Sexual dysfunction is a common toxicity and detrimental for the quality of life of women treated with
chemoradiotherapy for
anal cancer. Sexual dysfunction occurs because the vagina is closely approximated to the anal canal and typically receives substantial doses of radiation. Strategies for mitigation have largely been focused on posttreatment
therapy and symptom management. The use of daily vaginal dilator placement during
radiotherapy to mitigate dose to the vagina has been previously explored with modest gains, while
proton therapy is under active investigation for the treatment of
anal cancer. Use of
proton therapy for
anal cancer reduces dose to some organs at risk but may inadvertently increase vaginal toxicity if the
proton beam terminates in the vaginal tissue. Herein, we present the case histories of 2 women treated for
squamous cell carcinoma of the anal canal with the novel combination of intensity-modulated
proton therapy and daily vaginal dilator placement to maximally reduce dose to the vagina and
protect it from areas of increased energy deposition at the end of the
proton range.