|Ahead of print publication
Electron beam radiotherapy for Kaposi's sarcoma of the toe and web
Mi-Jo Lee1, Hyun-Jin Son2
1 Department of Radiation Oncology, Eulji University School of Medicine, Daejeon, Korea
2 Department of Pathology, Eulji University School of Medicine, Daejeon, Korea
Department of Radiation Oncology, Eulji University Hospital, 95, Dunsanseo-Ro, Seogu, Daejeon 35233
Source of Support: None, Conflict of Interest: None
Kaposi's sarcoma (KS) is an uncommon neoplastic vascular disease. The standard treatment for localized classic KS lesions is surgical excision or radiation. Superficial skin lesions are generally treated with electrons or low-energy photon fields using boluses. Radiotherapy (RT) can be used for poor surgical candidates or when surgery is expected to result in a poor cosmetic or functional outcome. This study is the first to describe a case of KS of the toe and web treated with electron RT, which precisely targeted the irregular skin lesion with a markedly higher presided effective treatment. An electron field is often limited in its effectiveness to deliver a homogeneous dose in cases with irregular contours. Here, we report our successful experience using low-energy electron beam radiation to treat KS of the toe and web. The patient was a 78-year-old woman who was diagnosed with KS located on the first and second toe and web, based on radiology, pathology, and immunohistochemical examinations. KS was located on the left foot and measured more than 2.5 cm. No regional nodal or distant organ metastasis was observed. She was medically inoperable. RT was performed using a 6-MeV electron with a 0.5-cm bolus and a dose of 50 Gy delivered in 25 fractions. Follow-up computed tomography 2 months after RT revealed a complete tumor response. Toxicity was limited to mild skin desquamation during treatment. The patient remains alive and has shown no evidence of disease for 2 years. This study suggests that electron RT is a safe and effective treatment option for skin lesions located on the toe and web.
Keywords: Kaposi's sarcoma, radiotherapy, toe, web
| > Introduction|| |
Kaposi's sarcoma (KS) is a multifocal angioproliferative neoplasm of endothelial origin consisting of four types: Classical or Mediterranean, epidemic or acquired immunodeficiency syndrome (AIDS) associated, African/endemic, and iatrogenic posttransplantation KS. All subtypes are invariably linked to human herpesvirus-8 and show a male predilection (male/female ratio: 4/1 in classic KS). Lesions occur mostly on the skin of lower limbs and more rarely, in internal organs., Localized cutaneous KS may be treated with radiotherapy (RT), cryotherapy, or intralesional injections of vinblastine or immunotherapy. In a review of classic KS treatment, a size reduction ≥50% was achieved in 62% of those treated with intralesional vincristine, in 50%–90% of those treated with interferon-α2, in 56% of those treated with imiquimod, and in 25% of those treated with nicotine patches, and complete remission was achieved in 60%–93% of lesions treated with RT. Few randomized studies of classic KS have been performed, because of its rarity and indolent nature; therefore, a standard treatment has not been established. Some asymptomatic lesions can be closely observed, while symptomatic lesions should be treated with local or systemic therapies according to the location, range, or rate of progression. RT plays an important role in the local control of KS. Several reports showed excellent response rates up to 98.7% after 13.5 years of follow-up.,, The incidence of KS in South Korea is very low; thus, most previous studies conducted in South Korea have been case reports., Toe lesions represent a special challenge from both a surgical and radiotherapeutic standpoint. Surgical resection of toe and web lesions may result in scar retraction, loss of function, or a need to amputate. It is unknown if standard RT delivered to a portion or the entire circumference of a toe may result in severe chronic fibrosis or relapse disease. Furthermore, low-energy photons are less affected by irregular surfaces and separations than are electron fields. Tumors occurring on the surfaces of extremities create dosimetric difficulties. We aimed to evaluate the efficacy of electron beam RT for KS of the toe and web.
