Dr Looi Wen Shen
Dr Looi Wen Shen uses proton therapy for prostate cancer treatment.

Dr Looi Wen Shen – Proton Therapy in Singapore at Biopolis

Head & Consultant
Radiation Oncologist
MBBS (SIN), FRCR (Clinical Oncology, UK), FAMS (Radiation Oncology)
Proton Therapy SG (biopolis)
Singapore Institute of Advanced Medicine

Clinical Assistant Professor
Duke-NUS Singhealth

Visiting Consultant Radiation Oncologist
KK Women’s and Children’s Hospital, Singapore

Visiting Consultant Radiation Oncologist
National Cancer Centre Singapore

Urologic cancers (prostate cancer, kidney cancer); sarcomas; skin cancer; lymphomas; liver cancer; head and neck cancers; thoracic cancers; formal subspecialty training in UFPTI for adult and paediatric proton therapy.

Article: Proton Therapy

Read about proton therapy above


Dr Looi Wen Shen is a radiation oncologist of Proton Therapy SG, Singapore Institute of Advanced Medicine. He graduated from Yong Loo Lin School of Medicine, National University of Singapore in 2008, and went on to complete his residency training in National Cancer Centre Singapore (NCCS), before receiving specialist accreditation in radiation oncology by the Specialist Accreditation Board. He worked as a Consultant in the Division of Radiation Oncology, National Cancer Centre Singapore; Clinical Assistant Professor in Duke-NUS medical school; and Clinical Teacher in the Lee Kong Chian School of Medicine. Dr Looi is a radiation oncologist with substantial experience in proton therapy, having practised at the University of Florida Proton Therapy Institute, which has the largest paediatric radiotherapy in the world, where he completed subspecialty fellowship training in proton therapy and paediatric radiotherapy as an Adjunct Clinical Post-Doctoral Associate.

He also received further proton therapy training at the Taiwan Medical University Hospital Proton Centre for regionally endemic diseases such as liver cancer and nasopharyngeal cancer. Dr Looi is proud to have been able to start the paediatric proton program at National Cancer Centre Singapore. During his time in public service in NCCS, Dr Looi oversaw the creation of a comprehensive paediatric radiation oncology program that integrated allied healthcare to improve patient satisfaction and experience. As an educator to the younger generation of doctors, Dr Looi obtained a certificate for Essential Skills in Medical Education for this. He is adept at 3D conformal radiotherapy (3DCRT), intensity modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), stereotactic body radiotherapy (SBRT), and intensity modulated proton therapy (IMPT).

Dr Looi is one of the few regional radiation oncologist members of the Children’s Oncology Group (COG). He was the NCCS representative for the IAEA Interregional Technical Cooperation Project INT6065: “Contributing towards Improved Survival in Childhood Cancer Using Radiation Medicine and Nutrition”. Additionally, he is a member of the organizing committee for the International Society of Paediatric Oncology (SIOP) Asia Congress of 2024. He is also a member of several other professional societies including the American Society for Radiation Oncology (ASTRO), Academy of Medicine, Singapore (AMS), Royal College of Radiology (RCR) (UK), Children’s Cancer and Leukaemia Group (CCLG) (UK), and the Paediatric Radiation Oncology Society (PROS). Today, Dr Looi continues to contribute to public healthcare as a Visiting Consultant in KK Women’s and Children’s Hospital and National Cancer Centre Singapore. Additionally, he is listed in the Chordoma Foundation Directory (Wen Shen Looi).

While in NCCS, his research was published in journals such as the International Journal of Radiation Oncology Biology and Physics, and Medical Physics, Pediatric Blood and Cancer, and the Archives of Disease in Childhood. Through his research, Dr Looi endeavours to decrease the acute and late side effects of radiation in patients, thus improving their quality of life. Dr Looi will continue his research in the Singapore Institute of Advanced Medicine (SAM), focusing on the clinical outcomes of proton therapy. SAM’s plans for incorporation of FLASH proton therapy will also add an exciting dimension to the local proton research and clinical scene.

