Radioactive skin patch offers less-invasive treatment option for basal cell carcinoma

March 1, 2010

Basal cell carcinoma (BCC) can be treated in a less-invasive manner than surgery via a skin patch that delivers radiotherapy, according to research from India.

Key Points

According to Priyanka Gupta, B.Sc., P.G. D.M., M.Sc., a radiation technologist in the department of nuclear medicine at All India Institute of Medical Sciences, New Delhi, and principal investigator of the study, the site of a BCC can make surgical management a difficult option.

"The most common type of treatment is surgery, but it may be difficult, depending on the site or if there are multiple sites," Ms. Gupta says, noting BCC is the most common but least aggressive of all skin cancers. "It may not be easy to graft a surgical operation."

"The damage to surrounding tissues or organs is unavoidable," Ms. Gupta says.

The skin patch "treats the lesion by direct radiation," Ms. Gupta says, noting the patch releases radioactive phosphorus-32 containing 1 mCi/sq.cm. "We wanted to determine the efficacy of the radioactive skin patch."

Study design

In the study led by Ms. Gupta, investigators enrolled subjects who were at least 18 and who had a confirmed diagnosis of BCC via biopsy on one site.

Four males and four females participated in the study. Subjects had a mean age of 57.25, and a median age of 57.

Investigators excluded pregnant and lactating women from the study, as well as individuals who had a history of blood disorders, liver disorders or BCC on multiple sites.

Four of the study patients had lesions near their eyes, while three had lesions on their noses and one had a lesion on the forehead. No patients in the study had lesions that had spread to underlying structures.

"Patients who had lesions near their eyes were very hesitant about going in for surgery," Ms. Gupta notes. "For the patient who had a lesion on the forehead, the dermatologist indicated that skin grafting would be difficult for that case."

In addition, patients expressed concerns about the negative impact that surgery might have on their aesthetic appearance.

Patch details

The sealed patches, which included radioactive phosphorus-32 containing 1 mCi/sq.cm, varied in size and were designed to fit the size and shape of the individual lesions.

"The patches were prepared according to the size of the lesion," Ms. Gupta says. "We left a small margin to make sure the lesion was covered."

Before the patches were locally applied to the site of the lesions for three hours, investigators verified if there was any possible leakage. The patches were re-applied on the fourth/fifth and seventh/eighth day after the initial application, for three hours at each time point.

"The entire procedure was carried out on an outpatient basis, with no hospitalizations of patients required," Ms. Gupta explains. "Patients were followed up at one week, one month and three months to determine efficacy."

Follow-up

At each follow-up visit, a dermatologist performed a clinical assessment, with a biopsy being performed in addition to the assessment at three months. Biopsies were taken from the center and margins of the lesions, and they proved negative for residual disease.

There were no serious adverse events related to hematological or biochemical examinations of patients. Some adverse events that did occur in patients included mild erythema and dermatitis.

"These were probably due to the radiation, but these (adverse) events waned," Ms. Gupta says.

The lesions either flattened after three months, or there was complete clinical resolution of the lesion, according to Ms. Gupta.

"There was destruction of the basal cell carcinoma using this patch," she says. "We concluded that this radioactive patch is effective in treating superficial skin cancers like basal cell carcinoma."

Limitations

The limitations of Ms. Gupta's research include the sample size and a short follow-up period. "We only followed up patients for three months, and we need to follow them for a longer period," she says, noting that patients will be followed for two years to ensure there is no recurrence or effects of radiation.

"We also only had eight patients," she adds. "We definitely want to increase the sample size to have more patients."

Investigators chose phosphorus as the active component of the skin patch because phosphorus emits pure beta-radiation, thereby avoiding the release of gamma radiation. Phosphorus also was chosen because of its ready availability, according to Ms. Gupta.

"Studies have looked at the effect of chromium as well, and there have been good results with that as well," she adds.

Disclosures: Ms. Gupta reports no relevant financial interests.

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