| > Case Report|| |
A 78 years woman with no evidence of human immunodeficiency viral infection presented with a history of hypertension. Our patient also presented with multifocal, purple-colored lesions with a maculopapular, nodular, violaceous appearance on the legs, and ulcerated lesions on the feet ( first toe and between the toes and web of the foot), limiting our patient's ambulation for 1 year [Figure 1]. To confirm the diagnosis of KS, an incisional biopsy was performed, confirming KS. And non-AIDS related KS was negative diagnosis from HIV blood test [Figure 2]. Our patient was not a candidate for systemic therapy due to comorbidities and high-toxicity risk. RT, as a single treatment, was carried out using a 6-MeV electron beam delivered by an Elekta Synergy Platform medical linear accelerator with one treatment field and 90% of the prescription dose, yielding a total dose of 50 Gy in 25 fractions (2 Gy/fraction).
|Figure 1: (a) Before radiotherapy treatment of a skin lesion located on the first and second toe and first web. (b) Treatment of the toe and web, with the patient's foot in the prone position and immobilized. (c) At 12 months following radiotherapy. The patient has maintained good extension and flexion of the toe with excellent strength|
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|Figure 2: Haphazardly oriented spindle cells proliferation with slit like space and extravasated RBCs. HEx100|
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| > Discussion|| |
RT has been shown to be effective for skin cancer. Orthovoltage therapy historically has been very effective for treating skin cancer but cannot treat deeper tumors without causing substantial skin toxicity. For these reasons, orthovoltage machines have since been replaced by higher-energy linear accelerators that can deliver high- and low-energy photons (4-6 MeV) that can effectively treat deeper lesions or curved surface lesions while also generating electrons in the treatment of superficial diseases. Since modern radiation facilities utilize linear accelerators, skin lesions are often treated with electrons. However, electrons can be less effective for lesions found on irregular surfaces such as the toes, resulting in dose inhomogeneities and potentially increased acute and chronic skin toxicities. When photons pass through a water box, scattered electrons are created and absorbed by the skin, thus generating a uniform dose distribution throughout the target volume. In the case of noncircumferential lesions, a strip of skin can also be spared using Cerrobend blocks, thus minimizing restriction of lymphatic flow in the toe.
RT has been used to treat KS and even more rarely, KP. Most studies of RT have reported only complete response rates, which are 60%–93% with local field RT, 70% with extended field RT, and 89% with megavoltage RT with a water bolus. Another study by Chang and Kim reported on 16 patients with non-AIDS-associated KS treated with a median RT dose of 36 Gy, and 16 patients treated with electron therapy. Complete and partial responses were observed in 2 (9%) and 19 (73%) lesions, respectively, while local failure occurred in 23% cases, and out-of-field recurrence occurred in 26%.
Caccialanza et al. treated 711 classic KS and 771 AIDS-associated KS lesions with traditional photon therapy. The total doses ranged from 10 to 40 Gy. In the classic KS group, complete and partial remission were achieved in 701 (98%) and 7 (1%) lesions, respectively, while 3 (1%) lesions were not evaluable. The cure rate was 99.4% at 5 years after RT completion, 99% at 10 years, and 98.7% at 13.5 years. For AIDS-associated KS, complete remission was observed in 705 (92%) lesions, partial remission in 52 (7%) lesions, and no response in 4 (1%) lesions. We also found three prospective studies in the literature.
Chang et al. reported a complete response in 39 (66%) lesions, a partial response with complete symptomatic relief in 15 (25%), and no response in 5 (8%). Only 6 of 59 (10%) lesions recurred in the RT field, with a median recurrence-free period of 8 months. Among the 33 epidemic KS lesions, 31 (94%) showed a complete response and 2 (6%) a partial response.
The optimal radiation dose to treat KS is uncertain. A prospective study comparing two doses of RT (8 versus 6 Gy) treated 203 total fields (51 in the 8 Gy group and 152 in the 6 Gy group) in 47 patients with KS.
