ESTRO 35 Abstract Book

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ESTRO 35 2016 S605
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EP-1286
Does dose-escalated neo-adjuvant radiotherapy improve
pathological response in rectal cancers?
N. Pasha
1Queen's Hospital, Clinical Oncology, Romford, United
Kingdom
1, D. Woolf1, M. Martinou1, K. Williams1, S. Ball1, S.
Raouf1
Purpose or Objective: Neoadjuvant chemoradiotherapy
(CRT) is considered a standard approach for locally invasive
rectal cancer. Several phase 3 studies have shown an
improvement in local control with combined radiotherapy
and capecitabine / 5-fluorouracil. There is good evidence
that increased dose of radiotherapy is associated with both
better pathological response and survival in many
malignancies, although the data in rectal cancer is less
convincing. In this study we assessed the impact of dose-
escalated radiotherapy on pathological outcome.
Material and Methods: We evaluated all patients who
received chemo-radiotherapy for rectal cancer and
subsequently had an anterior resection/ abdominoperineal
resection with a total mesorectal excision (TME) between
February 2012 and December 2014. Patients received 50.4Gy
1.8Gy fractions, and more recently those who have T3/4
disease with a threatened circumferential margin had a
simultaneous integrated boost of the primary tumour to a
total dose of 53.2Gy, with concurrent capecitabine
chemotherapy (825mg/m2 BD) daily throughout treatment.
Treatment was initially using 3-D conformal radiotherapy but
more recently has been using a VMAT technique with cone
beam CT used during treatment. Surgery was performed 8-12
weeks after completion of CRT.The primary end point was
pathological response (Dworak score 0-4) of the operative
specimen. Scores of 0-2 were considered to be non-
pathological responders and scores of 3-4 were considered to
be pathological responders.
Results: A total of 73 patients received neoadjuvant
chemoradiotherapy. 61 patients weretreated with a standard
radiotherapy fractionation of 50.4Gy in 28 fractions (Group A)
and 12 patients were treated with a dose escalated
fractionation to the primary tumour of 53.2Gy in 28 fractions
(Group B). The rate of pathological response was 39.3% in
Group A and 86.7% with Group B (t=3.55, p<0.001).
Conclusion: This study demonstrates the beneficial effects of
dose-escalated radiotherapy and wetherefore recommend
this regime be considered for inclusion in future phase 2
studies.
EP-1287
Radiation-induced rectal toxicity in prostate cancer: a
proctoscopy evaluation
E. Ippolito
1Campus Biomedico University, Radiotherapy Unit, Roma,
Italy
1, M. Nuzzo2 , G. Macchia2, F. Deodato2, S. Cilla3, M.
Ingrosso4, L. Fuccio5, A. Farioli5, G. Mantini6, V. Valentini6,
G.C. Mattiucci6, G. Siepe7, M. Ntreta7, S. Cammelli 7, A.
Guido7, M. Pieri7, A. Arcelli7, F. Bertini7, L. Ronchi7, A.G.
Morganti7
2Fondazione di Ricerca e Cura “Giovanni Paolo II”- Catholic
University of Sacred Heart, Radiotherapy Unit, Campobasso,
Italy
3Fondazione di Ricerca e Cura “Giovanni Paolo II”- Catholic
University of Sacred Heart, Medical Physics Unit,
Campobasso, Italy
4Fondazione di Ricerca e Cura “Giovanni Paolo II”- Catholic
University of Sacred Heart, Endoscopy Unit, Campobasso,
Italy
5Sant’Orsola-Malpighi Hospital- University of Bologna,
Department of Medical and Surgical Sciences - DIMEC,
Bologna, Italy
6Policlinico Universitario “A. Gemelli”- Università Cattolica
del Sacro Cuore, Department of Radiotherapy, Roma, Italy
7Radiation Oncology Center- Sant'Orsola-Malpighi Hospital-
University of Bologna, Department of Experimental-
Diagnostic and Specialty Medicine - DIMES, Bologna, Italy
Purpose or Objective: Early proctoscopy (1 year) can predict
late rectal mucosa changes and therefore can be used as
surrogate end-point for late rectal toxicity. The aim of this
study was to retrospectively analyze data of patients treated
at a single institution, consecutively enrolled in different
prospective clinical trials, trying to determine a correlation
between treatment parameters and VRS (Vienna Rectoscopy
Score) recorded at 1-year proctoscopy.
Material and Methods: Patients with prostate
adenocarcinoma treated with curative or adjuvant RT
underwent endoscopy one year after RT; 195 patients were
included in this analysis. Correlations between VRS > 2 and
several treatment parameters were investigated by
univariate and multivariate logistic analysis.
Results: Patients treated with an EQD2 dose > 75 Gy, with
hypofractionatied schedule and radiosurgery boost had a
higher incidence of VRS > 2 (p= < 0.001). On the contrary,
previous surgery and 3D-conformal radiotherapy (vs IMRT)
were associated with a lower incidence of rectal mucosal
changes (p=< 0.001; p= 0.003, respectively). At multivariate
analysis radiosurgery boost was associated with the highest
odd ratios for the risk of developing a VRS > 2 (OR: 4.143; CI:
1.24-13.81; p=0.001). Even surgery showed a significant
correlation with VRS > 2 (OR: 0.39; CI: 0.17-9.94; p=0.037,
Table 1).
Conclusion: Prolonged patients follow-up is needed to
“clinically” confirm the increased rectal toxicity produced by
radiosurgery boost.
EP-1288
Sphincter function and dose of radiation in rectal cancer. A
Single-Institutional study
F. Arias
1Complejo Hospitalario de Navarra, Department of
Radiotherapy-Oncology, Pamplona, Spain
1, C. Eito1, G. Asín1, I. Mora1, K. Cambra2, F. Mañeru3,
B. Ibáñez2, L. Arbea4, M. Errasti1, M. Barrado 1, M. Campo1, I.
Visus 1, J. García-Escobedo1, C. Torres1, M. Ciga5
2Complejo Hospitalario de Navarra, Statistics Department,
Pamplona, Spain
3Complejo Hospitalario de Navarra, Department of Physics,
Pamplona, Spain
4Clínica Universidad de Navarra, Department of
Radiotherapy-Oncology, Pamplona, Spain
5Complejo Hospitalario de Navarra, Department of Surgery,
Pamplona, Spain
Purpose or Objective: The objective of the study is to
determine the correlations among the variables of dose and
the sphincter function (SF) in patients with locally advanced
rectal cancer treated with preoperative
capecitabine/radiotherapy followed by Local Anterior
Resection(LAR) +TME.
Material and Methods: We have retrospectively reviewed 92
consecutive patients with LARC treated at our center with
LAR from 2006 and more than 1 year free from disease. We
re-contoured the anal sphincters (AS) of patients with the
help of the radiologist. SF was assessed with the Wexner
scale (0-20 points, being punctuation inversely proportional
to SF). All questionnaires were filled out between January
2010 and December 2012. Dosimetric parameters that have
been studied include: V20 V30, V40, V50, mean dose
(Dmean), mínimum dose (Dmin), D90 (dose received by 90%
of the sphincter) and D98 Statistical analysis: the correlations