食管癌常规照射与三维适形放疗的剂量学研究

目的 用三维适形治疗计划系统分析食管癌传统放疗及三维适形放疗中肿瘤和周围组织器官的剂量分布.方法 对44例首程放疗中晚期食管癌患者常规透视下模拟定位,确定病变中心和最佳入射角度,金属标记物标记前垂直野中心及野框后行CT模拟定位.CT扫描图像经局域网传输到治疗计划系统（CMS Focus 3.0或ADAC Pinnacle 6.2b）进行三维重建,由主管医师勾画大体肿瘤体积（GTV）、临床靶体积（CTV）和危及器官.物理师为每例患者设计3套治疗计划：即常规治疗计划、三维适形治疗计划和虚拟常规治疗计划.结果 （1）食管造影所示病变平均长度5.42cm,CT扫描平均长度8.42cm（P=0.000）.CT扫描肿瘤最大左右径平均5.48cm,GTV平均体积59.68 cm^3.常规模拟定位中心与三维适形治疗计划中心在X、Y、Z轴上分别相差7.67、13.21、7.68mm,两种定位方法的病变中心在X轴上的差异有统计学意义（P=0.001）;（2）全组中位处方剂量6600 cGy.常规治疗计划、虚拟常规治疗计划、三维适形治疗计划的GTV 100%体积剂量分别为3406.8、6379.1、6290.0 cGy;GTV95%体积剂量分别为4344.1、6484.7、6453.6 cGy,CTV 95%体积剂量分别为3303.0、6375.3、6081.8 cGy;PTV95%体积剂量分别为1739.4、6035.9、5243.9 cGy.可见三维适形治疗计划的GTV、CTV及PTV100%、95%体积剂量均高于常规计划.结论 三维适形放疗技术能够给予肿瘤靶区均匀的剂量分布,并使其周围正常组织得到保护.     

Role of radiotherapy in the treatment of cerebral meningiomas]

Cerebral meningiomas account for 15-20% of all cerebral tumours. Although seldom malignant, they frequently recur in spite of complete surgery, which remains the cornerstone of the treatment. In order to decrease the probability of local recurrence, radiotherapy has often been recommended in atypical or malignant meningioma as well as in benign meningioma which was incompletely resected. However, this treatment never was the subject of prospective studies, randomized or not. The purpose of this review of the literature was to give a progress report on the results of different published series in the field of methodology as well as in the techniques of radiotherapy. Proposals for a therapeutic choice are made according to this analysis. For grade I or grade II-III meningiomas, limits of gross tumor volume (GTV) include the tumour in place or the residual tumour after surgery; clinical target volume (CTV) limits include gross tumour volume before surgery with a GTV-CTV distance of 1 and 2 cm respectively. Delivered doses are 55 Gy into CTV and 55-60 Gy and 70 Gy into GTV for grade I and grade II-III meningiomas respectively.     

Stereotactically guided conformal radiotherapy for meningiomas.

PURPOSE: Stereotactically guided conformal radiotherapy, (SCRT) is a high precision technique of conformal radiotherapy (RT) which reduces the volume of normal tissue irradiated compared to conventional RT and may lead to a reduction in long-term toxicity We describe the technique and the preliminary results in patients with inoperable, residual or recurrent meningiomas. MATERIAL AND METHODS: From July 1993 to November 1997, 24 patients (median age: 56 years, range: 28-72) with base of skull (n = 21). falx or upper skull (n = 3) meningiomas were treated with SCRT. The technique employed immobilization in a Gill-Thomas-Cosman (GTC) frame and CT localization with a Brown-Roberts-Wells (BRW) fiducial system for stereotactic space definition. The planning target volume (PTV) was defined as gross tumour volume (GTV) and a 0.5-1 cm margin. Treatment was delivered with three (12 patients) or four non-coplanar conformal fixed fields (12 patients) Conformal blocking was achieved either with lead alloy blocks (n = 11) or with a multi-leaf collimator (MLC) (n = 13). Patients were treated on a 6 MV linear accelerator to doses of 50-55 Gy, in 30-33 daily fractions. The treatments were carried out as part of a routine work of a busy radiotherapy department. RESULTS: Median GTV for 24 meningiomas was 21.7 cm3 (range: 4.4-183 cm3). SCRT was well tolerated with minimal toxicity Three months after the end of radiotherapy, seven of 15 patients with neurological deficit had an improvement and eight remained unchanged. Two patients experienced early side effects (one VII nerve palsy, one Addisonian state). At a median follow-up of 13-months (range: 3-43) the 1 year progression free survival and overall survival are 100%. which is within the range expected for conventional fractionated radiotherapy for meningiomas. CONCLUSIONS: SCRT is a feasible technique of high precision conformal RT for patients with meningiomas. Potential advantages in tumour control, survival and toxicity over conventional RT, require evaluation in long-term prospective studies.     

