Electron beam radiotherapy for Kaposi's sarcoma of the toe and web.

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.

A woman with a dangling digit.

Ainhum (dactylolysis spontanea) is a distinct clinical and radiological disorder of dark-skinned people characterized by a progressive development of a constricting band encircling the toe which usually results in spontaneous amputation. Ainhum mainly occurs in African natives, but in times of global migration and tourism, Ainhum is likely to be more often encountered outside Africa. Even though the clinical presentation can mimic more common entities such as arthritis and trauma, the correct diagnosis and treatment is easy if one knows this unusual entity.

Rewarming index of the lower leg assessed by infrared thermography in adolescents with type 1 diabetes mellitus.

The aim of this study was to determine whether infrared thermography before and after challenge of the lower leg in cold water may be a useful tool to detect abnormalities in skin blood flow in adolescent asymptomatic patients with type 1 diabetes mellitus (DM1) and to assess the optimal setting of skin temperature measurements. Twenty-five adolescents (10 female, 15 male, mean age 21.2 +/- 6.2 years, body mass index [BMI] 23.0 +/- 2.1 kg/m2) with a duration of DMI of 13.8 +/- 5.4 years and mean HbA1c levels 8.5 +/- 1.3% were compared to age- and sex-matched controls (BMI 22.9 +/- 2.2 kg/m2). Seven defined sites of the lower leg were assessed by infrared thermography before and for 10 min after exposure of the leg to 14 degrees C cold water. As skin temperature before exposure to cold water differs from individual to individual and basal temperature was significantly warmer in patients at the tip of the first (p < 0.05) and fifth (p < 0.05) toe, the rewarming index was calculated in order to compare data. Rewarming indexes of skin temperature during the whole measurement procedure (0-10 min) were significantly lower at the tip of the first (p < 0.05) and fifth (p < 0.01) toes and from minute 2-10 also at the inner ankle (p < 0.05) in patients compared to healthy controls. Rewarming indexes of the other four sites were not significantly different between patients and controls. Infrared thermography of the lower leg after cold water exposure is an easily applicable method and a useful tool to detect abnormalities of skin blood flow in adolescents with DM1 especially at the tips of the first and fifth toes and the inner ankle.

A method for total skin electron treatment for infants.

Diseases such as mycosis fungoides require the treatment of a patient's total skin surface with superficial radiation. In a unique clinical situation, a 14-month-old child presented with a need for total skin treatment. A typical total skin technique requires overlapping electron beams, using 6 body positions, each with the gantry rotated for 2 angulations, or '6 positions-12 fields'. Adaptation of this technique for infants is complicated by the small diameter of some body parts, and by the necessity to treat while the patient is anesthetized. Even degraded, low energy electrons can easily penetrate fingers and toes. Therefore, dose from 6 positions becomes additive, and the total dose to small circumferences can be 3 to 4 times more than skin dose on the torso, raising concerns about uneven bone growth in the developing child. Special phantoms were designed for extensive dosimetry needed to determine both dose rate and dose summation from the overlapping beams. Computerized electron pencil beam calculations were compared to TLD measurements. Unique compensating techniques were used to deliver uniform dose. A modification of the 6 position-12 field technique will be described; and accessories used to reduce high dose regions will be illustrated.

A radiation accident at an industrial accelerator facility.

On 11 December 1991, a radiation overexposure occurred at an industrial radiation facility in Maryland. The radiation source was a 3-MV potential drop accelerator designed to produce high electron beam currents for materials-processing applications. This accelerator is capable of producing a 25 milliampere swept electron beam that is scanned over a width of 112.5 cm and which emerges from the accelerator vacuum system through a titanium double window assembly. During maintenance on the lower window pressure plate, an operator placed his hands, head, and feet in the beam. This was done with the filament voltage of the electron source turned "off," but with the full accelerating potential on the high voltage terminal. The operator's body, especially his extremities and head, were exposed to electron dark current. In an attempt to reconstruct the accident, radiochromic film and alanine measurements were made with the accelerator operated at two beam currents. Measured dose rates ranged from approximately 40 cGy s-1 inside the victim's shoe to 1,300 cGy s-1 at the hand position. Approximately 3 mo after the accident, it was necessary to amputate the four digits of the victim's right hand and most of the four digits of his left hand. Electron paramagnetic resonance spectrometry, which measures the concentration of radiation-induced paramagnetic centers in calcified tissues, was used to estimate the dose to the victim's extremities. A mean dose estimate of 55.0 +/- 3.5 Gy (95% confidence level) averaged over the mass of the bone was obtained for the victim's left middle finger (middle phalanx).