Opinion regarding WBRT Vs Hippocampus sparing WBRT Vs SRS for MBC

[misraw_fighter]

Hello, my mother (52) is suffering from Metastatic Breast Cancer (ER,PR-ve, HER2Neu3+) since 2015, she has undergone Bilateral mastectomies , radiation to left chest wall and AC+Taxane Chemo. Fine for two years and then presented with a persistent cough which turned out to be a lung lesion right in the centre of the chest cavity. Treated with 6 rounds of Taxol+ Trastuzumab which showed good response and then on 8 rounds of maintenance Trastuzumab. However the scan in August showed increase in size of the solitary chest lesion and lymphnodes, so my oncologist recommended Radiation to the chest wall and sent me for SBRT opinion where on a Pet Scan she was diagnosed with a single, mostly cystic brain lesion of 5cm*5cm which has since then been surgically resected (post op CT all clear) and she is in good spirits post surgery.Howeever our oncologist wants us to get radiation to the brain lesion , the radiation oncologist we met informed us that they'd like to perform WBRT (Whole Brain Radiation Therapy) along with palliative radiation to the chest lesion as it is close to the mediastinum. Another option is getting Hippocampus sparing WBRT which proposed to spare the hippocampus during brain irradiation so as to better preserve cognitive function down the line.

I would appreciate any help, regarding this if anyone has gone through it. Reading up I also felt that SRS should also have been an option .My mother is a champion and has borne all these procedures chemo et al with a smile on her face and minimal side effects but she is very worried about losing her mind. Currently on Tykerb and Capecitabine.

[Bestbird]

I am sorry to hear about your mother, and it is very loving of you to reach out on her behalf.

Having WBRT for a solitary lesion is not the current standard of care. Below from my book, "The Insider's Guide to Metastatic Breast Cancer" which contains a comprehensive chapter about treating brain metastasis, is an excerpt regarding therapeutic guidelines. For more information, please visit insidersguidembc.com/about

In an excellent 2019 video about the use of radiotherapy for brain metastasis, Dr. Paul Brown, Professor of Radiation Oncology at the Mayo Clinic, suggested the following guidelines for radiation treatment irrespective of where the cancer originated (breast, lung, colon, etc.). Those wishing to view the video may visit: vimeo.com/321234317/33959e4ee9

Another source for the information below is Adam Brufsky, MD, PhD, Professor of Medicine at the University of Pittsburgh School of Medicine medscape.com/viewarticle/91...

•For patients with a single large brain metastasis, surgery plus SRS is considered the standard of care. (Adding WBRT can help prevent additional brain metastases, but it fails to improve OS and can significantly diminish cognitive capabilities and QOL).

•For patients with one or two metastases that are relatively close together but in an area of the brain where the surgeon feels it won't cause too much damage to remove them, they may be excised surgically. If the metastases are in an area of the brain where the surgeon feels it would cause too much damage to remove them, SRS with CyberKnife, which is single focused-dose radiation, is a viable option.

•For patients with oligometastases (defined in the video as one to four brain metastases), Stereotactic RadioSurgery (SRS) is recommended. Adding Whole Brain Radiation Therapy (WBRT) thereafter helps to prevent additional brain metastases, but does not improve Overall Survival (OS) and can significantly degrade cognitive abilities and Quality Of Life (QOL). Therefore, SRS is considered the standard of care for these patients.

•For patients with up to 10 metastases: According to Dr. Brufsky, many clinicians use CyberKnife in a series - two or three times for up to 10 metastases - depending on their location in the brain.

•For patients with multiple (widespread) brain metastases, or patients who have a rapid recurrence (i.e. within a few months) of brain metastases treated with SRS, Hippocampal Avoidance (HA) WBRT with Memantine HCL is recommended, although using SRS alone for patients with up to 10 brain metastases may also be a viable option. (The role of systemic therapy in this context is still being explored).

HA (or Hippocampus-sparing) WBRT is a special form of WBRT that spares the hippocampus (a small region of the brain that is primarily associated with memory and spatial navigation) from being targeted by radiation. HA WBRT is accomplished by using Intensity-Modulated Radiation Therapy (IMRT), which is an advanced mode of high-precision radiotherapy that uses computer-controlled linear accelerators to deliver precise radiation doses to a malignant tumor or specific areas within the tumor. Memantine HCL is an Alzheimer’s drug that can help prevent cognitive decline.