Introduction:
De-intensification of cancer treatment in children and young adults has
gathered considerable momentumas the long-term childhood cancer
survivors are at an increased risk of serious health related
issuesrelatedto treatment[1,2]. Since radiation is one of the major
contributors to the late effects in children including growth defects,
neuro-cognitive defects, endocrinopathies, cardiovascular effects,
lymphedema and secondary malignant neoplasms (SMN) [3], there has
been a widespread evaluation of radiation de-intensification in the last
two decades for several haematological and solid tumors [4,5,6].
Radiation therapy however cannot be completely avoided in many clinical
protocols and remain an integral component of management and the best
possible conformal techniques of radiation should be employed in such
situations.
Proton beam therapy (PBT) owing to its superior physical property
results in significantly lower doses of radiation to the healthy normal
structures thereby has a potential tomitigate both acute and late
radiation related effects. This is especially impactful in children and
young adults due to much larger tumor to body volumes (compared to
adults) and also due to higher propensity to develop permanent radiation
sequelae. Multiple prospective and retrospective studies have shown that
the dosimetric benefit achieved results in favourable clinical
outcomes[7-11].Despite the lack of randomized controlled trials
demonstrating superiority of PBT over conformal photon-based techniques
most collaborative group trials conducted in North America (Children’s
Oncology group) and Europe allow patients to be treated with PBT [12,
13]. In fact, it is the preferred treatment modality for a majority of
leading pediatric oncologists of the worldfor most solid tumors
requiring radiation therapy[14]. The concerns related to safety of
the older generation passive scattering proton therapy (PSPT) such as
neutron contamination, higher rates of treatment related necrosis have
been addressed sufficiently with the advent of contemporary pencil beam
scanning (PBS) PBT with on-board volumetric imaging, modern planning
algorithms and better understanding of biological uncertainties of PBT.
Our multi-room PBT facility with fully rotating gantries capable of
delivering contemporary image guided PBS PBT is the first proton therapy
centre in the Indian subcontinent. The patient treatments began in Jan
2019 [15,16] and since then our centre has been the only referral
centre for PBT in this region. The patients and physicians of this
region, which is home to nearly one quarter of the world’s population
have diverse socio-economic, cultural and educational back grounds and
very little is known regarding their preference and adoption of this
relatively new and cost-intensive technology. We hereby report the
demographic profile and our initial experience of treating children and
young adults with image guided PBS PBT.