Scientific Abstract 3377; Table

VariablesNo. of

patients (%) VariablesNo. of

patients (%) VariablesNo. of

patients (%) VariablesNo. of

patients (%) VariablesNo. of

patients (%)

Age(years) Presentation Histology Grade Stage>50 63(43.3) primary 90(62.1) malignant fibrous histiocytoma 31(21.4) G1 29(20.0) I 29(20.0)�50 82(56.6) recurrent 55(37.9) liposarcoma 31(21.4) G2 92(63.4) II 109(75.2)Sex Tumor size(cm) synovial sarcoma 24(16.6) G3 24(16.6) III 7(4.8)men 83(57.2) �5 81(55.9) fibrosarcoma 26(17.9) Margin Dose(Gy)women 62(42.8) >5 64(44.1) rhabdomyosarcoma 3(2.1) negative 128(88.3) �64 93(64.1)Location Depth others 30(20.7) Microscopic positive 10(6.9) >64 52(35.9)extremities 108(74.5) superfacial 46(31.7) Macroscopic positive 7(4.8)trunk 37(25.5) deep 99(68.3)

Volume 90 � Number 1S � Supplement 2014 Poster Viewing Abstracts S753

Conclusions: When compared with conventional techniques, postoperative

IMRT seems to provide better LC and OS and less severe late toxicities in

patients with STS of extremities and trunk, though the differences were not

statistically significant. Demographic and treatment characteristics of 145

patients with postoperative IMRT or conventional RT

Author Disclosure: J. Wang: None. S. Wang: None. Y. Song: None. X.

Liu: None. J. Jin: None. W. Wang: None. Z. Yu: None. Y. Liu: None. Y.

Li: None.

3378Whole-Lung Irradiation for Adults With Pulmonary MetastasesFrom Ewing SarcomaD.L. Casey, K.M. Alektiar, N.K. Gerber, and S.L. Wolden; Memorial

Sloan-Kettering Cancer Center, New York, NY

Purpose/Objective(s): To evaluate feasibility and patterns of failure in

adult patients with Ewing sarcoma (ES) treated with whole lung irradiation

(WLI) for pulmonary metastases.

Materials/Methods: Retrospective review of all ES patients treated at age

18 or older with 12-15 Gy WLI for pulmonary metastases at a single

institution between 1990 and 2012. Twenty-four patients met study

criteria.

Results: The median age at WLI was 23.6 years (range, 18.0-40.2). Me-

dian follow-up of surviving patients was 4.5 years (range, 1.2-9.6). The 3-

year cumulative incidence of pulmonary relapse (PR) was 56%, with a 3-

year cumulative incidence of PR as the site of first relapse of 43%. The 3-

year event-free survival (EFS) and overall survival (OS) were 36% and

44%, respectively. Patients with exclusively pulmonary metastases had

better outcomes than those with extrapulmonary metastases: the 3-year PR

was 46% in those with exclusively lung metastases versus 77% in those

with extrapulmonary metastases (P Z .02); the 3-year EFS was 48%

versus 13% (P Z .002); and the 3-year OS was 60% versus 13% (P Z.01). There was a trend toward worse survival with a history of smoking: 3-

year EFS was 58% versus 11% (P Z .06) and OS was 57% versus 32% (P

Z .08). Two patients developed herpes zoster in the radiation field at 6 and

12 weeks post-radiation. No patients developed pneumonitis or cardiac

toxicity, and there were no significant acute or late sequelae observed

among the survivors.

Conclusions: WLI in adult patients with ES and lung metastases is well

tolerated and associated with freedom from pulmonary relapse of 44% at 3

years. Given the acceptable toxicity and potential therapeutic effect, WLI

for pulmonary metastases in Ewing sarcoma should be part of standard of

care therapy for adults as it is in pediatric patients. All patients should be

advised to quit smoking before WLI.

Author Disclosure: D.L. Casey: None. K.M. Alektiar: None. N.K.

Gerber: None. S.L. Wolden: None.

