a d PET Scan Sensitivity for Colon Cancer | Oncolink - Cancer Resources

PET Scan Sensitivity for Colon Cancer

Ultima Vez Modificado: 19 de agosto del 2007

Share article


Dear OncoLink "Ask The Experts,"

My husband was diagnosed with Stage 3 signet ring cell adenocarcinoma [of the colon] in December 2005 and had 5 months of chemotherapy. Within the past month, his CEA level has risen from 1.5 to 3.4. His doctor ordered a PET scan, and the results came back clear. It showed absolutely nothing. Are there any cancers that don't show up with a PET scan, or is his CEA too low, or is the PET scan right and there is no cancer?


Peeyush Bhargava, MD, Chief of Nuclear Medicine at The Michael E. DeBakey VA Medical Center, responds:

Colon cancer is an FDG-avid disease (meaning that it usually shows up on PET imaging). In centers where the combination PET-CT scan is available, it is preferred over PET scan alone. This is because the PET-CT combines both the PET and CT images to give more information, based on the metabolic and the anatomic information, respectively. It is generally accepted that PET is limited in the evaluation of subcentimeter lesions (those smaller than 1 centimeter), as lesions this small can be falsely negative. This means that the disease is not seen on the scan, even though it is present. It is also recognized that as a part of PET-CT, a contrast enhanced CT can provide more information. So in summary, the use of PET-CT may provide a more accurate assessment of a patient's clinical status.

I Wish You Knew

How an oncology social worker can improve your cancer experience

View More

Blogs and Web Chats

OncoLink Blogs give our readers a chance to react to and comment on key cancer news topics and provides a forum for OncoLink Experts and readers to share opinions and learn from each other.

OncoLink OncoPilot

Frente a un nuevo diagnóstico de cáncer o de cambiar el curso de su tratamiento actual? Deje que nuestro personal de enfermería cáncer que ayudan a pasar!

Más información