Proton beam therapy reduces overall dose to the patient

Education and Training

2020 – 2021 Postdoctoral Fellowship- Paediatric and Adult Proton Therapy at the University of Florida Health Proton Therapy Institute (UFPTI)
2020 United States Medical Licensing Examination (USMLE)
2017 Fellow, Academy of Medicine, Singapore (FAMS)
2017 Fellow of the Royal College of Radiologists (FRCR Clinical Oncology)
2013 – 2017 Residency- Radiation Oncology, National Cancer Centre, Singapore
2003 – 2008 Bachelor of Medicine, Bachelor of Surgery (M.B.B.S)- Yong Loo Lin, School of Medicine, National University of Singapore
Radiation oncologist training


2020—2022 Florida Board of Medicine
2020 Standard Certificate for United States Medical Licencing Examination (USMLE)- Education Commission for Foreign Medical Graduates (ECFMG)  
2019 Essential Skills in Medical Education Certificate (ESME)- Association for Medical Education in Europe (AMEE)
2017 Certificate of Specialist Accreditation, Radiation Oncology- Specialist Accreditation Board, Singapore
2017 Certificate of Specialist Registration, Radiation Oncology, Singapore Medical Council
2008 Certificate of Medical Registration, Radiation Oncology, Singapore Medical Council
Radiation oncologist certification

Past and Present Appointments

2023 Consultant, Proton Therapy Singapore, Singapore Institute of Advanced Medicine
2021 – Clinical Assistant Professor, Duke-NUS
2021 – 2023 Clinical Teacher, Lee Kong Chian, School of Medicine
2020 – 2021 Adjunct Clinical Postdoctoral Associate, University of Florida College of Medicine
2019 –            Visiting Consultant, Hematology/Oncology Service, KKH, Singapore.
2019 – 2021 Clinical Instructor at Duke-NUS Medical School
2017 – 2023 Consultant, Radiation Oncology, National Cancer Centre, Singapore

Professional Licensure

2008 – Practicing Certificate, Singapore Medical Council
2017 – Radiation Oncology Specialty Certificate, Specialist Accreditation Board of Singapore
2020 – 2022 Registration for Resident / House Physician, Florida Board of Medicine

Professional Memberships

2021 – Children’s Cancer and Leukaemia Group, International Member
2021 – Children’s Oncology Group, International Associate Member
2021 – VIVA Asia Brain and Solid Tumour Working Group Member
2020 – American Society for Radiation Oncology
2019 – Paediatric Radiation Oncology Society, Member
2018 – 2019 Singapore Radiological Society, Executive Committee Member (co-opted)
2017 – Royal College of Radiology (Clinical Oncology), Fellow (FRCR)
2017 – Academy of Medicine Singapore, Fellow (FAMS)
2008 – 2014 Singapore Medical Association


2019 Health Manpower Development Program (HMDP) award
2016 SAF resuscitation distinction award
2013 Republic of Singapore Air Force Air Power Generation Command Commendation 2013
2013 Resuscitation Distinction Award SAF Medical Corps
2009 Medical Society YLLSOM National University of Singapore Colours Award

Previous Grants

  1. Development of a Virtual/Mixed Reality Proton Gantry Room prototype to aid paediatric patient counselling, FY2021.
  2. Kids, adolescent and young adult (KAYA) electronic patient-reported outcomes for Quality of Life metric measurements following radiotherapy, FY2023.
  3. Improving comfort in Kids, Adolescent and Young adults during radiotherapy: Open-face masks in paediatric patients for immobilisation, FY2023.

Selected Publications (see Google Scholar for more)

