Intensity-modulated radiation therapy to bilateral lower limb extremities concurrently: a planning case study

Area of Science:

• Oncology
• Radiation Oncology
• Dermatology

Background:

• Non-melanoma skin cancers (NMSC) are prevalent in Australia, with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) being most common.
• A 71-year-old woman presented with extensive, tender superficial skin cancers on both lower limbs.

Purpose of the Study:

• To evaluate the feasibility and effectiveness of intensity-modulated radiation therapy (IMRT) for treating widespread NMSC on the extremities.
• To demonstrate IMRT as a viable alternative to surgery and conventional superficial radiation therapy for complex presentations.

Main Methods:

• Intensity-modulated radiation therapy (IMRT) was used, delivering 60 Gy to the planning target volume (PTV) with 1.0 cm bolus.
• A six-field beam arrangement was employed to minimize dose to surrounding tissues and avoid contralateral limb entry/exit.
• Treatment plans adhered to International Commission on Radiation Units and Measurements (ICRU) guidelines, with skin toxicity assessed using NCI: CTCAE v3.

Main Results:

• IMRT achieved highly conformal dose distributions and met ICRU guidelines.
• The treatment was well-tolerated, with excellent clinical outcomes despite the initial disease extent.
• Dosimetric results indicated effective target coverage and reduced toxicity to adjacent healthy tissues.

Conclusions:

• IMRT is a feasible and effective treatment modality for widespread superficial skin cancers on the extremities.
• This technique offers a valuable alternative to surgery and traditional radiation therapy for complex NMSC cases.
• IMRT provides conformal dose delivery, minimizing toxicity and achieving favorable outcomes in challenging patient presentations.