Marges dans le cancer pulmonaire : volume cible interne/volume cible anatomoclinique

The aim of this study was to carry out a review of margins that should be used for the delineation of target volumes in lung cancer, with a focus on margins from gross tumour volume (GTV) to clinical target volume (CTV) and internal target volume (ITV) delineation. Our review was based on a PubMed literature search with, as a cornerstone, the 2010 European Organisation for Research and Treatment of Cancer (EORTC) recommandations by De Ruysscher et al. The keywords used for the search were: radiotherapy, lung cancer, clinical target volume, internal target volume. The relevant information was categorized under the following headings: gross tumour volume definition (GTV), CTV–GTV margin (first tumoural CTV then nodal CTV definition), in field versus elective nodal irradiation, metabolic imaging role through the input of the PET scanner for tumour target volume and limitations of PET-CT imaging for nodal target volume definition, postoperative radiotherapy target volume definition, delineation of target volumes after induction chemotherapy; then the internal target volume is specified as well as tumoural mobility for lung cancer and respiratory gating techniques. Finally, a chapter is dedicated to planning target volume definition and another to small cell lung cancer. For each heading, the most relevant and recent clinical trials and publications are mentioned.     

Image fusion between 18FDG-PET and MRI/CT for radiotherapy planning of oropharyngeal and nasopharyngeal carcinomas

PURPOSE: Accurate diagnosis of tumor extent is important in three-dimensional conformal radiotherapy. This study reports the use of image fusion between (18)F-fluoro-2-deoxy-D-glucose positron emission tomography (18FDG-PET) and magnetic resonance imaging/computed tomography (MRI/CT) for better targets delineation in radiotherapy planning of head-and-neck cancers. METHODS AND MATERIALS: The subjects consisted of 12 patients with oropharyngeal carcinoma and 9 patients with nasopharyngeal carcinoma (NPC) who were treated with radical radiotherapy between July 1999 and February 2001. Image fusion between 18FDG-PET and MRI/CT was performed using an automatic multimodality image registration algorithm, which used the brain as an internal reference for registration. Gross tumor volume (GTV) was determined based on clinical examination and 18FDG uptake on the fusion images. Clinical target volume (CTV) was determined following the usual pattern of lymph node spread for each disease entity along with the clinical presentation of each patient. RESULTS: Except for 3 cases with superficial tumors, all the other primary tumors were detected by 18FDG-PET. The GTV volumes for primary tumors were not changed by image fusion in 19 cases (89%), increased by 49% in one NPC, and decreased by 45% in another NPC. Normal tissue sparing was more easily performed based on clearer GTV and CTV determination on the fusion images. In particular, parotid sparing became possible in 15 patients (71%) whose upper neck areas near the parotid glands were tumor-free by 18FDG-PET. Within a mean follow-up period of 18 months, no recurrence occurred in the areas defined as CTV, which was treated prophylactically, except for 1 patient who experienced nodal recurrence in the CTV and simultaneous primary site recurrence. CONCLUSION: This preliminary study showed that image fusion between 18FDG-PET and MRI/CT was useful in GTV and CTV determination in conformal RT, thus sparing normal tissues.     

Radiosurgery for brain metastasis: impact of CTV on local control.

