HER2 Support Group Forums - View Single Post

Joan M · 04-01-2013, 07:11 PM

Jilly,

A brain MRI is a scan that is like a CT scan. They show tumor morphology. For example, the report of the brain MRI that identified my brain nodule said that the nodule was cystic, rather than a solid tumor (I believe that all primary brain cancers are solids, but metastatic tumors can be cystic, as well). The report of the CT of my lung said the nodule had spiculated edges, which is a sure sign that the nodule was cancerous.

A PET scan measures metabolism, and the CT part of a PET/CT provides a better roadmap than the PET scan alone. A high rate of metabolism is involved in cancer cell metabolism, and when the rate is higher in one area than another, that spot lights up on PET. So PET scans don't show morphology, but rather a signal. However, just because an area lights up doesn't mean that it's cancerous, as nonmalignant causes, like tuberculosis can also light up, for example.

When my neuro-onc first recommended a brain PET, I was surprised because I didn't think it was possible since the brain has a lot of metabolic activity and would be lighting up all over like a Christmas tree. But he said that the metabolism factor is adjusted. As it turned out, the area of the craniotomy was exactly the same as the surrounding area, meaning that it didn't light up.

My neuro-onc explained that a brain PET was the next step in determining whether I might have regrowth of the tumor and would help to explain why my brain MRIs were showing increased enhancement every 3 months for several scans.

Hang in there!!

Joan

04-01-2013, 07:11 PM	#16
Joan M Senior Member Join Date: Oct 2007 Posts: 1,851	Re: Progression or Necrosis in the brain? Jilly, A brain MRI is a scan that is like a CT scan. They show tumor morphology. For example, the report of the brain MRI that identified my brain nodule said that the nodule was cystic, rather than a solid tumor (I believe that all primary brain cancers are solids, but metastatic tumors can be cystic, as well). The report of the CT of my lung said the nodule had spiculated edges, which is a sure sign that the nodule was cancerous. A PET scan measures metabolism, and the CT part of a PET/CT provides a better roadmap than the PET scan alone. A high rate of metabolism is involved in cancer cell metabolism, and when the rate is higher in one area than another, that spot lights up on PET. So PET scans don't show morphology, but rather a signal. However, just because an area lights up doesn't mean that it's cancerous, as nonmalignant causes, like tuberculosis can also light up, for example. When my neuro-onc first recommended a brain PET, I was surprised because I didn't think it was possible since the brain has a lot of metabolic activity and would be lighting up all over like a Christmas tree. But he said that the metabolism factor is adjusted. As it turned out, the area of the craniotomy was exactly the same as the surrounding area, meaning that it didn't light up. My neuro-onc explained that a brain PET was the next step in determining whether I might have regrowth of the tumor and would help to explain why my brain MRIs were showing increased enhancement every 3 months for several scans. Hang in there!! Joan __________________ Diagnosed stage 2b in July 2003 (2.3 cm, HER2+, ER-/PR-, 7+ nodes). Treated with mastectomy (with immediate DIEP flap reconstruction), AC + T/Herceptin (off label). Cancer advanced to lung in Jan. 2007 (1 cm nodule). Started Herceptin every 3 weeks. Lung wedge resection April 2007. Cancer recurred in lung April 2008. RFA of lung in August 2008. 2nd annual brain MRI in Oct. 2008 discovered 2.6 cm cystic tumor in left frontal lobe. Craniotomy Oct. 2008 (ER-/PR-/HER2-) followed by targeted radiation (IMRT). Coughing up blood Feb. 2009. Thoractomy July 2009 to cut out fungal ball of common soil fungus (aspergillus) that grew in the RFA cavity (most likely inhaled while gardening). No cancer, only fungus. Removal of tiny melanoma from upper left arm, plus sentinel lymph node biopsy in Feb. 2016. Guardant Health liquid biopsy in Feb. 2016 showed mutations in 4 subtypes of TP53. Repeat of Guardant Health biopsy in Jana. 2021 showed 3 TP53 mutations, BRCA1 mutation and CHEK2 mutation. Invitae genetic testing showed negative for all of these. Living with MBC since 2007. Stopped Herceptin Hylecta (injection) treatment in March 2020. Recent 2021 annual CT of chest, abdomen and pelvis and annual brain MRI showed NED. Praying for NED forever!! Last edited by Joan M; 04-01-2013 at 07:15 PM..