Role of PET/CT in Treatment Planning for Head and Neck Cancer Patients Undergoing Definitive Radiotherapy

Background: In this study, we aimed to investigate the benefits of 18F-deoxyglucose positron emissiontomography/computed tomography (FGD-PET/CT) imaging for staging and radiotherapy planning in patientswith head and neck cancer undergoing definitive radiotherapy. Materials and Methods: Thirty-seven headand neck cancer patients who had undergone definitive radiotherapy and PET/CT at the Uludag UniversityMedical Faculty Department of Radiation Oncology were investigated in order to determine the role of PET/CTin staging and radiotherapy planning. Results: The median age of this patient group of 32 males and 5 femaleswas 57 years (13-84years). The stage remained the same in 18 cases, decreased in 5 cases and increased in 14cases with PET/CT imaging. Total gross tumor volume (GTV) determined by CT (GTVCT-Total) was increasedin 32 cases (86.5%) when compared to total GTV determined by PET/CT (GTVPET/CT-Total). The GTV of theprimary tumor determined by PET/CT (GTVPET/CT) was larger in 3 cases and smaller in 34 cases comparedto that determined by CT (GTVCT). The GTV of lymph nodes determined by PET/CT (GTVLNPET/CT) waslarger in 20 cases (54%) and smaller in 12 cases (32.5%) when compared to GTV values determined by CT(GTVLNCT). No pathological lymph nodes were observed in the remaining five cases with both CT and PET/CT. Conclusions: We can conclude that PET/CT can significantly affect both pretreatment staging and assessedtarget tumor volume in patients with head and neck cancer. We therefore recommend examining such cases withPEC/CT before treatment.     

Fluorine-18-labeled fluoromisonidazole positron emission and computed tomography-guided intensity-modulated radiotherapy for head and neck cancer: a feasibility study

PURPOSE: Hypoxia renders tumor cells radioresistant, limiting locoregional control from radiotherapy (RT). Intensity-modulated RT (IMRT) allows for targeting of the gross tumor volume (GTV) and can potentially deliver a greater dose to hypoxic subvolumes (GTV(h)) while sparing normal tissues. A Monte Carlo model has shown that boosting the GTV(h) increases the tumor control probability. This study examined the feasibility of fluorine-18-labeled fluoromisonidazole positron emission tomography/computed tomography ((18)F-FMISO PET/CT)-guided IMRT with the goal of maximally escalating the dose to radioresistant hypoxic zones in a cohort of head and neck cancer (HNC) patients. METHODS AND MATERIALS: (18)F-FMISO was administered intravenously for PET imaging. The CT simulation, fluorodeoxyglucose PET/CT, and (18)F-FMISO PET/CT scans were co-registered using the same immobilization methods. The tumor boundaries were defined by clinical examination and available imaging studies, including fluorodeoxyglucose PET/CT. Regions of elevated (18)F-FMISO uptake within the fluorodeoxyglucose PET/CT GTV were targeted for an IMRT boost. Additional targets and/or normal structures were contoured or transferred to treatment planning to generate (18)F-FMISO PET/CT-guided IMRT plans. RESULTS: The heterogeneous distribution of (18)F-FMISO within the GTV demonstrated variable levels of hypoxia within the tumor. Plans directed at performing (18)F-FMISO PET/CT-guided IMRT for 10 HNC patients achieved 84 Gy to the GTV(h) and 70 Gy to the GTV, without exceeding the normal tissue tolerance. We also attempted to deliver 105 Gy to the GTV(h) for 2 patients and were successful in 1, with normal tissue sparing. CONCLUSION: It was feasible to dose escalate the GTV(h) to 84 Gy in all 10 patients and in 1 patient to 105 Gy without exceeding the normal tissue tolerance. This information has provided important data for subsequent hypoxia-guided IMRT trials with the goal of further improving locoregional control in HNC patients.     

