Introduction
The keloids are benign dermal fibro-proliferative tumors developed as a fibrotic scar during wound healing process at the site of surgery or trauma. They most commonly occur at high skin tension areas.
Therapies
- Medical therapies like verapamil, cyclosporin, D Penicillamine.
- Other options: Laser therapy, cryotherapy. Pain and depigmentation are the most common adverse effects.
- Photodynamic Therapy is a safe procedure but recuurence rate is high.
- External RT is a non invasive procedure but is asssociated with risk involving long term cosmetic problems and high recurrence rate.
- An intralesional injection of INF-alpha2b, INF-Gamma and other drugs like tamoxifen, 5FU, to inhibit collagenase activity, until the scar flattening has also been used with varaible success.
PATCH Therapy
Exterrnal radiation therapy using custom made locally applied radioactive patch is a new approach to treat superficial skin disease like basal cell carcinoma and keloids.
Beta emitters have been used because they have high linear energy transfer (LET) and low tissue penetration.
For better cosmetic results, high dose brachytherapy combined with surgical excision is the treatment of choice.
Radionuclides:
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Ho-166 skin patches have been reported to be safe and effective for the treatment of patients with superficial squamous cell carcinoma, basal cell carcinoma and Bowen’s disease.
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P-32 patch has been reported to treat patients having keloids and hypertrophic lesions with total remission in some cases
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Re-188 patch and creams have been prepared and demonstrated the usefulness of the patch for the treatment of skin cancer.
Advantages of using Re-188 for Patch therapy
- Re-188 is a generator produced beta emitting radionuclide having half life of 16.9hrs, maximum beta energy of 2.1Mev and maximum tissue range of 11mm.
- The availability of generator offers the ease to use the isotope on routine basis and performs treatment as an OPD procedure.
- Re-188 suitable to be used for keloid treatment due to high linear energy tranfer and low tissue penetration.
- Re-188 coated patch delivers uniform beta radiation to the keloidal lesions and minimum dose to the surrounding tissue.
- This methoid of using customised patch for therapy overcomes the disadvantages of external beam radiation therapy and allows flexibility in delivering the desired radiation dose to the keloid lesion.
- Measurements of activity required for patch preparation is easy with Re-188, and difficult and cumbersome for P-32 which is a pure Beta emitter.
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