PURPOSE: The purpose of the present analysis was to assess whether adding a 1 mm margin to the gross tumour volume (GTV) improves the control rate of brain metastasis treated with radiosurgery (RS). PATIENTS AND METHODS: All the patients had one or two brain metastases, 30 mm or less in diameter, and only one isocentre was used for RS. There were 23 females and 38 males. The median age was 54 years (34-76). The median Karnofsky performance status was 80 (60-100). At the time of RS, 23 patients had no evidence of extracranial disease and 38 had a progressive systemic disease. Thirty-eight patients were treated up-front with only RS. Twenty-three patients were treated for relapse or progression more than 2 months after whole brain radiotherapy. From January 1994 to July 1995, clinical target volume (CTV) was equal to GTV without any margin (33 metastases). From August 1995 to August 2000, CTV was defined as GTV plus a 1 mm margin (45 metastases). A dose of 20Gy was prescribed to the isocentre and 14Gy at the margin of CTV. RESULTS: The median follow-up was 10.5 months (1-45). The mean minimum dose delivered to GTV was 14.6Gy in the group without a margin and 16.8Gy in the group with a 1 mm margin (P<0.0001). The response of 11 metastases was never assessed because patients died before the first follow-up. Ten metastases recurred, eight in the group treated without a margin and two in the group treated with a 1 mm margin (P=0.01). Two-year local control rates were 50.7+/-12.7% and 89.7+/-7.4% (P=0.008), respectively. Univariate analysis showed that the treatment group (P=0.008) and the tumour volume (P=0.009) were prognostic factors for local control. In multivariate analysis, only the treatment group with a 1 mm margin was an independent prognostic factor for local control (P=0.04, RR: 5.8, 95% CI [1.08-31.13]). There were no significant differences, either in overall survival rate or in early and late side effects, between the two groups. CONCLUSION: Adding a 1 mm margin to the GTV in patients treated with RS significantly improves the probability of metastasis control without increasing the side effects.     

Radiothérapie des tumeurs cérébrales : quelles marges ?

Radiotherapy is a major modality in the treatment of brain tumours. The target volumes definition has to be precise for the radiation planification. The gross target volume (GTV) is most of the time delineated within the fusion of the planning CT scan with the appropriated MRI sequences. The clinical target volume (CTV) definition is more complex: it varies in time following the evolution of scientific knowledge and also depending of the school of thought. This article offers a review of the literature about the margins applied in brain tumours radiotherapy for gliomas (high grade, anaplastic, low grade and brain stem gliomas), embryologic tumours (medulloblastomas and primitive neuroectodermal tumours [PNET]), ependymomas, atypical teratoid rahbdoid tumours (ATRT), craniopharyngiomas, pineal gland tumours, primary central nervous cell lymphomas, meningiomas and schwannomas. New imaging modalities such as diffusion-weighted imaging, dynamic contrast enhanced, spectroscopic MRI and PET scan will allow us to delineate more precisely the target volumes and to realise dose-painting by adapting the dose to the tumour metabolism.     

Preliminary results from a Phase II trail of conformal radiation therapy for pediatric patients with localised low-grade astrocytoma and ependymoma

PURPOSE: To estimate the local control and patterns of failure for pediatric patients with low-grade astroglial tumors (LGA) and ependymoma (EP) treated with three-dimensional conformal radiation therapy (CRT) using an anatomically defined clinical target volume (CTV). METHODS AND MATERIALS: From an ongoing, prospective Phase II trial initiated in July 1997, 102 pediatric patients with LGA (n = 38) and EP (n = 64) have been treated with CRT using an anatomically defined CTV extending 1.0 cm beyond the gross tumor volume and a 0.5-cm margin (planning target volume) extending outside of the CTV. The prescribed dose was 54 Gy (LGA) and 59.4 Gy (EP). RESULTS: Patients with EP have been followed for a median of 17 months (range 3--43 months), and six failures have occurred. Patients with LGA have been followed for a median of 17 months (3--44 months), and four failures have occurred. Three-dimensional magnetic resonance (MR) studies performed to document treatment failure were registered with the MR and computed tomography (CT) data used in the treatment planning process. Failure occurred within the CTV for 5 patients with EP, including 3 with concurrent subarachnoid dissemination. One patient with EP developed metastatic disease with no evidence of local failure. Three patients with LGA failed within the CTV and one failed immediately outside of the CTV. CONCLUSIONS: Treatment of an anatomically defined CTV, encompassing 1.0 cm of non-involved brain beyond the margin of resection or neuroimaging-defined tumor, appears to be safe for pediatric patients with LGA and EP based on these preliminary data. Normal tissue sparing through the use of advanced radiation therapy treatment planning and delivery techniques should be beneficial to pediatric patients if the rate and patterns of failure are similar to conventional techniques and toxicity reduction can be objectively documented.     