18FDG] PET-CT-based intensity-modulated radiotherapy treatment planning of head and neck cancer

PURPOSE: To define the best threshold for tumor volume delineation of the (18) fluoro-2-deoxy-glucose positron emission tomography ((18)FDG-PET) signal for radiotherapy treatment planning of intensity-modulated radiotherapy (IMRT) in head and neck cancer. METHODS AND MATERIALS: In 25 patients with head-and-neck cancer, CT-based gross tumor volume (GTV(CT)) was delineated. After PET-CT image fusion, window level (L) was adapted to best fit the GTV(CT), and GTV(PET) was delineated. Tumor maximum (S) and background uptake (B) were measured, and the threshold of the background-subtracted tumor maximum uptake (THR) was used for PET signal segmentation. Gross tumor volumes were expanded to planning target volumes (PTVs) and analyzed. RESULTS: The mean value of S was 40 kBq/mL, S/B ratio was 16, and THR was 26%. The THR correlated with S (r = -0.752), but no correlation between THR and the S/B ratio was seen (r = -0.382). In 77% of cases, S was >30 kBq/mL, and in 23% it was 30% +/- 1.6% kBq/mL and 40% in tumors with S 相似文献   

Reproducibility of intratumor distribution of (18)F-fluoromisonidazole in head and neck cancer

PURPOSE: Hypoxia is one of the main causes of the failure to achieve local control using radiotherapy. This is due to the increased radioresistance of hypoxic cells. (18)F-fluoromisonidazole ((18)F-FMISO) positron emission tomography (PET) is a noninvasive imaging technique that can assist in the identification of intratumor regions of hypoxia. The aim of this study was to evaluate the reproducibility of (18)F-FMISO intratumor distribution using two pretreatment PET scans. METHODS AND MATERIALS: We enrolled 20 head and neck cancer patients in this study. Of these, 6 were excluded from the analysis for technical reasons. All patients underwent an (18)F-fluorodeoxyglucose study, followed by two (18)F-FMISO studies 3 days apart. The hypoxic volumes were delineated according to a tumor/blood ratio >or=1.2. The (18)F-FMISO tracer distributions from the two (18)F-FMISO studies were co-registered on a voxel-by-voxel basis using the computed tomography images from the PET/computed tomography examinations. A correlation between the (18)F-FMISO intensities of the corresponding spatial voxels was derived. RESULTS: A voxel-by-voxel analysis of the (18)F-FMISO distributions in the entire tumor volume showed a strong correlation in 71% of the patients. Restraining the correlation to putatively hypoxic zones reduced the number of patients exhibiting a strong correlation to 46%. CONCLUSION: Variability in spatial uptake can occur between repeat (18)F-FMISO PET scans in patients with head and neck cancer. Blood data for one patient was not available. Of 13 patients, 6 had well-correlated intratumor distributions of (18)F-FMISO-suggestive of chronic hypoxia. More work is required to identify the underlying causes of changes in intratumor distribution before single-time-point (18)F-FMISO PET images can be used as the basis of hypoxia-targeting intensity-modulated radiotherapy.     

The impact of positron emission tomography/computed tomography in edge delineation of gross tumor volume for head and neck cancers

PURPOSE: To study anatomic biologic contouring (ABC), using a previously described distinct halo, to unify volume contouring methods in treatment planning for head and neck cancers. METHODS AND MATERIALS: Twenty-five patients with head and neck cancer at various sites were planned for radiation therapy using positron emission tomography/computed tomography (PET/CT). The ABC halo was used in all PET/CT scans to contour the gross tumor volume (GTV) edge. The CT-based GTV (GTV-CT) and PET/CT-based GTV (GTV-ABC) were contoured by two independent radiation oncologists. RESULTS: The ABC halo was observed in all patients studied. The halo had a standard unit value of 2.19 +/- 0.28. The mean halo thickness was 2.02 +/- 0.21 mm. Significant volume modification (>or=25%) was seen in 17 of 25 patients (68%) after implementation of GTV-ABC. Concordance among observers was increased with the use of the halo as a guide for GTV determination: 6 patients (24%) had a 相似文献   

