Volume 87 � Number 2S � Supplement 2013 Poster Viewing Abstracts S307

Materials/Methods: Using our IRB approved retrospective database, 341

patients underwent Whipple surgery for definitive treatment of pancre-

atic cancer from 2000-2012 and had appropriate follow-up with imaging.

The majority of these patients received adjuvant treatment. Chemo-

therapy was gemcitabine or 5-FU based. Radiation therapy prescription

for most patients was 50.4 Gy or higher. Recurrence was identified by

imaging. Locoregional failures were defined as recurrences adjacent to

the operative bed or in regional nodal areas. Logistical regression and

Kaplan-Meier survival with log rank test was used for statistical

analysis.

Results: For all 341 patients, median follow-up was 17.5 months with

median survival of 19.5 months. Sixty-five patients had resection alone

(group A), 87 had adjuvant chemotherapy (B), and 135 had adjuvant

chemoradiation (C). Group A included poor performance patients and

those that declined adjuvant treatment. Demographically, age, gender, T

and N stage were similar between the three groups. The microscopic

margin positive rate for groups A, B, and C were 30%, 37%, and 39%.

Overall recurrences in groups A, B, and C were 26%, 47%, and 47%.

Locoregional failure was 60%, 63%, and 38% and distant failure was 64%,

65%, and 66% for groups A, B, and C, respectively. On univariate analysis,

angiolymphatic invasion and perineural invasion were correlated to

recurrence (p < 0.01). Chemoradiation significantly reduced the rate of

local recurrence compared to chemotherapy from 63% to 38% (p Z 0.01).

Median survival times for groups A, B, and C were 13, 23, and 26 months,

respectively. The survival difference between groups B and C did not reach

statistical significance (p Z 0.23). Survival in patients with locoregional

failure and combined locoregional and distant failure were also not

significantly different.

Conclusions: In our series of resectable pancreatic patients, adjuvant

treatment with chemotherapy or chemoradiation improves survival over

observation. Adjuvant chemoradiation significantly lowered the risk of

locoregional recurrence.

Author Disclosure: A. Kumar: None. G. Falk: None. K. Stephans: None.

M. Walsh: None. R. Pelley: None. M. Abdel-Wahab: None.

2273Intensity Modulated Radiation Therapy Reduces GastrointestinalToxicity in Locally-Advanced Pancreas CancerS. Prasad,1,2 F. Huguet,3 J.F. Chou,2 Z. Zhang,2 A.J. Wu,2

and K.A. Goodman2; 1University of North Carolina at Chapel Hill, Chapel

Hill, NC, 2Memorial Sloan-Kettering Cancer Center, New York, NY, 3Tenon

Hospital, APHP, University Paris VI, Paris, France

Purpose/Objective(s): Intensity modulated radiation therapy (IMRT) has

been shown to reduce gastrointestinal (GI) toxicity for patients receiving

adjuvant chemoradiation (CRT) for resected pancreas cancer as compared

to 3D conformal radiation therapy (3DCRT). We assessed the impact of

IMRT as compared with 3DCRT on GI and hematologic toxicity in the

setting of definitive CRT for patients with locally advanced pancreas

cancer (LAPC).

Materials/Methods: We retrospectively assessed 205 patients with LAPC

treated with definitive CRT from May 2003 e March 2012; of these, 134

were treated with IMRT and 71 with 3DCRT. Data regarding patient, tumor

and treatment characteristics and acute GI and hematology toxicity

according to CTCAE v3.0 were recorded. Multivariable logistic regression

models were used to test the association between acute grade 2+ GI and

hematologic toxicity outcomes and predictors. To reduce potential bias of

comparing acute grade 2+ GI toxicity between 3DCRT vs IMRT,

a propensity score analysis was performed to account for potential con-

founding variables, including age, gender, radiation dose, and chemo-

therapy type.

Results: The median age at diagnosis was 63 years and the median follow-

up time for survivors was 12 months. Median RT dose for all patients was

5045 cGy (range, 1980-5600 cGy), with a significantly higher median dose

for the IMRT vs 3DCRT group (5600 cGy vs 5040 cGy, p < 0.001). Sixty-

two percent received concurrent gemcitabine and 37% 5-fluorouracil

(5FU)-based chemotherapy. Twenty-four 3DCRT patients (34%) experi-

enced Grade 2+ GI toxicity, compared to 21 IMRT patients (16%). Using

propensity score analysis, 3DCRT was significantly associated with more

grade 2+ GI toxicity (Odds Ratio: 1.3 [95% CI, 1.1-1.45], p Z 0.001).

