Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_4505_Библиотеки_им_академика_М_И_Перельмана
.pdf
124
https://t.me/medicina_free
Part 2 Site-Specifi c Indications and Techniques
with thermoplastic mask for irradiation of the primary
tumor and upper neck nodes with wedge-pair photon
portals or IMRT.
Field borders for the initial target volume:
• Anterior border: at least 2 cm anterior to the tumor.
• Superior border: encompasses the insertion of the medial
pterygoid muscle at the pterygoid plate.
• Posterior border: 2 cm behind the mastoid tip and behind
the edge of the sternocleidomastoid muscle.
• Inferior border: just above the arytenoids.
A matching anterior photon portal is used to irradiate the
mid and lower neck nodes.
For the boost volume, the eld is reduced to cover initial
gross disease with 1- to 2-cm margins (see Case Study 8-4).
Case
Study
8-5
tonsil was rm. A biopsy of the tonsil done during examination under anesthesia revealed SCC. Stage was T1Nx
(pN1). It was elected to treat her with ipsilateral IMRT.
Figure 8.5 shows axial isodose distributions through
the superior tonsillar fossa and upper neck. e tonsillar
A 40-year-old woman presented a er an excisional biopsy of an asymptomatic le neck
mass. Histologic examination revealed SCC in
a 2.3-cm lymph node. Staging workup did not
reveal any residual nodal disease, but the le
Intensity-Modulated Radiation Therapy Planning
for Ipsilateral Treatment (for T1 to T2, N0 to N1
Tumors)
Clinical Target Volume
ree CTVs are generally delineated (see Case Studies 8-5
and 8-6).
• CTVHD delineates volumes to receive the highest dose,
which includes the primary and nodal GTVs with 0.5- to
1-cm margins. e entire tonsillar fossa is generally encompassed from the maxillary tuberosity (superior) to the hyoid
(inferior). An additional 1 cm is added if the GTV is at the
edges of or beyond these cranial and caudal landmarks.
CTVHD also encompasses the glossopharyngeal sulcus and
1 cm of the ipsilateral base of tongue. Laterally, CTVHD
region (red) received 66 Gy (Fig. 8.5A) and an additional
rim of surrounding tissues (green) along with ipsilateral
levels IB and II nodes received 60 Gy. e involved nodal
bed de ned from the prebiopsy imaging (blue) was prescribed a minimum dose of 63 Gy (Fig. 8.5B). e excision scar was wired for planning, and a 2-mm bolus was
applied over the scar. e le low neck was treated with an
appositional anterior eld to 50 Gy, matched with an isocentric technique to the IMRT elds. She had no evidence
of disease and had no sequelae 2 years a er therapy.
AB
Figure 8.5A,B
Chapter 8 Oropharynx
https://t.me/medicina_free
125
Case
Study
8-6
a right tonsillectomy. e right tonsil was found to contain
SCC. Stage T1 Nx (1) M0. As the primary disease was con ned to the tonsil, it was elected to prescribe ipsilateral IMRT.
CTVHD (66 Gy) encompassed the tonsillar and nodal
excision beds, CTVID (60 Gy) covered the remainder of
level II and level IB nodes, and CTVED (54 Gy) delineated the ipsilateral retropharyngeal nodes, superior parapharyngeal space, and the medial pterygoid muscle up to
the pterygoid plate.
A 43-year-old man presented with a right upper
neck mass. Excisional biopsy revealed SCC without obvious extracapsular extension. Postexcision CT scan did not reveal obvious disease. He
underwent an examination under anesthesia and
Figure 8.6 shows CTVHD (aqua), CTVID (khaki), and
CTVED (maroon) along with the isodose distributions on
representative axial images at the level of the high retropharyngeal nodes (Fig. 8.6A), mid-tonsillar fossa (Fig.
8.6B), and inferior tonsillar fossa (Fig. 8.6C), respectively.
Isocenter was placed above the thyroid notch.
Amatching le anterior–oblique beam, angled to be parallel to the right wing of the thyroid cartilage, was used to
treat the ipsilateral lower neck nodes to 50 Gy. is portal
was reduced to bring the total dose to the level III region to
60 Gy. Treatment was delivered in 30 fractions. Figure 8.6D
shows the isodose distribution on a coronal view through
the pharynx. e patient is doing well without disease
3years later.
A
C
Figure 8.6A-D
B
D
126
https://t.me/medicina_free
Part 2 Site-Specifi c Indications and Techniques
covers the parapharyngeal space and 1cm of the pterygoid
muscle. Many patients present a er tonsillectomy for
small-volume tonsillar disease. In this situation, the medial
pterygoid muscle should have 1 to 2cm of coverage.
