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Part 2 Site-Specifi c Indications and Techniques
Background Data
Table 14.1
Five-Year Survival After External Radiotherapy in Patients with Differentiated Thyroid Carcinoma:
Review of the Literature
References Complete Surgery (%) Incomplete Surgery (%) Inoperable Tumors (%)
Portmann 24/31 (77) 10/30 (33) —
Mabille 17/19 (90) 9/20 (45) 5/22 (23)
Smedal et al. 24/24 (100) 25/31 (81) —
Sheline et al. — 11/17 (65) —
McWhirter 54/61 (89) 20/63 (32) —
Jacobsson 28/29 (97) 16/27 (59) —
Windeyer 5/6 (83) 11/20 (55) —
Simpson — 23/54 (43) —
Staunton and Martin — — 3/14 (21)
Tubiana et al. 62/66 (94) 76/97 (78) 11/17 (65)
From Tubiana M, Haddad E, Schlumberger M, et al. External radiotherapy in thyroid cancers. Cancer 1985;55:2062–2071, with permission.
Table 14.2
Histology
Outcomes of Conformal Irradiation for Thyroid Cancer: the U.T. M.D. Anderson Experience
Patient Number
(Total/IMRT) Overall Survival (%)
Disease Specifi c
Survival (%)
Local–Regional
Control (%)
Well-differentiated carcinoma 131/57 73 (4 yr) 76 79
Medullary carcinoma 34/7 56 (5 yr) 62 87
Anaplastic carcinoma 53/13 19 (1 yr) 19 11
Data from Schwartz DL, Lobo MJ, Ang KK, et al. Postoperative external beam radiotherapy for differentiated thyroid cancer: outcomes and morbidity with
conformal treatment. Int J Radiat Oncol Biol Phys 2009;74:1083–1091; Schwartz DL, Rana V, Shaw S, et al. Postoperative radiotherapy for advanced medullary
thyroid cancer—local disease control in the modern era. Head Neck 2008;30:883–888; and Bhatia A, Rao A, Ang KK, et al. Anaplastic thyroid cancer: clinical
outcomes with conformal therapy. Head Neck 2010;32:829–836.
SUGGESTED READINGS
Benker G, Olbricht T, Reinwein D, et al. Survival rates in
patients with di erentiated thyroid carcinoma. In uence of postoperative external radiotherapy. Cancer 1990;65:1517.
Bhatia A, Rao A, Ang KK, et al. Anaplastic thyroid cancer:
clinical outcomes with conformal therapy. Head Neck 2010;32:829.
Brierley J, Tsang R, Simpson WJ, et al. Medullary thyroid
cancer: analyses of survival and prognostic factors and the role of
radiation therapy in local control. yroid 1996;6:305.
Brierley J, Tsang R, Panzarella T, et al. Prognostic factors and
the e ect of treatment with radioactive iodine and external beam
radiation on patients with di erentiated thyroid cancer seen at a
single institution over 40 years. Clin Endocrinol 2005;63:418.
Farahati J, Reiners C, Stuschke M, et al. Di erentiated thyroid
cancer. Impact of adjuvant external radiotherapy in patients with
perithyroidal tumor in ltration (stage T4). Cancer 1996;77:172.
Hill CS Jr, Ibanez ML, Samaan NA, et al. Medullary (solid)
carcinoma of the thyroid gland: an analysis of the M.D. Anderson Hospital experience with patients with the tumor, its special
features, and its histogenesis. Medicine 1973;52:141.
Levendag PC, De Porre PM, van Putten WL. Anaplastic
carcinoma of the thyroid gland treated by radiation therapy. Int
J Radiat Oncol Biol Phys 1993;26(1):125.
Nguyen TD, Chassard JL, Lagarde P, et al. Results of postoperative radiation therapy in medullary carcinoma of the thyroid: a
retrospective study by the French Federation of Cancer Institutes—
the Radiotherapy Cooperative Group. Radiother Oncol 1992;23:1.
