Researchers have started pilot clinical studies in head and neck cancer patients to determine if Raman spectroscopy, a noninvasive imaging technique, can effectively spare some patients of the toxic side effects of ineffective radiation therapy.

Researchers used the imaging technique and discovered differences between treatment-sensitive and treatment-resistant tumours in mice after radiation.

Their findings, published in Cancer Research, revealed statistically significant differences in lipid and collagen content that could potentially identify treatment-resistant tumours early in the therapeutic regimen.

"Identifying patients with radiation-resistant tumours prior to commencing treatment or immediately after it has begun would significantly improve response rates and help these patients avoid the toxic side effects of ineffective radiation therapy," said Narasimhan Rajaram, assistant professor of biomedical engineering at the University of Arkansas. "Our findings provide a rationale for translating these studies to patients with this as the ultimate goal."

Rajaram and Ishan Barman, assistant professor of mechanical engineering at Johns Hopkins University, used Raman spectroscopy, an optical fibre-based, non-invasive and highly specific imaging technique to map biomolecular changes in radiation-resistant and radiation-sensitive human lung tumours and two different types of head and neck tumours.

Their research team found that radiation-sensitive tumours had greater changes in the expression of lipids and collagen.

These changes were consistent across all tumours.

The human clinical trials are being conducted in partnership with the University of Arkansas for Medical Sciences (UAMS).

These findings follow a similar study published last year, in which Rajaram and a large interdisciplinary team of researchers at the University of Arkansas and UAMS used auto-fluorescence imaging to identify differences between the metabolic response of radiation-resistant and radiation-sensitive lung cancer cells after exposure to radiation and YC-1, a common chemotherapy drug.

Radiation is used, along with chemotherapy, to treat the majority of patients diagnosed with lung, head or neck cancers.

While these treatments can last up to seven weeks, there are no accepted methods to determine treatment response before or during the early stages of therapy, which means some patients undergo a full treatment regimen only to be identified later as non-responders.

The radiation-resistant and radiation-sensitive lung cancer cells used in this study were developed by Ruud Dings, assistant professor of radiation oncology and Robert Griffin, professor of radiation oncology at UAMS.

Histological evaluations of these tumours by Dr Matt Quick, associate professor of pathology at UAMS, were consistent with the Raman spectroscopic results.

Source:  University of Arkansas

Image credit: University of Arkansas / John Hopkins University / UAMS