作者：新加坡國際癌症中心 柯淞杰醫師（Dr Quah Song Chiek Daniel）
In life, one is sometimes presented with golden opportunities.
I am a dually-accredited Radiation Oncologist and Palliative Medicine Physician from National Cancer Centre, Singapore. I have been fascinated by Boron Neutron Capture Therapy (BNCT) since first hearing about it in 1989, years before I began medical school. Since then, as this technology is not available in Singapore, my contact with BNCT has been limited to journal articles and conferences.
Thus, for me, it was a golden opportunity when I had the great fortune of being invited to observe a patient undergoing BNCT in Taiwan. Obviously, I was thrilled and grabbed this chance, flying to Taiwan one day before the day of treatment.
The following day began early at 7am in Taipei Veterans General Hospital (TVGH), where the hospital team made preparations for the young patient who would receive BNCT later that day. By that early hour, the paediatric doctors and nurses were all ready to go; and they had with them a large box of essential medical equipment. Thereafter, it was a long drive to the Tsing Hwa Open-Pool Reactor (THOR). During which, I had a detailed discussion with Dr Chen Yi Wei, who was one of the prominent doctors in Taiwan well-versed in BNCT. The discussion ranged from the history of BNCT in Taiwan to its exciting future in the horizon.
The activities at THOR began with a discussion with all involved in the entire process of BNCT including the nuclear physicists who operate the reactor. The patient’s medical history, including pertinent imaging scans, was presented. This was then followed by a discussion of radiotherapy treatment plans for the patient. Different plans with different field positions and different irradiation time were considered before a final course of action was agreed upon and adopted.
This was followed by the simulation process. It was indeed fascinating to see the nuclear physicist performing patient positioning during simulation. Once that was completed and the relevant markings made on the patient, he was moved to another room for the infusion of boronopenylalanine (BPA). During the subsequent two-hour infusion, it was heart-warming to see everyone present trying to make this young patient feel as comfortable as possible. Two blood samples were obtained during this period which showed that the BPA levels within the blood were on course to reaching levels satisfactory for BNCT.
Finally, after two hours, it was time for the neutron irradiation. The patient was positioned within the treatment room amidst a flurry of activity all aimed in making the treatment a success. Under the watchful eyes of the medical team via close circuit monitoring, the treatment proceeded. During which I was taken for a quick tour of THOR, learning it history from numerous photographs on the walls, followed by an explanation of how the reactor functioned. The irradiation was over in less than 30 minutes.
Our time at THOR ended with a debrief amongst all the personnel involved in the treatment. Then everyone began the journey back to TVGH, which we reached about 4:30pm.
Overall, it was a very long day for everyone. However, for me, the whole journey was a time well spent which allowed me to experience, to an extent, what a patient in Singapore would have experienced should he or she decided to travel overseas for BNCT. It may have been a long journey. However, for these patients who have opted to undergo BNCT, they only do so when no other options are available to them. In other words, for them the choice is between waiting for disease progression and inevitable demise, or take a shot at an emerging therapy that may buy precious time for them and their family. I am sure that many of them would echo my feeling that this journey is one that was well taken.
The main contributor of the long day was the distance THOR was from TVGH. However, with the advent of accelerator-based neutron sources (ABNS), future BNCT facilities can be built within hospital compounds, minimising travelling time and distances. Indeed, the future of BNCT looks bright in the near future.
At the same time, this trip was not only about BNCT – it also allowed me to have a taste of medical tourism in Taiwan – an experience patients and their loved ones would have when they come from abroad to seek medical therapy in Taiwan. More importantly, for patients with progressive incurable diseases, every moment of their limited lifespan is precious. Thus, to be able to spend some sweet moments with their loved ones while receiving potentially life changing treatment is killing two birds with one stone.
