Equipment is lying idle, according to the survey

A survey by the Society of Radiographers also indicates that equipment is lying idle because there is no-one to operate it.

Hospitals also said they were unable to recruit and retain professional staff.

BBC social affairs editor Niall Dickson says cancer services have improved in recent years but the survey shows that seriously ill patients are still suffering.

Responding to the findings, Health Minister John Hutton, insisted the government was making progress in improving performance on combating cancer.

"The NHS has never had enough radiographers, that is absolutely true and we have never provided a good enough service for people who have cancer," he told the Today programme.

There's no question that we are somehow going to go soft on this Health minister John Hutton

"When we came into office in 1997 only 60% of (cancer) patients were seen by a specialist within two weeks, now it is very nearly 100%.

"We are making progress, there are more radiographers in the NHS than ever before. We have some of the most modern equipment of any health care system in Europe now being put into place.

"There's no question that we are somehow going to go soft on this."

Severe shortage

Around half of the radiotherapy departments in Britain responded to the survey.

Just one third of them were treating women with breast cancer within the recommended time, and other patients fared no better.

Our correspondent says a severe shortage of radiographers is at the heart of the problem.

More are being trained, but the Royal College of Radiologists believes some cancer patients are dying while the shortage remains, and it predicts the pressures will continue.

'Bottleneck'

News of the shortage follows a report last August, which said that almost half a million cancer patients were being forced to wait for important scans at NHS hospitals.

The independent watchdog the Audit Commission blamed shortages in equipment and staff, and inefficient use of machines for delays at hospitals across England and Wales.

It said the situation was causing a "bottleneck" in the NHS and preventing many patients from getting the medical care they needed.

The government is to trying to cut the length of time patients with cancer wait for treatment.

All patients with suspected cancer should currently receive a hospital appointment within two weeks of being referred by their GP.

Figures published in March showed 98% of patients were seen within this time.