Comparison of five segmentation tools for 18F-fluoro-deoxy-glucose-positron emission tomography-based target volume definition in head and neck cancer

PURPOSE: Target-volume delineation for radiation treatment to the head and neck area traditionally is based on physical examination, computed tomography (CT), and magnetic resonance imaging. Additional molecular imaging with (18)F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) may improve definition of the gross tumor volume (GTV). In this study, five methods for tumor delineation on FDG-PET are compared with CT-based delineation. METHODS AND MATERIALS: Seventy-eight patients with Stages II-IV squamous cell carcinoma of the head and neck area underwent coregistered CT and FDG-PET. The primary tumor was delineated on CT, and five PET-based GTVs were obtained: visual interpretation, applying an isocontour of a standardized uptake value of 2.5, using a fixed threshold of 40% and 50% of the maximum signal intensity, and applying an adaptive threshold based on the signal-to-background ratio. Absolute GTV volumes were compared, and overlap analyses were performed. RESULTS: The GTV method of applying an isocontour of a standardized uptake value of 2.5 failed to provide successful delineation in 45% of cases. For the other PET delineation methods, volume and shape of the GTV were influenced heavily by the choice of segmentation tool. On average, all threshold-based PET-GTVs were smaller than on CT. Nevertheless, PET frequently detected significant tumor extension outside the GTV delineated on CT (15-34% of PET volume). CONCLUSIONS: The choice of segmentation tool for target-volume definition of head and neck cancer based on FDG-PET images is not trivial because it influences both volume and shape of the resulting GTV. With adequate delineation, PET may add significantly to CT- and physical examination-based GTV definition.     

Planning study for available dose of hypoxic tumor volume using fluorine-18-labeled fluoromisonidazole positron emission tomography for treatment of the head and neck cancer

Purpose

To investigate the feasibility of fluorine-18-labeled fluoromisonidazole positron emission tomography/computed tomography (¹⁸F-FMISO PET/CT)-guided intensity-modulated radiotherapy (IMRT) in dose escalation to attack the hypoxic volume of a tumor mass without increasing the normal tissue dose in head and neck cancer patients.

Materials and methods

Eight consecutive head and neck cancer patients underwent ¹⁸F-FMISO PET/CT simulation. Hypoxic tumor volume (HTV) was defined using a tumor-to-cerebellum ratio (T/C) of 1.3 as the threshold for ¹⁸F-FMISO PET/CT. Dose-escalation plans for treating HTVs using ¹⁸F-FMISO PET/CT-guided IMRT were performed for these patients. The standard plan was 72 Gy to the gross tumor volume (GTV) administered as 30 daily fractions of 2.4 Gy. In biologically optimized IMRT plans, the daily dose to the HTV ranged from 2.6 to 3.6 Gy. Dose-volume histograms (DVHs) were generated as part of each plan, and the results of planning were analyzed.

Results

Dose-escalation IMRT plans, delivering 30 daily doses of 2.6 Gy (total of 78 Gy) to the HTVs without increases in normal tissue doses, were feasible for six patients. Further acceptable dose escalation on HTV depended primarily on the primary tumor site and the extent of disease.

Conclusions

It was possible to dose escalate the HTV radiation to 78 Gy in six of eight head and neck cancer patients using ¹⁸F-FMISO PET/CT-guided IMRT.     

Compensator-based intensity-modulated radiotherapy in head and neck cancer: our experience in achieving dosimetric parameters and their clinical correlation