337918F-FMISO PET/CT Visualization of Tumor Hypoxia in Patients WithChordoma of the Mobile and Sacrococcygeal SpineM.D. Cheney,1 Y. Chen,2 R. Lim,2 B.K. Winrich,2 A.L. Grosu,2

A.V. Trofimov,2 N. Depauw,2,3 H.A. Shih,2 J.H. Schwab,2 F.J. Hornicek,2

and T.F. DeLaney2; 1Harvard Radiation Oncology Program, Boston, MA,

2Massachusetts General Hospital, Boston, MA, 3University of Wollongong,

Wollongong, Australia

Purpose/Objective(s): Local recurrence rates in reported series of chor-

doma patients following treatment with surgery � radiation therapy (RT)

or definitive RT are high. Tumor hypoxia is associated with radioresistance

and local recurrence in animal models and human patients. [18F] fluo-

romisonidazole positron emission tomography/computed tomography

(FMISO-PET/CT) has been used to visualize hypoxic sub-volumes (HSV)

in skull base chordoma and the feasibility of its use in RT dose-escalation

has been demonstrated in head and neck cancer. The feasibility of FMISO-

PET/CT use for detection of targetable HSVs in patients with chordoma of

the mobile and sacrococcygeal spine is unknown and investigated in the

current study.

Materials/Methods: A prospective, pilot study of 20 patients with primary

or locally recurrent chordoma of the mobile or sacrococcygeal spine

treated with proton or combined proton/photon RT � surgery was

completed. FMISO-PET/CT was performed prior to RT and again after

19.8-34.2 GyRBE (relative biologic effectiveness). Gross tumor volumes

were delineated and HSVs defined including all voxels with a standardized

uptake value (SUV) � 1.4 times the mean muscle SUV. The pre-specified

threshold for FMISO-PET/CT feasibility was positive tracer uptake in 4/20

patients. Distributions of clinical characteristics and treatments received

were compared between patients with and without HSVs. Treatment out-

comes are reported.

Results: FMISO-PET/CT detected HSVs in 12 (60%; 12/20) patients, 8 of

which were of sufficient size (� 5 cc) to potentially allow for delivery of

an intensity modulated proton therapy boost. Patients with HSVs had

significantly larger gross tumor volumes (median Z 410.0 cc vs 63.4 cc; p

Z 0.02) and were significantly more likely to have stage T2 tumors (5/12

vs 0/8; pZ 0.04) compared to those without HSVs. After a median follow-

up of 1.8 years (range: 0.2-4.4), a local recurrence has yet to be observed.

Three patients developed metastatic disease, 2 of whom had HSVs.

Conclusions: FMISO-PET/CT is feasible for detection of targetable HSVs

within patients undergoing RT � surgery for treatment of chordoma of the

mobile and sacrococcygeal spine. Further study of its application in hyp-

oxia-directed, dose-escalated RT, particularly in patients at high risk for

local recurrence, is warranted.

Author Disclosure: M.D. Cheney: None. Y. Chen: None. R. Lim: None.

B.K. Winrich: None. A.L. Grosu: None. A.V. Trofimov: None. N.

Depauw: None. H.A. Shih: F. Honoraria; IJROBP Senior Editor. P.

Royalty; Up to Date. J.H. Schwab: G. Consultant; Stryker Spine, Bio-

m’Up. F.J. Hornicek: E. Research Grant; Sarcoma SPORE, NIH U01. G.

Consultant; Stryker Corporation, BioMed Valley Discoveries. K. Advisory

Board; ISOLS. Q. Patent/License Fee/Copyright; NSC23925. T.F. DeLa-

ney: A. Employee; Up to Date, Inc. E. Research Grant; National Cancer

Institute. P. Royalty; Wolters Kluwer Health.