Nutting CM, Convery DJ, Cosgrove VP, et al. Improvements
in target coverage and reduced spinal cord irradiation using intensity-modulated radiotherapy (IMRT) in patients with carcinoma of
the thyroid gland. Radiother Oncol 2001;60:173.
O’Connell ME, A’Hern RP, Harmer CL. Results of external beam radiotherapy in di erentiated thyroid carcinoma: a retrospective study from the Royal Marsden Hospital. Eur J Cancer
1994;30A:733.
Rougier P, Pannentier C, Laplance A, et al. Medullary thyroid carcinoma: prognostic factors and treatment. Int J Radiat
Oncol Biol Phys 1983;9:161.
Samaan NA, Maheshwari YK, Nader S, et al. Impact of therapy for di erentiated carcinoma of the thyroid: an analysis of 706
cases. J Clin Endocrinol Metab 1983;56:1131.
Chapter 14 Thyroid
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255
Schwartz DL, Rana V, Shaw S et al. Postoperative radiotherapy for advanced medullary thyroid cancer—local disease control
in the modern era. Head Neck 2008;30:883.
Schwartz DL, Lobo MJ, Ang KK, et al. Postoperative external
beam radiotherapy for di erentiated thyroid cancer: outcomes and
morbidity with conformal treatment. Int J Radiat Oncol Biol Phys
2009;74:1083.
Sia MA, Tsang RW, Panzarella T, et al. Di erentiated thyroid cancer with extrathyroidal extension: prognosis and the role of
external beam radiotherapy. J yroid Res 2010;2010:183461.
Simpson WJ. Anaplastic thyroid carcinoma: a new approach.
Can J Surg 1980;23:25.
Simpson WJ. Radioiodine and radiotherapy in the management of thyroid cancers. Otolaryngol Clin North Am 1990;
23:509.
Simpson WJ, Palmer JA, Rosen IB, et al. Management of
medullary carcinoma of the thyroid. Am J Surg 1982;144:420.
Strong EW. e treatment of thyroid cancer: a summary. In:
Najarian JS, Delaney JP, eds. Advances in cancer surgery. New York,
NY: Stratton, 1976.
Tennvall J, Lundell G, Hallquist A, et al. e Swedish
Anaplastic yroid Cancer Group. Combined doxorubicin, hyperfractionated radiotherapy, and surgery in anaplastic thyroid carcinoma. Report on two protocols. Cancer 1994;74:1348.
Tubiana M, Haddad E, Schlumberger M, et al. External radiotherapy in thyroid cancers. Cancer 1985;55:2062.
Wilson PC, Millar BM, Brierley JD. e management of
advanced thyroid cancer. Clin Oncol 2004;16:561.
Wu XL, Hu YH, Li QH, et al. Value of postoperative
radiotherapy for thyroid cancer. Head Neck Surg 1987;10:107.
15
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Skin
Key Points
• e majority of skin carcinomas, the most common
cancers in human, are treated with surgery.
• Upfront radiotherapy is an appealing alternative for
carcinomas on and around the nose, lower eyelids,
and ear as it can yield better cosmetic outcome.
• Postoperative radiotherapy is indicated in locally
advanced skin carcinomas, particularly those with
perineural spread along large nerves, invasion of bone,
cartilage, and skeletal muscle, positive section margin, or
nodal involvement with extracapsular extension (ECE).
• Intensity Modulated Radiation erapy is the preferred
technique when target volumes include the cranial nerves
such as the branches of the trigeminal or facial nerves.
• Adjuvant radiotherapy is indicated for the treat-
ment of malignant melanomas spreading to multiple
lymph nodes, particularly in the presence of ECE.
• Elective nodal irradiation is an alternative to nodal
dissection in selected patients with thick melanoma.
