Optimal size criteria of malignant lymph nodes in the treatment planning of radiotherapy for esophageal cancer: evaluation by computed tomography and magnetic resonance imaging

Principle and progress of radical treatment for locally advanced esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma is one of the most common malignant tumors in the digestive system in China and the world. Most patients are diagnosed as locally advanced or advanced stage. Concurrent chemoradiotherapy is the standard treatment for locally advanced esophageal squamous cell carcinoma. This study intends to summarize the evidence-based medical evidence of the treatment principle of locally advanced esophageal squamous cell carcinoma, the selection of radiotherapy dose, the outline of radiotherapy target and the selection of chemotherapy scheme. As a result, the effect of radiotherapy and chemotherapy is equivalent to that of surgery for the radical treatment of esophageal squamous cell carcinoma. In the era of immunization, it is recommended to use involved field irradiation. Fluorouracil plus cisplatin regimen is the standard chemotherapy regimen. FOLFOX regimen and paclitaxel plus fluorouracil regimen are optional concurrent chemotherapy regimens. The toxic and side effects of different chemotherapy regimens are different, which can be selected according to the actual situation of patients.

The Role of Magnetic Resonance Imaging in the Management of Esophageal Cancer

Esophageal cancer (EC) is the eighth more frequent cancer worldwide, with a poor prognosis. Initial staging is critical to decide on the best individual treatment approach. Current modalities for the assessment of EC are irradiating techniques, such as computed tomography (CT) and positron emission tomography/CT, or invasive techniques, such as digestive endoscopy and endoscopic ultrasound. Magnetic resonance imaging (MRI) is a non-invasive and non-irradiating imaging technique that provides high degrees of soft tissue contrast, with good depiction of the esophageal wall and the esophagogastric junction. Various sequences of MRI have shown good performance in initial tumor and lymph node staging in EC. Diffusion-weighted MRI has also demonstrated capabilities in the evaluation of tumor response to chemoradiotherapy. To date, there is not enough data to consider whole body MRI as a routine investigation for the detection of initial metastases or for prediction of distant recurrence. This narrative review summarizes the current knowledge on MRI for the management of EC.

Unresected small lymph node assessment predicts prognosis for patients with pT3N0M0 thoracic esophageal squamous cell carcinoma

Background

The role of unresected small lymph nodes (LNs) which may contain metastases for thoracic esophageal squamous cell carcinoma (TESCC) has not been addressed. The aim of the study was to investigate the role of unresected small LNs assessment using computed tomography (CT) in prognostic estimates of pT3N0M0 TESCC patients.

Methods

Between January 2009 and December 2017, 294 patients who underwent esophagectomy with R0 resection at Sichuan Cancer Hospital were retrospectively examined, and the last follow-up time was July 2018. Patients were classified into CT-suspect and CT-negative groups according to the shortest diameter and the shape (axial ratio) of the unresected small LNs on preoperative CT. The Kaplan–Meier method was used to compare survival differences in prognostic factors. Univariate and multivariate analyses were performed to identify prognostic factors for survival and recurrence.

Results

Eighty-four patients (28.6%) were classified as CT-suspect group according to the diagnostic criteria; survival analysis suggested that CT-suspect group of patients had a relatively poorer prognosis (P<0.05). Cox regression analysis indicated that unresected small LNs status, tumor grade, and postoperative adjuvant therapy were independent prognostic factors for patients with pT3N0M0 TESCC (P<0.05). Further analysis shown the rates of total recurrence (TR) and locoregional recurrence (LR) in the CT-suspect group were significantly higher than that in the CT-negative group (TR, P<0.001; LR, P<0.001). Among the LRs, the rate of supraclavicular lymph node recurrence in the CT-suspect group was significantly higher than that in the CT-negative group (P<0.001).

Conclusions

Unresected small lymph node assessment is critically important and predict prognosis for pT3N0M0 TESCC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02412-1.

Development of a prediction model for the risk of recurrent laryngeal nerve lymph node metastasis in thoracolaparoscopic esophagectomy with cervical anastomosis

Background

There are no effective preoperative diagnostic measures to predict the probability of left and right recurrent laryngeal nerve (RLN) lymph node (LN) metastasis using preoperative clinical data in patients undergoing thoracolaparoscopic esophagectomy with cervical anastomosis.

Methods

We retrospectively reviewed the clinical data of 1,660 consecutive patients with thoracic esophageal cancer who underwent esophagectomy with cervical anastomosis at the Department of Thoracic Surgery at the First Affiliated Hospital of Zhengzhou University between January 2015 and December 2020.

Results

A total of 299 and 343 patients who underwent left (Cohort 1) and right (Cohort 2) RLN LN dissection were included in the final analyses. The analyses were conducted within each cohort. Among the 299 patients in Cohort 1, left RLN LN involvement was found in 41 patients (13.7%). A multivariable analysis showed that age, tumor location, and short axis were significantly associated with RLN LN metastasis (all P<0.05). Among the 343 patients in Cohort 2, right RLN LN involvement was found in 65 patients (19.0%). A multivariable analysis showed that computed tomography (CT) appearance, tumor location, long axis, and short axis were significantly associated with RLN LN metastasis (all P<0.05). Based on the results of the multivariable analyses, we constructed nomograms that could estimate the probability of RLN LN metastasis. Finally, we stratified the 2 cohorts into risk subgroups using a recursive partitioning analysis (RPA). The risk of left and right RLN LN metastasis was found to be 9.3% and 7.5%, 27.3% and 21.4%, and 52.4% and 47.3% for the low-risk, intermediate-risk, and high-risk groups, respectively.

