A combined positron emission tomography and computed tomography (PET-CT) imaging test conducted six to eight weeks after patient’s complete chemoradiotherapy for head and neck cancer may help identify patients who will respond to treatment and those who will require surgical follow-up. This was published in a report in the November issue of Archives of Otolaryngology-Head & Neck Surgery, one of the JAMA/Archives journals.
During the past two decades, chemoradiotherapy — combining chemotherapy and radiation treatments — has become significant in helping preserve organs while treating advanced head and neck cancers.
In the research study, thirty one patients with advanced-stage head and neck cancer who were treated with chemoradiotherapy between 2004 and 2006 were examined.
James P. Malone, M.D., of the Southern Illinois School of Medicine, Springfield, and colleagues examined all the 31 patients.
All the patients experienced combined positron emission tomography and computed tomography (PET-CT) to identify evidence of persistent tumors six to eight weeks after the completion of treatment and then were tracked for a median (midpoint) of 24 months.
Assessing the response of the tumor to treatment with PET-CT had a sensitivity (rate of true positives) of 83%, specificity (rate of true negatives) of 54%, positive predictive value (probability that patients who test positive have the disease) of 31% and negative predictive value (probability that patients who test negative do not have the disease) of 92%.
In the 21 patients (78%) whose disease had spread to surrounding lymph nodes before treatment, sensitivity was 75%; specificity, more than 94%; positive predictive value, more than 75%; and negative predictive value, 94%. For the ten (32%) whose cancer was located in the neck only, specificity was 92% and negative predictive value more than 92%.
“On the basis of this study, PET-CT performed six to eight weeks after the completion of intra-arterial chemoradiotherapy for advanced squamous cell carcinoma of the head and neck is a valuable tool for measuring treatment response and facilitating clinical decision making,” the researchers conclude. “In addition to early prediction of treatment response, PET-CT provides early detection of distant metastases, which permits earlier intervention in patients with distant disease. Further investigations of PET-CT in homogenously treated patient populations with consistent timing of post-treatment scans are necessary to more clearly elucidate the role of this imaging modality in the management of advanced squamous cell carcinoma of the head and neck.”