• CTVID delineates volumes to receive an intermediate dose,
which includes an additional 1-cm margin of coverage
beyond the CTVHD toward the pterygoid musculature laterally, and superiorly, the retromolar trigone, so palate,
and base of tongue. In the presence of positive node(s),
CTVID encompasses the adjoining nodal compartment(s).
• CTVED delineates volumes to receive an elective dose for
subclinical disease. It is prudent to cover the medial pterygoid musculature to the pterygoid plates. In the N0 neck,
CTVED includes nodal levels II to IV and retropharyngeal
nodes. When level II node is involved, CTVED also includes
clinically uninvolved ipsilateral level IB nodes.
e primary tumor and nodal regions above the thyroid
notch are irradiated with IMRT and the lower neck nodes
Case
Study
8-7
cus to approximately 1.5 cm into the base of tongue. ere
was also extension to the anterior tonsillar pillar and so
palate, and posteriorly to the lateral pharyngeal wall. e
inferior border of the tumor was at the level of the tip of the
epiglottis. e largest dimension of the tumor was 4.5cm.
Tongue mobility was normal, and there was no trismus.
ere was also an area at the lower part of the contralateral
anterior tonsillar pillar with some nodularity and super cial
ulceration that raised suspicion. A 4.5 × 2.5 cm mobile node
was palpable in the right level II region. Biopsies from the
right tonsillar area as well as from the le anterior tonsillar
pillar showed SCC. e tumor inthe right tonsillar fossa
was staged as T3 N2 AM0 and the tumor on the le tonsillar
pillar was staged as T1 N0 M0. e patient received primary
radiotherapy for both lesions. e primary tumors and
upper neck nodes were treated with lateral–opposed elds
(Fig. 8.7). A seed was inserted to indicate the anterior and
superior border of the tonsillar fossa tumor. e palpable
lymph node was wired. e part of the node overlying the
spinal cord was relatively super cial and it was felt that this
could be supplemented with 9 MeV electrons a er o -cord
reduction. e mid and lower neck nodes were treated electively through an anterior appositional portal. Because the
inferior border of the boost eld was relatively close to the
edge of the node, the right midcervical region was boosted
with a lateral appositional 9 MeV electron eld matched to
A 63-year-old woman had a 1-month history
of sore throat and swelling of the right tonsil.
Physical examination revealed a large exophytic
and ulcerative tumor lling the right tonsillar
fossa, extending across the glossopalatine sul-
are irradiated with a matching anterior portal. is portal is
angled 5 to 10 degrees to be parallel to and skim the edge of
the ipsilateral thyroid cartilage.
Conventional Radiation Planning for Bilateral Treatment
Insertion of metal seeds at the borders of the tumor, when
feasible, and marking of oral commissures facilitate portal shaping (see Case Studies 8-7 and 8-8). e patient is
immobilized in a supine position.
Field borders for the initial target volume:
• Anterior border: at least 2 cm anterior to the tumor or
more anteriorly if necessary to encompass level IB nodes.
• Superior border: encompasses pterygoid plates and ret-
ropharyngeal nodes.
• Posterior border: just behind the spinous processes or
more posteriorly in the presence of large posterior cervical
nodal masses.
the inferior border of the photon eld. e dose delivered
to the larger primary tumor and involved neck nodes was
72Gy in 42 fractions over 6 weeks. e right midcervical
nodal group, adjacent to the big nodal mass, received 63 Gy
in 36 fractions over 6 weeks. Areas of subclinical disease
received 54 Gy in 30 fractions over 6 weeks. She had no evidence of disease 4 years a er completion of therapy.
Figure 8.7
Chapter 8 Oropharynx
https://t.me/medicina_free
127
Case
Study
8-8
revealed a 3-cm primary tumor located in the superior aspect
of the right tonsil and extending onto the so palate. ere
was no trismus. e neck examination revealed a 5-cm mass
of matted lymph nodes Stage T2 N2b M0. He was treated
with radiation alone using concomitant boost regimen.