Conclusions

Our nomograms and RPAs appear to be suitable for the risk stratification of left and right RLN LN metastasis in patients undergoing thoracolaparoscopic esophagectomy with cervical anastomosis. This tool could be used to help clinicians to select more effective locoregional treatments, such as surgical protocols and radiation area selection.

Mapping of Cervical and Upper Mediastinal Lymph Node Recurrence for Guiding Clinical Target Delineation of Postoperative Radiotherapy in Thoracic Esophageal Squamous Cell Carcinoma

Background

The lower neck and upper mediastinum are the major regions for postoperative radiotherapy (PORT) in thoracic esophageal squamous cell carcinoma (TESCC). However, there is no uniform standard regarding the delineation of nodal clinical target volume (CTVnd). This study aimed to map the recurrent lymph nodes in the cervical and upper mediastinal regions and explore a reasonable CTVnd for PORT in TESCC.

Methods

We retrospectively reviewed patients in our hospital with first cervical and/or upper mediastinal lymph node recurrence (LNR) after upfront esophagectomy. All of these recurrent lymph nodes were plotted on template computed tomography (CT) images with reference to surrounding structures. The recurrence frequency at different stations was investigated and the anatomic distribution of recurrent lymph nodes was analyzed.

Results

A total of 119 patients with 215 recurrent lymph nodes were identified. There were 47 (39.5%) patients with cervical LNR and 102 (85.7%) patients with upper mediastinal LNR. The high-risk regions were station 101L/R, station 104L/R, station 106recL/R, station 105 and station 106pre for upper TESCC and station 104L/R, station 106recL/R, station 105, station 106pre and station 106tbL for middle and lower TESCCs. LNR in the external group of station 104L/R was not common, and LNR was not found in the narrow spaces where the trachea was in close contact with the innominate artery, aortic arch and mediastinal pleura. LNR below the level of the cephalic margin of the superior vena cava was also not common for upper TESCC.

Conclusions

The CTVnd of PORT in the cervical and upper mediastinal regions should cover station 101L/R, station 104L/R, station 106recL/R, station 105 and station 106pre for upper TESCC and station 104L/R, station 106recL/R, station 105, station 106pre and station 106tbL for middle and lower TESCCs. Based on our results, we proposed a useful atlas for guiding the delineation of CTVnd in TESCC.

Survival Comparision of Three-dimensional Radiotherapy Alone vs. Chemoradiotherapy for Esophageal Squamous Cell Carcinoma

BACKGROUND AND OBJECTIVE

To compare the survival of esophageal squamous cell carcinoma (ESCC) patients who received chemoradiotherapy (CRT) or radiotherapy (RT) alone.

METHODS

A total of 753 well-matched patients were enrolled. A total of 299 patients were treated with CRT, and 454 patients were treated with RT alone. Propensity score matching (PSM) was performed with the R project. The Kaplan-Meier method was used to calculate survival rates, and the log-rank test was used to assess differences in survival.

RESULTS

The response rate was 99.0% with CRT and 98.3% with RT alone (p = 0.651). The 1-, 3-, 5- and 10 year overall survival (OS) rates were as follows: 72.2, 40.1, 30.7 and 13.9% with CRT, 68.1, 35.2%, 23.3 and 12.5% with RT alone (p = 0.033); 73.4, 40.1, 31.0 and 16.1% with concurrent chemoradiotherapy (CCRT); and 68.1, 35.2, 23.3 and 12.5% with RT alone (p = 0.028). There was no significant difference in OS between the CCRT group and the sequential chemoradiotherapy (SCRT) group (p = 0.527). Consolidation chemotherapy (CCT) after CCRT led to a significant increase in the OS rate compared with no CCT after CCRT (p = 0.003). Compared with the OS of patients who received 1∼2 cycles of CCT, the OS of patients who received 3∼4 cycles of CCT was significantly improved (p = 0.011). Acute toxic effects were more severe in the CRT, but no significant differences in late reactions. CRT exhibited more appetite loss and fatigue symptoms than RT alone, and dysphagia of CRT relief more obviously. The CRT group had a significantly lower rate of local control failure than the RT alone group (p = 0.019).

CONCLUSIONS

For patients with ESCC, CRT led to a significantly improved OS compared to RT alone, and this trend was more obvious with CCRT. CCT after CCRT prolonged OS, especially in patients who received at least 2 cycles of CCT. CRT can reduce the deaths due to local control failure compared to RT alone.

A nomogram prediction model for recurrent laryngeal nerve lymph node metastasis in thoracic oesophageal squamous cell carcinoma

Background

The metastasis rate to the recurrent laryngeal nerve lymph node (RLN LN) is high, but resection of it is challenging and increases complications. This study explored the risk factors for the RLN LN metastasis in thoracic oesophageal squamous cell carcinoma and developed a novel scoring system to predict it.

Methods

We retrospectively analysed the clinicopathological data of 265 patients between 2015 and 2018. Univariate and multivariate analyses were performed to screen for risk factors and establish a logistic regression model to predict the risk of RLN LN metastasis. A nomogram was constructed accordingly. Further analyses were conducted regarding right and left RLN LN metastasis alone.

Results

(I) The metastatic rates of the left and right RLN LN were 15.1% and 20.4%, respectively. (II) Multivariate logistic regression analysis showed that the short axis diameter of the left RLN LN, short axis diameter of the right RLN LN, maximum diameter of the tumor, tumor location, subcarinal lymph node status and paraoesophageal lymph node status were all independent risk factors for RLN LN metastasis. (III) Multivariate logistic regression analysis showed that the short axis diameter of right RLN LN, tumor location and subcarinal lymph node status were independent risk factors for right RLN LN metastasis. (IV) Multivariate logistic regression analysis showed that short axis diameter of left RLN LN was an independent risk factor for left RLN LN metastasis.

