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schedules have also been reported recently. RTOG 0415 with
only low-risk patients, showed that 70 Gy in 28 fr over 5.6
weeks is non-inferior to 73.8 Gy in 41 fr over 8.2 weeks for
low risk PCa patients.
The Dutch randomised phase III HYPRO
trial with 804 evaluable patients with intermediate/high-risk
PCa, comparing moderately hypofractionated RT (19 fr; 3.4
Gy/fr.) with conventional RT (39 fr; 2 Gy/fr), showed non-
inferiority with comparable toxicity.
Some prospective results of Sterotactic Body RadioTherapy
(SBRT) with 5 fractions and 7-8 Gy/fr suggest equal clinical
outcome compared to conventional RT and with acceptable
toxicity. The Scandinavian multicentre phase III trial “HYPO-
RT-PC” was recently closed, with 1200 patients recruited
during 2005-2015. All patients had intermediate risk PCa
(PSA≤20; one or two of the risk factors; T3, Gleason ≥7, PSA
10-20). No hormones were used. Patients were randomized to
either conventionally fractionated RT (39 fr; 2.0 Gy/fr) over
7 weeks, or to a schedule with extreme hypofractionation (7
fr; 6.1 Gy/ fr) in 2.5 weeks (always including two weekends)
.
The two treatment arms are designed to be equieffective for
late normal tissue complications assuming α/β=3 Gy. Primary
endpoint will be mature within 2 years, and toxicity data will
be reported by late this year.
SP-0300
Focal strategies: ready for prime time?
A.Bossi
1
Institut Gustav Roussy, Radiation Oncology, Villejuif, France
1
Abstract not received
SP-0301
Brachytherapy as a boost: the way to go?
P. Hoskin
1
Mount Vernon Hospital, Northwood Middlesex, United
Kingdom
1
Brachytherapy has always represented the most focal means
on delivering radiationh having the advantages of the inverse
square law around the radiation source which ensures
delivery of an intense high dose within the implant and a
rapid fall dose outside. These characteristics mean that
brachytherapy can deliver very high doses to the prostate
gland with in the tolerance doses of bladder and rectum and
that the characteristics of dose distribution with in the
implant mean that the volume receiving 150% and 200%
prescribed peripheral dose (the 150 and the 200) are
considerably greater than can be achieved with any external
beam technique.
Brachytherapy as a boost can be used in two distinct ways.
First is as a boost to the whole gland following external beam
radiotherapy. There is now grade a level I evidence from
randomised controlled trials that both low dose rate and high
dose rate brachytherapy achieve effective dose escalation
and consequently better biochemical relapse free survival.
There is also increasing interest in the use of brachytherapy
to deliver a focal boost to dominant lesions defined on multi-
parametric MR scanning and mapping template biopsies. Thus
within a whole gland brachytherapy volume sub volumes can
be defined within which the dose can be further escalated.
Planning studies have confirmed the feasibility of this
approach with both low dose rate and high dose rate
brachytherapy and the requirements for catheter or seed
placement to achieve these endpoints has been described.
The clinical application of this approach is still in its infancy
although early results confirm its feasibility.
Summary: both low dose rate and high dose rate
brachytherapy offer optimal means of focal dose delivery
within the prostate gland. The use of this modality for whole
gland treatment is now well established sound evidence base.
Emerging application sub volume posts to dominant tumour
volumes is under investigation.
Debate: This house believes that SBRT should become the
standard of care for T1 and small T2 NSCLC tumours
SP-0302
For the motion
K. Franks
1
St James Institute of Oncology, Clinical Oncology, Leeds,
United Kingdom
1
The current standard of care for T1 and small T2 early-stage
non-small cell lung cancer (NSCLC) is surgical resection with
lobectomy and nodal sampling/resection. There is
randomized evidence that wedge resection is an inferior
operation to lobectomy [1] but no large series randomized
evidence of surgery versus any other curative intervention for
early stage lung cancer. In addition, for patients over 71
years there may be no benefit of lobectomy over limited
resection[2]. Stereotactic body radiotherapy (SBRT) is not a
new treatment and has been used in medically inoperable
stage I NSCLC for 20 years[3]. Given the very high rates of
local control ~90% at 3-5 years[4], the low rates of acute
toxicity and little detriment to quality of life post
treatment[5] SBRT is now a standard of care for medically
inoperable peripherally located T1 and T2 tumours up to 5cm
in diameter. For medically operable patients where the risks
of surgery are low, surgery does offer a theoretical
advantage over local ablative treatment such as SBRT.
Optimum surgery with removal or the tumour and
surrounding lobe may remove occult cancer cells outside the
treated volume that may not be included in the SBRT
treatment volume. In addition, nodal resection may convey
an additional survival benefit and for those patients with
occult N1/2 disease those patients could further benefit with
the addition of adjuvant chemotherapy.
However, the average age at the time of diagnosis of lung
cancer is 70, often in patient’s with significant medical co-
morbidity that precludes lobectomy and reduces the chance
of them receiving adjuvant chemotherapy[6]. Surgical
mortality at both 30 and 90 days increases with age further
reducing the potential benefit from lobectomy and nodal
sampling/resection[7]. In addition, with PET/CT staging and
minimally invasive techniques (EBUS) for pathologically
sampling the mediastinum now routine practice, the chance
of missing occult N1/N2 nodal disease is small being <9% in
one series[8].
Propensity analysis of patients receiving surgery versus SBRT
have been performed on retrospective series with some
reports suggesting no difference in survival between the two
match groups and others suggesting a benefit with surgery.
Randomized controlled trials (RCT) of surgery versus SBRT
(STARS/ROSEL) have been attempted but have been closed
prematurely due to poor accrual. A recent pooled analysis of
the STARS and ROSEL studies showed no significant difference
between SBRT and surgery, though a trend for improved
survival with SABR but this was based on 58 patients[9].
Given the limited data from STARS/ROSEL and conflicting
results from propensity matched analysis there is a need for
successful randomized trials of surgery versus SBRT to prove
whether SBRT should be the standard of care. Hopefully, the
open SABRtooth (UK) and STABLE-MATES (USA) trial combined
with other planned trials of SBRT versus surgery will recruit
and provide the answer to this key question.