  1. Tan AJL, Tey ML, Seow WT, Low DCY, Chang KTE, Ng LP, Looi WS, Wong RX, Tan EEK, Low SYY. Intraoperative Fluorescein Sodium in Pediatric Neurosurgery: A Preliminary Case Series from a Singapore Children’s Hospital. NeuroSci. 2023; 4(1):54-64. https://doi.org/10.3390/neurosci4010007
  2. Liu KX, Indelicato DJ, Paulino AC, Looi WS, Catalano PJ, Chintagumpala MM, Gallotto SL, Marcus KJ, Haas-Kogan DA, Tarbell NJ, MacDonald SM, Mahajan A, Yock TI. Multi-institutional Characterization of Outcomes for Pediatric and Young Adult Patients With High-Risk Myxopapillary Ependymoma After Radiation Therapy. Int J Radiat Oncol Biol Phys. 2023 Jul 10:S0360-3016(23)04708-9. doi: 10.1016/j.ijrobp.2023.06.2293. Epub ahead of print. PMID: 37437812.
  3. Lim YG, Tan EE, Looi WS, Wong RX, Chang KT, Low DC, Seow WT, Low SY. Biopsy of paediatric brainstem intrinsic tumours: Experience from a Singapore Children’s Hospital. J Clin Neurosci. 2022 Oct 10;106:8-13. doi: 10.1016/j.jocn.2022.09.021. Epub ahead of print. PMID: 36228504.
  4. Hong KT, Han JW, Fuji H, Byun HK, Koh KN, Wong RX, Lee HL, Yoon HI, Lee JH, Phi JH, Kim SK, Kim DS, Lyu CJ, Choi JY, Kang HJ, Chen YW, Lee YY, Im HJ, Ra YS, Do Ahn S, Low SYY, Looi WS, Park HJ, Suh YG, Suh CO, Wang KC, Tan EEK, Wong TT, Kim JY. Outcomes of intracranial non-germinomatous germ cell tumors: a retrospective Asian multinational study on treatment strategies and prognostic factors. J Neurooncol. 2022 Aug 31. doi: 10.1007/s11060-022-04100-w. Epub ahead of print. PMID: 36045266.
  5. Lim JX, Tan EEK, Ng LP, Seow WT, Chang KTE, Wong RX, Looi WS, Low DCY, Low SYY. Monomodality versus Combined Therapy in Optic Pathway Gliomas-20-Year Experience from a Singapore Children’s Hospital. Front Surg. 2022 May 2;9:827675. doi: 10.3389/fsurg.2022.827675. PMID: 35586500; PMCID: PMC9108767.
  6. Li Y, Ong WS, Shwe MTT, Yit NLF, Quek SZH, Pang EPP, Looi WS, Nei WL, Wang MLC, Chua MLK, Tan TWK, Chua ET, Ng CT, Tuan JKL. Cardiovascular toxicities of androgen deprivation therapy in Asian men with localized prostate cancer after curative radiotherapy: a registry-based observational study. Cardiooncology. 2022 Mar 14;8(1):4. doi: 10.1186/s40959-022-00131-4. PMID: 35287756.
  7. Koh KN, Wong RX, Lee DE, Han JW, Byun HK, Yoon HI, Kim DS, Lyu CJ, Kang HJ, Hong KT, Lee JH, Kim IH, Phi JH, Kim SK, Wong TT, Lee HL, Lai IC, Kang YM, Ra YS, Ahn SD, Im HJ, Looi WS, Low SYY, Tan EEK, Park HJ, Shin SH, Fuji H, Suh CO, Chen YW, Kim JY. Outcomes of intracranial germinoma-a retrospective multinational Asian study on effect of clinical presentation and differential treatment strategies. Neuro Oncol. 2021 Dec 22:noab295. doi: 10.1093/neuonc/noab295. Epub ahead of print. PMID: 34935949.
  8. Yen Sin Koh, Jason Yongsheng Chan, Wen Shen Looi, Mohamad Farid, N Gopalakrishna Iyer, Ci-An Gerald Tay, Kiattisa Sommat, Ru Xin Wong. Outcomes of head and neck angiosarcoma with different treatment modalities: a 20-year single institutional experience. Precision Cancer Medicine 2022 March.
  9. Valerie Ting Lim, Angelie Cabe Gacasan, Jeffrey Kit Loong Tuan, Terence Wee Kiat Tan, Youquan Li, Wen Long Nei, Wen Shen Looi, Xinying Lin, Hong Qi Tan, Eric Chern-Pin Chua, Eric Pei Ping Pang. Evaluation of inter- and intra-observer variations in prostate gland delineation using CT-alone versus CT/TPUS. Rep Pract Oncol Radiother 2022;27(1):97-103. DOI: 10.5603/RPOR.a2022.0004
