRACTIONATED – 70 Gy @ 2
Gy per day
HYPERFRACTIONATED - 80.5 Gy
@ 1.15 Gy twice daily

24. RTOG 90-03
• 4 arms
Conventional fractionation – 70
Gy @ 2Gy daily fractions
Hyperfractionation – 81.6 Gy @
1.2 Gy twice daily fractions
Acclerated fraction with split
course – 67.2 Gy @ 1.6 Gy twice
daily with 2 week rest after 38.4
Gy
Accelerated fraction with
concomitant boost – 72 Gy @ 1.8
Gy fractions for 14 fractions
followed by 1.8 Gy morning and
1.5 Gy afternoon boost to gross
disease.
IMPROVED LRC
AND DFS

25. SIMULTANEOUS INTEGRATED BOOST
RADIOTHERAPY
RTOG 00-22
• T 1-2
• N 0-2
• Oropharyngeal cancer patients
• Treated with bilateral neck radiotherapy
• Doses –
• 2 yr OS & DFS – 95% and 82 % respectively
Gross tumor - 2.2 Gy Intermediate risk – 2 Gy Low risk PTVs – 1.8 Gy

26. NEOADJUVANT THERAPY
Licitra et al. – phase III study
• N = 195
• T 2 – 4 ( >3cm)
• N 0 – 2
• Sq CC of oral cavity
• Surgery alone versus three cycles of CDDP & 5 – FU.
• No difference in overall survival
• Possibility of neoadjuvant chemo for improving resectibility and
reducing need of adjuvant RT

27. Mohr et al.
• N = 268 pt
• T 2-4 / N 0-3
• Oral cavity and oropharyngeal carcinoma
• Preoperative chemoradiation with cisplatin or surgery alone
• Results – improvement in OS & LC with the use of preoperative
therapy.

28. RADIATION TECHNIQUES-
ORAL CAVITY
• Carcinoma of oral cavity traditionally treated with lateral opposed
fields, using either 2-D or 3-D (CT-based) techniques.
• Immobilisation with thermoplastic mask.
• Supine position
• Bite block – for tongue and floor of mouth cases, to depress the
tongue away from the hard palate.
• Short neck – shoulders are depressed by having the pt pull on a
tensioning device looped beneath the feet.

29. FIELD DESIGN
• Upper border- 1.5 to 2.0 cm from the tumor bed and regional lymphatics.
• Inferior border – thyroid notch,just above the true vocal cords.
• Posterior border – midvertebral body,if level V coverage not required.
For coverage of level V – behind C1 vertebral body.
• Lower neck – single half beam blocked AP field is matched to the inferior
border of the opposed lateral fields at the level of thyroid notch.
• Anterior larynx block is used.

32. • Megavoltage beams with energy 4 to 6 MV most suitable
• Cobalt-60 comparable to 4 MV beam.
• Bolus required for higher energy beams or large nodal volume disease or
extracapsular extension.
• Tissue compensators with lateral opposed fields if variation of separation > 3
cm.
• All fields should be treated daily with at least 5 treatments per week.

34. IDEAL CANDIDATE FOR IMRT-
• T1-4 primary lesion with less than or equal to N2b neck disease.
• IMRT not required in T1-2/N0 patients as bulk of parotid can be
excluded from opposed lateral portals.
• Patients with ipsilateral positive neck nodes, IMRT allows dose
limitation to the contralateral parotid gland without compromising
treatment results.
• In patients with bilateral neck disease(N2c), difficult to spare parotids
if level II is also involved.

35. BROAD PRINCIPLES OF PLANNING
• Most of the cases are treated post-operatively.
• CTV1 – high risk clinical target volume should include primary tumor
bed (based on preoperative imaging) + regions of grossly involved
adenopathy.
• CTV2 – intermediate risk clinical target volume should include the
pathologically positive hemineck
• CTV3 – low risk clinical target volume includes the prophylactically
treated neck- uninvolved low or contralateral neck.

37. • Neck dissection disrupts the anatomic landmarks, so entire surgical bed
should be encompassed within CTV1.
• For cases of lateralized disease , it is recommended that contralateral neck
be included when ipsilateral neck involvement is greater than N1.
• IMRT results in more conformal dose distributions but also more sensitive to
intertreatment setup variations than conventional radiotherapy.
• With the use of cone-beam CT , PTV expansions on the CTV may be limited to
2 to 5 mm.

