With hopes rising that a North West Radiotherapy Unit will be up and running within four years, public meetings are taking place over the next two days in Derry and Letterkenny to update people on what progress is being made.
The Western Trust and the HSE will brief medical professionals, campaign groups and members of the public.
The joint letter is signed by Western Health and Social Care Trust Chief Executive Elaine Way and Letterkenny General Hospital manager Sean Murphy, inviting stakeholder groups and members of the public to the meetings.
Tonight's meeting takes place in the MDEC Building at Altnagelvin Hospital in Derry, while tomorrow's meeting will be in the conference room of Letterkenny General Hospital.
The invitation letter says the meeting will provide an update on progress with the proposed unit at Altnegelvin.
Last month, Health Minister Edwin Poots told the assembly that construction of the unit at Altnagelvin should commence next year, with a view to the unit being fully operational by 2016.