Conclusions

The metastatic rates of the left and right RLN LNs were high and can be predicted according to these nomograms.

Failure patterns after adjuvant chemoradiotherapy following endoscopic resection for superficial esophageal squamous cell carcinoma

Background

This study evaluated the locations of lymph node recurrence and their association with irradiation fields used for radiotherapy after adjuvant chemoradiotherapy following endoscopic resection for superficial esophageal squamous cell carcinoma.

Methods

Medical records of 96 consecutive patients with superficial esophageal squamous cell carcinoma who underwent adjuvant chemoradiotherapy following endoscopic resection were reviewed. Computed tomography was used to identify whether nodal recurrences were within the elective nodal irradiation field. The cumulative incidence of recurrence was calculated, accounting for death as a competing risk. Univariate and multivariate analyses identified factors predicting nodal recurrence.

Results

The median follow‐up period was 61 months (range: 6‐137 months). Seven patients (7.3%) developed lymph node recurrence only; two patients (2.1%) developed nodal plus local recurrence. Six of the seven cases without local recurrence involved the elective nodal irradiation field, with five cases involving the recurrent nerve lymph nodes. The 5‐year cumulative incidence of lymph node recurrence was higher for T1b tumors with lymphovascular invasion than for T1a tumors with lymphovascular invasion (17.6% vs 6.2%, P = 0.086; HR: 3.74, 95% CI: 0.80‐17.52, P = 0.094) and T1b tumors without lymphovascular invasion (17.6% vs 3.3%, P = 0.031; HR: 6.78, 95% CI: 0.80‐57.63, P = 0.080).

Conclusions

Lymph node recurrence frequently involved the elective nodal irradiation field, with recurrent nerve lymph nodes being common metastasis sites. The high incidence of nodal recurrence for T1b tumors with lymphovascular invasion highlights a need for new strategies for treating this subset of superficial esophageal squamous cell carcinomas.

Prognostic significance of preoperative lymph node assessment for patients with stage pN0 esophageal squamous cell carcinoma after esophagectomy

Background

Accurate preoperative lymph node (LN) staging is important for surgical treatments of esophageal squamous cell carcinoma (ESCC). The aim of the study was to investigate the role of preoperative lymph nodes assessment by computed tomography (CT) scans in prognostic estimates and lymph nodes dissection strategy.

Methods

A total of 233 stage pN0 ESCC patients who underwent radical esophagectomy from 2009 to 2016 were included, with the last follow-up time in 2018. Survival analysis was conducted to assess the relationship between preoperative clinical LN metastasis and the prognosis of patients with pN0 ESCC.

Results

Ninety-nine patients were classified as clinical positive LN metastasis by CT scans, but were confirmed as stage N0 by postoperative pathological examination, and survival analysis suggested that these patients had relatively poorer prognosis (P=0.027). Cox regression analysis indicated that the clinical LN metastasis on CT scans was an independent negative prognostic factor for patients with pN0 ESCC (P=0.031). The number of LNs dissected affected the prognosis of pN0 patients. Patients with positive LN metastasis on CT would have better prognosis when the number of dissected LNs was equal to or more than 15 LNs (P=0.036). Especially for patients with higher T stage, they were would obtain prognostic benefit with at least 17 LNs dissected (P=0.037). On the other hand, for those with negative LN metastasis on CT, at least 12 LNs dissected indicated better prognosis (P=0.019).

Conclusions

Preoperative LN assessment for ESCC patients is critically important, the optimal LN dissection number should refer to the preoperative CT performance.

Diagnostic performance of MRI for assessment of response to neoadjuvant chemoradiotherapy in oesophageal cancer

Background

Patients with a pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) for oesophageal cancer may benefit from non‐surgical management. The aim of this study was to determine the diagnostic performance of visual response assessment of the primary tumour after nCRT on T2‐weighted (T2W) and diffusion‐weighted (DW) MRI.

Methods

Patients with locally advanced oesophageal cancer who underwent T2W‐ and DW‐MRI (1·5 T) before and after nCRT in two hospitals, between July 2013 and September 2017, were included in this prospective study. Three radiologists evaluated T2W images retrospectively using a five‐point score for the assessment of residual tumour in a blinded manner and immediately rescored after adding DW‐MRI. Histopathology of the resection specimen was used as the reference standard; ypT0 represented a pCR. Sensitivity, specificity, area under the receiver operating characteristic (ROC) curve (AUC) and interobserver agreement were calculated.

Results

Twelve of 51 patients (24 per cent) had a pCR. The sensitivity and specificity of T2W‐MRI for detection of residual tumour ranged from 90 to 100 and 8 to 25 per cent respectively. Respective values for T2W + DW‐MRI were 90–97 and 42–50 per cent. AUCs for the three readers were 0·65, 0·66 and 0·68 on T2W‐MRI, and 0·71, 0·70 and 0·70 on T2W + DW‐MRI (P = 0·441, P = 0·611 and P = 0·828 for readers 1, 2 and 3 respectively). The κ value for interobserver agreement improved from 0·24–0·55 on T2W‐MRI to 0·55–0·71 with DW‐MRI.

Conclusion

Preoperative assessment of residual tumour on MRI after nCRT for oesophageal cancer is feasible with high sensitivity, reflecting a low chance of missing residual tumour. However, the specificity was low; this results in overstaging of complete responders as having residual tumour and, consequently, overtreatment.