AimsTo review the Batra Hospital and Medical Research Centre experience of using compensator-based intensity-modulated radiotherapy (IMRT) to treat head and neck cancer.Materials and methodsBetween October 2003 and August 2004, 18 patients underwent IMRT for head and neck cancer at our institution. IMRT was delivered using partial transmission high-resolution compensator blocks.ResultsWith a median follow-up of 13.3 months, two patients had residual disease and two failed in the gross tumour volume (GTV). The complete response rate after surgical salvage was 94.5%. Both the locoregional relapse-free and disease-free survival rates were 81.8%. The target coverage in terms of average maximum, mean and minimum dose (in Gy) delivered was 78.6, 73.5 and 58.4 to the GTV–planning target volume, 82.3, 70.9 and 47.3 to clinical target volume 1 (CTV1) and 82.9, 66.2 and 29.6 to CTV2. The dose constraint of 30 Gy to less than 50% of the contralateral parotid volume was achieved in 12 (66.7%) patients. If the dose constraint was revised to 35 Gy, at least 50% of the parotid volume was spared in 17 (94.5%) patients. On average, 75% of the contralateral parotid volume received a dose less than 35 Gy in 13 (72.3%) patients with grade I xerostomia, whereas this was 49.3% in five (27.7%) patients with grade II xerostomia, and the difference was statistically significant (P = 0.001).ConclusionsIn our initial experience, compensator-based IMRT is feasible with regard to target coverage and parotid volume sparing. The parotid volume dose has significant clinical implications on the grade of xerostomia. Our results invoke rethinking into the issues of the parotid volume dose constraint in our subpopulation.     

头颈部癌调强放疗过程中腮腺及靶区体积变化的临床分析

目的 研究头颈部癌患者在放疗过程中腮腺体积及GTV变化。方法 5例头颈部鳞癌（4例口咽鳞癌和1例喉鳞癌）患者均接受全程调强放疗。从第一次放疗开始至结束，1次／周三维锥形束CT（CBCT）检查。每次的CBCT图像与疗前CT图像进行融合，在每层图像上勾画出腮腺外轮廓，同时将GTV内放疗中出现的气腔勾画出来。经统计后分析放疗中腮腺体积、GTV内气腔大小的变化。结果 放疗结束时腮腺体积为疗初的90．1％，52．3％，即腮腺体积缩小了9．9％～47．7％；GTV内气腔由疗前的0体积逐渐增加，疗终时气腔体积占GTV的3．7％。16．8％。结论 放疗过程中腮腺体积及GTV内气腔体积存在着明显变化，利用CBCr可分析这种变化，为二次调强计划的实施奠定基础。     

头颈部肿瘤HT剂量学研究

目的 比较头颈部肿瘤患者HT过程中靶区和OAR计划剂量与实际受量的区别。方法 对12例头颈部肿瘤患者使用HT根治性放疗且每次治疗均行图像引导。选取治疗开始后第2周起每周第1天的图像引导CT图像,在HT的Planned Adaptive模块中重新计算剂量分布,得到当次患者治疗的实际受量。将各CT图像进行形变配准,然后将各单次实际受量叠加得到总实际受量。采用配对t检验或Wilcoxon符号秩检验初始计划剂量与实际受量间差异。结果 总实际受量与初始计划剂量相比GTV的D₂、D₅₀相近(P=0.07、0.07),而D₉₅、D₉₈、D₁₀₀分别降低2.1%、2.7%、5.6%(P=0.02、0.02、0.02);PTV的D₂相近(P=0.08),而D₅₀、D₉₅、D₉₈、D₁₀₀分别降低0.8%、1.9%、3.9%、13.5%(P=0.01、0.00、0.00、0.01);OAR中脊髓D_max增加1.2%(P=0.04)。结论 头颈部肿瘤患者HT中最终靶区实际受量比初始计划剂量偏低,而脊髓实际受量比初始计划剂量偏高。对解剖结构变化较大者应适时对靶区及计划进行修改,以达到最佳治疗效果。     

Tumor hypoxia imaging with [F-18] fluoromisonidazole positron emission tomography in head and neck cancer.