3380Hypofractionated High-Dose-Rate Brachytherapy in NonmelanomaSkin Cancer TreatmentM. Arenas,1 M. Arguıs,1 L. Dıez-Presa,1 I. Henrıquez,1 M. Murcia-Mejıa,1

M. Gascon,1 D. Gomez,1 A. Lafuerza,1 E. Mur,2 and S. Sabater3;1Radiation Oncology Department. Hospital Universitari Sant Joan de

International Journal of Radiation Oncology � Biology � PhysicsS754

Reus, Reus, Spain, 2Radiation Oncology Department, Institut Oncologic

del Valles (IOV), Barcelona, Spain, 3Radiation Oncology Department,

Complejo Hospitalario Universitario de Albacete, Albacete, Spain

Purpose/Objective(s): Non-melanoma skin cancer (NMSC) is the most

frequently occurring cancer in humans. Different options currently exist to

treat NMSC, such as topical treatments, surgery and radiation. The aim of

this study was to analyze the outcomes, toxicity and cosmesis after patients

(pts) with NMSC were treated by hypofractionated high dose rate

brachytherapy (HHDR-B).

Materials/Methods: 141 NMSC lesions were treated by HHDR-B.

Hypofractionated treatment of 3 Gy was delivered three times a week, up

to a total dose of between 45 and 54 Gy. A fixed applicator was used on

106 lesions, whereas a customized mould was used on 35 lesions.

Results: With a median follow up of 24 months, local control at 2 years

was 92%. Complete regression was achieved in the 96.45% of the lesions.

Eleven treatment failures were observed: two partial responses, three with

persistent disease, and six marginal field recurrences. Fifty-five pts (40%)

had grade 2 or higher acute skin toxicity. Five patients (4.25%) had grade 4

acute skin toxicity. The cosmesis outcomes were excellent or good in 82%

of pts and fair in 10% of pts.

Conclusions: HHDR-B is an effective and well-tolerated treatment for

non-melanoma skin cancer.

Author Disclosure: M. Arenas: None. M. Arguıs: None. L. Dıez-Presa:

None. I. Henrıquez: None. M. Murcia-Mejıa: None. M. Gascon: None.

D. Gomez: None. A. Lafuerza: None. E. Mur: None. S. Sabater: None.

3381Feasibility of MRI-Guided Tri-Cobalt-60 IMRT for PreoperativeRadiation therapy of Soft-Tissue SarcomasA.U. Kishan, M. Cao, D.A. Low, P.A. Kupelian, M.L. Steinberg,

and M.R. Kamrava; University of California, Los Angeles, Los Angeles,

CA

Purpose/Objective(s): Contouring of extremity soft tissue sarcomas are

best accomplished using MRI guidance. Challenges exist with accurately

fusing MRI with CT simulation images as the patient is often in different

positions. The ability to simulate, plan, and treat using MRI alone presents

an opportunity to improve treatment for this group of patients both in terms

of target definition and minimizing daily treatment variations. We hy-

pothesized that a modulated MRI-guided cobalt 60 (60Co) planning system

could create IMRT plans that approximate linear accelerator (LINAC)

based plans.

Materials/Methods: The primary study population consisted of four pa-

tients with lower extremity sarcoma who were treated with pre-operative

IMRT to 50 Gy in 25 fractions in our department within the last year.

Target volumes were contoured as per the recent consensus guidelines

from Haas et al. CTV to PTV expansion was 5 mm. A commercially-

available MRI-guided tri-60Co planning system was used to generate

IMRT plans based on the same dosing schema and contours. A skin

corridor was defined as a volume 180 degrees from the center of the PTV,

encompassing 30-40% of the circumference of the extremity. Doses to the

Scientific Abstract 3381; Table Selected Average Dosimetric Parameters forLINAC and Modulated Cobalt-60 IMRT Plans (n Z 4)

LINAC Plans Modulated Cobalt-60 Plans

Skin CorridorD25 (Gy) 19.0 23.2Mean Dose (Gy) 13.6 17.4Max Dose (Gy) 40.7 36.9Long BoneD25 (Gy) 36.6 35.1Mean Dose (Gy) 25.5 25.0Max Dose (Gy) 48.6 53.6V40 (%) 31.5 34.1SkinD1cc (Gy) 52.3 56.5

bone, skin, skin corridor, and PTV were compared. D25, the dose received

by 25% of the target volume, inhomogeneity as per Wu et al.[(D2-D98)/

(prescription dose)*100] and R50 values were also compared.

Results: The average PTV volume was 1701.25 mL (range, 813.5-3190.0).