• Adjuvant radiotherapy plays a role in the treatment
of rare skin cancers such as Merkel cell carcinoma or
adnexal neoplasms.
SQUAMOUS CELL CARCINOMA
AND BASAL CELL CARCINOMA
is preferred for most patients, particularly for younger patients
who have years of exposure to sunlight ahead of them.
Primary radiotherapy is o en indicated for lesions on
and around the nose, lower eyelids, and ear, where it can
usually attain better functional and cosmetic results than
surgery. Extensive lesions of the cheek and oral commissures, which would require full-thickness resection, may also
show better results on irradiation.
Postoperative radiotherapy is indicated for positive surgical margins, perineural invasion, and invasion of bone,
cartilage, and skeletal muscle.
Rarely, patients have adenopathy at diagnosis. e choice
of treatment of the nodal disease is determined by the type
of therapy selected for the primary lesion and by the size of
the node. A combination of surgery and radiotherapy is indicated when nodal disease is >3 cm or when ECE is present.
Primary Radiotherapy
Target Volume
e initial target volume encompasses primary tumor with
1- to 2-cm margins, depending on the size, location, and type
of tumor (well-circumscribed vs. ill-de ned border). Elective
a large, in ltrative squamous cell carcinoma (SCC) or poorly
di erentiated.
e boost volume encompasses primary tumor with
0.5- to 1-cm margins, depending on the size, location, and
type of tumor.
Treatment Strategy
Surgery and radiotherapy are equally e ective in curing most
skin cancers. e choice of treatment modality is determined
by several factors, such as functional and cosmetic results,
patient age and occupation, treatment time, and cost. Surgery
Setup and Field Arrangement
e patient is immobilized in a position that gives the best
access to irradiate the tumor (preferably the plane of the skin
to be treated is parallel to the surface of the treatment couch
to avoid the need for gantry rotation) (see Fig. 16.1).
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Chapter 15 Skin
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257
An appositional eld is used in most cases. e borders
of the eld are chosen to include a 1- to 2-cm margin of
normal skin around the tumor (up to 1 cm for lesions <1-cm
tumor and 1 to 2 cm for larger tumors). Margins may be
smaller when treating areas close to the eye. More generous margins are appropriate for lesions with an ill-de ned
border.
Radiation treatment is given with orthovoltage x-rays
(usually 75 to 125 kilovolt potential [kVp]) or electrons
(usually 6 to 12 MeV). e energy of x-rays or electrons is
chosen on the basis of the thickness of tumor. e energy
of electron beams should be selected so that the distal
90%-isodose line is a few millimeters deeper than the base of
the tumor, including surface bolus.
e treatment distance for x-rays also depends on the
thickness of the lesion. A 23-cm focus skin distance (FSD)
cone is appropriate for super cial tumors, whereas a 50-cm
FSD with open elds and skin collimation is preferable for
thicker lesions to avoid a large dose gradient across the
lesion. e FSD for electrons is usually 100 cm.
Case
Study
15-1
lesion with raised borders, involving the le lateral dorsum of the nose, the medial aspect of the cheek, and the
medial canthus (Fig. 15-1A). e thickest part of the tumor
was close to the medial canthus. Biopsy revealed basal cell
carcinoma. Computed tomography scans showed a small
so tissue mass in the medial canthus of the le orbit. e
A 59-year-old man sought medical attention
because of a small ulcer at the le lateral dorsum of the nose that gradually increased in
size over a 4-year period.
Physical examination showed a ulcerating
A custom-made lead cutout is used for skin collimation.
e cutout should be large enough so that the portal size for
an electron beam is at least 4 × 4 cm.
Skin bolus or a perspex scatter plate is used with
electrons to ensure full surface dose.
An internal eye shield is inserted when treating an eyelid
lesion with orthovoltage x-rays or with electrons of 8 MeV or
less. (Note: Eye shields should be individually calibrated with
respect to the electron attenuating properties.)