PURPOSE: Advanced head and neck cancer shows hypoxia that results in biological changes to make the tumor cells more aggressive and less responsive to treatment resulting in poor survival. [F-18] fluoromisonidazole (FMISO) positron emission tomography (PET) has the ability to noninvasively quantify regional hypoxia. We investigated the prognostic effect of pretherapy FMISO-PET on survival in head and neck cancer. EXPERIMENTAL DESIGN: Seventy-three patients with head and neck cancer had pretherapy FMISO-PET and 53 also had fluorodeoxyglucose (FDG) PET under a research protocol from April 1994 to April 2004. RESULTS: Significant hypoxia was identified in 58 patients (79%). The mean FMISO tumor/bloodmax (T/Bmax) was 1.6 and the mean hypoxic volume (HV) was 40.2 mL. There were 28 deaths in the follow-up period. Mean FDG standard uptake value (SUV)max was 10.8. The median time for follow-up was 72 weeks. In a univariate analysis, T/Bmax (P=0.002), HV (P=0.04), and the presence of nodes (P=0.01) were strong independent predictors. In a multivariate analysis, including FDG SUVmax, no variable was predictive at P<0.05. When FDG SUVmax was removed from the model (resulting in n=73 with 28 events), nodal status and T/Bmax (or HV) were both highly predictive (P=0.02, 0.006 for node and T/Bmax, respectively; P=0.02 and 0.001 for node and HV, respectively). CONCLUSIONS: Pretherapy FMISO uptake shows a strong trend to be an independent prognostic measure in head and neck cancer.     

Patterns of local-regional recurrence following parotid-sparing conformal and segmental intensity-modulated radiotherapy for head and neck cancer

Purpose: To analyze the patterns of local-regional recurrence in patients with head and neck cancer treated with parotid-sparing conformal and segmental intensity-modulated radiotherapy (IMRT).

Methods and Materials: Fifty-eight patients with head and neck cancer were treated with bilateral neck radiation (RT) using conformal or segmental IMRT techniques, while sparing a substantial portion of one parotid gland. The targets for CT-based RT planning included the gross tumor volume (GTV) (primary tumor and lymph node metastases) and the clinical target volume (CTV) (postoperative tumor bed, expansions of the GTVs and lymph node groups at risk of subclinical disease). Lymph node targets at risk of subclinical disease included the bilateral jugulodigastric and lower jugular lymph nodes, bilateral retropharyngeal lymph nodes at risk, and high jugular nodes at the base of skull in the side of the neck at highest risk (containing clinical neck metastases and/or ipsilateral to the primary tumor). The CTVs were expanded by 5 mm to yield planning target volumes (PTVs). Planning goals included coverage of all PTVs (with a minimum of 95% of the prescribed dose) and sparing of a substantial portion of the parotid gland in the side of the neck at less risk. The median RT doses to the gross tumor, the operative bed, and the subclinical disease PTVs were 70.4 Gy, 61.2 Gy, and 50.4 Gy respectively. All recurrences were defined on CT scans obtained at the time of recurrence, transferred to the pretreatment CT dataset used for RT planning, and analyzed using dose–volume histograms. The recurrences were classified as 1) “in-field,” in which 95% or more of the recurrence volume (V_recur) was within the 95% isodose; 2) “marginal,” in which 20% to 95% of V_recur was within the 95% isodose; or 3) “outside,” in which less than 20% of V_recur was within the 95% isodose.

Results: With a median follow-up of 27 months (range 6 to 60 months), 10 regional recurrences, 5 local recurrences (including one noninvasive recurrence) and 1 stomal recurrence were seen in 12 patients, for a 2-year actuarial local-regional control rate of 79% (95% confidence interval 68–90%). Ten patients (80%) relapsed in-field (in areas of previous gross tumor in nine patients), and two patients developed marginal recurrences in the side of the neck at highest risk (one in the high retropharyngeal nodes/base of skull and one in the submandibular nodes). Four regional recurrences extended superior to the jugulodigastric node, in the high jugular and retropharyngeal nodes near the base of skull of the side of the neck at highest risk. Three of these were in-field, in areas that had received the dose intended for subclinical disease. No recurrences were seen in the nodes superior to the jugulodigastric nodes in the side of the neck at less risk, where RT was partially spared.

