Epidemiology:
Cutaneous T-cell lymphoma (CTCL) is a cancer of the T-lymphocytes and is rare, accounting for approximately only 1 in 20 cases of NHL. It is most common in people between 40 and 60 years of age. "Unlike other forms of non-Hodgkin lymphoma, CTCL mainly affects the skin." The cause of this is the uncontrolled growth of the T-cells, a type of white blood cell within the skin . "The most common types of CTCL are mycosis fungoides and Sezary syndrome. Sezary syndrome is a specific type of CTCL in which large areas of skin or lymph glands are affected, and abnormal T-lymphocytes are also found in the blood." When the blood is not affected, mycosis fungoides is the general name given to the other types of CTCL.1

In the U.S., there are about 58,870 new cases of non-Hodgkin lymphoma per year. Of these, there are about 1,500 new cases of CTCL per year. Men are twice as likely as women to have the disease and the average age at diagnosis is 55 years, with children rarely being affected.2 In addition, "blacks are twice as likely to be afflicted as whites."3
Etiology:
"The etiology of CTCL is unknown, but industrial exposure, genetic factors, and a type C retrovirus, human T-cell lymphoma virus type I, have been implicated."3
Signs & Symptoms:
Cutaneous T-cell lymphoma tends to remain localized to the skin for long periods of time. It can resemble eczema, psoriasis, or other inflammatory conditions. 4 CTCL begins with flat dry red itchy patches on the skin. CTCL is mostly slow growing, but a few cases progress rapidly. Figures 1.1 and 1.2 are examples of CTCL. 4
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Figure 1.1 Advanced Cutaneous T-Cell Lymphoma 4
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Figure 1.2 Early, patch stage Cutaneous T-Cell Lymphoma 4
Diagnostic Procedures:
The duration from onset of skin lesion to histological diagnosis is 8-10 years for CTCL patients. Punch biopsy specimens should be obtained from suspicious lesions. A complete diagnostic workup is listed below in figure 1.3. 3

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Figure 1.3 Diagnostic workup for CTCL 3
Histology:
There are two subgroups of Cutaneous T-cell lymphoma; mycosis fungoides (MF) and Sezary syndrome. Both types are malignant T-cell lymphoproliferative disorders that invade the epidermis and follicular epithelium of the skin. " The cellular infiltrate of CTCL consists of malignant T cells mixed with various numbers of normal white blood cells."3 These malignant T cells are often found circulating in the lymph nodes.
Lymph Node Drainage:
The status of the lymph nodes in the cervical, axillary, and inguinal regions should be evaluated. If a lymph node is palpable, it should be biopsied. An strong effort should be made to confirm the presence of extracutaneous involvement, if suspected. 3
Metastatic Spread:
All organ systems are at risk for metastatic spread. 6
Grading:
There is no grading system as of yet for cutaneous T-cell lymphoma.
Staging:
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Figure 2: Proposed staging of Cutaneous T-cell Lymphoma. 3
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Figure 2.1 Group staging for Cutaneous T-cell Lymphoma. 3
Radiation Side Effects:
A patient's skin treated with 10Gy of total skin electrons usually develops mild erythema, dry desquamation and hyperpigmentation. Doses above 25 Gy, may cause some patients to develop transient swelling of the hands, edema of the ankles and/or large blisters; may require shielding or the temporary discontinuation of radiation treatments. Loss of hair and nails can occur by the end of a treatment course unless they are shielded. They take approximately 4 to 6 months to grow back. Gynecomastia may develop. 3
Prognosis:
There is a poorer prognosis associated with increased age and TNM stage.
There is a significantly shorter survival rate with patients older than 60 years of age because they more often present with advanced disease.
"Defacement of nodal architecture by malignant T cells is associated with a median survival of less than 2 years."
5-yr Survival rates for T1=90%, T2=67%, T3=35%, and T4=40%.
3-yr survival rates of patients without nodal involvement=85%, with enlarged nodes in one region=68%, and with enlarged nodes in more than one region=60%.
"Visceral involvement is associated with a median survival of less than 1 year."
3
Treatments:
Treatment for CTCL depends on the type and stage of the disease. Treatment options include phototherapy, radiation, topical therapy, systemic single-agent chemotherapy, combination chemotherapy and combined therapies. Patients with localized early-stage disease are usually treated with topical agents such as nitrogen mustard, skin-softening agents, anti-itch agents and gradual exposure to sunlight or ultraviolet light. 5

Total-body electron irradiation is the preferred treatment modality, with very high local control rates (85%-100%) and favorable survival.
Both irradiation and chemotherapy produce initial response, but rapid extracutaneous dissemination occurs in large cell T-cell lymphoma. 3


The most effective treatment for CTCL is ionizing radiation. Because of the possibility for treating areas adjacent to those that have already been treated, it is very important to take photos documenting areas that have already been treated. In addition, it is helpful to have accurate portal drawings and tattoos at the corners of the fields. Data has indicated that excellent local control can be achieved with doses of 10 to 20 Gy given over 1 to 2 weeks.