三维适形放射治疗常规外照射后复发的非小细胞肺癌

目的：研究三维适形放射治疗常规放射治疗后复发的非小细胞肺癌可行性，观察近期疗效及早期并发症的发生率。方法：2000年10月至2001年2月，12例非小细胞肺癌疗后复发病例，由美国CMS公司2．6．1三维治疗计划系统设计放射治疗计划，剂量体积直方图（DVH）评价和优化放射治疗计划，体部固定装置及多叶光栏技术实施适形放射治疗。计划靶区为临床所见肿瘤区外放1．0－1．5cm，计划照射剂量为40－60Gy,2.5-3.0Gy/次，1次／d,5d/周。照射方法为固定野、非共面野或旋转弧。计划靶区体积（PTV）中位体积为295cm^3(76.4-512.4cm^3)。按美国放射肿瘤学协作组（RTOG）和世界卫生组织（WHO）标准观察急性放射反应及近期疗效。结果：12例患者均顺利完成治疗。初次放射治疗至再放射治疗的中位间隔时间为19个月（12－32个月），再放射治疗肿瘤中位剂量51．2Gy(42.0-67.5Gy)。近期疗效为完全缓解（CR）8．3％（1／12），部分缓解（PR）66．7％（8／12），无变化（NR）25．0％（3／12），进展（PD）0％（0／12），总有效率为75．0％（9／12）。根据PTOG分级，急性放射性食管炎发生率1－2级16．7％（2／12），3级0％（0／12）；急性放射性肺炎发生率1－2级16．7％（2／12），3级0％（0／12）；骨髓抑制发生率1－2级8．3％（1／12）；3级0％（0／12）；心脏损伤发生率1－2级16．7％（2／12），3级0％（0／12）。12例患者的中位随访期为5个月（3－7个月），随访率为100％。结论：三维适形放射治疗后复发的非小细胞肺癌有较好的近期疗效，早期并发症较低，能为患者耐受，晚期并发症的发生率及远期疗效有待进一步观察。     

Implications of contrast-enhanced CT-based and MRI-based target volume delineations in radiotherapy treatment planning for brain tumors

Delineation of various target volumes using contrast-enhanced magnetic resonance imaging (MRI) and/or computed tomography (CT) constitutes the primary step for radiation therapy planning (RTP) in brain tumors. This study presents a quantification and comparative evaluation of the various clinical target volumes (CTV) and gross target volumes (GTV) as outlined by contrast-enhanced CT and MRI, along with its implications for postoperative radiotherapy of brain tumors. Twenty-one patients of gliomas were considered for this prospective study. Peritumoral edema as CTV and residual tumor as GTV were delineated separately in postoperative contrast-enhanced CT and MRI. These volumes were estimated separately and their congruence studied for contrast-enhanced CT and MRI. Compared to MRI, CT underestimated the volumes, with significant differences seen in the mean CTV (mean +/- SD: -62.92 +/- 93.99 cc; P = 0.006) and GTV (mean +/- SD: -21.08 +/- 36.04 cc; P = 0.014). These differences were found to be significant for high-grade gliomas (CTV: P = 0.045; GTV: P = 0.044), while they were statistically insignificant for low-grade gliomas (CTV: P = 0.080; GTV: P = 0.117). The mean differences in the volumes for CTV and GTV were estimated to be -106.7% and -62.6%, respectively, taking the CT volumes as the baseline. Thus, even though, electron density information from CT is essential for RTP, target delineation during postoperative radiotherapy of brain tumors, especially for high-grade tumors, should be based on MRI so as to avoid inadvertent geographical misses, especially in the regions of peritumoral edema.     

Fractionated stereotactic conformal radiotherapy following conservative surgery in the control of craniopharyngiomas.