Neck Lymph Node Metastasis as A Poor Prognostic Factor in Thoracic Esophageal Squamous Cell Carcinoma Patients Receiving Concurrent Chemoradiotherapy: A Propensity Score-Matched Analysis

The present study investigated the clinical impact of neck lymph node (LN) metastasis in locally advanced inoperable thoracic esophageal squamous cell carcinoma (ESCC) patients who underwent concurrent chemoradiotherapy (CCRT) with a curative intent. There were 404 ESCC patients enrolled, including 35 patients with neck LN metastasis and 369 patients without such metastasis. Through the propensity score matching method, 35 patients of the 369 patients without neck LN metastasis were matched to the 35 patients with neck LN metastasis. Progression-free survival (PFS) and overall survival (OS) were found to be significantly worse in the neck LN metastasis group compared to the full non-neck LN metastasis group (9.8 months versus 5.9 months, P < 0.001, and 18.2 months versus 9.7 months, P = 0.001) and the matched non-neck LN metastasis group (9.9 months versus 5.9 months, P = 0.006, and 19.4 months versus 9.7 months, P = 0.007). In order to determine the difference between neck LN and supraclavicular LN metastasis, seventy patients with supraclavicular LN metastasis were also selected from the 369 patients without neck LN metastasis for comparison. Subsequently, when compared to the ESCC patients with supraclavicular LN metastasis, significantly worse PFS (8.5 months versus 5.9 months, P = 0.026) and OS (17.2 months versus 9.7 months, P = 0.047) were still found in the ESCC patients with neck LN metastasis. Our study indicates that neck LN metastasis is an independent poor prognostic factor for locally advanced inoperable thoracic ESCC patients who have undergone CCRT.

Comparative study of computed tomography (CT) and pathological diagnosis toward mediastinal lymph node metastasis in esophageal carcinoma

OBJECTIVE

To investigate the diagnostic criteria of mediastinal lymph node metastasis (MLNM) in esophageal carcinoma (EC) by comparing the lymph node sizes measured by computed tomography (CT) and obtained by postoperative pathological examination.

METHOD

A total of 305 EC patients were selected. MLNM location, shortest diameter and number were investigated one week before surgery, and then compared with their pathological findings.

RESULTS

The receiver operating characteristic (ROC) curve analysis revealed that the minimum diameters of MLNM in the thoracic cavity was 8 mm (area under curve [AUC] = 0.766, Youden index = 0.424), 5 mm in supraclavicular fossa (AUC = 0.785, Youden index = 0.494), 6 mm in tracheoesophageal groove (AUC = 0.755, Youden index = 0.405); the sensitivity was increased significantly, and the Youden index was increased significantly when compared with 10 mm.

CONCLUSION

The shortest diameter of diagnostic criteria of lymph nodes in EC could be less than 10 mm on CT.

Clinical Significance of the Pre-therapeutic Nodal Size in Patients Undergoing Neo-Adjuvant Treatment Followed by Esophagectomy for Esophageal Squamous Cell Carcinoma

BACKGROUND

The clinical significance of pre-therapeutic nodal size in patients with esophageal squamous cell carcinoma (ESCC) is not clear. We investigated whether nodal size was correlated with survival in patients undergoing neo-adjuvant treatment followed by esophagectomy for ESCC.

METHODS

In 2009-2013, 222 patients who underwent neo-adjuvant treatment followed by esophagectomy for ESCC were enrolled in this retrospective study. Nodal size was measured along the short axis of the largest node using pre-therapeutic CT images. Patients were then stratified based on this short axis, and nodal size was correlated with clinicopathological factors and survival.

RESULTS

Patients with larger nodes were likely to have deeper cT, higher cN status, and poorer survival. Among the clinical factors cT, cN, cM, and nodal size, only cT and nodal size were independent prognostic factors in multivariate analysis [hazard ratio (HR) 2.0, 95 % confidence interval (CI) 1.1-3.5, p = 0.025 and HR 1.5, 95 % CI 1-2.3, p = 0.036, respectively]. In addition, nodal size was significantly associated with hematological recurrence (p = 0.007), but not lymphatic relapse (p = 0.272).

CONCLUSIONS

The short axis of the largest node before neo-adjuvant treatment in patients with ESCC is a prognostic factor.

Distribution patterns of metastases in recurrent laryngeal nerve lymph nodes in patients with squamous cell esophageal cancer

Esophageal cancers frequently metastasize to recurrent laryngeal nerve lymph nodes (RLNNs). Knowledge of anatomic metastatic RLNN (mRLNN) distributions is needed for lymph node dissection during esophageal cancer surgery. Among 189 patients with esophageal cancer who underwent esophagectomy between 2008 and 2010, 51 (27.0%) had mRLNN. Sixty-four mRLNNs (right, 31; left, 33) were identified via preoperative computed tomography (CT); more than 2 unilateral metastases and/or nodes with unclear boundaries were excluded. Anatomical characteristics, including vertical distance from the sternal notch level, circumferential angle to the mid-sagittal tracheal plane, and short and long axes, were measured via CT. Respective mean right and left vertical distances from the sternal notch were +2.0 ± 13.1 mm and -14.5 ± 23.8 mm (p = 0.0006). Left mRLNNs existed in vertically wider and inferior areas along recurrent laryngeal nerve, compared to right mRLNNs. The respective mean right and left circumferential angles around the trachea (from the anterior mid-sagittal plane) were 137.2 ± 11.2° and 94.3 ± 31.6° (p < 0.0001). Left mRLNNs were distributed more widely around the trachea, especially anteriorly. The short axes were larger for right mRLNNs than for left mRLNNs (8.6 mm vs. 6.8 mm, p = 0.026). Compared with the right side, left mRLNNs were smaller and had a vertically longer and circumferentially wider distribution. Careful attention should be given to the left side during curative RLNN dissection.

Identification of a predictive factor for distant metastasis in esophageal squamous cell carcinoma after definitive chemoradiotherapy

BACKGROUND AND PURPOSE

Distant metastasis (DM) after definitive chemoradiotherapy has not been a focus of research in esophageal carcinoma. At present, local-regional control is improving following advances in salvage treatments after definitive chemoradiotherapy. There is a need to focus on suppressing the development of DM. The aim of this study was to identify pre-treatment factors associated with DM after definitive chemoradiotherapy.

