ESTRO 36 Abstract Book

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S96 ESTRO 36 2017
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Mechanical uncertainties (type B) of PMMA jig position
relative to OD1000 array were estimated to be 0.2mm.
Repeated measurements with different afterloaders
(without dismantling set-up) are plotted in figure 2. The
maximum standard deviation was found to be 0.6mm for
R26, 0.5mm for R30 ring. A non-linear least squares fit was
made (Gander et al. 1994) to the mean positions R26 and
R30 rings resulting in a radius of 13.2mm and 14.9mm,
geometric centre location of (0.15,0.13) and (0.20,0.10)
respectively.
Conclusion
Initial results indicate that the measurement technique is
robust and reproducible. Repeated measurements with
different afterloaders indicate a maximum standard
deviation of 0.6mm (R26), 0.5mm (R30). Other central
inserts can be devised for other applicators, and
afterloader systems. Thus the technique is versatile but
requires an high resolution 2D array and specialized
measurement jig. Moreover our technique is currently
limited to 2D source path determination viz. in the
measurement plane, parallel to the ring plane.
PV-0190 The analysis of prostate cancer with median
lobe hyperplasia treated I-125 brachytherapy
K. Muraki1 , H. Suefuji1, E. Ogo1, H. Eto1, C. Tsuji 1, C.
Hattori1, Y. Miyata1 , H. Himuro1, T. Abe1, S. Hayashi2, K.
Chikui2, M. Nakiri2, T. Igawa2
1 Kurume University, Radiology, Kurume, Japan
2 Kurume University, Urinology, Kurume, Japan
Purpose or Objective
Most patients with median lobe hyperplasia (MLH) have a
large-volume prostate and severe dysuria. Prostate cancer
with MLH is a relative contraindication of permanent
prostate brachytherapy (PPB), because of the increased
risk of post-implant urination disorder and the technical
difficulties of stability while implanting intravesical
tissue. We examined that the treatment outcome, seed
migration, urination disorder after treatment in MLH
patients who received PPB. The purpose of our research
concerns is to what degree could MLH implant be
stabilized.
Material and Methods
Between March 2007 and December 2014, 250 patients
with localized prostate cancer underwent PPB, of which
32 patients had MLH identified radiologically on the MRI
scan. These patients were divided into three MLH groups,
mild(<5mm), moderate(5-10mm), severe(>10mm), by
measuring the distance of MLH (dMLH); between the
posterior transitional zone and the prostatic tissue
protruding into the bladder. We retrospectively analyzed
seed migration, DVH, operation time, genitourinary (GU)
toxicity, and DFS.
Results
Median follow-up is 53.5 months (range; 9-104months) and
median age is 68.5 years old(range; 57-75yo). MLH group
were respectively classified mild in 12, moderate in 12,
severe in 8. D’Amico risk classification were low risk in 21,
intermediate risk in 11.Median prostate volume was such
as 34.4cc/32.8cc/28.6cc (severe/moderate/mild). The
median D90 was 145Gy. All patients still have achieved
relapse-free survival. Implant migration and low-dose
level of median lobe tended to increase in severe
MLH.There was no relapse and PSA failure. The IPSS
(International Prostate Symptom Score) for most patients
worsened during the immediate post-implant period, but
most of these patients were resolved by their second
follow-up at 6 months. The median IPSS one month or six
months after post-implant were respectively 21.5 or
observed Grade 2 acute toxicity. The late toxicity
such as Grade 2 was observed in 25%, such as erectile
dysfunction, urinary hemorrhage and urethralgia.
Hemorrhage in Grade 3 was observed in just one case, who
had taken an aspirin for cerebral infarction. There was no
Grade 4 complication and the all complication was
acceptable.
Conclusion
In our study, MLH does not appear to be a strong
contraindication to PPB because there were no significant
differences in DFS and GU toxicity. However, we
experienced that seed migration and cold spot degree
tended to increase in severe MLH cases, we have to pay
attention to treat severe MLH.
Award Lecture: Honorary Members’ Award Lectures
SP-0191 Optimizing the Treatment of HPV-related
Oropharyngeal Cancer: the difficult journey back
B. O'Sullivan1
1Princess Margaret Cancer Centre University Health
Network, Toronto, Canada
Traditional approaches to head and neck cancer (HNC)
have used either surgery +/- adjuvant radiotherapy, or
radiotherapy +/- chemotherapy. Thus treatment was
practiced with a paradigm that head and neck cancer
(HNC) is one disease requiring the same treatment,
modulated according to anatomic constraints influencing
whether function might be preserved, largely governed by
psychosocial attitudes directed at avoidance of surgical
ablation with resulting loss of function and esthetic
appearance. In fact, while avoiding surgery, a philosophy
evolved that greater intensity of non-surgical
management is optimal. However, current evidence
suggests the contrary and strong evidence that treatment-
related death (e.g. pharyngeal disabilities or other
problems) is claiming 10-20% of contemporary HNC
survivors (Forastiere et al JCO 2013) For the recently
emerged HPV-related oropharyngeal cancer (OPC),
approaches are even more complex since the traditional
cause of death (local or regional recurrence) is now rare
and most patients who die of disease succumb to distant
metastases (DM). Stage-for-Stage HPV-related OPC has
extremely favorable outcomes in terms of locoregional
control, overall survival, and outcome of salvage
treatments compared to traditional HNCs and the