Treatment started with two lateral portals and an anterior portal matched at a single isocenter above the arytenoids as shown in Figure 8.8A,B. e large lateral portals
received 41.4 Gy. To encompass the gross disease in the
photon elds, for the o –spinal cord reduction and boost
A 49-year-old man presented with several
months of otalgia and sore throat. Examination revealed a right neck mass. A ne needle
aspirate specimen of this mass was positive for
poorly di erentiated SCC. Physical examination
elds, parallel–opposed oblique elds were used. e
posterior cervical strips were treated with 9 MeV electrons to 54 Gy. e boost was delivered concomitantly, 18
Gy in 12 fractions. e anterior eld continued to 54 Gy
with a full midline block inserted at 45 Gy to shield the
spinal cord. e gross nodal disease in the mid neck was
boosted with a posterior photon beam, matched at the single isocenter. Figures 8.8C,D: Digital reconstructions of the
blocks for theboost elds with the GTV contoured. Axial
views ofthe isodoses through the primary target (T) and
through the mid neck are shown in Figures 8.8E,F. A selective right neck dissection was performed because a residual
neck mass remained 6 weeks a er completion of radiotherapy. Ten lymph nodes were removed from levels II and III,
but none contained viable tumor.
A B
C D
Figure 8.8A-D
128
https://t.me/medicina_free
Part 2 Site-Specifi c Indications and Techniques
E F
Figure 8.8E,F
Inferior border: just above the arytenoids. In the presence
•
of large nodal disease below this level, the border can be
extended more inferiorly.
An anterior appositional photon eld is used for elective
treatment of the mid and lower neck nodes bilaterally.
For the boost volume, the lateral portals are reduced to
include the primary tumor with 1- to 2-cm margins and the
involved upper neck nodes. In the presence of trismus, the
ipsilateral medial pterygoid muscle is included in the boost
elds. Nodal disease outside the primary boost eld is generally treated with anterior–posterior glancing photon elds.
An additional boost with interstitial brachytherapy is
given if there is residual palpable disease, particularly in the
tongue base.
Intensity-Modulated Radiation Therapy Planning
for Bilateral Treatment
IMRT has now been widely adopted for the treatment of
patients requiring bilateral irradiation because of its potential
for exclusion of a large portion of at least one of the parotid
glands from the high-dose volume, thereby reducing xerostomia without compromising the coverage of the primary
tumor and draining lymphatics. e patient is immobilized
in a supine position with an extended head and shoulder
thermoplastic mask. in-cut CT scans are obtained in treatment position. e GTV, CTVs, and PTVs are outlined for
dosimetric planning (see Case Studies 8-9 to 8-12).
As for ipsilateral treatment, CTV
delineates the pri-
HD
mary and nodal GTVs with 0.5- to 1-cm margins. CTVID
extends an additional 1 cm beyond CTVHD to include, for
example, at least the retromolar trigone anteriorly, 1 cm of
the base of tongue medially, and the remaining pterygoid
muscle between CTV
and the mandible laterally. Margins
HD
are de ned by the nature of tumor invasion and may include
the inner cortex of the ascending ramus of the mandible and
larger volume of tongue base, so palate, or medial pterygoid muscle, etc. In the presence of positive node(s), CTVID
encompasses the adjoining nodal compartment(s).
CTVED delineates volumes to receive an elective dose for
subclinical disease. In the N0 neck, CTVED includes nodal
levels II to IV and retropharyngeal nodes. When level II
node is involved, CTVED also includes clinically uninvolved
ipsilateral level IB nodes.
e primary tumor and nodal regions above the thyroid notch are irradiated with IMRT and the lower neck
nodes are irradiated with a matching anterior portal to
allow shielding of the larynx. e presence of bulky level
III nodes may necessitate treating all target volumes (primary tumor and neck nodes including level IV region) using
IMRT. With this technique, it is important to outline the larynx and esophagus (at least the arytenoids and esophageal
inlet) as avoidance structures to minimize the dose to these
organs, and thus reducing the risk for long-term swallowing
dysfunction.
Dose
Dose fractionation regimens used are similar to those presented in detail above in the “So Palate” Section. Brie y,
for patients with T1 and super cial T2 N0: conventional
technique delivering 50 Gy in 25 fractions to the initial target volume followed by 16 Gy in 8 fractions to the boost
Chapter 8 Oropharynx
https://t.me/medicina_free
129
Case
Study
8-9
treatment with IMRT to a dose of 66 Gy in 30 fractions.
