Additional PET/CT alters treatment, predicts survival for certain cancer patients

Oral cavity squamous cell carcinoma (OSCC) is a painful and debilitating cancer. Another PET/CT after surgery and before adjuvant therapy could improve survival for these patients, according to a study published in the Journal of Nuclear Medicine.

Tzu-Chen Yen, MD, PhD, from the department of nuclear medicine, Chang Gung Memorial Hospital at Linkou in Taoyuan, Taiwan, and colleagues aimed to find out if additional PET/CT could restage disease and improve cancer management with either radiotherapy or chemoradiotherapy in a large population study set in Taiwan.

“Despite public health policies aimed at reducing common risky oral habits (e.g., alcohol drinking, betel nut chewing, and cigarette smoking), the incidence of OSCC in the Taiwanese population rose steeply by 30 percent in the last five years,” wrote Yen et al. “Because of its adverse functional, cosmetic, and prognostic impact, OSCC poses a serious threat to public health and health care systems, and carries heavy personal and societal costs.”

For this study, researchers evaluated 674 patients with OSCC who had been administered adjuvant therapy following surgery, and 136 of these had another PET/CT prior to therapy. The patients from the PET group and those who did not receive an additional scan were observed and disease-free survival (DFS) and disease-specific survival rates (DSS) over a two-year period were quantified by statistical analysis.

Findings of the study revealed 80 percent DFS for those who received an additional PET vs. 70 percent for those who did not. Lymphatic involvement and extracapsuler spread were independent risk factors and predictive of DFS as well as DSS for those who underwent PET prior to therapy.

Changes in treatment plans occurred in 14 percent of patients due to the results of pretreatment PET/CT. Of these, 15 were treated to cure because of the location of disease focused in one area, whereas four received palliative treatment because of metastatic disease. Seven of the 15 patients are still alive today.

“An additional pre-RT/CCRT PET/CT scan may be justified for patients with advanced OSCC who present with extracapsular spread or lymphatic invasion,” the researchers concluded.