Standing

Undergraduate

Type of Proposal

Poster Presentation

Faculty

Schulich School of Medicine Windsor

Faculty Sponsor

Dr. Ming Pan

Abstract/Description of Original Work

Purpose:

The development of brain metastases heralds a dismal prognosis and remains a substantial contributor of high mortality in patients with advanced-stage cancer. Historically, craniotomy and whole-brain irradiation (WBI) have been standard of care for patients with brain metastases, with median survival only 3 to 4 months. However, long-term neurotoxicity and associated complications from WBI encouraged the use of a more localized radiation modality. This study reviews our single-institution experience with brain metastasis patients' outcomes during two years since adopting hypofractionated stereotactic radiotherapy (HSRT).

Methods:

This retrospective study was approved by our institution’s Research Ethics Board. All charts of patients with brain metastases between November 2018 and April 2021 were reviewed. A total of 51 patients and 75 lesions were treated with HSRT to a median prescribed dose of 30 Gy (range 20-30 Gy) in 5 fractions every other day; nine of them also received WBI with dose of 20 Gy in 5 fractions every day. Patients underwent follow-up with MRI, generally every 3 months after HSRT.

Results:

The cohort's mean age was 66 years (37-90), 55% were female, and 55% had two or more major comorbidities. Of the 51 patients analyzed, most primary sites were from lung (67%), breast (12%), colorectal (6%), gastric (6%), melanoma (4%), head and neck (2%), and unknown primary (2%). The longest dimension of the brain metastases ranged from 4 mm to 39 mm (median 12 mm) on diagnostic MRI. Sixty-nine percent patients presented with solitary lesion and 31% with two to four oligo brain metastases. The most common tumour locations were the frontal lobe 36%, parietal lobe 17% and cerebellum 17%. According to the Kaplan-Meier curve, the overall survival at 3, 6, and 12 months were 72.7%, 45.5%, and 30.8%, respectively. The median survival after HSRT was 6 months. Using Response Evaluation Criteria in Solid Tumors (RECIST) guideline, local control rates at 3, 6, and 12 months were 91.8%, 77.4%, and 66.3%, respectively. Radionecrosis emerged in only four of 75 lesions (5.3%).

Conclusions:

HSRT achieved good local control and survival in patients with brain metastases, with acceptable low rate of radionecrosis. Our findings suggest that it is safe and well-tolerated. HSRT could be a good alternative for solitary or oligo brain metastases if craniotomy and WBI are not desired. Further randomized controlled trials with larger cohorts and longer follow-up are warranted.

Special Considerations

Amber Shaheen

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Brain Metastasis Hypofractionated Stereotactic Radiotherapy Outcome in a Single Institution

Purpose:

The development of brain metastases heralds a dismal prognosis and remains a substantial contributor of high mortality in patients with advanced-stage cancer. Historically, craniotomy and whole-brain irradiation (WBI) have been standard of care for patients with brain metastases, with median survival only 3 to 4 months. However, long-term neurotoxicity and associated complications from WBI encouraged the use of a more localized radiation modality. This study reviews our single-institution experience with brain metastasis patients' outcomes during two years since adopting hypofractionated stereotactic radiotherapy (HSRT).

Methods:

This retrospective study was approved by our institution’s Research Ethics Board. All charts of patients with brain metastases between November 2018 and April 2021 were reviewed. A total of 51 patients and 75 lesions were treated with HSRT to a median prescribed dose of 30 Gy (range 20-30 Gy) in 5 fractions every other day; nine of them also received WBI with dose of 20 Gy in 5 fractions every day. Patients underwent follow-up with MRI, generally every 3 months after HSRT.

Results:

The cohort's mean age was 66 years (37-90), 55% were female, and 55% had two or more major comorbidities. Of the 51 patients analyzed, most primary sites were from lung (67%), breast (12%), colorectal (6%), gastric (6%), melanoma (4%), head and neck (2%), and unknown primary (2%). The longest dimension of the brain metastases ranged from 4 mm to 39 mm (median 12 mm) on diagnostic MRI. Sixty-nine percent patients presented with solitary lesion and 31% with two to four oligo brain metastases. The most common tumour locations were the frontal lobe 36%, parietal lobe 17% and cerebellum 17%. According to the Kaplan-Meier curve, the overall survival at 3, 6, and 12 months were 72.7%, 45.5%, and 30.8%, respectively. The median survival after HSRT was 6 months. Using Response Evaluation Criteria in Solid Tumors (RECIST) guideline, local control rates at 3, 6, and 12 months were 91.8%, 77.4%, and 66.3%, respectively. Radionecrosis emerged in only four of 75 lesions (5.3%).

Conclusions:

HSRT achieved good local control and survival in patients with brain metastases, with acceptable low rate of radionecrosis. Our findings suggest that it is safe and well-tolerated. HSRT could be a good alternative for solitary or oligo brain metastases if craniotomy and WBI are not desired. Further randomized controlled trials with larger cohorts and longer follow-up are warranted.