Dose
E ective regimens for treating most skin cancers include
a dose of 50 to 55 Gy in 20 fractions, a dose of 45 Gy in
15fractions, or a dose of 40 Gy in 10 fractions. In general,
protracted treatment provides better cosmetic results.
For large tumors close to crucial structures (e.g., eye),
maximum tolerance is obtained with a dose of 60 to 70 Gy in
30 to 35 fractions (see Case Study 15-1).
If the patient is in poor general condition, hypofractionation (e.g., 4 fractions of 8 Gy) may be used.
deepest point of this mass was 1.5 cm from the surface.
Stage: T2 N0 M0. e lesion was treated with an appositional
le anterior oblique eld of 9-MeV electrons. Figure15-1
shows a custom-made eye shield mounted on a contact lens
used to protect the cornea and lens (Fig. 15-1B), a lead mask
with extra layers over the contralateral eye for skin collimation (Fig. 15-1C), and a 1/4-inch scatter plate placed in
the beam to eliminate the skin-sparing e ect (Fig. 15-1D).
A dose of 60 Gy, prescribed to 90% isodose line, was delivered in 2-Gy fractions, which resulted in local control with
good cosmetic and functional outcome (Fig. 15-1E,F).
A
Figure 15.1A,B
B
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Part 2 Site-Specifi c Indications and Techniques
w w
C
E
F
D
Figure 15.1C-F
Chapter 15 Skin
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259
Dose Specifi cation
x-Rays are prescribed at D
with electrons at the 90% line.
max
is di erence in prescription accounts for the relative biologic e ectiveness di erence between the two beam qualities.
Postoperative Radiotherapy
Most frequent indications are lymphatic spread to the parotid
gland, upper neck nodes, or both, and perineural extension
along the branches of the trigeminal nerves, facial nerves, or
both.
Target Volume
e initial target volume encompasses the primary tumor
bed and ipsilateral parotid and neck nodes, or trigeminal or
facial nerve pathways, depending on the indication.
e boost volume encompasses areas of known disease
with 1- to 2-cm margins.
Setup and Field Arrangement
For the treatment of parotid and neck nodes or branches of
the facial nerve, the technique is similar to that for primary
parotid tumors (see Chapter 13). e patient is immobilized in an open neck position. e anterior margin of the
parotid portal can be slightly less generous because there is
no need to encompass the parotid duct. Treatment is given
with an electron beam of appropriate energy (e.g., 12 MeV
for parotid and upper neck nodes and 9 MeV for lower neck
nodes).
For the treatment of perineural extension through the
supraorbital, infraorbital, or mandibular branches of the
trigeminal nerve, the patient is immobilized in a supine position. e head is slightly hyperextended for irradiation of the
infraorbital and mandibular nerves and is slightly exed for
the supraorbital nerve. A wedge-pair technique using 6-MV
x-rays can be used for the treatment for these situations,
which allows irradiation of the nerve track to the gasserian
ganglion, with sparing of most of the eye. e portal margins
depend on the tumor extent. IMRT, similar to that used for
the treatment of sinonasal primary tumors (see Chapter 12)
usually provides better coverage for rather convoluted target volumes in such case while sparing more optic structures
and, therefore, has largely replaced wedge-pair technique.
Dose
e dose consists of 50 to 54 Gy in 25 to 27 fractions to the
initial target volume followed by a dose of 6 to 12 Gy in 3 to
6 fractions to the boost volume.
Dose Specifi cation: See “General Principles.”
Background Data
Table 15.1
Diagnosis
Basal cell carcinoma 444 20 2 426/444 (95.9)
SCC 156 12 — 144/156 (92.3)
Keratoacanthoma 12 0 — 12/12 (100)
Modifi ed from Solan MJ, Brady LW, Binnick SA, et al. Skin cancer. In: Perez CA, Brady LW, eds. Principles and practice of radiation oncology. 2nd ed.
