The purpose of this study is to determine whether Alkagin paste is effective at preventing radiodermatitis in patients receiving external beam radiation therapy to the perineal area.

Inclusion Criteria:

• Patients receiving a dose of 45 Gy or more with concomitant chemotherapy to the perineal skin (for treatment of anal canal, low rectal or gynecological cancer).
• Patients able to understand and sign an informed consent form.
• Patients that do not have active connective tissue disorders.
• Patients 18 years or older.
• Patients that did not receive any previous radiation.
• Patients that do not have any known allergy to any ingredients of the Alkagin Paste
• Patients need to be able to apply the creams themselves or have help with applying the creams.
• Patients who have been offered to purchase silver clear underpants but have refused

Exclusion Criteria:

• Patients that have a type V or type VI skin type according to the Fitzpatrick scale (because these patients will likely have less radiodermatitis and if they do, it will be harder to evaluate it)

The Fitzpatrick Scale:

• Type I (scores 0-7) White; very fair; freckles. Always burns, never tans

• Type II (scores 8-16) White; fair. Usually burns, tans with difficulty

• Type III (scores 17-25) Beige; very common. Sometimes mild burn, gradually tans

• Type IV (scores 25-30) Beige with a brown tint; typical Mediterranean Caucasian skin. Rarely burns, tans with ease

• Type V (scores over 30) Dark brown. Very rarely burns, tans very easily

• Type VI Black. Never burns, tans very easily

  2) Patients with an allergic reaction to Alkagin Paste