MATERIALS AND METHODS

This study included 144 patients with thoracic esophageal squamous cell carcinoma (Stage I/II/III/IV; 35/17/69/23) (TNM 7th) who underwent definitive chemoradiotherapy; >50 Gy was prescribed to all gross tumors with concurrent administration of 5-fluorouracil ± platinum. Pre-treatment factors included age, gender, performance status, tumor location, T/N/M status, tumor length, size of metastatic lymph nodes (LN size), and the presence of intramural metastasis or multiple primary tumors. The effects of pre-treatment factors on overall survival (OS) and DM were evaluated.

RESULTS

The median follow-up period was 48 months. DM occurred as an initial progression in 21 % of patients, and LN size correlated with DM development (hazard ratio [HR] = 5.12; p = 0.0013) and poor OS (HR = 2.20; p = 0.0076) in univariate and multivariate analyses.

CONCLUSIONS

LN size is a quantitative pre-treatment prognostic factor that should be assessed prior to definitive chemoradiotherapy. Patients with large metastatic lymph nodes are at high risk of DM and should be monitored.

Unidimensional Measurement May Evaluate Target Lymph Nodal Response After Induction Chemotherapy for Nasopharyngeal Carcinoma

The aim of the study was to evaluate whether short axis and long axis on axial and coronal magnetic resonance imaging planes would reflect the tumor burden or alteration in size after induction chemotherapy in nasopharyngeal carcinoma. Patients with pathologically confirmed nasopharyngeal carcinoma (n = 37) with at least 1 positive cervical lymph node (axial short axis ≥15 mm) were consecutively enrolled in this prospective study. Lymph nodal measurements were performed along its short axis and long axis in both axial and coronal magnetic resonance imaging planes at diagnosis and after 2 cycles of induction chemotherapy. In addition, lymph nodal volumes were automatically calculated in 3D treatment-planning system, which were used as reference standard. Student's t test or nonparametric Mann-Whitney U test was used to compare the continuous quantitative variables. Meanwhile, the κ statistic and McNemar's test were used to evaluate the degree of agreement and discordance in response categorization among different measurements. Axial short axis was significantly associated with volumes at diagnosis (P < 0.001). A good agreement (κ=0.583) was found between axial short axis and volumetric criteria. However, the inconsistent lymph nodal shrinkage in 4 directions was observed. Axial short-axis shrinking was more rapid than the other 3 parameters. Interestingly, when utilizing the alternative planes for unidimensional measurements to assess tumor response, coronal short-axis showed the best concordance (κ=0.792) to the volumes. Axial short axis may effectively reflect tumor burden or change in tumor size in the assessment of target lymph nodal response after induction chemotherapy for nasopharyngeal carcinoma. However, it should be noted that axial short axis may amplify the therapeutic response. In addition, the role of coronal short axis in the assessment of tumor response needs further evaluation.

Combination of FDG PET/CT and contrast-enhanced MSCT in detecting lymph node metastasis of esophageal cancer

BACKGROUND

Lymph node metastasis is believed to be a dependent negative prognostic factor of esophageal cancer. To explore detection methods with high sensitivity and accuracy for metastases to regional and distant lymph nodes in the clinic is of great significance. This study focused on clinical application of FDG PET/CT and contrast-enhanced multiple-slice helical computed tomography (MSCT) in lymph node staging of esophageal cancer.

MATERIALS AND METHODS

One hundred and fifteen cases were examined with enhanced 64-slice-MSCT scan, and FDG PET/CT imaging was conducted for neck, chest and upper abdomen within one week. The primary lesion, location and numbers of metastatic lymph nodes were observed. Surgery was performed within one week after FDG PET/CT detection. All resected lesions were confirmed histopathologically as the gold standard. Comparative analysis of the sensitivity, specificity, and accuracy based on FDG PET/CT and MSCT was conducted.

RESULTS

There were 946 lymph node groups resected during surgery from 115 patients, and 221 were confirmed to have metastasis pathologically. The sensitivity, specificity, accuracy of FDG PET/CT in detecting lymph node metastasis were 74.7%, 97.2% and 92.0%, while with MSCT they were 64.7%, 96.4%, and 89.0%, respectively. A significance difference was observed in sensitivity (p=0.030), but not the others (p>0.05). The accuracy of FDG PET/CT in detecting regional lymph node with or without metastasis were 91.9%, as compared to 89.4% for MSCT, while FDG PET/CT and MSCT values for detecting distant lymph node with or without metastasis were 94.4% and 94.7%. No significant difference was observed for either regional or distant lymph node metastasis. Additionally, for detecting para-esophageal lymph nodes metastasis, the sensitivity of FDG PET/CT was 72%, compared with 54.7% for MSCT (p=0.029).

CONCLUSIONS

FDG PET/CT is more sensitive than MSCT in detecting lymph node metastasis, especially for para-esophageal lymph nodes in esophageal cancer cases, although no significant difference was observed between FDG PET/CT and MSCT in detecting both regional and distant lymph node metastasis. However, enhanced MSCT was found to be of great value in distinguishing false negative metastatic lymph nodes from FDG PET/CT. The combination of FDG PET/CT with MSCT should improve the accuracy in lymph node metastasis staging of esophageal cancer.

Investigation of using diffusion-weighted magnetic resonance imaging to evaluate the therapeutic effect of esophageal carcinoma treatment

AIM

To explore the associations of diffusion-weighted magnetic resonance imaging (DWI) measurements with the therapeutic effect (TE) on and survival of esophageal carcinoma patients treated with chemoradiotherapy (CRT).