In all cases, both the clinically delivered LINAC plan and the modulated60Co plan covered 95% of the PTV. The mean R50 values were 2.07 and

2.42 for the LINAC and 60Co plans, respectively, while the mean PTV

inhomogeneity values were 9.78 and 13.51. Dosimetric parameters for the

skin corridor, in-field long bone (either the femur [n Z 3] or the tibia-

fibula complex [n Z 1]), and skin are shown in Table 1.

Conclusions: An MRI-guided radiation therapy system utilizing modu-

lated 60Co beams can deliver IMRT for preoperative STS with comparable

dosimetry to clinically delivered LINAC-based IMRT. Even greater im-

provements can be achieved as MRI-guided radiation therapy allows for

smaller planning margins. Based on this analysis, a clinical trial is being

initiated to evaluate treatment outcomes and toxicities using modulated60Co IMRT.

Author Disclosure: A.U. Kishan: None. M. Cao: None. D.A. Low: K.

Advisory Board; Feasibility of MRI-guided Tri-Cobalt-60 IMRT for Pre-

operative Radiotherapy of Soft Tissue Sarcomas. P.A. Kupelian: K.

Advisory Board; Scientific Advisory Board for ViewRay Inc. M.L.

Steinberg: None. M.R. Kamrava: None.

3382Acute Skin Toxicity Using High-Dose-Rate Electronic Brachytherapyfor Nonmelanoma Skin CancerM.K. Cheung, Y. Kim, S.E. Sckolnik, J.L. Grow, B.G. Slane, J.D. Gordon,

and B. Stea; University of Arizona, Tucson, Arizona, AZ

Purpose/Objective(s): High Dose Rate Electronic Brachytherapy (HDR-

EBT) is an alternate treatment modality for patients with non-melanom-

atous skin cancers who are not candidates for surgery. This study seeks to

identify and characterize factors associated with treatment toxicity using

this radiation modality.

Materials/Methods: Retrospective review of 33 patients with 50 lesions

treated at our institution from April 2011-May 2013 was performed with

IRB approval. All lesions were pathologically confirmed malignant basal

(56%) or squamous (44%) cell carcinoma. Median age was 76 years

(range: 43-92) and median tumor size was 1cm (range: 0.2cm-3cm). A

HDR-EBT system delivered a median BED of 60Gy (a/b Z 10; range:

BED 6.3-69.6Gy/2-29fx) to a depth of 0.1-0.5cm using an appropriate

sized applicator (range: 1-5cm diameter). Treatment toxicity was evaluated

using the RTOG/EORTC Acute/Late Radiation Morbidity Scoring Criteria.

Results: Local control is 100% with a median follow-up of 3.6 months.

Acute grade 3 moist desquamation developed in 9 of the treated lesions

(18%). Acute grade 4 ulceration manifested in 3 lesions in the lower ex-

tremity (6%) and 1 lesion on the upper lip (2%) and occurred a median of 23

days from the start of treatment. Table 1 compares the acute toxicities be-

tween lower extremity vs head and neck (HN) sites (ear, eyelid, nose, and

scalp). The proportion of lesions developing acute grade 2-3 toxicity was

similar between the two groups (47.1% vs 48.5%), but a greater proportion

of acute grade 4 toxicity developed in lower extremity lesions (17.6% vs

3.0%). There was also a greater proportion of acute grade 4 toxicity in

lesions treated with fraction size �500cGy vs 70, p Z 0.10), treatment

depth (�2mm vs>2mm, pZ 0.22), number of treatment fractions (21 days,

p Z 010). One patient developed late grade 4 toxicity with a non-healing

ulcer in the lower extremity 3.4 months after completion of treatment.

Scientific Abstract 3382; Table Acute Toxicity by Lesion Location

Toxicity Grade

LowerExtremity Lesions

(n Z 17)Head and NeckLesions (n Z 33)

Fisher ExactTest

Grade 1 6 (35.3%) 16 (48.5%) P Z .009Grade 2 8 (47.1%) 7 (21.2%)Grade 3 0 (0.0%) 9 (27.3%)Grade 4 3 (17.6%) 1 (3.0%)