What is New in the Treatment of Eyelid Tumors with Radiation Therapy?

Abstract

EditorialMalignant tumors of the eyelids can cause considerable functional and aesthetic complications. Most common eyelid tumor is basal cell carcinoma (BCC) followed by squamous cell carcinoma, sebaceous gland carcinoma, Merkel cell carcinoma and malignant melanoma (rare) [1]. They can be located at lower eyelid (most common site) or upper eyelid, outer canthus and inner canthus. Surgical excision is the standard primary treatment option for the eyelid tumors. However, in cases with incompletely excised primary tumors, recurrent tumors, or inoperable large primary tumors and elderly patients who cannot tolerate general anesthesia with significant co-morbidities, radiation therapy (RT) is considered as an effective alternative/adjuvant treatment modality [2][3][4][5][6][7]. Different radiation therapeutic methods such as external beam radiotherapy (EBRT) with x-rays [superficial (45-100 Kv), orthovoltage (100-250 Kv)] or megavoltage photons & electrons and radionuclide plaque brachytherapy has been used to treat various eyelid tumors with good success [2][3][4][5][6][7][8][9]. However, acute and chronic radiation side-effects (skin reactions, eyelid telangiectasia, eyelid atrophy, eyelash loss (madarosis), epiphora (tearing), ocular surface disorders (dry eyes), cataract, radiation papillopathy, retinopathy & maculopathy and second malignant neoplasms) can lead to significant functional and visual disabilities. Recently new techniques to precisely deliver the radiation to the target tumor has been developed that prevent damage to the surrounding healthy tissues and cause minimal radiation toxicities. Currently, interstitial highdose-rate (HDR) brachytherapy and electronic surface brachytherapy (ESB) are the new techniques being used to treat various nonmelanoma skin malignancies including the eyelid carcinomas [10][11][12][13][14][15].Contact X-ray radiotherapy (50 kV) was used in the past to treat the small (<2 cm) eyelid tumors. At a dose of 42 Gray (Gy)/7 fractions/ 4 weeks, there was excellent regression of the tumors with long-term tumor control in 98%. However, loss of eye lashes, punctal stenosis, skin depigmentation was noticed even at doses of 1 or 2 fractions of 6 Gy per week. Also local tumor relapse was seen in few cases around the irradiated area. The cosmetic results were good with x-ray RT [2]. Following orthovoltage radiotherapy of medial canthal BCC, 10-year tumor control rate was 94% with no recurrence rates. However, patients developed significant complications within the radiation field such as madarosis, epiphora, ocular surface disorders and conjunctival scarring [3]. When eyelid tumors (1-4 cm size) were treated by electron beam therapy at a dose of 45-70 Gy in daily fractions of 2-4 Gy, though there was reasonable local tumor regression, few cases had recurrences (11%) and few had local radiation side effects such as skin atrophy and mild deformities [4].EBRT can be considered another option for treating the eyelid tumors [5][6][7]. Primary eyelid tumors when treated with median radiatio...