In a study comparing the effects of a single dose of 6 Gy with 8 Gy, the complete response rate was better in the 8 Gy group, although the overall response and progression-free survival rates were not different between the groups. The 1-year local control rate was 93% in the first arm and 86% in the second arm. The corresponding 1-year complete response and progression-free survival rates were 93% versus 60% and 80% versus 88%, respectively, in the first versus second arm. Local recurrence was found in 7% of patients in both groups of Piccinno's study. Contact X-ray therapy and half-deep X-ray therapy were used to treat 594 lesions in 65 patients with KS. The total doses administered ranged from 5 to 45 Gy for contact X-ray therapy and 4 to 20 Gy for half-deep X-ray therapy. Complete remission was achieved with pigmentation in 405 (68%) lesions and with good cosmetic results in 105 (18%) lesions. In 80 (13.5%) lesions, only a size reduction or pain palliation was achieved. These lesions had an overall failure rate of 52% (11/21), with 25% recurring during the first 4 months of follow-up.
Seven cases of severe radionecrosis were noted, and all required amputation at the interdigital clefts. These lesions had a high incidence of subsequent regional and distant failure. Because there was no technical or dose information provided by the authors and no specific mention of in situ versus invasive lesions, it is difficult to compare these findings with those from our current series. Similar to that reported in Regnier's study, symptom control was achieved in 93% of lesions in this study. However, symptom relief was not included as one of the endpoints in some studies.
Our study suggests that this technique, when used to treat KS lesions on the toes, results in normal movement of the toes, even when treating a superficial irregular skin lesion obscured in locations such as between the toes and web.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed
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Conflicts of interest
There are no conflicts of interest.
| > References|| |
Chang Y, Cesarman E, Pessin MS, Lee F, Culpepper J, Knowles DM, et al.
Identification of herpesvirus-like DNA sequences in AIDS-associated Kaposi's sarcoma. Science 1994;266:1865-9.
Yildiz F, Genc M, Akyurek S, Cengiz M, Ozyar E, Selek U, et al.
Radiotherapy in the management of Kaposi's sarcoma: Comparison of 8 gy versus 6 gy. J Natl Med Assoc 2006;98:1136-9.
Tappero JW, Conant MA, Wolfe SF, Berger TG. Kaposi's sarcoma. Epidemiology, pathogenesis, histology, clinical spectrum, staging criteria and therapy. J Am Acad Dermatol 1993;28:371-95.
Chang JH, Kim IH. Role of radiotherapy in local control of non-AIDS associated Kaposi's sarcoma patients in Korea: A single institution experience. Radiat Oncol J 2012;30:153-7.
Régnier-Rosencher E, Guillot B, Dupin N. Treatments for classic Kaposi sarcoma: A systematic review of the literature. J Am Acad Dermatol 2013;68:313-31.
Caccialanza M, Marca S, Piccinno R, Eulisse G. Radiotherapy of classic and human immunodeficiency virus-related Kaposi's sarcoma: Results in 1482 lesions. J Eur Acad Dermatol Venereol 2008;22:297-302.
Huang KM, Hsu CH, Cheng JC, Lai MK, Jeng SC, Ting LL, et al.
Radiotherapy of classic Kaposi's sarcoma in Taiwan, an area where classic Kaposi's sarcoma is not prevalent. Anticancer Res 2006;26:4659-63.
Hauerstock D, Gerstein W, Vuong T. Results of radiation therapy for treatment of classic Kaposi sarcoma. J Cutan Med Surg 2009;13:18-21.
Choi KH, Byun JH, Lee JY, Cho BK, Park HJ. Kaposi sarcoma after corticosteroid therapy for idiopathic thrombocytopenic purpura. Ann Dermatol 2009;21:297-9.
Joo M, Soon Lee S, Jin Park H, Shin HS. Iatrogenic Kaposi's sarcoma following steroid therapy for nonspecific interstitial pneumonia with HHV-8 genotyping. Pathol Res Pract 2006;202:113-7.
Park SY, Ahn BS, Park JM, Ye SJ, Kim IH, Kim JI, et al.
Dosimetric comparison of 4 MeV and 6 MeV electron beams for total skin irradiation. Radiat Oncol 2014;9:197.
Chang LF, Reddy S, Shidnia H. Comparison of radiation therapy of classic and epidemic Kaposi's sarcoma. Am J Clin Oncol 1992;15:200-6.
Piccinno R, Caccialanza M, Cusini M. Role of radiotherapy in the treatment of epidemic Kaposi's sarcoma: Experience with sixty-five cases. J Am Acad Dermatol 1995;32:1000-3.
[Figure 1], [Figure 2]