Endobronchial brachytherapy is underused for the palliation of symptoms in end-stage lung cancer despite its high response rate and low toxicity, NSW research suggests.
According to a review of 95 procedures performed in 86 patients at St George Hospital, Sydney, between 1997 and 2016, the overall response rate was 73%.
Patients with haemoptysis responded particularly well to endobronchial brachytherapy with a 92% clinical response rate.
Other patients presenting with symptoms of air obstruction such as chronic cough or dyspnea, comprising 85% of the study population, had a response rate of 71%.
And while delivered as a palliative treatment, patients who had a response to brachytherapy had a significantly longer survival than patients who did not respond (14 v 4 months).
The researchers suggest the survival benefit could be explained by a delay in terminal events such as fatal haemoptysis or pneumonia secondary to airway obstruction.
Their study also found that patients with metastatic disease were more likely to respond to brachytherapy than those with primary lung cancer.
As well, patients who had received previous external beam radiotherapy (EBRT) with a palliative intent were more likely to respond to subsequent brachytherapy than those who had received EBRT with a curative intent.
Other factors such as location of the lesion or brachytherapy modality – pulsed dose rate versus high dose rate – were not associated with response rate.
The study found toxicities were largely limited to mild and transient exacerbation of cough, likely due to catheter irritation or radiation bronchitis.
The researchers said referrals for endobronchial brachytherapy had declined substantially in recent years.
Dr Matthew Knox, from the hospital’s department of radiation oncology, told the limbic there were practical issues in accessing endobronchial brachytherapy due to the multiple specialties involved.
“It’s a very niche procedure and there are logistical issues associated with it. It’s certainly not something that every radiotherapy centre could offer but in a high output brachytherapy centre like St George, where we run a dedicated prostate unit, it’s quite easy for us to implement.”
He said for medically stable patients, endobronchial brachytherapy was a day procedure with the radiation delivered in about five minutes.
“There are a niche cohort who have previously had high dose EBRT and are told there is no further radiotherapy option yet endobronchial brachytherapy would benefit them.”
“It’s all about patient selection so respiratory physicians can try cryotherapy and laser and if that doesn’t work then consider a referral to us and we are happy to review.”
“We were even a little bit surprised at the high degree of efficacy, particularly in stopping haemoptysis.”
Dr Knox said medical palliation of haemoptysis with tranexamic acid was not as effective as radiotherapy.
He added there was some interest in trialling combinations of therapies such as cryotherapy and brachytherapy to find an optimal way to manage lung cancer patients.
“These patients are going to have to live with these problems for quite a while and it should be considered as routine to refer for radiation and then we can consider which mode of radiation would be most appropriate.”