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Dr Leong Sum

Clinical Appointments

  • Senior Consultant Vascular and Interventional Radiology Singapore General HospitalSingapore General Hospital
  • Senior Consultant SingHealth Duke-NUS Vascular Centre


​Dr Leong Sum, is an Interventional Radiologist at the Department of Vascular and Interventional Radiology, Singapore General Hospital (SGH).

He graduated as a scholar from Trinity College Dublin in 2005. Following internship and basic surgical training, he underwent 5 years radiology training under the Faculty of Radiology, Royal College of Surgeons in Ireland (2008-2013). He subsequently joined the Department of Diagnostic Radiology, SGH in 2014 and appointed Consultant in 2015.

Dr Leong’s field of interest lies in minimally-invasive cutting-edge treatment of cancers [including liver (chemoembolization, Y90 radioembolization, radiofrequency ablation), kidney (cryoablation), lung (microwave ablation), thyroid nodules (radiofrequency ablation)] and oncological pain management (nerve block, vertebroplasty, cementoplasty). He also performs thrombolysis, angioplasty and stenting for peripheral vascular disease and dialysis access (AVF/AVG). In addition, he also performs embolization for peripheral aneurysms, arteriovenous fistulas and vascular malformations. He is a co-investigator for many ongoing interventional radiology clinical trials including Phocus trial (Pexavec for HCC), Optima trial (Thermodox for HCC), drug eluting and cutting balloon angioplasty studies. He enjoys building rapport with patients from all walks of life aided by fluent English, Malay, Cantonese and Mandarin.


  • MSc Medical Education (Queens’ University Belfast)
  • MB BCh BAO (Trinity College Dublin)

Professional Appointments and Committee Memberships

  • Adjunct Assistant Professor​, Duke-NUS Medical School
  • Clinical Lecturer, NUS
  • RADSC ACP Clinical Learning Environment Review (CLER) Committee


  • ​Best Oral Presentation MYSIR 2016
  • Best Poster Presentation MYSIR 2014
  • Best JACR Education Article 2013
  • CIRSE visiting Scholarship 2012
  • ECR Invest in the Youth Sponsorship 2011
  • Recommended Poster Award ESGAR 2010
  • Audit Prize Faculty of Radiology RCSI Annual Scientific Meeting 2009
  • Scholarship of BSIR Annual Scientific Meeting 2009
  • Distinction in Anatomy, Trinity College Dublin 2003
  • Scholarship of Trinity College Dublin 2003

