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stage I, II, IIIA, and IIIB, respectively. Median age was 61.7
years (range: 35-87). After a median planned gap of 2 weeks
(range, 0-4; no gap in 25 patients since 2011), a boost dose
was delivered with either IMRT (n = 16, until 2011), VMAT (n
= 16), HT (n = 37) or 3D-CRT (n = 68). Concomitant CTX was
delivered in 127 patients, maily using a mitomycinecapecitabine combination (n = 117). Median follow-up was 42
months (range: 2-97). Four-year LC, OS, DFS, and CFS rates
were 80%, 84%, 78% and 90%, respectively. Time to
progression was 4 months (range: 0-41). A total of 24 patients
presented a recurrence (local only in 14, locoregional in 1,
locoregional and distant in 1, local and distant in 3, regional
only in 2, and distant only in 3 patients). Twelve patients
underwent a colostomy because of local recurrence (n = 12)
or pretreatment dysfunction (n = 2). Grade 3 acute toxicity
was observed in 33 patients (2.4%); i.e. erythema (26/33) or
diarrhoea (9/33). No late G3 cutaneous toxicity was
recorded. At the time of analysis, 127 patients presented
more than 6 months of followup and were considered
evaluable for late toxicity: 5 of 127 patients present a late
G3 gastrointestinal toxicity (anal incontinence). No G4 acute
or late toxicity was recorded. No significant difference was
observed in terms of local control or acute G3 toxicity
between MRT techniques and 3D-CRT boost techniques.
Conclusions: A total dose of 59.4 Gy to the anal canal and
involved nodes, including 36 Gy to the uninvolved nodes, is
effective and safe when delivered using modern IMRT
techniques and daily IGRT. For these reasons, VMAT or HT
and concurrent CTX are the standard of care in our
institutions.
PO-0704
Proton beam t herapy for hepatocellular carcinoma wit h
ext ensive portal vein tumor thrombosis
T. Okumura1, N. Fukumitsu1, M. Mizumoto1, H. Ishikawa1, K.
Ohnishi1, K. Murofushi1, H. Numajiri1, K. Fukuda2, M. Abei2, T.
Aihara1, T. Sakae1, K. Tsuboi1
1
University of Tsukuba, Department of Radiation Oncology,
Tsukuba, Japan
2
University of Tsukuba, Department of Gastroenterology,
Tsukuba, Japan
Purpose/ Obj ective: To evaluate the efficacy of proton beam
therapy (PBT) for hepatocellular carcinoma with extensive
tumor thrombosis in the main trunk or major branches of the
portal vein.
Materials and Methods: Eighty patients with hepatocellular
carcinoma were treated by PBT. There were 65 men and 15
women, and the median age was 65 years old (range: 25 –
88). The CTV ranged from 15.2 cm3 to 1687 cm3 (median:
238.9 cm3). The clinical stages were 3B, 3C, 4A, and 4B in 65,
1, 5, and 9 patients, respectively. Thirty-two patients had
primary tumors, and 48 had recurrent tumors. The delivered
total dose ranged from 70 to 80.47 Gy10 (median: 80.47Gy10)
in terms of equivalent dose in 2Gy fractions.
Results: Seventy-seven patients (96.3%) completed the
planned treatment. Median survival rate for all the patients
was 12 months. MST for the patients treated with PTV that
encompassed all the detectable lesions was 26.9 months, and
MST for the patients who had viable tumor outside of their
PTV was 6.3 months. Local recurrence after PBT was
observed in 3 patients. Forty-five patients died of tumor
3rd ESTRO Forum 2015
progression, and 28 of them had recurrence out of the PTV.
Multivariate analysis revealed existence of viable tumor
outside of the PTV, clinical stage, and value of des-gammacarboxy prothrombin as significant factors affecting the OS.
Conclusions: PBT was effective for patients with extensive
portal tumor thrombus, if the PTV encompassed all the
detectable lesions.
PO-0705
Could acute toxicity predict tumor regression rate in rectal
cancer patients undergoing neoadj uvant treatment?
E. Ozsahin1, B. De Bari1, A. Saidi1, D. Hanhloser2, D. Wagner3,
P. Yan4, O. Matzinger5, J. Bourhis6
1
Centre Hospitalier Universitaire Vaudois, Department of
Radiation Oncology, Lausanne Vaud, Switzerland
2
Centre
Hospitalier
Universitaire
Vaudois,
Surgery
Department, Lausanne Vaud, Switzerland
3
Centre Hospitalier Universitaire Vaudois, Medical Oncology
Department, Lausanne Vaud, Switzerland
4
Centre Hospitalier Universitaire Vaudois, Pathology
Department, Lausanne Vaud, Switzerland
5
Riviera Hospital, Radiation Oncology Department, Lausanne
Vaud, Switzerland
6
Centre Hospitalier Universitaire Vaudois, Radiation
Oncology Department, Lausanne Vaud, Switzerland
Purpose/ Obj ective: Some studies already showed that acute
toxicity during chemo +/- radiotherapy (CT +/- RT) was
correlated to the clinical response of the tumor. In this
retrospective study, we report our analysis of acute toxicity
of rectal cancer cancer patients treated with an homogenous
schedule of CT +/- RT.
