Intensity-modulated Whole Pelvic Radiotherapy Provides Effective Dosimetric Outcomes for Cervical Cancer Treatment With Lower Toxicities

Cancer/Radiothrapie 18 (2014) 745752

Disponible en ligne sur

ScienceDirectwww.sciencedirect.com

Original article

Intensi y provides effectivedosimetric outcomes for cervical cancer treatment with lowertoxicities

La dosimpour le c

Y. Lv , F. WDepartment of

a r t i c

Article history:Received 19 FeReceived in reAccepted 5 Au

Keywords:Cervical canceIntensity-modBladder lling

Mots cls :Cancer du col Radiothrapiemodulation dRemplissage v

CorresponE-mail add

http://dx.doi.o1278-3218/ trie de la radiothrapie conformationnelle avec modulation dintensitancer du col utrin permet une diminution de la toxicit

ang , L. Yang , G. Sun

Radiotherapy, The First Afliated Hospital of Anhui Medical University, 281, Jixi Road, Hefei, Anhui 230022, Peoples Republic of China

l e i n f o

bruary 2014vised form 24 July 2014gust 2014

rulated radiotherapy (IMRT)

a b s t r a c t

Purpose. To compare the efcacy of intensity-modulated radiotherapy, three-dimensional conformalradiotherapy, and conventional radiotherapy for cervical cancer treatment.Materials and methods. Whole pelvis intensity-modulated radiotherapy, three-dimensional conformalradiotherapy, and conventional radiotherapy plans were designed for 16 patients with stage IIB cervicalcancer, each using the prescribed dose of 50.4 Gy/28 fractions. Dosevolume histograms of the targetvolume and organs at risk were evaluated.Results. Compared to the 3D conformal and conventional radiotherapy plans, the intensity-modulatedradiotherapy plan demonstrated superior conformal treatment. The mean planning target volume doseof all three plans reached the target effective therapeutic dose. The planning target volume dose of theintensity-modulated radiotherapy plan was signicantly higher than that of either the three-dimensionalconformal radiotherapy or conventional radiotherapy plan (P < 0.05). When more than 30 Gy was admin-istered in intensity-modulated radiotherapy, organs at risk including the small intestine, rectum, bladder,and bone marrow received a signicantly reduced volume of radiation. In comparison of the average plan-ning target volume doses, signicant volume reductions in irradiation of organs at risk were obtainedwith full bladders.Conclusions. An intensity-modulated radiotherapy plan with appropriate margins encompassing theprimary tumour and potential microscopic pelvic disease reduces the dose to organs at risk withoutcompromising target coverage. Intensity-modulated radiotherapy is an appropriate denitive treatmentfor patients with cervical cancer.

2014 Published by Elsevier Masson SAS on behalf of the Socit franaise de radiothrapieoncologique (SFRO).

utrin conformationnelle avecintensitsical

r s u m

Objectif de ltude. Comparer lefcacit de la radiothrapie conformationnelle avec modulationdintensit, de la radiothrapie conformationnelle tridimensionnelle et de la radiothrapie classique dansle cancer du col utrin.Matriels et mthodes. Une radiothrapie pelvienne de 50,4 Gy en 28 fractions a t planie pour16 patientes atteintes dun cancer du col utrin de stade IIB avec chacune des trois techniques. Les rsultatsde la dosimtrie ont t compars avec les histogrammes dosevolume du volume cible et des organes risque.

ding author.ress: sunguoping@ahmu.edu.cn (G. Sun).

rg/10.1016/j.canrad.2014.08.0052014 Published by Elsevier Masson SAS on behalf of the Socit franaise de radiothrapie oncologique (SFRO).ty-modulated whole pelvic radiotherap

746 Y. Lv et al. / Cancer/Radiothrapie 18 (2014) 745752

Rsultats. La radiothrapie conformationnelle avec modulation dintensit a donn les meilleurs rsul-tats, la dose dlivre dans le volume cible prvisionnel tant suprieure celle atteinte avec les deuxautres techniques (p < 0,05). Ds que la dose dpassait 30 Gy, la dose dlivre par radiothrapie confor-mationnelle avec modulation dintensit dans lintestin grle, le rectum, la vessie et la moelle osseuse tait

age v

nformes ext

risqu utrSAS p

1. Introdu

Cervicaland was thworldwide cervical canpathologicaa good targadenocarcingenerally coget dose forthe surrounmakes it ac