Conclusions: The majority of local-regional recurrences after conformal and segmental IMRT were “in-field,” in areas judged to be at high risk at the time of RT planning, including the GTV, the operative bed, and the first echelon nodes. These findings motivate studies of dose escalation to the highest risk regions.     

肿瘤局部相关因素对N0期食管癌IMRT预后影响

目的 探讨食管癌肿瘤局部相关因素对接受根治性放化疗N0期食管鳞癌患者GTV内复发的影响,并分析对10年长期生存的影响。方法 对河北医科大学第四医院2005-2010年收治的根治性放化疗临床N0期食管鳞癌患者374例进行回顾分析。284例累及野照射,90例择性淋巴结照射。69l例同期放化疗,38例序贯放化疗。Kaplan-Meier法生存分析,Cox模型多因素预后分析。结果全组患者出现GTV内复发143例(38.2%),GTV内复发者GTV最大横径(GTV-D)、GTV体积(GTV-V)和GTV-体积/长度(GTV-V/L)均显著长于GTV内未失败者(P=0.008、0.043、0.001)。ROC曲线分析结果显示GTV-D、GTV长度(GTV-L)、GTV-V和GTV-V/L判断GTV内复发的最佳诊断阈值分别为3.5cm、5.5cm、24.0cm³和4.6cm²(P=0.000、0.003、0.000、0.000),且其值较大者GTV内复发比率均大于其余组(P=0.000、0.002、0.001、0.000)。GTV-L和GTV-V/L为影响GTV内复发的因素(P=0.021、0.009)。全组3、5、10年生存率分别为42.9%、23.2%和7.9%,多因素分析结果显示年龄、T分期、联合化疗、GTV-D和GTV-V/L为影响生存的因素(P=0.027、0.000、0.018、0.009、0.034)。生存时间≥5年的主要死亡原因仍与肿瘤相关。结论 食管癌肿瘤局部相关因素对接受根治性放化疗临床N0食管鳞癌患者GTV内复发有显著影响,可作为GTV内复发的预测指标。GTV-D和GTV-V/L为显著影响患者10年生存的因素。     

基于MRI动态图像观察吞咽时器官动度对头颈部肿瘤调强放疗靶区影响

目的 利用MRI技术连续采集头颈部肿瘤患者吞咽时图像,观察并测量软腭、舌、喉的运动规律及最大活动度。方法 随机选取2018年7月-10月在中国医学科学院肿瘤医院接受调强放疗的原发头颈部恶性肿瘤20例患者,其中男17例、女3例,中位年龄58.5岁(28~78岁)。20例患者中鼻咽癌7例,口腔癌3例,口咽癌5例,下咽癌3例,鼻腔鼻旁窦2例。根据AJCC第八版分期Ⅰ-Ⅱ期患者2例,Ⅲ期8例,Ⅳ期10例。结果 吞咽时软腭向上移动移动距离为(1.06±0.31) cm且服从正态分布,向后移动距离为(0.83±0.24) cm且近似正态分布。舌体向后移动距离为(0.77±0.22) cm,且服从正态分布。含压舌板行图像采集患者舌上移位移为0,无压舌板患者舌体中位上移距离为1.23 cm (0.59~1.41 cm)。喉向上移动距离为(1.14±0.22) cm且服从正态分布,向前移动的中位距离为0.4 cm (0.27~0.90 cm)。结论 吞咽运动有可能发生于头颈部肿瘤患者放疗过程中,并引起大体肿瘤体积(GTV)及周围正常组织移动;因此在制定放疗计划时应注意GTV至PGTV的个体化外放距离,以保证肿瘤处方剂量。     

Unknown primary head and neck cancer treated with intensity-modulated radiation therapy: to what extent the volume should be irradiated