38. DOSE RECOMMENDATIONS:
• High risk PTV (PTV1) – 60 to 66 Gy @ 2Gy/#.
If microscopically positive margin or extracapsular spread is present- 64 to
66 Gy @ 2Gy/#.
• Intermediate risk regions (without ECE or microscopically positive margins)
may receive 60 Gy.
• PTV 2 & PTV 3 should receive 60 Gy & 50 to 54 Gy , respectively.
• Most common dose fractionation – 1.8 to 2.0 Gy per fraction.

39. • For close or positive microscopic margins or extracapsular nodal extension, a
4- to 6-Gy localized boost should be considered.
• For gross residual disease – focal boosting upto 70 Gy is adviced.
• Regions of lesser risk (clinically or pathologically uninvolved neck) – 50 to 54
Gy.

41. BRACHYTHERAPY
• Used to boost the ptimary site in the oral cavity before or followed by
EBRT or as a sole modality small early stage lesions.
• For tumors < 1cm size – single-plane implants are adequate. Also
surface mold radiation can also be considered.
• For tumors > 2.5 cm – it is difficult to avoid cold spots in the implant
volume,so it recommended that a part of treatment should be given
with EBRT.
50 Gy over 5 weeks with EBRT followed by 30 Gy with brachytherapy
implant.

42. • Decroix and Ghossein – reported outcomes in 602 patients with cancer of
oral tongue, treated with radium implantation or implantation + EBRT.
Recurrence at the primary site or the primary site and the neck was 14% and
22% for T1 & T2 lesions respectively.
• The Royal Marsden Hospital reported local control rates of 90% at 5 years for
T1 & T2 tumors treated with interstitial radiation with or without EBRT.
• Pernot et al. reported local control rates of 96% for T1 , 85% for T2 and 64%
for T3 lesions of the oral cavity treated with brachytherapy and neck
dissection. The locoregional control rates were 83% , 70% and 44%
respectively.

45. INTRAORAL CONE
• Another delivery tool to enable boosting of radiation dose to sites
within the oral cavity while avoiding direct dose to mandible.
• Generally best suited for anterior oral cavity lesions in edentulous
patients.
• Palatal arch sites can also be targeted with the intraoral cone.
• 100- to 250-kilovolt (peak) kvp x-rays or electron beams in the 6- to
12- MeV range.

46. • Lesions upto 3 cm are amenable to treatment.
• Requires careful daily positioning and verification by physician.
• Device is equipped with periscope to visualize the lesion.
• The cone abuts the mucosa and is centered directly over the lesion.
• Intraoral cone treatment should take place prior to EBRT so that the lesion is
adequately visible.
• Major advantage – highly focal to tumor bed but noninvasive.

48. SUBSITE SPECIFIC TREATMENT AND RESULTS

49. LIP
• Early lesions may be cured equally well with
surgery or RT.
• Surgical treatment for early lesions (0.5-1 . 5
em) uses a V- or W-shaped excision.
• Lip cancer may be successfully treated by EBRT,
interstitial brachytherapy, or a combination of
both.
• EBRT techniques use orthovoltage ( 5 5 . 8 Gy at
1 . 8 Gy per fraction) or electrons ( 60-66 Gy at 2
Gy per fraction) with lead shields behind the lip
to limit exit EBRT.
• For early-stage lesions, orthovoltage photons
(100 to 200 keV) or electrons may be used. The
electron energy should be chosen based on the
thickness of the lesion (commonly 6 to 9 MeV).
• “Moustache field” for elective irradiation of the
perifacial lymphatics (approximately 50 Gy) for
more advanced upper lip lesions

50. PARALLEL OPPOSED FIELDS, INCLUDING THE LIP
LESION AND
THE LEVEL I AND II LYMPH NODES

51. FLOOR OF MOUTH AND ORAL TONGUE
• Surgical resection is generally preferred
Depending:
on the size
depth of invasion
grade of the primary tumor
nodal status
• Postoperative radiotherapy is recommended in
the following situations
large primary tumor (e.g., T3 or T4)
close or positive surgical margins
presence of perineural spread
vascular invasion
presence of multiple positive nodes
• Primary radiotherapy is generally reserved for
patients who refuse surgery or those who are
borderline operable.