PURPOSE: To describe the technique and results of stereotactically guided conformal radiotherapy (SCRT) in patients with craniopharyngioma after conservative surgery. METHODS AND MATERIALS: Thirty-nine patients with craniopharyngioma aged 3-68 years (median age 18 years) were treated with SCRT between June 1994 and January 2003. All patients were referred for radiotherapy after undergoing one or more surgical procedures. Treatment was delivered in 30-33 daily fractions over 6-6.5 weeks to a total dose of 50 Gy using 6 MV photons. Outcome was assessed prospectively. RESULTS: At a median follow-up of 40 months (range 3-88 months) the 3- and 5-year progression-free survival (PFS) was 97% and 92%, and 3- and 5-year survival 100%. Two patients required further debulking surgery for progressive disease 8 and 41 months after radiotherapy. Twelve patients (30%) had acute clinical deterioration due to cystic enlargement of craniopharyngioma following SCRT and required cyst aspiration. One patient with severe visual impairment prior to radiotherapy had visual deterioration following SCRT. Seven out of 10 patients with a normal pituitary function before SCRT had no endocrine deficits following treatment. CONCLUSION: SCRT as a high-precision technique of localized RT is suitable for the treatment of incompletely excised craniopharyngioma. The local control, toxicity and survival outcomes are comparable to results reported following conventional external beam RT. Longer follow-up is required to assess long-term efficacy and toxicity, particularly in terms of potential reduction in treatment related late toxicity.     

Radiothérapie conformationnelle prostatique : quelles marges ?

The planning CT allows the delineation of the prostate (clinical target volume, CTV) but with an imprecision at the apex and the inability to visualize the intraprostatic cancer. MRI enables accurate visualization of the prostate outlines and in some extent the intraprostatic tumour (gross tumour volume [GTV]). The integration of MRI data within the CT remains still complex. Analysis of prostatectomy specimen has guided the definition of a CTV beyond the capsule, depending on pretreatment factors. In practice, the CTV can be defined as follows: prostate-only, for good prognosis tumours; prostate (+ 0 to 5 mm margins, excluding the rectum) and seminal vesicles (possibly limited to 2 cm of their proximal region) for intermediate-risk tumours; prostate (+ 5 mm margins) and seminal vesicles for high-risk tumours. The planning target volume (PTV) should be between 5 mm and 10 mm depending on the space directions, in the absence of image-guidance (IGRT). It could be reduced to 5 mm in case of IGRT. In the adjuvant setting after prostatectomy, the definition of the CTV should follow the recommendations from cooperative groups. It takes into account both the analysis of pattern of local recurrence after prostatectomy, but also the specific histological analysis of the surgical specimen of the patient. The corresponding PTV margin is 6 to 8 mm.     

Early improvements in vision after fractionated stereotactic radiotherapy for primary optic nerve sheath meningioma.

BACKGROUND AND PURPOSE: To report on the efficacy and follow-up of 23 patients with primary optic nerve sheath meningioma (ONSM) with fractionated stereotactic conformal radiotherapy (SCRT). PATIENTS AND METHODS: Between 1996 and 2003, 23 patients ( = 23 eyes) with ONSM were treated. Indications for primary stereotactic radiotherapy were tumour progression documented by imaging or symptoms (loss of vision, pain). All patients received SCRT with a median dose of 50.4Gy in 6 weeks. RESULTS: After a median follow-up of 20 months (1-68 months) a 95% (21 of 22) visual control was seen: vision improved in 16 patients and remained stable in 5. For 13/16 patients improvement was documented already within 1-3 months after SCRT. Vision became worse in one patient. An improvement of pain was observed after radiotherapy in 6 patients as well as of proptosis in 1 patient. For 1 patient pain was persistent after SCRT. In one patient 4 years after SCRT a radiation retinitis and vitreous haemorrhage was seen. CONCLUSIONS: Fractionated stereotactic radiotherapy improves vision, often shortly after treatment, and is thus a viable treatment option for this tumour entity.     

