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CT vs PET/CT chest scans for initial metastatic assessment of head and neck cancers

14 Jan 2019

By analysing nearly 152,000 cases of head and neck squamous cell carcinoma, researchers at Fox Chase Cancer Center determined that chest CT scans are an appropriate option for an initial distant metastasis (DM) workup in some stages of head and neck cancer

“We hypothesised that distant metastases are rare in head and neck cancer. Since the lungs are the most common site of metastases, we wanted to evaluate if a chest CT scan would be just as effective PET/CT scans for some patients,” said Jeffrey Liu, MD, FACS, an attending surgeon at Fox Chase who specialises in otolaryngology.

Liu is first author of the paper, “Patterns of distant metastasis in head and neck cancer at presentation: Implications for initial evaluation,” which was published in the January 2019 edition of the journal Oral Oncology.

The findings suggest that while PET/CT scans offer many advantages for initial evaluation of this disease, for example showing metabolic functional data to aid in the evaluation of any masses, given the pattern and frequency of DM in head and neck cancer, a CT chest scan may be just as effective for evaluation of DM.

Liu and his fellow researchers assessed data from the National Cancer Data Base from 2010 to 2015, focusing on cancers of the oral cavity, oropharynx, larynx, hypopharynx, and nasopharynx.

Their analysis showed that the nasopharynx had the highest percentage of DM disease (9.1 percent), followed by hypopharynx (7.3 percent).

Excluding the nasopharynx, 3.1 percent of all sites cases presented with DM. Advanced T-stage, positive N-stage, and N3 status were all predictors of DM on univariate and multivariate analysis for all subsites (P < 0.05). Where the site of metastasis was available, 53.1 percent of DM cases presented with at least lung involvement.

Among nasopharynx cancers, only 32.8 percent of DM included the lung.

“Our findings confirm that checking for distant metastasis in this group of patients using a chest CT instead of a PET/CT scan would save patients time and money, and spare them from a more involved procedure,” said Thomas Galloway, MD, chief of the Division of Head and Neck Radiation Oncology at Fox Chase, who contributed to the paper.

Current National Cancer Comprehensive Network (NCCN) guidelines recommend workup for distant metastatic disease for head and neck cancers, but do not indicate which specific imaging studies are recommended.

“PET/CT offers many other benefits, but its role in evaluating distant metastasis is most effective in advanced head and neck disease, the nasopharynx, and hypopharynx, where the risk of distant metastasis is elevated,” said Liu.

Source: Fox Chase Cancer Center