Referral

A 6-year-old female neutered staffy X referred for a right medial canthus MCT.

Patient History

Owner first saw the lesion 12 months earlier, but it grew significantly in the 2-3 weeks prior to consult. On presentation it was inflamed, and the patient had been rubbing at it. An FNA done on 26/1/2019 confirmed MCT. Given the difficult location of the lesion patient was referred to the oncology team for evaluation.

Diagnostics and Treatment Options

Based on the tumour location options discussed included, wide excision with enucleation and more marginal debulking and lid reconstruction with adjuvant radiation therapy to spare he eye. Staging diagnostics done on 1/2/2019 included thoracic radiographs and abdominal ultrasound which were both clear of disease. The owner elected to proceed with eye sparing option.

Plan

Debulking surgery with reconstruction flap was done by specialist ophthalmologist on 6/2/2019. Biopsy confirmed a high grade MCT with lateral margins 1mm. The patient did well and returned for suture removal on 18/2/2019. 1 additional week of wound healing was recommended prior to proceeding with radiation therapy. CT sim for radiation planning was done on 25/2/2019 and treatment commenced on 27/2/2019. She received 3 X 8Gy fractions to a total dose of 24Gy using 6MeV electrons. The eye was shielded with a special lead “contact lens’.

Outcome

Apart from periocular alopecia with mild dermal conjunctivitis, no significant adverse effects were noted. 3 months post treatment the hair began to grow back with no evidence of tumour regrowth and no ocular pathology post radiation therapy.

The last update on the patient was at 32 months post treatment with no evidence of recurrence and has since been lost to follow up.

Conformal electron radiation therapy (CERT) 3 day course of treatment to the right inner canthus (eye savage)

Electron radiation therapy was prescribed to post excision site

24Gyin 3 fractions to the Target volume

Electron energy: 6 MeV

4cm electron cutout 1cm skin bolus Internal eye shield

15 minute treatment time including setup with insertion of internal eye shield