Philadelphia, PA: JB Lippincott, 1992:479–495.
Table 15.2
Histologic Finding Primary Tumors Recurrent Tumors Total 5-yr Control %
Basal cell carcinoma 686 376 1,062 1,009 95.0
SCC 62 42 104 97 93.3
Total 748 418 1,166 1,106 94.8
a
Most of the primary tumors were controlled and the few failures were salvaged by surgery. Of the 1,166 tumors, 745 (64%) were <2 cm in diameter.
Adapted from Fitzpatrick PJ. Skin cancer of the head—treatment by radiotherapy. Int J Radiat Oncol Biol Phys 1984;10:450.
Control of Malignant Skin Lesions with Radiation Therapy: Hahnemann University Experience,
1960 to 1980
No Evidence of
No. Treated with
Radiotherapy
Clinical Experience with 1,166 Eyelid Tumors Treated by Radiotherapy (1958 To 1978)
No. of Treatment
Failures
No. of Recurrences
Controlled by Reirradiation
Disease 4 Yr or
Longer (%)
a
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Part 2 Site-Specifi c Indications and Techniques
Table 15.3
Size No. of Patients Failures %
<2 cm 602 42 7
2–5 cm 32 12 37
>5 cm 12 6 50
Total 646 60 9
Modifi ed from Petrovich Z, Kuisk H, Langholz B, et al. Treatment results and
patterns of failure in 646 patients with carcinoma of the eyelids, pinna, and
nose. Am J Surg 1987;154:447.
Carcinoma of the Eyelids, Pinna, and
Nose Treated with Radiotherapy:
Distribution of Patients and Treatment
Failure by Lesion Size
MELANOMA
Treatment Strategy
e primary treatment for cutaneous melanoma is complete local excision (which is essential for tissue diagnosis and microstaging) and, for palpable nodes, neck
dissection. An exception is large facial lentigo maligna
melanoma, which can be treated e ectively with primary
radiotherapy when wide surgical resection requires an
extensive reconstruction or is anticipated to yield poor
cosmetic outcome.
Our indications for adjuvant postoperative radiotherapy
following therapeutic nodal dissections are as follows:
• Lymph node >3 cm or multiple lymph nodes.
• ECE.
• Nodal recurrence without distant metastases.
• Local excision of macroscopic disease only.
Sentinel lymph node biopsy with directed lymphadenectomy has replaced routine elective regional radiotherapy
following wide local excision of primary lesions 1.5-mm
thick or greater (American Joint Committee on Cancer
stage II or III) or Clark’s level IV or higher without clinical
evidence of lymphadenopathy. Elective nodal irradiation
is indicated if the procedure cannot detect the sentinal
basin or if the patient’s condition precludes a therapeutic
dissection.
Postoperative Radiotherapy
Target Volume
For stages II and III, the target volume encompasses the primary tumor bed and ipsilateral draining lymph nodes down
to the supraclavicular nodes.
For nodal recurrence, the entire ipsilateral neck is
included. e primary tumor bed is also irradiated if excision was carried out <1 year before the nodal recurrence.
Setup and Field Arrangement
Setup and
eld arrangement varies with the site of the
primary lesion. Most patients are treated with electrons
of appropriate energies
(see Case Study 15-2). Patients
are usually immobilized in an open neck position. Cutaneous melanoma of frontal, temporal, and preauricular
areas; auricle; and cheek are usually treated with two or
three elds depending on the distance between the primary and parotid nodes. A eld, similar to that of parotid
gland tumors, is used to irradiate intraparotid and upper
neck nodes with 12-MeV electrons. is eld covers most
of the tumor beds of lesions arising in these locations. An
adjoining eld is added to irradiate the tumor bed with 6to 9-MeV electrons if the site of the primary tumor is outside the boundary of the parotid eld. A matching portal
is used to treat the lower neck nodes, as described in the
subsequent text.