Figure 8.9 shows the GTVs (primary tonsillar
tumor and solitary lymph node) contoured along with
axial isodose distributions at the levels of the pterygoids
(Fig.8.9A), mid-tonsil (Fig. 8.9B), inferior oropharyngeal
A 60-year-old man presented with an asymptomatic le neck mass. A ne needle aspiration
showed metastatic SCC. Physical examination
revealed a 3-cm exophytic le tonsillar mass
and a 3-cm mobile le level II node. He received
wall and midlevel II (Fig. 8.9C), and a coronal isodose
distribution through the tonsil tumor and involved lymph
node (Fig. 8.9D). e IMRT elds were matched above the
arytenoids to an anterior supraclavicular eld, which delivered 50 Gy in 25 fractions. Le level III received additional
irradiation to a total of 60 Gy (low neck dosimetry not
shown). A selective neck dissection performed a er radiotherapy revealed no residual disease. He had no evidence of
disease at the last follow-up for over 2 years a er treatment.
He has been able to eat all types of foods including bread.
A B
CD
Figure 8.9A-D
130
https://t.me/medicina_free
Part 2 Site-Specifi c Indications and Techniques
Case
Study
8-10
SCC. Stage T2 N1 M0. He was treated with IMRT,
using a concomitant boost-type fractionation regimen. e primary tumor and ipsilateral level II node
with margin received 57 Gy in 30 fractions. e primary tumor and gross lymph node with 0.5- to 1-cm
A 60-year-old man presented with right
otalgia was found to have a tumor of the
right superior tonsil extended onto the
lateral aspect of the so palate. Tumor
biopsy revealed a poorly di erentiated
margins received a concomitant IMRT boost of 15 Gy in
10fractions for a cumulative prescribed dose of 72 Gy.
Figure 8.10 shows a representative axial (Fig. 8.10A)
and coronal (Fig. 8.10B) isodose distribution through the
tonsillar tumor. Note that the tumor (T) caused loss of
the fat space between the fossa and pterygoid muscle. e
lower neck was treated with a matched anterior portal (not
shown). He had a complete response, so a neck dissection
was not performed. At last follow-up visit, he was free of disease, although he had grade 1 xerostomia and mild trismus.
A B
Figure 8.10A,B
Case
Study
8-11
the inferior aspect of the right tonsil.
Figure 8.11A shows a representative slice of diagnostic
CT scan, which con rmed the physical exam ndings, demonstrating the involved node (red arrow) and the primary tonsillar tumor (green arrow). Stage: T2 N2a M0. As the primary
tumor was relatively small (albeit T2) and exophytic, he was
treated with radiation alone. e pros and cons of ipsilateral
versus bilateral irradiation were discussed with the treatment
team and the patient, and it was decided to treat bilaterally.
GTV (primary, orange; node, magenta), CTV
Gy), and CTVID (60 Gy), which encompassed additional 0.5to 1-cm margins beyond CTVHD, level IB, and the remainder of ipsilateral level II nodes, respectively, were delineated
A 66-year-old male presented with a right
upper neck mass without any associated symptoms. A ne needle aspiration of the mass was
positive for SCC. Examination revealed a 4-cm
neck mass and a 2.5-cm exophytic tumor of
(66
HD
along with CTV
and le level II nodes. Figures 8.11B,C show representative
axial isodose distributions at the level of the mid-tonsil (Fig.
8.11B) and hyoid (Fig. 8.11C). e tumor and nodal GTVs
are shown with thick orange and magenta lines, respectively.
e isocenter was placed above the thyroid notch, and
the low neck was treated with an anterior beam. A larynx
block was used for the rst 40 Gy, and then a full midline
block was added for 10 Gy. e ipsilateral level III node was
boosted to 60 Gy with glancing photon elds and to 69 Gy
with 9 MeV electrons as the inferior aspect of the node was
split at isocenter. e electron treatments were delivered as
second daily doses. Figure 8.11D shows the low neck photon
eld, the location of the match between the IMRT elds, and
mid neck boost elds and the isodose distribution on a coronal view. e primary tumor and neck node had a complete
response so a neck dissection was not performed. e patient
remains without disease over 5 years out from treatment.
(54Gy) that covered the retropharyngeal
ED
Chapter 8 Oropharynx
https://t.me/medicina_free
131
A
C
Figure 8.11A-D
Case
Study
8-12
pharyngoepiglottic fold inferiorly. Biopsy of the primary
tumor revealed squamous cell cancer, positive for HPV.
Figure 8.12 shows slices of staging head and neck CT
scan at the level of the ascending ramus of the mandible
(Fig. 8.12A) and level II region (Fig. 8.12B) demonstrating
the bulky primary tumor (green arrow) and the lymphad-
enopathy just posterior to the jugular vein (red arrow). She
was treated with IMRT given in 33 fractions with concurrent high-dose cisplatin delivered on weeks 1, 4, and 7.
