Microwave Treatment for Actinic Keratosis

Inclusion Criteria:

1. Provision of signed and dated informed consent form.
2. Stated willingness to comply with all study procedures and availability for the duration of the study.
3. Age 18-85 years inclusive (EU); 22-85 years inclusive (US).
4. AK lesions for randomization in this study: Clinical diagnosis by a dermatologist of precancerous Actinic Keratosis.
5. Cutaneous location.
6. 10, 12 or 14 distinct AK lesions (3-6mm in diameter inclusive), for randomization in this study, located on the subjects' scalp or hands (AK lesions on the scalp and hands for randomization cannot be mixed).

   * There must be at least 2 AK lesions on the left and right side of the scalp or left and right hand.
   * An even number of distinct AK lesions (10, 12 or 14) are to be selected.
   * The maximum possible number of available distinct AK lesions should be selected (10, 12 or 14).
   * The subject may present with any number of AK lesions, however only 10, 12 or 14 distinct AK lesions will be selected for randomization. For example, if a subject presents with 21 AK lesions, an even number of distinct AK lesions are to be selected (i.e. 14 distinct AK lesions with at least 2 distinct AK lesions on the left and right side of the scalp or left and right hand).
7. If currently receiving treatment for Actinic Keratosis, agree to stop their current medication for at least 28 days prior to the start of study treatment.
8. Agrees to refrain from using any other Actinic Keratosis products or treatments during the study period, unless specified by the Investigator.
9. Agrees to refrain from using any topical metallic or ionic treatment (e.g., aluminum chloride, silver nitrate, zinc oxide) during the study period.
10. Free of any disease state or condition which, in the investigator's opinion, could impair evaluation of AK or could expose the subject to an unacceptable risk by study participation.
11. Able to perform study assessments.

Exclusion Criteria:

1. AK lesions at potential treatment sites on lip, nose crease, near eyes or ear.
2. Confluent AK associated with field change at potential treatment sites.
3. Fewer than 2 AK lesions on the left and right side of the scalp or left and right hand.
4. AK lesions at potential treatment sites assessed as clinically ambiguous.
5. Implantable Cardioverter Defibrillator (ICD), pacemaker or other implantable electronic devices.
6. Metal implants at site of treatment.
7. Known allergy or intolerance to microwave therapy.
8. Unstable co-morbidities (cardiovascular disease, active malignancy, vasculopathy, inflammatory arthritis).
9. Previous history of skin cancer in the study treatment or observation area.
10. Previous history of squamous cell carcinoma (SCC) or keratoacanthoma (KA) in any location.
11. Pregnancy or breast feeding.
12. Participating in another interventional study or have done so within the last 30 days.
13. Anticipated relocation or extensive travel outside of the local study area preventing compliance with study procedures.
14. Circulatory conditions affecting the acral areas - peripheral vascular disease, peripheral ischemia, vasculitis, Raynaud's, or related conditions.
15. Peripheral neuropathy.
16. Subject who is immunosuppressed (organ transplant recipients, hematologic malignancies, HIV).
17. Subject who has had any topical metallic or ionic treatment (e.g, aluminum chloride, silver nitrate, zinc oxide) within the last 6 months at potential treatment sites.
18. Subjects with AK on the scalp and who have hearing aid(s) and are unable or unwilling to remove hearing aids prior to microwave treatment.