Palmerston North radiation therapists have joined their Waikato counterparts in settling their industrial dispute, meaning only Auckland cancer patients will be affected by next week's strike.

The therapists' union, Apex, claims the Auckland District Health Board is "playing games" in not settling the pay dispute.

Therapists at Palmerston North and Waikato have agreed to a minimum starting rate of $40,000 - instead of about $32,000 - and a pay rise up to 20 per cent.

Poor pay has led to a national shortage in radiation therapists and long waiting times for radiation therapy, prompting the Government to send patients to Australia to clear the backlog. Most radiation therapist graduates in the past two years have taken better-paid jobs overseas.

Apex national secretary Dr Deborah Powell said the new starting rate would keep graduates in New Zealand and begin to entice others back.

But she said Apex had found the Auckland District Health Board and its chief operating officer, Neil Woodhams, difficult to deal with.

"Waikato settled in five hours, Palmerston North took six. Auckland is playing games."

Dr Powell would not elaborate on the point of conflict with Auckland, but said when Auckland was negotiating for all three health boards there was no movement.

Auckland radiation therapists will strike from 5.30 pm on Tuesday until the following Monday.

Mr Woodhams said Auckland was considering its position and would meet the union on Monday.

He said Auckland was in a unique position because it had the largest radiation unit in the country and would also have a full complement of 48 staff in March.

An Auckland cancer patient and retired doctor, who did not want to be named, told the Weekend Herald that he would miss the last of his 15 treatments on Wednesday if the strike continued.

"Nobody knows for certain what effect it will have but nobody can tell me it's good for me either."