52. • Intraoral stent is used to exclude the following
organs from the radiation
a large area of the buccal mucosa,
lower lip
oral commissure
• Parallel opposed-lateral photon fields are used
to treat the primary tumor bed and upper neck
nodes.
• Field borders are,
Anterior border: just in front of the mandible
for anterior tumors or 2 cm in front of the scar
for posterior oral cavity lesions.
Superior border: 1 to 1.5 cm superior to the
dorsum of the tongue or the scar if part of the
oral tongue can be spared.
Posterior border: usually is dictated by the
surgical scar. The level II nodes are usually
irradiated,so the posterior border is behind the
spinous processes
Inferior border: just superior to the arytenoids.
• An anterior appositional field is used to treat
the mid- and lower neck nodes
• To deliver the boost dose to the primary tumor
and upper neck nodes, the size of lateral fields is
reduced to encompass the known disease
locations. To boost the upper neck without the
primary site, a lateral appositional electron field
is used. To deliver the boost to the mid- or
lower neck, a lateral appositional electron field
or glancing photon fields are used.

53. RETROMOLAR TRIGONE AND ANTERIOR FAUCIAL PILLAR
• Primary radiotherapy is for relatively early
tumors (T1-T2 and selected cases of T3)
• Larger tumors are treated with either
combination of radiation and chemotherapy or
surgery and postoperative radiotherapy
Target Volume
• A well-lateralized tumor without
lymphadenopathy: primary lesion (at least 2-cm
margins) and ipsilateral level IB (submandibular)
and level II (subdigastric) nodes.
• A well-lateralized tumor with a single small
ipsilateral node (N1): primary lesion and the
entire ipsilateral neck (including supraclavicular
nodes).
• Other cases (larger tumors and/or more
advanced N-stage): primary lesion and bilateral
neck.
• Anterior border: at least 2 cm anterior to the
tumor.
• Superior border: includes the pterygoid plates
when the tonsillar fossa is involved (this border
is at least 1 to 1.5 cm rostral to the hard palate).
• Posterior border: just behind the mastoid
process (N0) or behind the spinous processes
(N+).
• Inferior border: just above the arytenoids

55. BUCCAL MUCOSA
• The buccal mucosa includes the mucosal surfaces of the cheek and
lips from the line of contact of the opposing lips to the
pterygomandibular raphe posteriorly.
• This extends to the line of attachment of the mucosa of the upper
and lower alveolar ridge superiorly and inferiorly.

56. • T1 to T2 lesions: surgery or primary radiotherapy
• T3 to T4 lesions, surgery followed by postoperative radiotherapy is generally
recommended.
Target Volume
• T1 -T2 N0: primary tumor and ipsilateral level IB (submandibular) and level II
(subdigastric) nodes.
• T1 -T2 N1: primary tumor and entire ipsilateral neck.
• N2 to N3: bilateral irradiation.
• Boost volume encompasses the primary tumor and, when present, involves lymph
nodes.

57. • Anterior and superior borders: at least 2-cm
margins from the visible-palpable tumor
borders.
• Posterior border: just behind the mastoid
process (N0) or behind the spinous processes
(N+).
• Inferior border: just above the arytenoids

58. • Target Volume
• the entire surgical bed, including primary site and ipsilateral
submandibular and subdigastric nodes, and the ipsilateral mid- and
lower neck
• boost volume encompasses areas of known disease locations.
• The anterior and superior field borders are determined by the spread
pattern of the primary tumor and by the extent of surgery
• The initial target volume receives 50 Gy in 25 fractions.
• For external beam technique, 16 Gy in eight fractions for T1 and 20 Gy
in ten fractions for T2 lesions are administered.
• For brachytherapy, 25 to 30 Gy is administered.

59. • IMRT in the postoperative setting, treatment is given in 30 fractions.
• Generally, the tumor bed target volume receives 60 Gy, the operative
bed 57 Gy, and undissected regions 54 Gy.

60. HARD PALATE AND UPPER ALVEOLAR RIDGE
• Primary radiotherapy is indicated for small, superficial squamous cell
carcinomas (SCC).
Target Volume
• The entire surgical bed
• the location of the primary lesion, the extent of surgery
• treatment with opposed-lateral fields
• Ipsilateral irradiation is used in well-lateralized lesions of the alveolar
ridge.

61. • Anterior and superior borders: at least 2 cm beyond the surgical bed.
If disease extended into the maxillary sinus, the entire sinus is
included up to the floor of the orbit.
• Posterior border: at midvertebral bodies for non-SCC and N0; behind
the mastoid process for SCC and N0; behind the spinous processes for
N+ (or more posteriorly to cover large surgical bed).

62. • Inferior border: just above the arytenoids for squamous cell
carcinoma with no nodal involvement, or 2 cm below the surgical
margin for low-grade minor salivary gland tumors.
• presence of positive nodes, an anterior photon field is used for
irradiation of the mid- and low cervical nodes.

