TORONTO--The use of whole-body fluorine-18-fluorodeoxyglucose
positron emission tomography (FDG-PET) offers an opportunity to
improve the outcome for patients with advanced head and neck cancers.
Two papers presented at the 45th annual meeting of the Society of
Nuclear Medicine found that FDG-PET was more accurate than
conventional imaging for the diagnosis of regional and distant recurrence.
"The prognosis for head and neck cancer is poor, with survival
rates only at 20% at 5 years," said Val J. Lowe, MD, director of
PET, St. Louis University Health Sciences Center. The majority of
relapses, he said, occur within the first year after completion of
therapy. "We postulated that earlier detection of recurrence may
improve survival in this group and that PET may allow earlier
diagnosis of recurrent disease," he said.
The St. Louis study included 44 patients with advanced head and neck
cancer (stage III and IV) who were participating in a neoadjuvant
organ preservation protocol that included chemotherapy, surgical
salvage, and postoperative radiation therapy. PET scans were
performed twice during the first post-treatment year, at 4 months and
10 months. Additional scans have been taken each subsequent year that
the patients are alive and enrolled in the study.
After therapy, patients were divided into subsets of complete
response (27 patients) or residual disease (6 patients). Eleven
patients were withdrawn from the study due to an inability to
tolerate imaging or to development of an immediate recurrence in the
The group of complete responders to therapy was further divided into
two subsets: patient without evidence of disease (13) or with
recurrence (14) at least 1 year after completion of therapy.
In the recurrent subset, 5 patients had recurrence detected by PET
alone; 3 by PET and other correlative imaging (CI) such as head and
neck CT and chest x-ray; 4 by PET and physical exam with negative CI;
and 2 by PET, CI, and physical exam. Only PET detected all
recurrences in these patients, and in the first group where PET was
the only identifier, 4 of the 5 patients were diagnosed at the first
"PET can detect head and neck tumor recurrence when it may be
undetectable by other clinical methods," Dr. Lowe said. "Our
research suggests that FDG-PET scans should be performed at least
twice in the first year post-treatment."
A study by the Northern California PET Imaging Center and several
California medical centers included 51 patients with known or
suspected recurrence of head and neck cancer. Each patient received a
whole-body FDG-PET scan, and presence or absence of tumor was
established in 49 patients using surgery (26), biopsy (8), and
imaging/clinical follow-up (15).
In a subset of 33 cases, FDG-PET was compared with CT and MRI. In
these patients, PET sensitivity for local recurrence was 90% vs 74%
for CT/MRI. For regional recurrence, PET sensitivity was 89% vs 84%
for CT/MRI. In addition, in 12 of the 51 patients, PET correctly
identified 15 sites of distant metastases (eight lung, two
mediastinal/hilar, two liver, two bone, and one retro-orbital).
"Pretreatment imaging with FDG-PET avoids the morbidity and cost
of attempted curative surgery or radiotherapy in patients with
undiagnosed distant recurrences who may really be candidates for
chemotherapy," said Dr. Elma Abella-Columna, research fellow at
the Northern California PET Imaging Center.