Due to the Hurricane our offices will be closed on the 29th and 30th. If you need to speak with a provider regarding an urgent need, please call your physician's office and you will be directed to our after hours line. If you have a medical emergency, please call 911. We hope that you and your families remain safe through the storm and look forward to seeing you on Monday.
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Dr. Brian Deegan is board-certified in radiation oncology and practices at our Fleming Island and St. Augustine locations. After receiving his Bachelor of Arts in Chemistry and Biology from Luther College, he enrolled in a joint-degree program at the University of Miami. There, he received his Doctor of Philosophy in Cancer Biology and his Doctor of Medicine.

Dr. Deegan completed his residency training at the University of Texas, MD Anderson Cancer Center before joining CSNF’s growing radiation oncology department.

“It’s a tremendous privilege to take care of patients and their families during a difficult period in their life,” he says. “I appreciate that responsibility and opportunity to earn their trust during their care.”

Putting a focus on his patient’s personal values while caring for them allows him to further build that trust. “I aim to get to know my patients and find out what is important to them before explaining their treatment course,” he says.

When not in the office, Dr. Deegan enjoys traveling, watching sports, listening to music, and enjoying all of the outdoor activities North Florida has to offer with his wife and kids.

Curriculum Vitae


Radiation Oncology


American Society for Radiology and Oncology
American Medical Association
Texas Radiological Society
American Brachytherapy Society


The University of Texas MD Anderson Cancer Center


University of Texas Health Sciences Center


University of Miami School of Medicine
Doctor of Medicine
University of Miami School of Medicine
Doctor of Philosophy in Cancer Biology
Luther College
Bachelor of Arts in Chemistry & Biology


MD Anderson Cancer Survivorship Research Award
MD Anderson Trainee Research Day Bristol-Myers Squibb Award in Clinical Research
NCCN Oncology Fellows Recognition Program, National Comprehensive Cancer Network 22nd Annual Conference
ASTRO Abstract Award Winner – Basic/Translational Science


Journal of Neurosurgery
The use of spine stereotactic radiosurgery for oligometastatic disease.
The FEBS Journal
pH modulates the binding of early growth response protein 1 transcription factor to DNA.
Biophysical Chemistry
Heat-induced fibrillation of BclXL apoptotic repressor.
Biophysical Chemistry
Structural landscape of the proline-rich domain of Sos1 nucleotide exchange factor.
Journal of Molecular Recognition
Allostery mediates ligand binding to Grb2 adaptor in a mutually exclusive manner.
Rambam Maimonides Medical Journal
Prevention of Venous Thrombotic Event in Brain Injury: Review of Current Practices.
Archives of Biochemistry and Biophysics
Acidic pH promotes oligomerization and membrane insertion of the BclXL apoptotic repressor.
Journal of Molecular Biology
Biophysical Basis of the Binding of WWOX Tumor Suppressor to WBP1 and WBP2 Adaptors.
The FEBS Journal
Bivalent binding drives the formation of the Grb2-Gab1 signaling complex in a noncooperative manner.
). Multivalent binding and facilitated diffusion account for the formation of the Grb2-Sos1 signaling complex in a cooperative manner.
The Journal of Molecular Biology
Ligand Binding and Membrane Insertion Compete with Oligomerization of the BclXL Apoptotic Repressor.
The FEBS Journal
Energetic coupling along an allosteric communication channel drives the binding of Jun-Fos heterodimeric transcription Factor to DNA
Journal of Molecular Recognition
Structural and thermodynamic consequences of the replacement of zinc with various environmental metals on ERα- DNA interactions.
Biophysical analysis of binding of WW domains of the YAP2 transcriptional regulator to PPXY motifs within WBP1 and WBP2 adaptors.
Journal of Molecular Recognition
). Binding of the cSH3 domain of Grb2 adaptor to two distinct RXXK motifs within Gab1 docker employs differential mechanisms.
Archives of Biochemistry and Biophysics
). Genetic variations within the ERE motif modulate plasticity and energetics of binding to the ERα nuclear receptor.
Binding of the ERalpha nuclear receptor to DNA is coupled to proton uptake.
Biochemical and Biophysical Research Communications
Dissecting the role of leucine zippers in the binding of bZIP domains of Jun transcription factor to DNA.
Archives of Biochemistry and Biophysics
). Assembly of the Sos1-Grb2-Gab1 ternary signaling complex is under allosteric control.
Bhat V, Farooq A (2009). DNA plasticity is a key determinant of the energetics of binding of Jun-Fos heterodimeric transcription factor to genetic variants of TGACGTCA motif.
SH3 Domains of Grb2 Adaptor Bind to PXyPXR Motifs within the Sos1 Nucleotide Exchange Factor in a Discriminate Manner.
). Single Nucleotide Variants of the TGACTCA Motif Modulate Energetics and Orientation of Binding of the Jun-Fos Heterodimeric Transcription Factor.
Archives of Biochemistry and Biophysics
Evidence that the bZIP Domains of the Jun Transcription Factor Bind to DNA as Monomers Prior to Folding and Homodimerization.
Archives of Biochemistry and Biophysics
Structural Basis of the Differential Binding of the SH3 Domains of Grb2 Adaptor to the Guanine Nucleotide Exchange Factor Sos1.
Biochemical and Biophysical Research Communications
Thermodynamic Analysis of the Heterodimerization of Leucine Zippers of Jun and Fos Transcription Factors.
Archives of Biochemistry and Biophysics
Grb2 Adaptor Undergoes Conformational Change Upon Dimerization.
Archives of Biochemistry and Biophysics
Coupling of Folding and DNA-Binding in the bZIP Domains of Jun-Fos Heterodimeric Transcription Factor.
Journal of Materials Research
Synthesis, structure and superlattice formation.