Research Interests


  1. Venkatanarasimha N, Damodharan K, Gogna A, Leong S, Too CW, Patel A, Tay KH, Tan BS, Lo R, Irani F. Diagnosis and Management of Complications from Percutaneous Biliary Tract Interventions. Radiographics. 2017 Mar-Apr;37(2):665-680. doi: 10.1148/rg.2017160159.
  2. Damodharan K, Patel A, Irani FG, Burgmans MC, Gogna A, Tay KH, Lo RH, Too CW, Leong S, Venkatanarasimha N, Chan S, Win HH, Sivanathan C, Tan BS.  Drug Eluting Stents in Infrapopliteal Arterial Disease: A Pilot Safety Study in an Asian Population. Ann Acad Med Singapore. 2017 Apr;46(4):155-159.
  3. Leong Sum; Kok Hong Kuan; Delaney Holly; Feeney John; Lyburn Iain; Munk Peter; Torreggiani William. The Radiologic Diagnosis and Treatment of Typical and Atypical Bone Hemangiomas: Current Status. Canadian Association of Radiologists journal = Journal l'Association canadienne des radiologistes 2016; 67(1):2-11 (Article; Published in Print)
  4. Chow Pierce K H; Choo Su Pin; Ng David C E; Lo Richard H G; Wang Michael L C; Toh Han Chong; Tai David W M; Goh Brian K P; Wong Jen San; Tay Kiang Hiong; Goh Anthony S W; Yan Sean X; Loke Kelvin S H; Thang Sue Ping; Gogna Apoorva; Too Chow Wei; Irani Farah Gillian; Leong Sum; Lim Kiat Hon; Thng Choon Hua. National Cancer Centre Singapore Consensus Guidelines for Hepatocellular Carcinoma. Liver cancer 2016; 5(2):97-106 (Article; Published in Print)
  5. Too Chow Wei; Sayani Raza; Lim Elvin Yuan Ting; Leong Sum; Gogna Apoorva; Teo Terence K. REcanalisation and Balloon-Oriented Puncture for Re-Insertion of Dialysis Catheter in Nonpatent Central Veins (REBORN). Cardiovascular and interventional radiology 2016; 39(8):1193-1888 (Article; Published in Print)
  6. Aung Tin Htun; Too Chow Wei; Kumar Nanda; Damodharan Karthikeyan; Urlings Thijs August; Patel Ankur; Chan Shaun; Toh Luke; Gogna Apoorva; Irani Farah; Lo Richard; Tan Bien Soo; Tay Kiang Hiong; Sum Leong. Severe Bleeding after Percutaneous Transhepatic Drainage of the Biliary System. Radiology 2016; 278(3):957-988 (Letter; Published in Print)
  7. Salati Umer; Leong Sum; Donnellan John; Kok Hong Kuan; Buckley Orla; Torreggiani William. Out of Hours Emergency Computed Tomography Brain Studies: Comparison of Standard 3 Megapixel Diagnostic Workstation Monitors With the iPad 2. Canadian Association of Radiologists journal = Journal l'Association canadienne des radiologistes 2015; 66(4):363-377 (Article; Published in Print)
  8. Kok Hong Kuan; Leong Sum; Torreggiani William C. Is magnetic resonance imaging comparable with computed tomography in the diagnosis of retroperitoneal metastasis in patients with testicular cancer? Canadian Association of Radiologists journal = Journal l'Association canadienne des radiologistes 2014; 65(3):196-188 (Article; Published in Print)
  9. Leong Sum; Kok Hong Kuan; Govender Pradeep; Torreggiani William. Reducing risk of transjugular intrahepatic portosystemic shunt using ultrasound guided single needle pass. World journal of gastroenterology 2013; 19(22):3528-3303 (Article; Published in Print)
  10. Kok H K; Govender P; Leong S; Browne R F J; Torreggiani W C. Percutaneous computed tomography-guided oesophageal needle biopsy. Irish medical journal 2014; 107(2):N.A.-N.A. (Letter; Published in Print)
  11. Kok H K; Leong S; Govender P; Browne R; Torreggiani W C. Percutaneous renal artery angioplasty and stenting: indications, technique and results. Irish journal of medical science 2013; 182(3):351-366 (Article; Published in Print)
  12. Kok Hong Kuan; Leong Sum; Salati Umer; Torreggiani William C; Govender Pradeep. Left atrial and systemic air embolism after lung biopsy: importance of treatment positioning. Journal of vascular and interventional radiology : JVIR 2013; 24(10):1587-1888 (Letter; Published in Print)
  13. Leong Sum; Mc Laughlin Patrick; O'Connor Owen J; O'Flynn Siun; Maher Michael M. An assessment of the feasibility and effectiveness of an e-learning module in delivering a curriculum in radiation protection to undergraduate medical students. Journal of the American College of Radiology : JACR 2012; 9(3):203-299 (Article; Published in Print)
  14. Leong S; Fanning N F. Persistent neurological deficit from iodinated contrast encephalopathy following intracranial aneurysm coiling. A case report and review of the literature. Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences 2012; 18(1):33-41 (Article; Published in Print)
  15. Keeling Aoife N; Khalidi Karim; Leong Sum; Wang Tim T; Ayyoub Alaa S; McGrath Frank P; Athanasiou Thanos; Lee Michael J. Below knee angioplasty in elderly patients: predictors of major adverse clinical outcomes. European journal of radiology 2011; 77(3):483-499 (Article; Published in Print)
