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Research
Volume 12 No 2
I
March 2016
15
The Radiation Oncology
Research Committee is
committed to promoting the
critical importance of research
as part of good practice
through the administration of
grants and awards. In 2014, the
committee awarded the Ferring
Pharmaceuticals Research Grant
to Dr Kumar Gogna and his
team for their research study
‘A single arm, prospective Phase
II study of Split-Course Pelvic
Radiotherapy for patients with
Locally Progressive Castrate
Resistant Prostate Cancer’.
Background
In a majority of the patients with castrate
resistant prostate cancer (CRPC) who
in the past have principally been
managed with androgen deprivation,
skeletal metastases usually dominate
the clinical picture. However, about
10-18 per cent
1, 2
of these patients can
present with disconcerting morbidity
from locally progressive disease, usually
characterised by significant urinary
symptoms. Some patients may also
present with pelvic pain and/or rectal
symptoms.
Managing the urinary symptoms may
require multiple surgical interventions.
Response can be short lived and repeat
procedures can be challenging. Pelvic
exenteration
3
is an option, but clearly
difficult to justify in the majority. The
effect of newer systemic therapies on
locally progressive disease has not been
defined.
Whilst there is a lack of prospective data,
the utility of pelvic radiation therapy
(RT) in effectively palliating locally
progressive CRPC is supported by a
number of retrospective case series
4-9
with most suggesting improved results
with higher doses and possibly longer
courses of treatment. This includes
our own experience with a high dose
hypo-fractionated split course regimen
10
based on the following principles:
• Prostate cancer has a low
α
/
β
ratio
and therefore one would anticipate
a better response with hypo-
fractionation.
• A break in treatment may assist in
minimising acute toxicity. Accelerated
re-population
11
is usually not an issue
with prostate cancer and therefore
unlikely to compromise local control.
• Overall treatment is shortened and
inconvenience to patients and carers is
minimised.
• If clinically dictated, the second half
of RT course may be omitted in the
knowledge that the initial course is
likely to provide some benefit at least
in the short term
12
.
Summary
The current Phase II trial is a single
arm locally based study designed
to prospectively investigate the split
course regimen further with the
hypothesis being that it (i) results in
improved bladder and bowel related
quality of life (measured on the EPIC
QoL instrument),
12
(ii) has low acute
toxicity, (iii) is effective and results in a
durable response, and (iv) further local
interventions are likely to be minimised.
Treatment Regimen:
3D conformal RT/IMRT: 55Gy in 22
fractions given as two courses of
25Gy and 30Gy in 10 and 12 fractions
respectively separated by a one week
treatment break.
The initial aim is to accrue 20 patients
and based on the results, the
subsequent plan would be to undertake
an extended study either in its original
format or with modifications through the
auspices of the Trans-Tasman Radiation
Oncology Group and the ANZUP Cancer
Trials Group.
To date, 10 patients have been accrued
and it is hoped that the target accrual
will be reached in 12-15 months’ time.
Study Aims to Progress
Prostate Cancer Treatment
continued over...