GTV, CTV
encompassed additional 0.5- to 1-cm margins beyond
A 43-year-old woman presented with a right
neck mass, right otalgia, and odynophagia.
Physical examination revealed a bulky right
tonsillar mass extending to the right lateral
so palate superiorly and to just above to the
(70 Gy), and CTVID (62 Gy), which
HD
B
D
and the remainder of ipsilateral level II nodes, were
CTV
HD
delineated along with CTVED (57 Gy) that covered the retropharyngeal, level IB, and le level II nodes. Figure 8.12
also shows representative axial isodose distributions at the
level of the pterygoid plates (Fig. 8.12C), epicenter of the
primary tumor (Fig. 8.12D), and level II neck (Fig. 8.12E),
and a coronal view with the tumor GTV outlined in thick
red line (Fig. 8.12F).
e isocenter was placed above the thyroid notch, and
the low neck was treated with an anterior beam. Alarynx
block was used for the rst 40 Gy, and then a full midline block was added for 10 Gy. e right level III node
wasboosted to 60 Gy with glancing photon elds. An axial
view of the isodose distribution at the level of the mid
neck is shown in Figure 8.12G. e patient did well and is
without disease 6 years later.
132
https://t.me/medicina_free
Part 2 Site-Specifi c Indications and Techniques
A
C
B
D
E
Figure 8.12A-F
F
G
https://t.me/medicina_free
Figure 8.12G
Chapter 8 Oropharynx
133
volume or IMRT administering 66 Gy to CTVHD given in
30 fractions over 6 weeks.
For patients with larger tumors who do not receive sys-
temic therapy: concomitant boost schedule to total doses of
72 Gy in 42 fractions or IMRT delivering 70 Gy to CTVHD
in 35 fractions over 6 weeks (1 day a week of twice-a-day
irradiation) or a concomitant type regimen (72 Gy in 42 fractions over 6 weeks), which requires two IMRT plans.
For patients with T3 to T4 or N2 to N3 tumors who receive
systemic therapy: 70 Gy in 35 fractions over 7 weeks (when
combined with three cycles of concurrent cisplatin or a er
TPF induction chemotherapy) or either 70 Gy given in 35 fractions over 6 weeks (1 day a week of twice-a-day irradiation) or
70 Gy to CTVHD given in 33 fractions over 6.5 weeks when
combined with two cycles of cisplatin or weekly cetuximab.
Postoperative Radiotherapy
Adjuvant radiotherapy is indicated in occasional patients
treated with upfront surgery. e principles are similar to
those for the treatment of retromolar trigone or posterior
oral cavity tumors as presented in detail, including illustrative cases, in Chapter 7.
Target Volume
e initial target volume encompasses the entire surgical bed
and all nodal areas of the neck.
e boost volume encompasses areas of known disease
location with 1- to 2-cm margins.
Setup and Field Arrangement
e general technique is the same as that described under
“Primary Radiotherapy.” Marking of the external surgical
scar facilitates portal design. e anterior and superior eld
borders or CTVs are mainly determined by the local spread
of the primary tumor and the extent of surgery (scar/ ap). It
is prudent to include 1- to 2-cm margins beyond the mucosal
scar.
Dose
• A dose of 60 Gy in 30 fractions to areas with high-risk
features, that is, close or microscopically positive margins,
perineural extension, vascular invasion, positive nodes, or
extranodal extension. An additional boost dose of 6Gy
may be given when indicated, such as when multiple
adverse features are present or when the interval between
surgery and radiation is much longer than 6 weeks.
Patients who had no evidence of disease a er diagnostic tonsillectomy are treated similarly as those having
T1 disease.
• A dose of 56 Gy in 28 fractions to the surgical bed.
• A dose of 50 Gy in 25 fractions to undissected regions to
receive elective irradiation.
Timing of Postoperative Radiotherapy
It is desirable to commence postoperative radiotherapy as
soon as possible a er healing of surgical wounds. With good
communication between surgical, radiation, and dental
oncologists, simulation can usually take place 3 to 4 weeks
a er surgery, and radiotherapy can start within a week in
most patients. When delayed wound healing postpones
commencement of postoperative radiation to beyond 5 to
6 weeks, we administer accelerated fractionation, such as
concomitant boost, by delivering twice-a-day irradiations for
5 treatment days, either once a week or toward the end of the
radiation course, to reduce the potential hazard of prolonged
cumulative treatment time.
Соседние файлы в папке Библиотека им академика М.И. Перельмана