Results
47 patients with a median age of 9 years (2-25 years)were treated at our
institution with image guided PBS PBT till the cut-off period. During
this period this patient population constituted 28% of the total
patients treated with PBT at our centre. Table-1 describes the baseline
characteristics of the patients. 27 patients were diagnosed with a CNS
tumor, and the rest with a non-CNS tumor [Fig-1a and 1b].The most
common diagnosis was ependymoma followed by rhabdomyosarcoma (RMS) and
glioma. 23 patients who had recurrent disease were referred for PBT of
which 7 patientswere for re-irradiation.13 children (80% of children
younger than 6 years and 2 children between 6-8 years) required atleast
one procedure of sedation during either simulation and/or
treatment[Fig 2a and 2b]. Of these, only 7 required sedation during
the entire treatment (all of them were <4 years except one
autistic child who was 8 years old).
Treatment related characteristics have been described in Table-2. Among
patients who received CSI, 3 patients were younger than 6 years, 7 were
between 7-15 years and 3 were >15 years. One 15-year-old
girl with an intracranial germinoma received whole ventricular
irradiation (WVI).On analysis of the technique of PBT planning, MFO was
used in 21 patients (of which 17 were non-CNS tumors), SFO was used in
11 patients (all of them being CNS tumors) and hybrid planswere used in
15 patients (including all 13 patients of CSI). Median number of
fractions received was 30 (23-33) for CNS patients to a median dose of
54CGE(40-55.8Gy) and 32 (17-35) for non-CNS patients to a median dose of
59.4CGE (30.6-70.4). One patient of recurrent para-meningeal RMS
received hyperfractionation with 52.8CGE in 40 fractions with a twice
daily fractionation.
Median number of CBCT’s per patient for CNS tumors was 16 (4-29),
whereas for patients with non-CNS tumors it was 20 (7-33). 6 patients
underwent an adaptive re-planning based on the check CT scans and/or
CBCT imaging. 16 patients (34%) also received concurrent chemotherapy
as per the original treatment plan.