Materials and Methods: Between 01/2010 and 08/2014, 83
locally advanced rectal cancer patients consecutively treated
in our institution were analyzed. All these patients received
long-course neoadjuvant chemoradiotherapy (45 Gy on pelvic
nodes and mesorectum and 50 Gy on gross tumor volume and
corresponding mesorectum, delivered with a simultaneous
integrated boost). All patients were treated with helical
Tomotherapy (HT) and daily image guided radiotherapy, and
all of them underwent radical surgery. Concomitant
chemotherapy with oral capecitabine was delivered in all the
patients. Primary endpoint of this study was to report the
rate of acute toxicity (G2 or more) of this therapeutic
approach and to correlate acute toxicity to the Mandard
tumor regression rate (TRG). Toxicity were retrospectively
scored using CTC-AE score (v. 4.0). The considered acute
toxicity were: skin toxicity, diarrhoea, blood loss, cystitis,
anorectal pain. We performed logistic regression analyses,
and we correlated the TRG with the presence of acute
toxicity (any grade), the presence of any acute toxicity grade
> 2, and with a 'sum of toxicity' (ST) of each toxicity grades
(i.e: this ST in a patient presenting a G2 bladder toxicity , a
G1 pain and a G3 diarrhoea was 6, 2+1+3).
Results: Globally, 22/83 patients presented an acute > G2
toxicity (26.5%), with only one patients presenting a G3 acute
skin toxicity. Data about TRG were available for 69 patients.
Logistic regression showed that better TRG have been found
in patients presenting higher TS, both when TRG was
considered as an ordinal (p=0.028) or as a continuous variable
(p=0.03).
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Conclusions:
Long-course
chemo-radiotherapy
with
simultaneous integrated boost is safe in the treatment of
rectal cancer patients. Patients presenting more pronounced
and/or several toxicity showed a significant trend toward a
better TRG. Immunological local reactions could potentially
explain these results, and should be further explored.
PO-0706
Individualised margin calculations for different
regions in anal cancer IMRT
target
L. Durrant1, F. Van den Heuvel1, M. Robinson1, M.A. Hawkins1,
R. Muirhead1
1
CRUK/MRC Oxford Institute for Radiation Oncology,
Department of Oncology, Oxford, United Kingdom
Purpose/ Obj ective: UK IMRT anal cancer treatment uses
large fields to uninvolved nodal groups (40Gy) with
simultaneous integrated boost to the primary tumour (50.4Gy
T1/T2; 53.2Gy T3/T4) and involved nodes (50.4Gy). With a
simple bony match online, iliac nodes are well covered and
the margins required are well documented, however the
margins for prophylactic inguinal nodes (pIN) and primary
tumour are not well established as data from daily imaging
are limited; these form the focus of this study.
Materials and Methods: Anal cancer patients treated at a
single institution under current UK IMRT guidelines were
screened; 11 consecutive inguinal node negative patients
were studied. Supine treatment comprised 28 fractions with
daily imaging: CBCT fractions 1-5, 10, 15, 20 and 25;
orthogonal kV imaging all other fractions.
99 CBCT’s were re-matched automatically to the planning
CT. A bony match was performed using a clipbox
encompassing the bony pelvis. Re-matches were performed
within the same clipbox using the clinician defined tumour
(GTVA) as a region of interest (ROI), then repeated with the
pIN ROI. Accuracy of auto-matches were assessed visually to
ensure clinical relevance.
Bony match values were subtracted from the GTVA and pIN
measurements to evaluate differences in the optimal
treatment position for the tumour or the nodes relative to a
simple bony match. Margins were calculated using van Herk’s
recipe.
Results: Differences (mm) between GTVA/ bony matches
were larger than inguinal/ bony matches in all axes ( lat -3.1
to 4.2; -2 to 1.5, vert- 6.9 to 12.7; -3.6 to 2.9, long -13.3 to
17.2; -8.5 to 7.3 in GTV and pIN respectively). This was
statistically significant in the long axis (p<0.05) shown in
Fig.1. GTVA had consistently larger systematic and random
errors than pIN, reflected in the margin calculations (mm):
GTVA lat 2.8, long 9.8, vert 5.8; pIN lat 1.5, long 3.1, vert
3.1.
Conclusions: With a simple bony match, the margin around
pIN can be reduced to 1.5mm laterally and 3.1mm in all
other directions potentially reducing toxicity to the groin,
genitalia and bladder.
The GTVA to PTV margin incorporates microscopic disease,
the motion of the soft tissues of the anus which can be
affected by tumour size, location, bowel filling and BMI; and
the set up error. The margin reported in this study covers set
up error and soft tissue motion of the anus. An individualised
margin incorporating these factors can be calculated and
applied during the treatment course with the aim of reducing
toxicity in adjacent organs such as vagina, bladder and penile
bulb.
Further investigation is warranted to demonstrate reduced
toxicities with these strategies.
PO-0707
Multidisciplinary clinic models deliver higher value care for
patients with pancreatic cancer
S. Elnahal1, B. Luber2, A.T. Wild3, A. Dholakia1, H. Wang2, T.
Pawlik4, J.M. Herman1, S. Alcorn1
1
Johns Hopkins Kimmel Comprehensive Cancer Center,
Radiation Oncology, Baltimore, USA
2
Johns Hopkins Kimmel Comprehensive Cancer Center,
Biostatistics, Baltimore, USA
3
Memorial Sloan Kettering Cancer Center, Radiation
Oncology, New York City, USA
4
Johns Hopkins Kimmel Comprehensive Cancer Center,
Surgery, Baltimore, USA
Purpose/ Obj ective: Multidisciplinary clinics (MDCs) offer
patients an initial evaluation by all three oncologic
specialists, radiologists, pathologists, and others. The costs
and overall value (defined as quality divided by costs) of care
in MDCs are not well-described. For patients with pancreatic
cancer, we compared direct care costs, patient retention
rates, patient phone calls with symptoms, patient ED visits
with symptoms, and survival outcomes for patients treated in
a pancreatic MDC to patients evaluated outside of the MDC.
Materials and Methods: Two cohorts of patients with
pancreatic cancer seen at our institution were analyzed and