Ways Forward with Brain Cancer in Neurosurgery
Dr Muruga Kumar, Consultant Neurosurgeon of Subang Jaya Medical Centre (SJMC) elaborates on the various advancements currently available for patients of brain cancer to obtain a better quality of life.
According to the Malaysia Cancer Statistic Data and Figures Peninsular Malaysia, primary brain cancer is listed as the 9th most frequent cancer for women and 10th most frequent for their male counterparts. Until 2012, this marked up to 4.6 cases out of 100,000 individuals diagnosed with cancer each year but these numbers are quickly increasing due to longer lifespan and improved early detection methods.
Grades of cancerous brain tumour
In general, brain cancer is an abnormal mass of cells in your brain that either primarily formed there or was secondarily spread to the brain by cancerous cells originating from other parts of the body. Gliomas (primary brain cancer) are divided into four grades based on how fast they spread: Grade 2 being the least aggressive while Grade 4 is the most.
Since 2016, the WHO has issued a clearer way of grading cancers, using genetic markers 1p19q Codeletion, IDH mutation and TERTp to determine the severity of the cancer. This grading also aids neurosurgery doctors when planning the treatment, including detecting high grade cancer that may have the appearance of a lower grade cancer instead.
“The primary goal of our treatment is for gross total macroscopic excision of the cancer,” says Dr Muruga Kumar. “However, even with the best surgical attention, patients with the higher grade cancer, glioblastoma, live for 18 months to two years, while individuals with lower grades of cancer may live up to 15 years. Nonetheless, almost all lower grade cancers will eventually recur as a high-grade cancer,” he explains.
Advancements in brain cancer treatments
Although as of now there is no known cure for primary brain cancer, numerous treatments are available to help ease the symptoms, allowing for a better quality of life. “Now with the use of new technology such as advanced microscopes and computers in surgery together with new lines of radiotherapy and chemotherapy, as well as possibly IORT (Intraoperative Radiation Therapy) in the future, we are able to extend a glioblastoma patient’s survival period up to 3 years, effectively doubling it,” assures Dr Kumar.
High-Definition Fibre Tracking & FMRI
For a successful outcome, various steps are taken before operating on the patient. These include cutting-edge medical imaging modalities such as High-Definition Fibre Tracking which permit doctors to identify motor fibres that are closest to the cancer so as to not damage them when removing the malignant cells, and Functional Magnetic Resonance Imaging (FMRI) to map out important speech and movement areas that need to be avoided as well. These images are then incorporated to the Image Guidance Surgery (IGS) to achieve up to 95 per cent resection of the cancer.
“On top of that, during the surgery we also utilise intraoperative imaging(ie) intraoperative MRI and intraoperative ultrasound; to see how much of the tumour is left behind after our first round of resection in order to achieve a complete resection. The more complete resections we do the higher the chances postoperative radiotherapy and chemotherapy are effective,” Dr Kumar expounds.
Awake Brain Surgery (Craniotomy)
Such real-time scanning of the patient during the surgery while the brain is exposed enables surgeons to better assess how much of tumour is left for immediate removal on the operating table during surgery.
“Another method that is possible for us to use is Awake Brain Surgery (Craniotomy), which means we awake the patient up after we have opened the cranium and using all the modalities available to us we assess the patient’s speech and motor skills while we continue to resect the tumour, stopping when necessary to preserve function. This gives us a higher chance of complete tumour resection,” he continues.
Cortical Stimulation Mapping
In addition, other techniques like Cortical Stimulation Mapping allow identification of sensitive areas on the brain surface using small electrodes while its Subcortical counterpart goes below the brain surface to detect tracks that control the patient’s motor functions.
A high rate of resection is also made possible with Fluorescence IGS, which entails administering fluorescent dye either orally or intravenously into the patient. The cancer cells take up the dye and lights up which is visualised in special operating microscope light, enabling the surgeon to excise the tumour yet preserving normal brain. This has been a game changer in tumour surgery.
“Once a successful surgery is done, and the intraoperative imaging modalities reveal that a complete resection has been performed, we could then immediately proceed with the experimental IORT in the cavity of the tumour that we’ve removed, in order to sterilise any remaining cancer cells that may still be attached to the brain cells. This would then be followed by chemotherapy and post-operative radiotherapy for the best results,” says Dr Kumar.
STUPP Protocol for glioblastoma
Post-surgery, the STUPP protocol, a worldwide standard of care for the treatment of glioblastoma is followed. This protocol involves giving oral chemotherapy and daily radiotherapy on the tumour bed as well as areas adjacent to it for a duration of 28 fractions.
Brain tumour recurrence
“However, the tumour may recur again in 18 months to 2 years. This is where our new therapy protocols such as the Second-Line Chemotherapy have come into play. Apart from that, we can also look at resecting the cancer/tumour again and proceed with alternate chemotherapy to eliminate cells that were resistant to the initial therapy. With these, we hope to extend the lifespan of our patients from 2 years to 3 years,” Dr Kumar reveals.
“At the end of the day, the aim is to give our patients more time as well as preserve a reasonable quality of life that is valuable to them and their loved ones,” he says.