主动呼吸控制结合三维适形放疗非小细胞肺癌的初步研究

目的 探讨医科达公司主动呼吸控制(ABC)系统结合三维适形放疗技术治疗非小细胞肺癌(NSCLC)可行性.方法 29例Ⅱ～Ⅳ期未能手术的NSCLC患者分别在自由呼吸(FB)状态和ABC控制下行CT扫描,并在两个重建图像序列中按同样条件分别设计FB和ABC后的三维适形放疗计划.选择屏气触发方式为吸气后屏气,触发阈值设定为呼吸曲线峰值的80%,每次最长屏气时间为25 s.上叶病灶计划靶体积(PTV)为临床靶体积(CTV)外放0.6 cm;中下叶病灶PTV为CTV外放1.0 cm.采用3～5个野进行共面适形治疗.通过剂量体积直方图评价两个计划的大体肿瘤体积(GTV)、CTV、PTV、双肺体积(V_(lung))、双肺V_(20).和平均肺剂量(MLD).近期疗效按世界卫生组织肿瘤疗后客观效果评分.正常组织急性反应按美国国家癌症研究所CTC3.0标准评价.结果 除1例患者因经济原因中断治疗,其他患者均顺利完成治疗.使用ABe技术后GTV、CTV、PTV均较FB技术有一定缩小[36.35 cm~3:31.40 cm~3(t=9.70,P<0.001)、82.33 cm~3:70.83 cm~3(t=8.19,P<0.001)、230.73 cm~3:197.59 cm~3(t=5.72,P<0.001)],双肺V_(20)、MLD均低于FB技术[21.66%:18.76%(t=11.16,P<0.001)、1329.07 Gy:1143.14 Gy(t=13.24,P<0.001)].总有效率为64%(18例).急性放射性食管炎发生率1、2级分别为68%(19例)、18%(5例);急性放射性肺损伤发生率1、2级分别为82%(23例)、7%(2例);骨髓抑制发生率1、2、3级分别为57%(16例)、25%(7例)、14%(4例);急性心脏损伤1、2级分别为86%(24例)、14%(4例).结论 ABC的临床应用可行,靶区定位更为精确,可减少正常肺组织照射剂量,从而减少放射副反应的发生率.     

病例为基础的局部晚期NSCLC靶区勾画共识与争议

目的 分析局部晚期NSCLC靶区勾画中的专家共识与争议。方法 调查国内12家单位对NSCLC靶区勾画相关15个问题意见。由复旦大学附属肿瘤医院选择1份局部晚期NSCLC病例,将定位CT图像和病史资料发送至12家单位,各单位自行组织讨论并委派1位医师在第六届肿瘤精准放化疗暨肺癌多学科高峰论坛上主讲对该病例靶区勾画情况及理论认识,参会专家共同讨论。结果 12家单位全部填写问卷并按时发回。肺癌靶区勾画标准肺窗的窗宽/窗位为800~1600/-600~-750 HU,纵隔窗为350~400/20~40 HU。呼吸动度的测量:经验外扩2~5 mm、模拟定位机测定、四维CT测定、模拟定位机+四维CT测定。GTV外扩CTV距离:原发灶鳞癌5~6 mm、腺癌5~8 mm;纵隔淋巴结转移灶6家单位采用5 mm,6家单位采用同原发病灶一致距离。摆位误差:10家单位5 mm、1家单位3 mm、1家单位4~6 mm。双肺V₂₀限定:10家单位<30%、1家单位<35%、1家单位<28%。局部晚期NSCLC同步放化疗放疗剂量:9家单位60 Gy分30次、1家单位62.7 Gy分33次、1家单位50~60 Gy分25~30次、1家单位60~70 Gy分25~30次。肺内原发病灶靶区勾画:3家GTV→IGTV→PTV、8家GTV→CTV→ITV→PTV、1家GTV→CTV→PTV或GTV→IGTV→CTV→PTV;纵隔淋巴结转移灶靶区勾画:3家GTV→IGTV→PTV、8家GTV→CTV→ITV→PTV、1家GTV→CTV→PTV。放疗过程中10%~100%患者需要改野,38~50 Gy时改野合适。关于PET-CT定位及靶区勾画SUV值尚无统一标准,7家单位已开展MRI定位,10家单位已开展了SBRT治疗早期NSCLC。早期NSCLC (T_1-2N₀M₀)的SBRT靶区勾画:5家单位GTV→IGTV→PTV、3家单位IGTV→PTV、2家单位GTV→CTV→ITV→PTV。周围型早期NSCLC分割6.0~12.5 Gy/次,3~12次;中央型早期NSCLC分割4.6~10.0 Gy/次,5~10次。靶区勾画讨论结果:肺癌靶区勾画目前应采用4DCT或模拟机测定呼吸动度;勾画肺癌靶区时CT肺窗的窗宽/窗位为1600/-600 HU,纵隔窗为400/20 HU;争议主要是纵隔转移淋巴结CTV_nd为累及野照射还是选择性淋巴结预防照射。结论 对局部晚期NSCLC靶区勾画的CT的窗宽、窗位,呼吸运动和摆位误差测量、原发灶靶区勾画方法、同步放化疗放疗剂量及改野时机均已基本达成共识。主要争议和尚未达成共识的是PET-CT定位勾画靶区时显示病灶的最佳SUV值、SBRT治疗早期NSCLC最佳剂量分割模式、CTV_nd的勾画。     