To evaluate the efficacy and feasibility of irradiation with intensity-modulated radiotherapy (IMRT) technique in patients with head and neck carcinoma of unknown primary (HNCUP). Between February 2000 and November 2006, 22 consecutive patients diagnosed with HNCUP were treated with IMRT. Of these, four patients were excluded because two of them underwent IMRT only as a boost and the other two had distant metastasis at presentation and were treated palliatively. Of the remaining 18 patients eligible for analysis, 6 had definitive IMRT and 12 had postoperative IMRT (8 with neck dissection and 4 with excisional biopsy). One patient with abnormal lymph node found unexpectedly during carotid endarterectomy was treated to ipsilateral neck only. The target volumes for the other 17 patients include nasopharynx, oropharynx, retropharyngeal lymph nodes, and bilateral neck. In 1 patient who had extensive lymph node involvement, the hypopharynx and the larynx were defined as target. In all other patients the larynx including hypopharynx were defined as dose-limiting structures. The parotids, cervical esophagus, spinal cord, brain stem, optic nerves and the orbits are also outlined as dose-limiting structures. All patients completed their treatment without interruption and severe complications. With a median follow-up time of 25.5 months, 2 patients had persistent cervical lymphadenopathy and 2 had distant metastases. Another patient developed a lung cancer and a second pyriform sinus cancer 25 months after treatment. The 2-year overall survival, regional recurrence-free survival and distant metastases-free survival were 74.2%, 88.5%, and 88.2%, respectively. Six patients had prophylactic percutaneous endoscopic gastrostomy (PEG) tubes placed before radiation. Most had PEG tubes removed within 7 months after the completion of treatment. IMRT delivered to comprehensive bilateral neck and putative mucosal site (including nasopharynx, oropharynx, and retropharyngeal lymph nodes) appears to be effective for patients with HNCUP. Our preliminary results show that such approach does not compromise local-regional control. Further studies with more patients and longer follow-up are necessary to validate this approach.     

肿瘤局部相关因素对N0期食管癌IMRT预后影响

目的 探讨食管癌肿瘤局部相关因素对接受根治性放化疗N0期食管鳞癌患者GTV内复发的影响,并分析对10年长期生存的影响。方法 对河北医科大学第四医院2005-2010年收治的根治性放化疗临床N0期食管鳞癌患者374例进行回顾分析。284例累及野照射,90例择性淋巴结照射。69l例同期放化疗,38例序贯放化疗。Kaplan-Meier法生存分析,Cox模型多因素预后分析。结果全组患者出现GTV内复发143例(38.2%),GTV内复发者GTV最大横径(GTV-D)、GTV体积(GTV-V)和GTV-体积/长度(GTV-V/L)均显著长于GTV内未失败者(P=0.008、0.043、0.001)。ROC曲线分析结果显示GTV-D、GTV长度(GTV-L)、GTV-V和GTV-V/L判断GTV内复发的最佳诊断阈值分别为3.5cm、5.5cm、24.0cm³和4.6cm²(P=0.000、0.003、0.000、0.000),且其值较大者GTV内复发比率均大于其余组(P=0.000、0.002、0.001、0.000)。GTV-L和GTV-V/L为影响GTV内复发的因素(P=0.021、0.009)。全组3、5、10年生存率分别为42.9%、23.2%和7.9%,多因素分析结果显示年龄、T分期、联合化疗、GTV-D和GTV-V/L为影响生存的因素(P=0.027、0.000、0.018、0.009、0.034)。生存时间≥5年的主要死亡原因仍与肿瘤相关。结论 食管癌肿瘤局部相关因素对接受根治性放化疗临床N0食管鳞癌患者GTV内复发有显著影响,可作为GTV内复发的预测指标。GTV-D和GTV-V/L为显著影响患者10年生存的因素。     

Intraobserver and interobserver variability in GTV delineation on FDG-PET-CT images of head and neck cancers