64. • For boost volume:-
• fields are reduced to encompass the tumor volume with at least 1-cm
margins
• involved upper neck nodes are included in the lateral fields or in a
separate appositional electron field
• involved mid- and lower neck nodes are irradiated with an
appositional electron field
• For ipsilateral irradiation, the patient is immobilized in a supine
position. Anterior and ipsilateral wedge-pair photon fields are used to
treat the primary tumor bed .

65. • A lateral appositional electron field is used for elective treatment of
the submandibular and subdigastric nodes when ipsilateral treatment
is adopted for SCCs.
• Superior border: matches the inferior border of the photon fields (a
small triangle over the cheek may be spared).
• Anterior border: just short of fall-off.
• Posterior border: behind the mastoid process.
• Inferior border: at the thyroid notch.

66. • TARGET DELINEATION GUIDELINES IN MALIGNANCIES OF THE ORAL CAVITY

67. RADIATION TECHNIQUES IN OROPHARYNX
• T1-2 N0-1 : Definitive RT.
Alternative, surgery with post-op RT as indicated

68. • PORT Indication:
• Large primary-T3 or T4
• Close (<5mm) or positive margins of excision
• Deep infiltrative tumor
• Lymphovascular invasion
• Perineural invasion
• Bulky nodal disease N2 /N3
• Extra capsular extension
• Multiple level involvement (level IV , V)
Post-op chemo-RT indications :
• Extracapsular nodal spread,
• Postive margin

69. • Simulate patient supine with head
hyperextended.
• The shoulders should be positioned as caudally
as possible to allow adequate exposure of the
neck.
• Tongue immobilization can be useful for
oropharyngeal cancer patients with oral
tongue involvement.
• Bite blocks are also useful because they often
elevate the hard palate with its minor salivary
glands.
• Mark involved LN with lead wire

70. Borders of the lateral fields :
Superior border: (1.5 to 2 cm above the superior extent)
• This should cover the retropharyngeal and jugulodigastric lymph nodes and
approach the jugular fossa in patients with advanced nodal disease.
• The ipsilateral medial pterygoid insertion for early-stage tumors and the pterygoid
plates for more advanced stage tumors .
Anterior border:
• The most anterior extent of the primary site with margin ,may be extended more
anteriorly if level IB lymph node coverage is warranted.
• Tonsillar carcinoma fields have traditionally covered the ipsilateral retromolar
trigone.
• Anterior coverage of BOT tumors ext. 2 cm considering infiltrative nature of
primary tumor.

71. Posterior border:
• Approx. 2 cm behind the mastoid process and just posterior to the
cervical vertebral spinous processes, with additional posterior
extension if warranted by level V nodal metastases.
• Adequate dosimetric margins must be ensured with posterior
pharyngeal wall tumors,
• Offcord boost (Phase II) is typically placed at the posterior third of
the vertebral body.
• The posterior margin may be moved 1 to 2 cm anteriorly for early-
stage, node-negative tonsillar and soft palate tumors.

72. Inferior border:
• Extends to the thyroid notch.
• This is placed just cranial to the arytenoids to limit post-treatment
supraglottic edema.
• However, this border may be lowered to account for extension of the
primary tumor into the larynx or hypopharynx.

74. AP supraclavicular field :
• Extends from the inferior lateral photon border to the bottom of the
sternoclavicular joints and covers the middle and lower neck nodes.
• Laterally, the supraclavicular field extends to the mid-clavicle and
typically measures 18 to 20 cm in width, again tailored to known
nodal disease.
• Beam-split above larynx at
thyroid notch, if possible,
to allow laryngeal sparing

75. • Broad opposed lateral fields covering the primary tumor bed and upper neck
extending to the thyroid notch are initially treated to 42 to 44 Gy in 2-Gy fractions.
(4 - 6-MV photons)
• The isocenter is typically placed at approximately the C1 to C2 level just anterior
to the intervertebral space.
• An off-cord boost (Phase II) is then created by shifting the posterior field border
anteriorly to split the vertebral bodies vertically.
• The final field reduction boost carries the tumor GTV plus a margin to 66 to 70 Gy.
(Phase III)

76. • POSTERIOR ELECTRON BOOST
• Electron fields (commonly, 6 to 9 MeV; occasionally, 12 MeV for bulky nodal
disease) are matched on the skin to abut the posterior aspect of the off-cord
photon field and thereby treat the posterior neck to 50 to 54 Gy, with higher
doses if positive posterior nodes are present
• Involved nodes at the match line warrant 2 to 3 mm of photon-electron field
overlap to limit underdosing at depth.
• The posterior electron field border can be extended by 5 mm to help compensate
for electron dose constriction at depth.