METHODS

From March 2010 to December 2011, 77 patients were prospectively enrolled into a cohort study. DWI was performed at the beginning and 1-3 months after CRT. The immediate post-CRT TE was evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST). The associations between the disappearance status of hyperintense expression (HE) in DWI and the apparent diffusion coefficient (ADC) of DWI with the complete response (CR) as TE and survival were analyzed.

RESULTS

3 patients were excluded due to the absence of HE in DWI. Analysis of the remaining 74 patients indicated that their ADC values were significantly improved from 1.64 ± 0.48 to 2.65 ± 0.58 mm2/s from pre-CRT to post-CRT (p = 0.000). Both univariate and multivariate Cox model analyses showed that high post-CRT ADC values and the disappearance status of HE associated significantly with the TE (CR rate) and survival.

CONCLUSIONS

DWI examination could afford useful markers to predict the treatment response as well as the survival of patients with esophageal squamous cell carcinoma. The non-disappearance of HE in DWI and low ADC values after CRT were risk factors.

Imaging strategies in the management of oesophageal cancer: what's the role of MRI?

OBJECTIVES

To outline the current role and future potential of magnetic resonance imaging (MRI) in the management of oesophageal cancer regarding T-staging, N-staging, tumour delineation for radiotherapy (RT) and treatment response assessment.

METHODS

PubMed, Embase and the Cochrane library were searched identifying all articles related to the use of MRI in oesophageal cancer. Data regarding the value of MRI in the areas of interest were extracted in order to calculate sensitivity, specificity, predictive values and accuracy for group-related outcome measures.

RESULTS

Although historically poor, recent improvements in MRI protocols and techniques have resulted in better imaging quality and the valuable addition of functional information. In recent studies, similar or even better results have been achieved using optimised MRI compared with other imaging strategies for T- and N-staging. No studies clearly report on the role of MRI in oesophageal tumour delineation and real-time guidance for RT so far. Recent pilot studies showed that functional MRI might be capable of predicting pathological response to treatment and patient prognosis.

CONCLUSIONS

In the near future MRI has the potential to bring improvement in staging, tumour delineation and real-time guidance for RT and assessment of treatment response, thereby complementing the limitations of currently used imaging strategies.

KEY POINTS

• MRI's role in oesophageal cancer has been somewhat limited to date. • However MRI's ability to depict oesophageal cancer is continuously improving. • Optimising TN-staging, radiotherapy planning and response assessment ultimately improves individualised cancer care. • MRI potentially complements the limitations of other imaging strategies regarding these points.

Confirmation of histology of PET positive lymph nodes recovered by hand-video-assisted thoracoscopy surgery

PET/CT (Positron Emission Tomography-Computed Tomography) is an advanced diagnostic imaging device that combines both PET and an X-ray CT. This study evaluates the effects of PET/CT on detecting primary tumors and metastases, and looks at the therapeutic effect of minimally invasive surgery on esophageal cancer patients. Eighty patients with esophageal cancer were enrolled in the study between January, 2004 and December, 2007, who were randomly divided into two groups of 40, one of which was treated with hand-video-assisted thoracoscopy surgery (HVATS) esophagectomy and one of which was treated with conventional surgery. All patients underwent a PET/CT scan 2-3 weeks before their operation, and their cervical, thoracic and upper abdominal lymph nodes were biopsied. All the primary esophageal lesions showed high FDG uptake. The maximum standardized uptake value (SUV) was 3.78-25.64 (11.73±5.32), while the mean SUV was 3.65=16.92 (9.12±4.37). Using 2.5 as the SUV standard, all esophageal lesions were detected by PET/CT image. Of the 80 patients, 53 had lymph nodal metastases, with a total of 142 metastatic lymph nodes, which showed high FDG uptake. The maximum SUV was 2.77-14.63 (7.98±3.25), and the mean SUV was 2.31-12.84 (5.34±3.19). The visual analysis from the PET/CT scan showed a sensitivity of 86.62%, a specificity of 95.85%, a positive predictive value of 93.89%, a negative predictive value of 90.69% and an accuracy of 91.94%. The PET/CT scan showed a high sensitivity and specificity in detecting primary esophageal cancer and lymph nodal metastases. The mean post-surgery life expectancies for patients undergoing HVATS and conventional surgery are 27.93 months and 28.05 months, respectively. The two groups showed no statistically significant difference. We thus conclude that PET/CT combined with HVATS is a new choice for esophageal carcinoma patients.

Recursive partitioning analysis for new classification of patients with esophageal cancer treated by chemoradiotherapy

BACKGROUND

The 7th edition of the American Joint Committee on Cancer staging system does not include lymph node size in the guidelines for staging patients with esophageal cancer. The objectives of this study were to determine the prognostic impact of the maximum metastatic lymph node diameter (ND) on survival and to develop and validate a new staging system for patients with esophageal squamous cell cancer who were treated with definitive chemoradiotherapy (CRT).

METHODS

Information on 402 patients with esophageal cancer undergoing CRT at two institutions was reviewed. Univariate and multivariate analyses of data from one institution were used to assess the impact of clinical factors on survival, and recursive partitioning analysis was performed to develop the new staging classification. To assess its clinical utility, the new classification was validated using data from the second institution.

RESULTS

By multivariate analysis, gender, T, N, and ND stages were independently and significantly associated with survival (p < 0.05). The resulting new staging classification was based on the T and ND. The four new stages led to good separation of survival curves in both the developmental and validation datasets (p < 0.05).

CONCLUSIONS

Our results showed that lymph node size is a strong independent prognostic factor and that the new staging system, which incorporated lymph node size, provided good prognostic power, and discriminated effectively for patients with esophageal cancer undergoing CRT.