Conventof brachytbrachytheraradiotherapthe presencbeam radiolesions (palymph nodtor, and prthe pelvic cintestine, arisk from iracute radiaand grade receiving cothat compliin 5 to 30Three-dimedeveloped tformal radiwhich are snormally hpriate, convsuch as comtechnologieonance imatechniques modulated cancer. Theby the sumclinical taruence canwhich reprfore, when complex 3Dand steep dment, whethe target Intensity-m

l tisstoxic11]

comr ce

nearile oesenture

is atd thperio

of 4 aveeportnsityve costatuh then pr

onveity-msime

at ribonetics

teria

tient

rova boaeen esenncludervicencin: 38r lld to xt 15signicativement rduite. Le remplissdans les organes risque.Conclusion. Une radiothrapie coadquates de la tumeur primaire et dde la dose dlivre dans les organes traitement appropri du cancer du col

2014 Publie par Elsevier Masson

ction

cancer is the third most commonly diagnosed cancere fourth leading cause of cancer deaths among womenin 2008 [1]. The majority of patients diagnosed withcer received radiation as a treatment component. Thel and anatomic characteristics of cervical cancer make itet for radiotherapy. First, squamous cell carcinoma andoma are sensitive to radiotherapy. Second, tumours arenned to the pelvis during development. Third, the tar-

the tumour can be reached with limited irradiation toding organs. Finally, the natural cavity of the vagina

cessible for brachytherapy.ional radiotherapy for cervical cancer is composedherapy and external beam radiotherapy. Althoughpy boosts the local dose to the tumour, external beamy aims to reduce the size of the gross tumour ande of microscopic disease in the pelvic area. Externaltherapy targets include primary tumours, subclinicalrametrical uterine tissue, and vagina), and regionales (common iliac, external and internal iliac, obtura-esacral nodes) [2]. Because the cervix is localized inentre and surrounded by the bladder, rectum, smallnd vagina, it is difcult to protect these organs atradiation using conventional radiotherapy. Grade 3/4tion proctitis was observed in up to 16.7% of patients3/4 acute cystitis occurs in up to 18.3% of patientsnventional radiotherapy [3]. Multicentre data suggestcations, including radiation proctitis and cystitis, occur% of cervical cancer patients after radiotherapy [4].nsional conformal radiation therapy was subsequentlyo avoid organs at risk irradiation. Conventional 3D con-otherapy is composed of a set of xed radiation beams,haped using the projection of the target volume andave uniform intensity across the eld. When appro-entional elds can be modied using simple devices,pensating lters or wedges. With advances in new

s, including computed tomography (CT), magnetic res-ging (MRI), and 3D planning software, radiotherapyhave signicantly improved. More recently, intensity-radiation therapy has been proposed to treat cervical

intensity of each beam can be purposely alteredmation of hundreds of beamlets in order to satisfy

normaacute rapy [6

Onerapy foorgansin mobalso prthe naorgansing, anand sumentsare thebeen rof inteeffectilling

Witbased opare cintenstive doorganspelvic acterisstates.

2. Ma

2.1. Pa

Appreview

Sixtthat prwere iwith ccomm(rangebladdeadvisethe neget goals and normal tissue doses. In addition, the be adjusted within individual beamlets, the sum ofesents the entire apertures contribution [5]. There-individual contributions from each beam are summed,

dose clouds can be generated with concave shapesose gradients. This results in highly conformal treat-

re the high dose regions of the plan are conned toonly, and doses to organs at risk can be minimized.odulated radiotherapy has been shown to reduce

radiotheraptreatment

2.2. Method

2.2.1. PositAll patie

bags (Klarisupine posisical aboutissait aussi une diminution de la dose dlivre

ationnelle avec modulation dintensit avec des margesensions potentielles microscopiques permet une diminutione sans compromettre la couverture de la cible et savre un

in.our la Socit franaise de radiothrapie oncologique (SFRO).

ue irradiation [6] and has been associated with reducedity compared to conventional 3D conformal radiothe-.plication in utilizing intensity-modulated radiothe-

rvical cancers is the interfractional position change of the cervix. Utilizing intensity-modulated radiotherapyrgans not only results in underdose to the target butts a high risk of overdose to nearby organs because ofof the steep dose gradient. In general, motion of thetributable to variations in bladder lling and rectal ll-e majority of motion occurs in the anteriorposteriorrinferior directions, with mean interfraction move-7 mm [1214]. However, it is worth noting that these

rage distances, and in some instances the distance hased to be as large as 2.8 cm [14]. To avoid complications-modulated radiotherapy in cervical cancer patients,ntrol of the clinical target volume position and bladders is critical [2,15].

aim of addressing the inconsistencies that have arisenevious studies, we conducted a dosimetric study to com-ntional radiotherapy, 3D conformal radiotherapy, andodulated radiotherapy plans. We