三维适形放射治疗鼻咽癌后程大分割的剂量学研究

目的寻求1种较理想的鼻咽癌三维放疗的分割方式,从而提高局部控制率。方法对15例行三维适形放射治疗的鼻咽癌患者进行模拟的剂量学研究,将后程大分割（分次量2.5Gy和3.0Gy）与常规分割（2.0Gy）进行剂量学对比。结果大分割放疗可以较大幅度增加肿瘤区（GTV）的剂量。2.5组脊髓最大剂量、腮腺、颞颌关节、脑干平均剂量提高均不超过1.0Gy,脑干最大剂量增加2.3Gy。3.0组腮腺及颞颌关节的平均剂量增加幅度较大达3.4Gy和1.4Gy,脑干最大剂量增加4.5Gy。结论分次量2.5Gy的后程大分割放疗能够较大幅度地增加GTV剂量,且对正常器官的剂量增加幅度较小,并发症增加较少。     

Imagerie fonctionnelle et métabolique en radiothérapie

These past fifteen years have seen major developments in three-dimensional conformal radiotherapy (3D-CRT), with and without intensity-modulated, respiratorygated, or image-guided techniques. However, one of the fundamental prerequisites for 3D-CRT is the determination of gross tumour volume (GTV), clinical target volume (CTV), and planning target volume (PTV), always taking into account the limitations of the radiotherapy used. Although computed tomography (CT) in the treatment position remains the gold standard in radiotherapy planning, functional imaging — including positron emission topography (PET)/CT imaging, single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS) and functional magnetic resonance imaging (f MRI) — provides complementary data and may contribute to improving treatment quality. Furthermore, functional imaging can be used as an aid in developing treatment strategy, as a predictive factor in tumour response, and as a tool to evaluate tumour response after RT.     

肿瘤靶体积对Ⅲ期非小细胞肺癌三维适形放疗长期疗效的影响

目的 分析肿瘤靶体积大小对Ⅲ期非小细胞肺癌（NSCLC）三维适形放疗（3D-CRT）长期疗效的影响。方法 收集2000年8月-2004年12月行三维适形放疗的72例Ⅲ期NSCLC患者资料。其中,ⅢA期29例、ⅢB期43例。单纯放疗32例、放疗联合化疗40例;采用前程常规+后程三维适形放疗者28例、全程三维适形放疗者44例;中位等效生物剂量6 625 cGy(范围5 000~7800 cGy)。采用剂量体积直方图（DVH）计算肿瘤靶体积（GTV）、临床靶体积（CTV）、计划靶体积（PTV）。放射性肺炎和放射性食管炎采用RTOG标准评价。结果 随访5年,随访率95.8%。放疗后CR 14例、PR 42例、SD 16例,1、3、5年总生存率及中位生存期分别为45.8%、15.3%、10.5%和10.2月 。按照GTV中位值155 cm3分为两组,只有GTV＞155 cm3组2级以上放射性肺炎发生率高（P＜0.05）;而性别、年龄、T、N、TNM、等效生物剂量、照射方式、化疗、近期疗效和放射性食管炎,两组间分别比较,差异无统计学意义（P＞0.05）。GTV≤155 cm3和＞155 cm3放疗后1、3、5年生存率和中位生存期分别为61.1%、19.4%、16.2%、17月和30.6%、11.1%、4.2%、9月（χ²=5.16,P=0.023）。CTV和PTV按照中位值分两组,两组间生存率的比较差异均有统计学意义（P＜0.05）。全组预后单因素分析显示GTV、CTV、PTV、近期疗效（CR+PR/SD）与预后生存有关（P＜0.05）;多因素分析显示GTV和近期疗效是独立预后因素。结论 肿瘤靶体积大小是影响Ⅲ期非小细胞肺癌放疗预后的重要因素,近期疗效也影响预后生存。