Lymphatic tumor emboli detected by D2-40 immunostaining can more accurately predict lymph-node metastasis

BACKGROUND

Resected specimens of superficial squamous cell carcinoma of the esophagus (SSCCE) underwent D2-40 immunostaining to accurately assess lymphatic tumor emboli (LY) and to analyze correlations between LY and lymph node metastasis (N). This present study was designed to determine the accuracy of LY grade for predicting the risk of N.

MATERIALS AND METHODS

We studied 75 patients with SSCCE who underwent surgical resection of their tumors. Resected specimens were sliced into continuous sections at 5 mm intervals. Intramucosal cancers are classified into three groups (m1, m2, m3), and submucosal cancers are also divided into three groups (sm1, sm2, sm3). The numbers of LY present in lymphatic ducts on D2-40 immunostaining, venous tumor emboli (V) on CD34 immunostaining, and lymphatic tumor emboli (ly) and V on hematoxylin-eosin staining (HE) and elastica van Gieson staining (EVG) were counted for each case. The presence of lymphatic tumor emboli was graded according to the total number of LY per case as follows: 0, LY0; 1 to 2, LY1; 3 to 9, LY2; and 10 or more, LY3.

RESULTS

All m1 and m2 cases were LY- and N- Lymphatic tumor emboli were present in 54% of m3 cases, 70% of sm1 cases, 54% of sm2 cases, and 75% of sm3 cases. Determination of N was positive in 18% of m3 cases, 47% of sm1 cases, 36% of sm2 cases, and 62% of sm3 cases. The frequency of LY significantly correlated with the number of N (p < 0.0001). Multiple regression analysis showed that only LY and V significantly correlated with N. When the detection rate of N was compared between LY and ly, LY was superior to ly in terms of specificity, accuracy, positive predictive value, and false positive rate. As for LY grade, N was positive in 39.1% of LY1 cases, 81.8% of LY2 cases, and 100% of LY3 cases. Even in LY-, N was positive in one sm1 case and in two sm2 cases. In the sm1 case, the depth of invasion was 350 μm from the lower margin of the muscularis mucosae.

CONCLUSIONS

Evaluation of lymphatic invasion on the basis of LY is more accurate for the prediction of N than conventional techniques, and LY grade strongly correlates with N. In patients with SSCCE, mucosal cancers (m1, m2, and m3) and submucosal cancers with a depth of invasion of ≤ 200 μm from the lower margin of the muscularis mucosae on endoscopic mucosal resection have a low risk of N if the number of LY is 0. Endoscopic mucosal resection alone can provide good treatment outcomes in such patients.

Prognostic impact of the 6th and 7th American Joint Committee on Cancer TNM staging systems on esophageal cancer patients treated with chemoradiotherapy

PURPOSE

The new 7th edition of the American Joint Committee on Cancer TNM staging system is based on pathologic data from esophageal cancers treated by surgery alone. There is no information available on evaluation of the new staging system with regard to prognosis of patients treated with chemoradiotherapy (CRT). The objective of this study was to evaluate the prognostic impact of the new staging system on esophageal cancer patients treated with CRT.

METHODS AND MATERIALS

A retrospective review was performed on 301 consecutive esophageal squamous cell carcinoma patients treated with CRT. Comparisons were made of the prognostic impacts of the 6th and 7th staging systems and the prognostic impacts of stage and prognostic groups, which were newly defined in the 7th edition.

RESULTS

There were significant differences between Stages I and III (p < 0.01) according to both editions. However, the 7th edition poorly distinguishes the prognoses of Stages III and IV (p = 0.36 by multivariate analysis) in comparison to the 6th edition (p = 0.08 by multivariate analysis), although these differences were not significant. For all patients, T, M, and gender were independent prognostic factors by multivariate analysis (p < 0.05). For the Stage I and II prognostic groups, survival curves showed a stepwise decrease with increase in stage, except for Stage IIA. However, there were no significant differences seen between each prognostic stage.

CONCLUSIONS

Our study indicates there are several problems with the 7th TNM staging system regarding prognostic factors in patients undergoing CRT.

Radiotherapy with or without concurrent chemotherapy for lymph node recurrence after radical surgery of thoracic esophageal squamous cell carcinoma

PURPOSE

To retrospectively compare the outcomes of patients with lymph node recurrence after radical surgery of esophageal cancer, when given radiotherapy with or without concurrent chemotherapy.

METHODS AND MATERIALS

Between January 1996 and December 2005, the data from 73 patients with lymph node recurrence after radical surgery of thoracic esophageal squamous cell carcinoma were retrospectively reviewed. The patients were separated into two groups: radiochemotherapy (RC, 31 patients) and radiotherapy alone (RA, 42 patients). Patients in the RC group received at least two cycles of 5-fluorouracil/cisplatin chemotherapy concurrently with radiotherapy.

RESULTS

The median duration of follow-up was 11 months (range, 2-48). The overall survival rate for all patients was 46.7% and 4.7% at 1 and 3 years, respectively. The median overall survival time was 9 months (95% confidence interval, 6.96-11.04) and 17 months (95% confidence interval, 13.61-20.39) for RA and RC groups, respectively. The survival rate at 1 and 3 years was 62.5% and 10.5% in the RC group and 33.8% and 0% in the RA group (p = .0049, log-rank test; hazard ratio for death, 0.52; 95% confidence interval, 0.30-0.92). Acute toxicities were more frequent in the RC group than in the RA group. No significant differences were found in the late toxicity profiles between the two groups.

CONCLUSION

The results of the present retrospective analysis suggest that RC should be considered an effective and well-tolerated treatment of patients with thoracic esophageal squamous cell carcinoma and postoperative lymph node recurrence.