Cutaneous melanoma of the nose and nasolabial fold is
irradiated with the technique described for nasal vestibule,
except that lower-energy electrons (<9 MeV) are used for the
tumor bed. Field borders encompass nodal areas and the surgical bed with approximately 2-cm margins. Bolus is used to
prevent underdosage to the primary tumor bed when 9-MeV
electrons or lower-energy electrons are used.
An appositional electron or photon eld may be used
to treat the mid and lower neck nodes when indicated.
e junctions between the elds are moved a er the second
and fourth radiation fractions to improve dose homogeneity.
Melanoma of some locations, such as lip or suboccipital
region, may require irradiation with opposed–lateral photon
portal
(see Case Study 15-3). e use of missing tissue com-
pensator or eld-in- eld technique is necessary in this setting to avoid hot spots, which can dramatically increase the
risk of normal tissue injury by increasing both the fraction
size and total dose (“double trouble”).
Dose
e dose consists of 30 Gy in 5 fractions, 2 fractions per
week, for elective irradiation. An additional fraction of 6Gy
may be added to a total dose of 36 Gy in 6 fractions for residual disease (see Case Study 15-4).
Dose Specifi cation: at D
max
e dose to the spinal cord or brachial plexus should not
exceed 24 Gy in 4 fractions.
Chapter 15 Skin
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261
Case
Study
15-2
nation showed a 2-cm excision scar with surrounding erythema and a 1-cm le subdigastric node. Workup for distant
metastasis was negative. She then underwent a wide reexcision of the skin of the le cheek along with a le super cial
parotidectomy and supraomohyoid neck dissection. Examination of the specimens revealed presence of residual melanoma in the dermis of the cheek and metastatic deposit in
three level II and one level III nodes. She received adjunctive
radiotherapy to the tumor bed and ipsilateral neck nodes
through two abutting appositional elds to a given dose of
30Gy in 5fractions (6 Gy per fraction). e le cheek and
upper neck nodal basin were irradiated with 12-MeV electrons and the lower neck with 9-MeV electrons. Skin collimation was used around the eye and a 0.5-cm bolus was placed
on the cheek. e eld junction was moved twice during
treatment. She did well until a right parietal brain metastasis
was diagnosed 3 years later. ere was no evidence of local–
regional disease.
A 51-year-old woman underwent excision of
a 2.3-cm skin lesion located in the le cheek
(Fig 15-2). Histologic examination revealed a
6.5-mm thick malignant melanoma. She was
referred for further treatment. Physical exami-
Figure 15.2
Case
Study
15-3
Center for further therapy. Review of the record of the latest surgery revealed that the excision margin was microscopically positive. It was thought that wide excision would
involve removal of most of the lower lip and, therefore, the
patient was o ered radiotherapy.
On physical examination, there was a scar in the
center of the lower lip but no evidence of gross residual disease (Fig. 15-3A). ere was no palpable adenopathy. An
intraoral stent was used to separate the lips and to displace
A 75-year-old man underwent repeated excisions of a lesion in the middle of the lower lip
over a period of 1.5 years. Final diagnosis, a er
review of all slides, was melanoma, and the
patient was referred to M.D. Anderson Cancer
the tongue posteriorly and cranially (Fig. 15-3B,C). e
lower lip and bilateral upper neck nodes (i.e., submental,
submandibular, and subdigastric) were irradiated through
le and right parallel–opposed cobalt photon elds.
Figure15-3D shows that with the aid of the stent, the commissures (wired) and the oral tongue could be excluded
from the portals. A maximum dose of 30 Gy was delivered
in ve fractions, twice a week, through the lateral elds.
Following this, an additional fraction of 6 Gy was delivered
to the tumor bed through an anterior appositional 8-MeV
electron beam. A second intraoral stent was constructed;
it served to atten the lower lip and to open the mouth; in
addition, lead alloy was inserted in the anterior part of the
stent to shield the lower gum (Fig. 15-3E,F).
