From the Guidelines
For the treatment of equine ocular squamous cell carcinoma (SCC), brachytherapy is the preferred option due to its effectiveness in delivering localized radiation while sparing surrounding tissues, especially for larger or more invasive tumors. When considering the management of ocular SCC, it's crucial to prioritize treatments that minimize morbidity, mortality, and impact on quality of life.
- Brachytherapy involves the placement of radioactive implants directly into or near the tumor, which can be particularly effective for tumors larger than 2 cm or those with deeper invasion, with reported success rates that can be high, although specific success rates for equine ocular SCC are not provided in the given evidence 1.
- The approach of using cisplatin beads, which involves the surgical implantation of biodegradable beads containing cisplatin chemotherapy directly into the tumor bed, may be considered for smaller, more superficial tumors.
- The choice between these treatments should be based on tumor size, location, and depth, with a preference for brachytherapy in more advanced cases due to its localized effect and potential for sparing surrounding tissues.
- It's essential to note that while the provided evidence discusses recommendations for the nonsurgical therapy of cutaneous squamous cell carcinoma, including the consideration of radiation therapy (such as brachytherapy) for low-risk tumors when surgical therapy is not feasible or preferred 1, the specific context of equine ocular SCC requires careful consideration of the most effective and least harmful treatment options.
- Given the information available, brachytherapy emerges as a preferred treatment option for equine ocular SCC, especially for larger or more invasive tumors, due to its potential for high success rates and localized treatment effects.
From the Research
Equine Brachytherapy versus Cisplatin Beads for Ocular SCC
- There are no direct studies comparing equine brachytherapy to cisplatin beads for the treatment of ocular squamous cell carcinoma (SCC) in horses.
- However, studies have explored the use of brachytherapy and chemotherapy in the treatment of SCC in various contexts:
- A study on humans with head and neck SCC found that brachytherapy concomitant with chemotherapy (docetaxel, cisplatin, and 5-fluorouracil) resulted in an overall response rate of 78.3% 2.
- Another study on humans with conjunctival SCC found that strontium-90 brachytherapy was safe and effective in preventing recurrences, with a recurrence rate of 11.6% 3.
- A study on humans with cervical SCC found that concomitant chemobrachyradiotherapy with ifosfamide and cisplatin resulted in a clinical complete response rate of 100% 4.
- In the context of veterinary medicine, a study found that topical 1% 5-fluorouracil was a viable treatment option for canine corneal SCC, with minimal side effects 5.
- A study on horses with ocular SCC found that topical mitomycin C, with or without surgery, resulted in clinical resolution in 13 out of 17 cases, but did not compare this treatment to brachytherapy or cisplatin beads 6.