Follow-up CT scans in patients who do not respond to radiation therapy for vocal chord cancer can result in earlier salvage surgery than clinical exams alone, according to a study in the March issue of Radiology.
Clinicians from several institutions retrospectively analyzed the follow-up CT scans in 66 patients who had undergone radiation therapy for laryngeal or hypopharyngeal carcinoma to determine if imaging could catch local recurrence sooner than a clinical exam. The researchers hailed from University Hospitals in Leuven, Belgium, the Netherlands Cancer Institute in Amsterdam and the University of Florida College of Medicine in Gainesville.The group studied 66 patients who had irradiation with curative intent between 1980 and 1993. All patients underwent hyperfractionated, continuous course radiation therapy twice daily for a total dose of 6,720-7,920 cGy.
CT scans were performed one to six months after completion of radiation therapy; 3 mm contiguous sections were obtained with the plane of the section parallel to the true vocal cord. Patients were followed for two years and rated on a 1-3 point system: Those with no evidence of disease scored a 1, those with a suspicion of local recurrence or complication were given a 2, and patients with definite recurrence or complication were assigned a 3.
According to the CT results, 56%, or 37, patients remained free of disease at the primary site after radiation treatment, while 44%, or 29, developed local failures. One patient counted among the local failures had a recurrence at the primary site more than two years after treatment.
In 12 of those 29 patients with local failures, CT was able to pinpoint the recurrence earlier than a clinical exam. In half of those dozen cases, radiologic diagnosis was confirmed “rapidly,” with results of biopsy or laryngectomy, the authors said. In the remaining six patients, the clinical exam did not show evidence of disease, but CT scans confirmed recurrence within five months.
For those patients with a score of 3, the CT scan had a sensitivity of 83%, a specificity of 95% and an accuracy of 89%. The negative predictive value was 88% and the positive predictive value was 92%. False-positive findings in two cases turned out to be focal fibrosis or chronic inflammation, the authors reported. New cases of carcinoma were seen in eight patients after CT scan.
Patients with a score of two, an estimated tumor reduction of less than 50%, or a focal mass with a diameter of at least 1 cm, have a high probability of local failure. A CT scan, along with clinical follow-up is “necessary to detect progressive, soft-tissue changes,” the study concluded.
To view the article in full, visit http://radiology.rsnajnls.org/cgi/content/full/214/3/683
Clinicians from several institutions retrospectively analyzed the follow-up CT scans in 66 patients who had undergone radiation therapy for laryngeal or hypopharyngeal carcinoma to determine if imaging could catch local recurrence sooner than a clinical exam. The researchers hailed from University Hospitals in Leuven, Belgium, the Netherlands Cancer Institute in Amsterdam and the University of Florida College of Medicine in Gainesville.The group studied 66 patients who had irradiation with curative intent between 1980 and 1993. All patients underwent hyperfractionated, continuous course radiation therapy twice daily for a total dose of 6,720-7,920 cGy.
CT scans were performed one to six months after completion of radiation therapy; 3 mm contiguous sections were obtained with the plane of the section parallel to the true vocal cord. Patients were followed for two years and rated on a 1-3 point system: Those with no evidence of disease scored a 1, those with a suspicion of local recurrence or complication were given a 2, and patients with definite recurrence or complication were assigned a 3.
According to the CT results, 56%, or 37, patients remained free of disease at the primary site after radiation treatment, while 44%, or 29, developed local failures. One patient counted among the local failures had a recurrence at the primary site more than two years after treatment.
In 12 of those 29 patients with local failures, CT was able to pinpoint the recurrence earlier than a clinical exam. In half of those dozen cases, radiologic diagnosis was confirmed “rapidly,” with results of biopsy or laryngectomy, the authors said. In the remaining six patients, the clinical exam did not show evidence of disease, but CT scans confirmed recurrence within five months.
For those patients with a score of 3, the CT scan had a sensitivity of 83%, a specificity of 95% and an accuracy of 89%. The negative predictive value was 88% and the positive predictive value was 92%. False-positive findings in two cases turned out to be focal fibrosis or chronic inflammation, the authors reported. New cases of carcinoma were seen in eight patients after CT scan.
Patients with a score of two, an estimated tumor reduction of less than 50%, or a focal mass with a diameter of at least 1 cm, have a high probability of local failure. A CT scan, along with clinical follow-up is “necessary to detect progressive, soft-tissue changes,” the study concluded.
To view the article in full, visit http://radiology.rsnajnls.org/cgi/content/full/214/3/683