A
Figure 15.3A,B
B
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Part 2 Site-Specifi c Indications and Techniques
C
E
Figure 15.3C-F
Case
Study
15-4
scar was found and excised as well. is second lesion was
a satellite metastasis invading connective tissue. He had no
palpable lymphadenopathy. He received adjuvant radiation
to the right neck delivered with 12-MeV electrons to a dose
of 30 Gy given in 5 fractions. e patient was treated in an
open neck position.
Figure 15-4 shows a representative axial isodose
through the upper neck.
A 50-year-old man presented with a melanoma
located 2 cm below the right earlobe. It was
excised with negative margins. Histologic
review showed invasion into the subcutaneous tissue. An additional lesion adjacent to the
D
F
Figure 15.4
Background Data
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Chapter 15 Skin
263
Table 15.4
Status D N D + N DM Median Follow-Up Total
Elective
Adjunctive
Total 9 15 8 138 — 317
D, dermal recurrence; N, nodal relapse; DM, distant metastasis.
a
Stage I or II cutaneous melanoma treated with wide local excision of the primary followed by elective regional radiation.
b
Patients with cervical nodal metastases treated with surgery and radiation.
Data from Ballo MT, Bonnen MD, Garden AS, et al. Adjuvant irradiation for cervical lymph node metastases from melanoma. Cancer 2003;97:1789–1796;
Bonnen MD, Ballo MT, Myers JN, et al. Elective radiotherapy provides regional control for patients with cutaneous melanoma of the head and neck. Cancer
2004;100:383–389.
MERKEL CELL CARCINOMA
Pattern of Failure after Elective or Adjunctive Radiotherapy for Cutaneous Melanoma
a
b
4 10 5 57 68 mo 157
5 5 3 81 78 mo 160
e boost volume encompasses areas of known disease
with 1- to 2-cm margins.
Treatment Strategy
e primary therapy for Merkel cell carcinoma is surgery
to establish tissue diagnosis and resect primary tumor and
nodal masses.
Adjunctive postoperative radiotherapy is recommended
in most patients because the rate of local–regional relapse
a er surgery is high.
Postoperative Radiotherapy
Target Volume
e initial target volume encompasses the surgical bed with
4- to 5-cm margins, except when the lesion is situated at
or close to crucial structures (e.g., optic apparatus) and the
draining lymphatics. For Merkel cell carcinoma of the head
and neck region, the whole ipsilateral neck is irradiated.
Setup and Field Arrangement
Setup and
eld arrangement varies with the site of the primary lesion. Most patients are treated with electron beams of
appropriate energies, with patients immobilized in an open
neck position, as described for cutaneous melanoma of the
head and neck region.
Dose
e dose for the initial target volume is 46 Gy in 23 fractions.
e dose for the boost volume is 10 Gy in 5 fractions
to the tumor bed, 14 Gy in 7 fractions to positive section
margins, or 20 Gy in 10 fractions to bulky macroscopic
disease.
Dose Specifi cation: See “General Principles.”
Background Data
Table 15.5
Method No. of Patients Local Recurrence
Surgery only 34 15 (44%) 29 (85%) 11 (32%) 1 (3%)
Surgery and radiation 26 3 (12%) 7 (27%) 11 (42%) 13 (50%)
Radiation only 6 1 (17%) 4 (44%) 2 (33%) 1 (17%)
P (radiation vs. no
radiation)
Adapted from Gillenwater AM, Hessel AC, Morrison WH, et al. Merkel cell carcinoma of the head and neck: effect of surgical excision and radiation on
recurrence and survival. Arch Otolaryngol Head Neck Surg 2001;127:149.
Pattern of Failure of Merkel Cell Carcinoma by Treatment Methods
Regional
Recurrence
0.01 <0.001 0.59 <0.001
Distant
Recurrence No. Recurrence
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