  16. Al-azawi Dhafir; Leong Sum; Wong Limy; Kay Elaine; Hill Arnold D K; Young Leonie. HER-2 positive and p53 negative breast cancers are associated with poor prognosis. Cancer investigation 2011; 29(5):365-399 (Article; Published in Print)
  17. Leong Sum; O'Connor Owen J; Doyle Deirdre; Murphy Desmond M; Maher Michael M. Increased fluoro-deoxy-D-glucose uptake on positron emission tomography-computed tomography postbronchoalveolar lavage: a potential cause of radiologic misinterpretation.Journal of thoracic imaging 2011; 26(3):W89-091 (Article; Published in Print)
  18. Craig OF, O’Neill SB, Leong S, O’Neill F, O’Connor OJ, Maher MM, Shanahan F. A Prospective Trial of Low-Dose Abdominal Computerised Tomography (CT) With Iterative Reconstruction vs Conventional CT in Crohn’s Disease. Gasteroenterology. 2011;140:1–72. 2011; 140():1-72 (Meeting Abstract; Published in Print)
  19. Leong S, Twomey M, Crush L, Murphy K, Barry J. Non-clinical errors using voice recognition software for radiology reports in an oncology setting. Cancer Imaging (2011) 11, S5 2011; 11():N.A.-N.A. (Meeting Abstract; e-Published Only (Never in Print))
  20. Malik Vinod; Goh King Soon; Leong Sum; Tan Angeline; Downey David; O'Donovan David. Risk and outcome analysis of 1832 consecutively excised basal cell carcinomas in a tertiary referral plastic surgery unit. Journal of plastic, reconstructive & aesthetic surgery : JPRAS 2010; 63(12):2057-2636 (Article; Published in Print)
  21. Leong S; Keeling A N; McGrath F P; Lee M J. Transcatheter embolisation of renal angiomyolipoma. Irish journal of medical science 2010; 179(2):211-266 (Article; Published in Print)
  22. Keeling Aoife N; Khalidi Karim; Leong Sum; Given Mark F; McGrath Frank P; Athanasiou Thanos; Lee Michael J. Subintimal angioplasty: predictors of long-term success. Journal of vascular and interventional radiology : JVIR 2009; 20(8):1013-1222 (Article; Published in Print)
  23. Leong Sum; Keeling Aoife N; Lee Michael J. A survey of interventional radiology awareness among final-year medical students in a European country. Cardiovascular and interventional radiology 2009; 32(4):623-699 (Article; Published in Print)
  24. Keeling A N; Leong S; Logan P M; Lee M J. Empyema and effusion: outcome of image-guided small-bore catheter drainage. Cardiovascular and interventional radiology 2008; 31(1):135-141 (Article; Published in Print)
  25. Leong S; Abbas S; Galvin L; Moroney J; Brennan P; Thornton J. Emergency stenting of an acute internal carotid artery occlusion from spontaneous dissection. Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences 2008; 14(1):69-72 (Article; Published in Print)
  26. Tsang J S; Naughton P A; Leong S; Hill A D K; Kelly C J; Leahy A L. Virtual reality simulation in endovascular surgical training. The surgeon : journal of the Royal Colleges of Surgeons of Edinburgh and Ireland 2008; 6(4):214-220 (Article; Published in Print)
  27. Leong Sum; Coffey John C; Hill Arnold D K. Hepatic resection for colorectal metastases. Value for risk scoring systems? Annals of surgery 2008; 247(4):N.A.-N.A. (Letter; Published in Print)
  28. Leong S, Alazawi D, Wong L, Kay E, Hill ADK. The Association between p53 and HER-2 expression in breast cancer may reduce the incidence of recurrence in breast cancer. Irish Journal of Medical Science Volume 176. September 2007 2007; 176():N.A.-N.A. (Meeting Abstract; Published in Print)
  29. Leong S, Naughton P, McGrath F, Kelly P, Leahy A, Lee MJ. High risk Abdominal Aortic Aneurysm patients: Endovascular Repair (EVAR) experience in a Single Centre. Irish Journal of Medical Science Volume 176. September 2007 2007; 176():N.A.-N.A. (Meeting Abstract; Published in Print)
  30. Leong S; Cahill R A; Mehigan B J; Stephens R B. Considerations on the learning curve for laparoscopic colorectal surgery: a view from the bottom. International journal of colorectal disease 2007; 22(9):1109-1151 (Article; Published in Print)
  31. Leong S, Smith F, Reynolds JV. Side effects and resistance of rectal tumours to neoadjuvant radiochemotherapy. Irish Journal of Medical Science Volume 175 Number 3 July, August, September 2006 2006; 175(3):N.A.-N.A. (Meeting Abstract; Published in Print)
  32. Leong S, Cahill RA, Stephens RB, Reynolds JV. Evaluating the learning curve of Laparoscopic Colectomy: A view from below. Irish Journal of Medical Science Volume 175 Number 1 January, February, March 2006 2006; 175():N.A.-N.A. (Meeting Abstract; Published in Print)

Research Trials