There is a Chinese saying, 百闻不如一见, whose literal translation is “seeing once is better than hearing a hundred times” or “Seeing is believing”. This trip has indeed been an eye-opener for me. At the same time, I left Taiwan with a mixed bag of feelings: firstly, I was elated to have finally seen BNCT in action after reading about it for close to three decades; secondly, I felt hopeful that more patients in the future could have BNCT as an option; and lastly, I cannot help but feel envious of the BNCT staff in Taiwan who have the chance of being part of an international effort to enter a new phase of radiation oncology. I am very thankful for Dr Chen for giving this valuable opportunity to observe and learn, and I am looking forward to future visits to Taiwan to learn even more about BNCT.
BNCT in Taiwan – My Second Experience
Three days before Christmas of 2017, I was delighted to have the opportunity of observing Boron Neutron Capture Therapy (BNCT) in action a second time. As before, it was under the kind invitation and guidance of Dr Chen Yi-Wei of Taipei Veterans General Hospital. Most of the events of the day were familiar reminders of my previous fruitful trip – beginning with an early morning trip to Tsing Hua Open-Pool Reactor, spending a whole day there, before returning in the late afternoon. It was an equally enriching and eye-opening experience like my last trip from which I learnt more about BNCT. However, there were a few notable differences between the treatment this time and my first experience about a month ago.
The first noticeable difference is linked to the fact that I had already observed BNCT in action once, and had noted the similarity and differences to normal photon radiotherapy that I perform daily, thus, making it easier to immerse myself into the whole process this time round. This included appreciating the discussion and the final decision of choosing of the treatment plan utilising two beam angles (which had better treatment parameters compared to three angles), to the differences in the timing of neutron irradiation between the two treatment fields. I was also able to have hands-on experience in the simulation process by helping out to compare the actual beam’s eye view of the neutron treatment port to that on the digitally reconstructed radiographs. Along the way, there was time to appreciate all the hustle and bustle that was going on – such as the collection and analysis of serum levels of boronophenylalanine, as well as the urgency to for the treatment staff to enter and exit the irradiation chamber quickly during the change of treatment position, to minimise radiation exposure.
The more important difference for this treatment was the patient herself. She was a young lady with a recurrent brainstem glioma. These recurrent tumours are invariably fatal with current standard therapy. That she was given a possible second chance at life with BNCT is something that is very remarkable and would have not been possible if not for the combined effort of the BNCT team. I was later informed that her treatment was a historical milestone for Taiwan as she was the first patient with brain stem tumour treated with BNCT. Prior to this, studies were conducted on simulation images of patients with similar patients, and these dosimetric evaluations demonstrated the safety of BNCT in these group of patients.
However, what struck me most about this patient was her attitude throughout the whole process. She was smiling and joking with the whole team. At certain points, she even asked for her photograph to be taken to allow her to relate her whole experience to her friends and relatives. Not once throughout the whole process did she give the impression that she was fearful about the dagger the tumour held over her head.
That really got me thinking about a special feature that BNCT has over other standard therapy. Most patients who opted for BNCT have no further standard therapy for their relentless disease. In other words, death is an inevitable eventuality in time to come. That meant that the time for them to spend with their loved ones to create wonderful memories is short. Thus, these patients should not be wasting this precious commodity of theirs on what Dr Ira Byock terms “disproportionate medical intervention”. BNCT is unique as it allows these patients to have their cake and eat it. BNCT provides hope that no other standard treatment can, and it only takes up a small proportion of the limited “lifespan currency” of patients. This is the main reason why I am so passionate about BNCT – it gives hope and a possible way out for patients who are placed on “palliative care”. I would like to think that it may also be this same reason for this patient’s demeanour throughout her treatment. I would also hope that the international BNCT community understands and tap on this “patient-centricity” of BNCT as new centres open across the world – while there is no doubt that BNCT would result in favourable clinical response of tumours, the issue is whether the patient finds meaning in their sacrifice of a portion their precious limited remaining time.
I would like to express my gratitude to Dr Chen and the rest of the BNCT team, the knowledge I gained during this trip was one of my best Christmas present I have ever received.