A new and highly-precise radiotherapy technique has been shown to produce greater survival rates in patients with inoperable lung cancer compared to conventional radiotherapy.

Stereotactic Ablative Body Radiotherapy (SABR) was found to be more effective for patients in the head-to-head CHISEL study, which was led by Peter Mac and run by TROG Cancer Research.

SABR is a new, highly-targeted technique for delivering very high radiotherapy doses targeted at a patient’s tumour. The high doses ensure patients complete their treatment sooner than for conventional radiotherapy, as the required dose can be given over fewer trips to hospital.

The CHISEL study was a Phase III clinical trial involving 101 patients with inoperable early-stage Non-Small Cell Lung Cancer, from Australia and New Zealand, and who were randomised to receive either SABR or conventional radiotherapy. 

Peter Mac’s Professor David Ball headed the trial, and its practice-changing results are published online today by the journal Lancet Oncology. 

“Our trial found that for patients with early-stage lung cancer, SABR was more effective in controlling cancer growth, resulting in longer life expectancy and is just as safe as traditional radiotherapy,” says Prof Ball who is Peter Mac’s Director of Lung Cancer Service. 

“We found that 89% of cancers were controlled two years after SABR treatment and this compared to 65% for conventional radiotherapy, and there was also a clear benefit in overall survival.”

Professor David Ball explains to patient Maureen Chrul how the Linac machine delivers SABR.

After two years, 77% of the patients who received SABR treatment were surviving compared to 59% of those who received conventional radiotherapy.

Conventional radiotherapy for this cancer requires the patient to return to hospital regularly over six or seven weeks to receive their required radiation dose in small amounts. With SABR, the same treatment is delivered in a more concentrated dose - and in a highly-targeted way - requiring only three to four visits to hospital over around two weeks.

“As the SABR technique is much more precise, only the cancer is treated and the surrounding healthy tissue is unaffected,” Prof Ball says.

“Not only is the treatment more effective, but it is more convenient with fewer hospital attendances which is a significant bonus.” 

The trial, which began in 2010, is the first to demonstrate a survival benefit from SABR in non-small cell lung cancer. 

Peter Mac patient Maureen Chrul, of Melbourne, received SABR as part of the trial and also experienced conventional radiation therapy for another cancer treatment.

“I didn’t have any side effects with the SABR technique and I had just three treatments, which was much better than the six weeks of radiation treatment I had to treat another lung tumour,” Ms Chrul says.

This trial was a collaboration involving TROG Cancer Research and the Australasian Lung Cancer Trials Group (ALTG).  The trial was funded with grants from Cancer Australia, The Cancer Society of New Zealand and the Cancer Research Trust New Zealand.

Read the full paper in Lancet Oncology.

About TROG Cancer Research

TROG Cancer Research is a global leader in the field of cancer clinical trials research, working to improve the way in which radiation treatment is delivered, improving outcomes and quality of life for cancer patients. Working with more than 70 cancer treatment centres and hospitals across Australia and New Zealand, TROG has conducted more than 100 clinical trials with the help of 14,500 patient volunteers.

About non-small cell lung cancer (NSCLC)

This is the most common type of lung cancer, accounting for around 80% of cases. There are sub-types of NSCLC, the most common being 1. Adenocarcinoma - Begins in mucus-producing cells and makes up about 40% of lung cancers. While commonly diagnosed in current or former smokers, it is also the most common lung cancer in non-smokers. 2. Squamous cell (epidermoid) carcinoma - Commonly develops in the larger airways of the lung. 3. Large cell undifferentiated carcinoma - can appear in any part of the lung and are not clearly squamous cell or adenocarcinoma. A person’s prognosis depends on the type and stage of cancer as well as their age and general health at time of diagnosis. More: https://www.cancer.org.au/about-cancer/types-of-cancer/lung-cancer.html