Medullary thyroid cancer (MTC) is the third most common type of thyroid cancer, making up about 3 percent of all thyroid cancer cases. Although considered very rare, this type of cancer can spread fast to other areas of the body. Both physicians and patients, therefore, stay wary of the possibility of recurrence even after successful treatments. Fortunately, modern imaging exams, PET scan in particular, can aid in detecting signs that the cancer has returned.
Increasing Calcitonin Levels
According to a study conducted by researchers at the University of Zagreb in Croatia, a follow-up PET scan can identify significant increase of calcitonin levels in MTC patients. Elevated calcitonin levels usually indicate that the cancer has returned.
The researchers scanned patients who were reported to have increasing calcitonin after their visits following thyroidectomy for medullary cancer. They were subjected to PET scans after other imaging exams including ultrasound and CT of the thorax, abdomen and pelvis came back with negative results.
The PET scan, however, showed a different outcome. Fifty-seven percent of the patients or 16 out of 28 participants had positive findings due to metabolically active neck and mediastinal lymph nodes metastases. Meanwhile, six patients had previously unknown metastases and four patients with very low calcitonin values came back with positive scans.
Changing Therapy Options
According to the authors of the study, changes were implemented with management and therapy of the patients who showed positive results. Some opted for surgery, radiotherapy and chemotherapy based on the findings of the study.
PET scan is clearly a clinically useful modality for MTC, especially if there is noticeable increase in calcitonin levels. However, patients who show moderate elevation in calcitonin should also be closely monitored. This would only allow for therapy to be individualized and even more efficient.
PET/CT A Sharp-Eyed Ally Against Comeback Thyroid Cancer, HealthImaging.com
Thyroid Cancer: Medullary Cancer, EndocrineWeb.com