Patients in the greater Auckland region now have access to the latest equipment used in the diagnosis and treatment of cancers of the upper gastrointestinal tract and lung.



Photograph Left to right: Staff Nurses Victoria Alzate and Rebecca Trembath, and Dr Russell Walmsley

Capital investment from the Waitemata District Health Board and a training grant from the Genesis Oncology Trust have resulted in the establishment of an Endoscopic Ultrasound, or EUS, service at North Shore Hospital.

Dr Russell Walmsley of the North Shore Hospital's Gastroenterology Department is the only specialist in the Auckland area qualified in EUS. He hopes ultimately to train others in the advanced technology which provides more accurate information about the cancer and safer tissue sampling.

"Conventional ultrasound is from the outside in, like in the scans of pregnant women," he says. "However, with EUS we pass the ultrasound camera down the oesophagus into the stomach and the images obtained are from the inside out. This reduces interference and allows us to get closer to the tumour, greatly increasing the quality and diagnostic value of the image as well as allowing tissue samples to be taken from suspect masses or lymph nodes with very few complications."

Dr Walmsley says he estimates about 230 patients will benefit from the new equipment each year. Although these are mainly North Shore patients, he has had referrals from other Auckland hospitals and from Christchurch, Rotorua and Northland.

He says the key to obtaining the best outcomes for cancer patients is accurate diagnosis and staging of the tumour.

Staging refers to the size, appearance and spread of the tumour and the "TNM" system is used - T0-4 for the size of the primary tumour, N0-3 for the involvement of regional lymph nodes and M0-1 for metastases (secondary tumours). So a cancer described as T1 N0 M0 indicates a small tumour, without lymph node involvement and no spread to other parts of the body, while a T4 N3 M1 staging indicates advanced cancer.

Of course there are many grades in between and the oncologist relies heavily on this information to design treatment regimens. A T1 N0 M0 tumour might be simply cut out without no further treatment while the best option for a patient presenting with T4 N3 M1 cancer might be the development of a palliative care plan.

Gathering this diagnostic information can involve a range of specialists and techniques - and might include biopsy, laboratory analysis, X-rays, CAT and MRI scans, and ultrasound. Endoscopic Ultrasound has been developed over the past 20 years and has now become an obligatory aid in the therapeutic decision making process for cancers of the oesophagus, stomach and pancreas.

Obtaining the ultrasound images is the relatively easy part of EUS, it is interpretation of the pictures requires skill and experience.

'When you introduce a new medical procedure you need to use it in parallel with existing technologies until you are certain that the new procedure is at least as good as that which it is designed to replace or supplement," says Dr Walmsley,

"In the case of EUS, once we had the equipment the small New Zealand population meant that it would have taken several years to see sufficient patients to allow us to be confident in our interpretation of the images. The answer was to spend time in the world-renowned endoscopy unit at the Chinese University of Hong Kong where they perform dozens of EUS procedures a week."

The plan was for Dr Walmsley to use the Genesis Oncology Trust grant to spend two 10-week spells in Hong Kong. Unfortunately the first of these training visits was cut short by the SARS epidemic, but to compensate Dr YT Lee from Hong Kong came down to New Zealand to provide in-situ training.

Says Dr Walmsley, "the support provided by the Trust and our colleagues in Hong Kong has been fantastic. Our EUS unit is now fully operational and already our patients are benefiting from more accurate diagnosis. There are also cost benefits to EUS and by giving the most appropriate treatment and, more importantly, avoiding unnecessary treatment a significant number of bed-days will be saved."