77. • Ipsilateral Radiation for Tonsillar Cancer :
• Conventional irradiation to the ipsilateral neck for
early stage tonsillar cancers typically consists of a two-
field, wedge-pair beam arrangement (anterior &
posterior obliques) covering the primary tumour and
ipsilateral level II lymph nodes.
• The level III and IV LN ipsilaterally are covered by
an anterior supraclavicular field directed to the
hemineck

79. • Upper Nodal Border :
• Some cases of marginal failure in the
retrostyloid space have been reported after
IMRT. (Eisbruch et al )
• In case of involvement of upper level II (IIa or
IIb) with one or more lymph nodes, it is
recommended to extend the upper border of
level II to include the retrostyloid space up to
the base of skull.

80. • Lower Nodal Border :
• Similarly, in case of involvement of level IV or Vb with one or more lymph nodes, it is
recommended to extend the lower border to include the SC fossa in the CTV.

81. • Post-op CTV :
• Entire operative bed should be covered, especially in ECE.
• If level II (IIa or IIb) pN+, include retrostyloid space up to base of skull.
• If level V pN+, include the SCF.
• When a pathological lymph node abuts or invades a muscle – include the muscle
at least in the entire invaded level.
• In selected LN dissection with one or few (pN1) marginal nodes affected – include
adjacent level.
• In pharyngeal tumors with pN+, include lateral retropharyngeal nodes.

82. SIMULATANEOUS INTEGRATED BOOST RT (IMRT)
• The RTOG completed a study (00-22) in early-stage (T1-2, N0-2) oropharyngeal
cancer patients treated with bilateral neck radiotherapy using doses of 2.2 Gy, 2
Gy, and 1.8 Gy to gross tumor, intermediate-risk, and low-risk planning target
volumes (PTVs), respectively.
• Two-year overall survival was 95%, and disease-free survival was 82%.

83. • Lymph node coverage:
N0 include levels II–IV and retropharyngeal node(RPN)
N1 include levels IB–IV and RPN
N2-3 include IB–V and lateral RPN

84. FRACTIONATION
Standard Fractionation 70 Gy in 35 fractions of 2 Gy per day, 5 days
/week
Accelerated fractionation 66 -70 Gy , 2 Gy /fraction , 6 days /week
Hyperfraction 81.6 Gy in 68 fractions,
1.2 Gy twice daily (interval of 6 hrs)
Accelerated split-course
fractionation
67.2 Gy in 42 fractions, 1.6 Gy twice daily with
a 2-week rest after 38.4 Gy
Accelerated fractionation
with a concomitant boost
72 Gy in 42 fractions over 6 weeks; 54 Gy in 30
fractions of 1.8 Gy to initial fields plus 18 Gy in
1.5-Gy fractions
to a cone-down boost field as a second daily
dose during the final 12 treatments

85. •Improved LRC were seen with both the hyperfractionation and accelerated
fractionation with concomitant boost in this large, randomized study of 1113
patients, of whom 60% had oropharyngeal primary tumors.
•These schedules also trended toward improved DFS, although DFS and OS
were not significantly different.
•Significantly greater acute side effects were present with all three altered
fractionation groups

86. BRACHYTHERAPY -- Guidelines
• Care should be taken to delineate the pretreatment tumor extent because regression is
not always uniform
• The CTV used is recommended by ESTRO to be 5 mm at minimum and more commonly 1
to 1.5 cm for base of tongue tumors.
• The PTV is usually equal to the CTV as the implanted catheters move with the tumor.
• Catheters are typically positioned parallel and equidistant at 1 to 1.5 cm apart.

88. BRACHYTHERAPY -- DOSE
GEC-ESTRO - guidelines for HDR Brachytherapy
• 45 to 50 Gy external-beam radiotherapy followed by
- 25 to 30 Gy boost for tonsillar tumors,
- 30 to 35 Gy boost to BOT tumors.
• Total brachytherapy boost dose is fraction-size dependent :
- 21 to 30 Gy in 3-Gy fractions & 16 to 24 Gy in 4-Gy fractions.

93. THANK YOU
NEXT CLASS – NASOPHARYNX BY Dr. SHUCHITA PATHAK