This study is a prospective observational study evaluating the natural history of coronary plaque burden in participants with melanoma treated with ICI. The study will be conducted at various sites across Australia.

Inclusion Criteria:

• Capable of providing informed consent and willing to adhere to all protocol requirements
• patients aged > or equal to 40 years
• Histologically confirmed melanoma of any stage planned for, commenced, or completed treatment with ICI
• having acceptable imaging quality deemed by the core laboratory
• Investigator believes that the participant is willing to adhere to all protocol requirements, including returning for follow up CTCA.

Exclusion Criteria:

• Known clinically manifest cardiovascular disease
• Female participants must not be pregnant, breastfeeding or plan to become pregnant during the study.
• Estimated glomerular filtration rate of <45 mL/min calculated using the Chronic Kidney Disease Epidemiology Collaboration equation
• Severe liver disease or cirrhosis
• History of any other malignancy within the past 5 years in addition to melanoma with the exception of non-melanoma skin cancers
• Prognostic factors associated with an expected survival less than 18 months at Investigators' discretion (e.g. unresectable brain metastases)
• Evidence of any other clinically significant non-cardiac disease or condition that, in the opinion of the Investigator, would preclude participation in the study
• Major allergy to iodine
• Participation in another clinical trial that does not allow participation in multiple trials at the same time

Patients aged 40 years and older with melanoma of any stage, who are planned for, currently receiving or have received treatment with an ICI may be considered for this study.

The Steering Committee will decide if and how IPD will be shared. It is expected that study Co Investigators will be able to access data once the primary results have been presented.