Definitive radiation therapy should be recommended for primary keratinocyte cancer in patients who have declined or have contraindications for conventional surgery, and for cases of persistent, recurrent or advanced keratinocyte cancer where adjuvant radiation can complement surgery to improve control rates (Cancer Council Australia Keratinocyte Cancers Guideline Working Party 2019). Radiation therapy is also an important local modality in the palliative setting. Radiation therapy may also be the primary treatment for appropriate histologically proven tumours, usually where other treatment modalities are less appropriate.

For lesions that will be treated by radiotherapy alone, a confirmatory biopsy is advisable.

Clinical scenarios where patients with keratinocyte cancer may benefit from radiation therapy include the following.

Definitive radiation therapy:

• patients unsuitable for surgery
• where surgery creates significant functional and/or aesthetic morbidity that is unacceptable to the patient (e.g. near the lip, eyes or nose).

Adjuvant radiation therapy:

• patients with incompletely excised keratinocyte cancer where re-excision would result in significant morbidity; adjuvant radiation therapy provides comparable control rates to re-excision and may be a good alternative in these scenarios (Cancer Council Australia Keratinocyte Cancers Guideline Working Party 2019)
• patients with locally advanced or node-positive disease
• patients with neurotropic or recurrent lesions.

Symptom palliation:

• bleeding, fungating, rapidly growing or painful skin lesions.

If the excision specimen shows evidence of perineural invasion (PNI) in more than one nerve, in nerves larger than 0.1 mm or evidence of PNI extending away from the main tumour mass, the patient should be referred for an opinion about postoperative radiotherapy because these patients are at higher risk of local recurrence.

Timeframe for starting treatment

Adjuvant radiation therapy should start as soon as possible once the surgical wounds have healed, usually within four to six weeks of surgery.

Training and experience required of the appropriate specialists

The appropriate specialist should be a radiation oncologist (FRANZCR) with adequate training and experience, institutional credentialing and agreed scope of practice in keratinocyte cancer.

The training and experience of the radiation oncologist should be documented.

Health service unit characteristics

To provide safe and quality care for patients having radiation therapy, health services should have these features:

• linear accelerator (LINAC) capable of image-guided radiation therapy (IGRT)
• dedicated CT planning
• access to MRI and PET imaging
• automatic record-verify of all radiation treatments delivered
• a treatment planning system
• trained medical physicists, radiation therapists and nurses with radiation therapy experience
• coordination for combined therapy with systemic therapy, especially where facilities are not co-located
• participation in Australian Clinical Dosimetry Service audits
• an incident management system linked with a quality management system.