PURPOSE: To determine if the addition of fluorodeoxyglucose positron emission tomography (FDG-PET) data changes primary site gross tumor volumes (GTVs) in head and neck cancers. METHODS AND MATERIALS: Computed tomography (CT), contrast-enhanced CT, and FDG-PET-CT scans were obtained in 10 patients with head and neck cancers. Eight experienced observers (6 head and neck oncologists and 2 neuro-radiologists) with access to clinical and radiologic reports outlined primary site GTVs on each modality. Three cases were recontoured twice to assess intraobserver variability. The magnitudes of the GTVs were compared. Intra- and interobserver variability was assessed by a two-way repeated measures analysis of variance. Inter- and intraobserver reliability were calculated. RESULTS: There were no significant differences in the GTVs across the image modalities when compared as ensemble averages; the Wilcoxon matched-pairs signed-rank test showed that CT volumes were larger than PET-CT. Observers demonstrated the greatest consistency and were most interchangeable on contrast-enhanced CT; they performed less reliably on PET-CT. CONCLUSIONS: The addition of PET-CT to primary site GTV delineation of head and neck cancers does not change the volume of the GTV defined by this group of expert observers in this patient sample. An FDG-PET may demonstrate differences in neck node delineation and in other disease sites.     

Prognostic value of 18F‐fluoroazomycin arabinoside PET/CT in patients with advanced non‐small‐cell lung cancer

This study evaluated the prognostic value of positron emission tomography/computed tomography (PET/CT) using ¹⁸F‐fluoroazomycin arabinoside (FAZA) in patients with advanced non‐small‐cell lung cancer (NSCLC) compared with ¹⁸F‐fluorodeoxyglucose (FDG). Thirty‐eight patients with advanced NSCLC (stage III, 23 patients; stage IV, 15 patients) underwent FAZA and FDG PET/CT before treatment. The PET parameters (tumor‐to‐muscle ratio [T/M] at 1 and 2 h for FAZA, maximum standardized uptake value for FDG) in the primary lesion and lymph node (LN) metastasis and clinical parameters were compared concerning their effects on progression‐free survival (PFS) and overall survival (OS). In our univariate analysis of all patients, clinical stage and FAZA T/M in LNs at 1 and 2 h were predictive of PFS (P = 0.021, 0.028, and 0.002, respectively). Multivariate analysis also indicated that clinical stage and FAZA T/M in LNs at 1 and 2 h were independent predictors of PFS. Subgroup analysis of chemoradiotherapy‐treated stage III patients revealed that only FAZA T/M in LNs at 2 h was predictive of PFS (P = 0.025). The FDG PET/CT parameters were not predictive of PFS. No parameter was a significant predictor of OS. In patients with advanced NSCLC, FAZA uptake in LNs, but not in primary lesions, was predictive of treatment outcome. These results suggest the importance of characterization of LN metastases in advanced NSCLC patients.     

Interobserver reliability of computed tomography-derived primary tumor volume measurement in patients with supraglottic carcinoma

BACKGROUND: Prior studies have determined that macroscopic ("gross") tumor volume (GTV), as calculated from pretreatment computer tomography (CT), was capable of predicting local control in squamous cell carcinoma arising in different subsites in the head and neck in patients who were treated with nonsurgical organ-preservation therapy. The majority of these studies were single-institution, retrospective investigations. Consequently, there has been concern that GTV measurements may not be reproducible by different readers at different institutions. The objective of the current study was to measure the interobserver reliability for GTV measurements for squamous cell carcinoma of the supraglottic larynx (SGSCCA) performed by different readers at different institutions. METHODS: Eight experienced readers (4 neuroradiologists and 4 radiation oncologists) from different institutions independently measured the pretreatment GTV of 20 patients with SGSCCA. The CT scans were obtained from patients entered into the definitive radiation therapy arm of Radiation Therapy Oncology Group protocol 91-11, who had supraglottic carcinoma and underwent pretreatment CT scans of the neck. Statistical analysis focused on interobserver reliability as measured by the intraclass correlation coefficient. RESULTS: The intraclass correlation coefficient was 0.81 (95% lower confidence bound, 0.71). This value was interpreted as "excellent." CONCLUSIONS: GTV measurements were reliable and reproducible when performed by neuroradiologists and radiation oncologists who were experienced in the interpretation of CT scans of the extracranial head and neck in patients with SGSCCA. The result implied that the correlation between GTV and local control should be reproducible across institutions.