1、Rib fracture after 177 patients withHiroshi Onishi, Rihito Tominaga, Marino, Takafumi Komiyama, KengoUniversity of Yamanashi, stereotactic body stage I non-smallTsuyota Koshiishi, Shinichi Aoki. Kuriyama, Eiichi Sawada, AtsushiYamanashi, Japanradiotherapy in cell lung cancer Masayuki Araya, Ryo Sait

2、o, Kan Nambu, Naoki Sano, Tsutomu Araki BackgroundDespite the increasing popularity of SBRT, experiencewith extremely hypofractionated, high-doseradiotherapy regimensand their posttreatment radiologic findings and clinicaltoxicity remains limited.Multiple Phase I and II SBRT studies of the treatment

3、 of Stage I-II NSCLC have reported chest wall (CW) pain and/or rib fracture as a part of the toxicity profile. But an exact frequency of rib fracture after SBRT and risk factors for it was unknown.Purpose The aim of the study was to assess the relationship between the background of factors in patien

4、ts or the treatment and the development of rib fracture*.* Definition of the rib fracture in the study : A CT findings of linear line indicating fracture on rib on high dose-irradiated areaTotal casesAgeStageTumor diameterDistance to chest wall 177 (male 132, female 45)55-92 (median 78) yearsT1N0M0

5、118, T2N0M0 598-55 (median 25) mm 0-53 (median 6) mmPatients characteristicsIrradiated from 2001.11 to 2009.4Dose and prescriptionTotal dose / fractionations/ days40Gy / 10 fr / 4-7 days48 Gy / 4 fr / 4-7 days60 Gy / 10 fr / 5-8 days70 Gy / 10 fr / 5-8 daysBED(a/b=3Gy)93.3 Gy240 Gy180 Gy233.3 GyPres

6、criptionD95(PTV)IsocenterD95(PTV)D95(PTV)SBRT planningInstruct patient to reproduce patients self-judged breath-holds according to a respiratory indicator (ABCHES). Measurement of reproducibility of the patients self-inspired breath-hold by 3 times of CT scanningThree dimensional (3D) treatment plan

7、ning was performed. Planning target volume (PTV) was defined as gross tumor volume (GTV) + reproducibility of the patients self-breath-hold + 5mm safety margin.Port margin around PTV 5mm in the protocol of 48Gy/4fr 0mm in the protocol of 60Gy/10fr and 70Gy/10frBeams: 6MV-X ray, non-coplanar multiple

8、 (6) static ports or multiple (400 degrees) dynamic arcsCalculation algorithm: Clarkson or ConvolutionHeterogeneity correction (+)The treatment procedureIn every fractionReassurance of reproducibility of patients self-breath-holds Adjustment of the isocenter of the PTV to the planned position using

9、CT- linac system under patients self-judged breath hold according to a respiratory indicator (ABCHES).Irradiation performed under patients self-breath-holds The tumor position in the irradiation port during irradiation was monitored with a real-time electronic portal imaging device (EPID)The tumor p

10、osition was verified using CT just after irradiation【CT】【Symptom (pain)】2223366666111111333333333333SBRTSBRTFollowing up examination( months after SBRT)AnalysisTime duration to detection of rib fractureClinical symptom (pain)Comparison between cases with fracture (+) versus (-) a. Distance between t

11、umor and chest wall b. Patient characteristics c. CT findings of chest wall d. Maximum dose of the ribResults Positive rib fracture (+):41 cases No rib fracture (-) for more than 24 months until the last follow-up : 46 cases40Gy / 4 fr / 4-7 days48 Gy / 4 fr / 4-7 days60 Gy / 10 fr / 5-8 days70 Gy /

12、 10 fr / 5-8 days T1 T2Fracture (+) Fracture (-) 0 / 1 (0.0%)16 / 37 (43.2%)14 / 34 (41.2%)11 / 15 (73.3%)25 / 61 (41.0%)16 / 26 (61.5%) 1 / 1 (100.0%)21 / 37 (56.8%)20 / 34 (58.8%) 4 / 15 (26.7%)36 / 61 (59.0%)10 / 26 38.5%)Time duration from SRT to detection of rib fractureMedian : 15 monthsMean :

13、 16.8 monthsCases numberTime duration (months)Pain*Fractute (+)(n=41)Fracture (-)(n=46)Grade 027/41(65.9%)39/46(84.8%)Grade 17/41(17.1%)4/46(8.7%)Grade 27/41(17.1%)3/46(7.7%)Grade 30/41(0%)0/46(0%)*CTCAE(Common Terminology Criteria for Adverse Events) v3.0Clinical symptom (pain )Distance between tum

14、or and chest wall (mm)16mmFracture (-)Fracture (+)Comparison between cases with fracture (+) versus (-)Distance between tumor and chest wallFracture (+)(n=41)Fracture(-)(n=46)AgeMean 76.9(64-89)Mean78.5(61-91)Gendermale: female24 : 1736 : 10 p 0.05 (chi-square test)Comparison between cases with frac

15、ture (+) versus (-)Patient characteristicsFracture (+) (n=41)Fracture (-) (n=46)Chest wall edema35(85.4%)10(21.7%)Thinning or erosion of the rib30(73.2%)6(13.0%)Comparison between cases with fracture (+) versus (-)CT findings Case24月後86 y.o. femaleadenoca,T2N0M070Gy/10fr24 months after6 months after

16、Chest wall edema and thinning of rib cortexRib fractureRisk factor* for rib fractureOdds ratio95% confidential intervalAge1.0280.929-1.138Gender(Female)4.8621.135-20.819Distance between tumor and chest wall0.7820.696-0.879* Stepwise Logistic regression anlysisFracture (+)(n=9)Fracture (-)(n=8)Maximu

17、m chest wall dose(BED Gy)257.6 48.2141.0 76.1Comparison between cases with fracture (+) versus (-)Maximum dose in chest wall( in 17 cases in which detailed dose was calculated) a/b = 3 Gyp0.01 t-testFracture (+)(BED Gy)Comparison between cases with fracture (+) versus (-)Maximum chest wall dose (BED

18、) a/b = 3 GyFracture (-)ROC analysisChest wall maximum BED225.5Gy Sensiivity 0.71 1-Specificity= 0.11Sensitivity(1-specificity)Comparison between cases with fracture (+) versus (-)Maximum chest wall dose (BED)Fracture (-)Fracture (+)(Gy)225.5GyLikelihood ration=sensitivity/ (1-specificity)0.71/0.11=

19、6.45Comparison between cases with fracture (+) versus (-)Maximum chest wall dose (BED)J. Thorac Oncol 2009:4:1035-37.Int J Radiat Oncol Biol Phys 2010; 76:796-801. Radiotherapy and Oncology 2009;91:360-68. Lung Cancer 2005;48:107-14.Lung Cancer 2008;60:193-9.Lung Cancer 2006;51:97-103.AuthorTotal Dose (Gy)High risk factorsVoloney(1)Dunlap(2)Pettersson(3)Zimmermann4) Fritz(5)Nyman(6)33 - 533 513Distance to chest wall 30G