Tongue cancer patients may choose an alternative way of assessing tumours that saves money and time, doctors have said.
University of Hong Kong medics suggest using an ultrasound scan instead of magnetic resonance imaging (MRI) to measure the thickness of tumours before treatment.
There are about 130 new cases of tongue cancer in Hong Kong each year, according to the Hospital Authority's cancer registry, and twice as many men as women suffer from the disease.
A study at Queen Mary Hospital, where ultrasound scans had been in use since 2001, found a 90 to 95 per cent accuracy rate in judging the size of tumours.
This is comparable to MRI, which costs 10 times as much and takes up to six times as long.
Ear, nose and throat specialist Anthony Yuen Po-wing said an ultrasound scan in a private clinic would cost a few hundred dollars and take five minutes, compared with thousands of dollars and 30 minutes for an MRI scan.
The hospital conducted the study on 45 patients from 2001 to 2006. Results are published in the international medical journal Head & Neck.
Professor Yuen said measuring a tumour's thickness was important because it helped surgeons choose the best treatment.
Tumours less than 3mm thick can be excised from the tongue. Those 4mm to 9mm thick may also require a neck dissection in which the lymph nodes and surrounding tissue are removed. Those 10mm thick or more are usually treated by excision and radiotherapy.
Smoking, drinking and chewing betel nuts can cause the cancer.