There was no difference in grade 2+ hematologic toxicity between the

groups; however, grade 2+ hematologic toxicity was significantly greater

among patients receiving concurrent gemcitabine vs those receiving

concurrent 5FU (62% vs 29%, p < 0.0001).

Conclusions: IMRT is associated with a statistically significant decrease in

Grade 2+ GI toxicity when compared to 3DCRT for patients undergoing

definitive CRT for LAPC. Since it appears to be better tolerated even with

higher RT doses, IMRT may allow for further dose escalation, potentially

improving local control for this highly aggressive disease. Further

prospective studies to evaluate the benefits of dose-escalated CRT using

IMRT are warranted.

Author Disclosure: S. Prasad: None. F. Huguet: None. J.F. Chou: None. Z.

Zhang: None. A.J. Wu: None. K.A. Goodman: None.

2274Hypofractionated Chemoradiation Therapy With Gemcitabine PlusOxaliplatin for Unresectable Nonmetastatic Locally-AdvancedPancreatic CancerA. Romeo, E. Parisi, A. Passardi, S. Bellia, D. Arpa, G. Ghigi, E. Neri,

A. Sarnelli, A. Tesei, and R. Polico; IRCCS Istituto Scientifico Romagnolo

per lo Studio e la Cura dei Tumori (IRST), Meldola, Italy

Purpose/Objective(s): We previously published our experience of

hypofractionated radiation therapy in 30 patients with locally advanced

pancreatic cancer (LAPC). In this study we present our preliminary data on

feasibility and efficacy of hypofractionated radiation therapy at higher

doses “sandwiched” between chemotherapy cycles in patients with locally

advanced inoperable pancreatic cancer.

Materials/Methods: Ten patients with non resectable LAPC were enrolled

onto the first year of a phase I study ongoing at our institute and treated

between June 2011 and October 2012. They received a gemcitabine

(GEM) and oxaliplatin (OX) regimen every two weeks for 4 cycles, then

(15 days after completion of chemotherapy) radiation therapy and 15 days

later a further 4 cycles of GEMOX, followed by restaging. A multiphase

computed tomography (CT) with and without contrast medium was

acquired. Three different target volumes were identified: gross tumor

volume (GTV), clinical target volume (CTV) 1, including all visible

adenopathies and CTV 2, including regional lymph nodes at risk of

microscopic disease diffusion. The identified organs at risk (OAR) were

the liver, kidneys, spinal cord, small intestine and in particular duodenum

and stomach. Treatment was delivered by helical tomotherapy at the dose

of 35 Gy (with an increasing inhomogeneous dose distribution inside the

target volume of up to 30% of the prescription dose) in 7 fractions, one

fraction per day, in 9 days on GTV; 28 Gy up to 35 Gy on CTV1-CTV2 on

the basis of nodal status.

Results: Documented GEMOX-induced toxicity was similar to that re-

ported elsewhere. Radiation therapy was well tolerated and the most

frequently encountered adverse events were mild to moderate nausea and

vomiting, abdominal pain and fatigue. Almost all of the adverse effects

disappeared within 3/4 weeks of radiation therapy completion. Two

patients did not complete the second phase of GEMOX because of

persistent thrombocytopenia. Two out of 10 patients underwent palliative

radiation/chemotherapy for distant progression during the first 4 cycles of

GEMOX. All but one of the remaining 8 patients (7/8) obtained a partial

tumor response, of which 5 underwent surgical laparotomy (3 radical

pancreatic resection and 2 explorative laparotomy).

Conclusions: Our results show the feasibility and promising neoadjuvant

potential of accelerated hypofractionated radiation therapy plus GEMOX

regimen in unresectable LAPC.

Author Disclosure: A. Romeo: None. E. Parisi: None. A. Passardi: None.

S. Bellia: None. D. Arpa: None. G. Ghigi: None. E. Neri: None. A.

Sarnelli: None. A. Tesei: None. R. Polico: None.