Radiation treatment to a postresection primary mucoepidermoid carcinoma (MEC) of the conjunctiva with positive margins at the Tenon's fascia-A case study

摘要: The primary occurrence of mucoepidermoid carcinoma (MEC) the conjunctiva is extremely rare, aggressive, and easily mistaken for squamous cell carcinoma. With fewer than 50 cases reported in literature, there no consensus on most effective treatment. Radiation an alternative to enucleation or orbital exenteration with potential eye preservation. We investigated several radiation approaches a case postresection positive margins at Tenon's fascia, patient's clinical course during treatment short time thereafter. An otherwise healthy 64-year-old male presented MEC extending deep margin fascia. Plans 4 different therapy modalities (Intensity Modulated Therapy [IMRT], Volumetric [VMAT], double scattering (DS) proton, reverse plaque low dose rate [LDR] ) were created compared based tumor coverage normal tissue doses. planning target volume (PTV) was too large nonuniform application. Using largest available (22 mm), calculated minimum PTV 57% while skin 1000% prescription. proton plan completely spared contralateral ocular structures reduced max doses ipsilateral macula optic nerve, but not clinically IMRT VMAT plans produced similar distributions each other, further minimized eye. Due uniqueness this case, thorough study options deemed necessary. All external beam techniques acceptable producing best case. patient treated prescription 6600 cGy 30 fractions. At 5 months post-treatment, recovering from expected acute responses follow ups scheduled.