"Bulky tumors and lesions in locations where retreatment could compromise functional or cosmetic outcome should be treated to a full dose (30 Gy over 3.0 to 3.5 weeks) for optimal control. Complete clinical response may take up to 6 to 8 weeks."

The most common approach for treating CTCL in the U.S. is total-skin electron beam (TSEB) irradiation. At the present time, the best technique with the most reasonable dose uniformity is a six-dual-field technique. "An electron beam with an effective central-axis energy of 3 to 6 MeV is used to treat three anterior and three posterior stationary treatment fields, each of which has a superior and inferior portal with beam angulation 20 degrees above and 20 degrees below the horizontal axis. The patient is placed in front of the beam in six positions during treatment. The straight anterior, right posterior oblique, and left posterior oblique fields are treated on the first day of each treatment cycle, and the straight posterior, right anterior oblique, and left anterior oblique fields are treated on the second day of each cyle." During each 2-day cycle, the entire wide-field skin surface receives 1.5 to 2 Gy. Generally, the radiation is given 4-days per week with the total doses depending on the intent of treatment--palliative or curative. For curative treatment, doses of 30-40Gy are given over 8 to 10 weeks with a break of 1 to 2 weeks when the dose reaches 18-20 Gy. For palliative treatment, 10 to 20 Gy is given.

When treating TSEB, eye shields (internal or external) are used to protect the lens and cornea. "Shielding of the digits and lateral surfaces of the hands or feet may be necessary because of overlapping treatment fields in these areas." When treating for palliation, it is recommended that you shield any uninvolved skin. "Areas not directly exposed to the path of the electron path of the electron, such as the soles of the feet, perineum, medial upper thighs, axillae, posterior auricular areas, inframammary regions, vertex of the scalp, and areas under the skin folds are treated with separate electron beam fields with an appropriate energy."

For advanced CTCL more agressive methods have been used. High-dose TSEB and total nodal irradiation have been used with complete response recorded in nearly all cases. "Fractionated total-body irradiation and TSEB irradiation with total-body irradiation and chemotherapy supported by autologous bone marrow transplantation may show future promise for advanced CTCL."
3

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Figure 3. Geometry of TSEB treatment.3

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Figure 4: Four of the six standard treatment positions for the modified Stanford Technique for total skin electron beam treatments. Positions include: anterior, left posterior oblique, right posterior oblique, posterior, left anterior, and right anterior oblique. 8
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Figure 5: The six field cycle for total skin elctron treatments for figure 4 positions. 8
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Figure 6: Total skin electron beam treatment position.
8
TD5/5:
Since CTCL is treated with total body electrons the organs at risk are the lenses of the eyes and the skin.
TD 5/5
Skin - 5500 cGy
Lenses - 500 cGy 7

References:
1. Macmillan Cancer Support. Cutaneous T-cell Lymphoma (CTCL). Available at: http://www.macmillan.org.uk/Cancerinformation/Cancertypes/Lymphomanon-Hodgkin/TypesofNHL/CutaneousT-cell.aspx Accessed: February 8, 2010.
2. The Leukemia & Lymphoma Society. Cutaneous T-Cell Lymphoma. Available at: http://www.ia.leukemia-lymphoma.org/attachments/National/br_1163608564.pdf Accessed: February 8, 2010.
3.
Chao KS, Perez CA, Brady LW. Radiation Oncology Management Decisions. 2nd edition. Philadelphia, PA: Lippincott Williams & Wilkins. 1999, 2002; 123-128, 598, 124.
4. Med Scape from WebMD. Available at http://images.search.yahoo.com/search/images?-adv-prop=image&fr=yfp-+-892-s&va=cutaneous+t_cell+lymphoma&sz=all . Accessed Feb. 10, 2010.
5. The Leukemia and Lymphoma Society. Cutaneous T-Cell Lymphoma. Available at: http://www.ia.leukemia-lymphoma.org/attachments/National/br_1163608564.pdf. Accessed. February 11, 2010.
6. Lenards N. Cutaneous T-Cell Lymphoma. Presented at: University of Wisconsin, Desire to Learn. February 12, 2010. Clincal Oncology.
7. Washington CM, Leaver D. Principles and Practice of Radiation therapy. Second Edition. St. Louis, Missouri: Mosby. Inc. 4

2004; 80-81.
8.Levitt, SH, Purdy, JA, Perez, CA, & Vijayakumar, S. Technical Basis of Radiation Therapy. Fourth revised edition. Germany: Springer Science and Business Media. 2006:163.