  10. Hyperfractionated-Accelerated Reirradiation with Proton Therapy for Radiation-Associated Breast Angiosarcoma. Wen Shen Looi, MBBS, FRCR; Julie A. Bradley, MD; Xiaoying Liang, PhD; Christiana M. Shaw, MD; Mark Leyngold, MD; Raymond B. Mailhot Vega, MD, MPH; Eric D. Brooks, MD; Michael S. Rutenberg, MD, PhD; Lisa R. Spiguel, MD; Fantine Giap, MD; Nancy P. Mendenhall, MD. International Journal of Particle Therapy. https://doi.org/10.14338/IJPT-21-00031.1 2022/1/18
  11. Li Y, Chan Kong Ngai T, Zhou S, Yap Haw Hwong J, Pang Pei Ping E, Ong Li Kuan A, Wang Lian Chek M, Chua Lee Kiang M, Looi WS, Nei WL, Chua ET, On WLK, Tan Wee Kiat T, Yuen Shyi Peng J, Tuan Kit Loong J. A comparative analysis between low-dose-rate brachytherapy and external beam radiation therapy for low- and intermediate-risk prostate cancer in Asian men. Acta Oncol. 2021 Jul 14:1-5. doi: 10.1080/0284186X.2021.1950921. Epub ahead of print. PMID: 34259123.
  12. Looi WS, Indelicato DJ, Rutenberg MS. The Role of Radiation Therapy for Symptomatic Desmoid Tumors. Curr Treat Options Oncol. 2021 Mar 1;22(4):34. doi: 10.1007/s11864-021-00831-6. PMID: 33649873.
  13. Bte Syed Sulaiman N, Kuick CH, Chang KTE, Wan KR, Looi WS, Low DCY, Seow WT, Low SYY. Cytokines in Pediatric Pilocytic Astrocytomas: A Clinico-Pathological Study. NeuroSci. 2021; 2(1):95-108. https://doi.org/10.3390/neurosci2010006
  14. Indelicato DJ, Bates JE, Mailhot Vega RB, Rotondo RL, Hoppe BS, Morris CG, Looi WS, Sandler ES, Aldana PR, Bradley JA. Second tumor risk in children treated with proton therapy. Pediatr Blood Cancer. 2021 Feb 9:e28941. doi: 10.1002/pbc.28941. Epub ahead of print. PMID: 33565257.
  15. Indelicato DJ, Rotondo RL, Mailhot Vega RB, Holtzman AL, Looi WS, Morris CG, Sandler ES, Aldana PR, Bradley JA. Local Control Following Proton Therapy for Pediatric Chordoma. Int J Radiat Oncol Biol Phys. 2020 Nov 27:S0360-3016(20)34591-0. doi: 10.1016/j.ijrobp.2020.11.051. Epub ahead of print. PMID: 33253819.
  16. Looi WS, Indelicato DJ, Mailhot Vega RB, Morris CG, Sandler E, Aldana PR, Bradley JA. Outcomes following limited-volume proton therapy for multifocal spinal myxopapillary ependymoma. Pediatr Blood Cancer. 2020 Nov 23:e28820. doi: 10.1002/pbc.28820. Epub ahead of print. PMID: 33226179.
  17. Low SYY, Bte Syed Sulaiman N, Tan EEK, Ng LP, Kuick CH, Chang KTE, Tang PH, Wong RX, Looi WS, Low DCY, Seow WT. Cerebrospinal fluid cytokines in metastatic group 3 and 4 medulloblastoma. BMC Cancer. 2020 Jun 15;20(1):554. doi: 10.1186/s12885-020-07048-0. PMID: 32539808; PMCID: PMC7296667.
  18. Pang EPP, Knight K, Park SY, Lian W, Master Z, Baird M, Chan JWX, Wang MLC, Tan TWK, Chua MLK, Chua ET, Looi WS, Nei WL, Tuan JKL. Duration-dependent margins for prostate radiotherapy-a practical motion mitigation strategy. Strahlenther Onkol. 2020 Jul;196(7):657-663. doi: 10.1007/s00066-019-01558-y. Epub 2020 Jan 13. PMID: 31932995.
  19. Looi WS, Goh SH, Tan CJ, Yeoh KW, Seng MS. Adolescent with facial swelling. Arch Dis Child Educ Pract Ed. 2019 Oct 22:edpract-2019-317654. doi: 10.1136/archdischild-2019-317654. Epub ahead of print. PMID: 31641021.
  20. Looi WS, Low DCY, Low SYY, Goh SH. Neonatal orbital swelling due to intracranial teratoma. Arch Dis Child Fetal Neonatal Ed. 2019 Jul;104(4):F365. doi: 10.1136/archdischild-2018-316337. Epub 2018 Dec 14. PMID: 30552092.