A 11 year 4 month old FS Whippet was referred to discuss options for extensive solar induced cutaneous HAS and SCC lesions over the ventrum.

Patient presented on 4/5/23 to discuss options for recurrence and progression of multiple dermal actinic malignancies on the ventral chest and abdomen linked to sun bathing. On 30/1/23 she had an actinic haemangiosarcoma removed with 1mm margins on the ventral abdomen and a second actinic haemangioma lesion removed from the right sternum with 2mm margins. Now superficial, ulcerated dermal lesions diffusely over the ventrum and a larger solid raised and infiltrative mass over the midline.

Staging diagnostics with abdominal ultrasound and thoracic radiographs showed no evidence of metastatic or other disease. Given the extent of the disease and field effect associated with actinic neoplasia further surgery was not feasible and radiation therapy was discussed as the best option for local tumour control. Bloodwork (CBC/chemistry) was all within normal limits.

CT simulation was done on 9/5/23 with the patient in dorsal recumbency in a body moulded vacbag to ensure accurate positioning. Plan prescription was for 3x8Gy fractions to a diffuse ventral abdomen and chest wall region with a VMAT protocol. Treatment was delivered on 3 consecutive days between 10/5/23-12/5/23. She did well throughout therapy and was sent home with a course of amoxiclav 200mg BID.

3 days after completion of RT the patient presented for vomiting and diarrhoea. This coincided with the owner going away and staying with her carer. She was hospitalised on IV fluids, antibiotics and ant nausea meds and showed steady improvement with discharge after 4 days of conservative management. In that time there was mild erythema of the skin in the radiation field. She returned for recheck on 3/6/23 in good spirits with resolution of GI issues and notable improvement in her ventral abdominal skin lesions. Two weeks later (5 weeks post completion of RT) she presented doing very well at home with marked resolution of ventral skin lesions. A solitary central skin lesion persisted and was removed surgically on 21/7/23. The patient is now 5 months out with no evidence of progressive disease.