Determination of the irradiation field for clinical T1-T3N0M0 thoracic/abdominal esophageal cancer based on the postoperative pathological results

OBJECTIVE

In patients with thoracic/abdominal esophageal cancer with no clinical evidence of lymph node metastasis, there is no consensus about whether the irradiation field should include regional lymph nodes. In this study, the extent of the irradiation field for clinical stage T1-3N0M0 esophageal cancer was determined based on the postoperative pathological results.

METHODS

From July 1989 to June 2008, 103 patients diagnosed with clinical stage T1-3N0M0 thoracic/abdominal esophageal cancer underwent standard esophagectomy and regional lymph node dissection at the Aichi Cancer Center Hospital. Of these 103 patients, the pathological results of the resected specimens could be confirmed in 95 (92%) patients. The pathological lymphatic spread was reviewed retrospectively, and the extent of the irradiation field was determined based on the postoperative pathological results.

RESULTS

Of 95 patients with clinical stage T1-3N0M0 esophageal cancer, 40 (42.1%) had pathological lymph node metastases, and the frequency of nodal metastases was studied by tumor location. The rates of lymph node metastases for the upper, middle, lower and abdominal esophagus were 37.5%, 32.5%, 46% and 70%, respectively.

CONCLUSIONS

Pathological lymph nodes metastases are often seen after operation in clinical stage T1-3N0M0 esophageal cancer. In the present study, the optimal lymph nodes to be included in the irradiation field were determined according to the primary site in the esophagus.

Neoadjuvant chemoradiation followed by surgery versus surgery alone for patients with adenocarcinoma or squamous cell carcinoma of the esophagus (CROSS)

Background

A surgical resection is currently the preferred treatment for esophageal cancer if the tumor is considered to be resectable without evidence of distant metastases (cT1-3 N0-1 M0). A high percentage of irradical resections is reported in studies using neoadjuvant chemotherapy followed by surgery versus surgery alone and in trials in which patients are treated with surgery alone. Improvement of locoregional control by using neoadjuvant chemoradiotherapy might therefore improve the prognosis in these patients. We previously reported that after neoadjuvant chemoradiotherapy with weekly administrations of Carboplatin and Paclitaxel combined with concurrent radiotherapy nearly always a complete R0-resection could be performed. The concept that this neoadjuvant chemoradiotherapy regimen improves overall survival has, however, to be proven in a randomized phase III trial.

Methods/design

The CROSS trial is a multicenter, randomized phase III, clinical trial. The study compares neoadjuvant chemoradiotherapy followed by surgery with surgery alone in patients with potentially curable esophageal cancer, with inclusion of 175 patients per arm.

The objectives of the CROSS trial are to compare median survival rates and quality of life (before, during and after treatment), pathological responses, progression free survival, the number of R0 resections, treatment toxicity and costs between patients treated with neoadjuvant chemoradiotherapy followed by surgery with surgery alone for surgically resectable esophageal adenocarcinoma or squamous cell carcinoma. Over a 5 week period concurrent chemoradiotherapy will be applied on an outpatient basis. Paclitaxel (50 mg/m2) and Carboplatin (Area-Under-Curve = 2) are administered by i.v. infusion on days 1, 8, 15, 22, and 29. External beam radiation with a total dose of 41.4 Gy is given in 23 fractions of 1.8 Gy, 5 fractions a week. After completion of the protocol, patients will be followed up every 3 months for the first year, every 6 months for the second year, and then at the end of each year until 5 years after treatment. Quality of life questionnaires will be filled out during the first year of follow-up.

Discussion

This study will contribute to the evidence on any benefits of neoadjuvant treatment in esophageal cancer patients using a promising chemoradiotherapy regimen.

Trial registration

ISRCTN80832026

Lymph node staging

Cancers of the head and neck (HNC) include cancers of the larynx, nasal passages/nose, oral cavity, pharynx, salivary glands, buccal regions, and thyroid. In these cancers, lymph node staging and localization of pathological lymph nodes are necessary to decide on either (neo) adjuvant or surgical therapy and are a major factor for the prognosis in HNC patients. Cervical node metastases have different incidence, and their presence is associated with a decrease in global survival to roughly half and with higher recurrence rates. The node metastases can be categorized in the following 2 groups: overt (clinical) or nonovert (occult). The latter can be subcategorized as metastases detectable by traditional methods (eg, staining) or "submicroscopic" metastases, only evident with immunohistochemical or molecular analysis. Compared with clinical invasive and laboratory examinations, which may have complications and are expensive, radiology plays an important role in lymph node staging. Mainly, the overt node metastases are the field of radiological imaging, and second, the detection of nonovert metastases is important and holds promise for the future because many patients of those initially classified as cN0 have, in fact, occult metastatic disease (pN1). Vice versa, radiological imaging has to avoid false-positive results that can lead to an elective or radical neck dissection, which are associated with increased morbidity and mortality and thus overshadow the improvement in survival. Radiological imaging plays a role not only as an initial staging of N+ but also in the case of N0 due to the continuing controversy for the treatment of N0 patients. A close observation of the patient may reveal a positive node in the follow-up. The imaging modalities used for the node staging in HNC patients include ultrasound, contrast-enhanced computed tomography, contrast-enhanced magnetic resonance imaging (MRI), and positron emission tomography scans. None of the above-mentioned methods reaches a 100% sensitivity or specificity, and the accuracy of the exact number of metastases or levels involved has not been studied; thus, neck dissection with subsequent pathological examination remains the gold standard for node staging. Among the described cross-sectional imaging modalities, MRI presents a lot of advantages mainly due to the increased soft tissue contrast and the ability to obtain tissue characteristics in different sequences, including diffusion- and perfusion-weighted sequences and proton spectroscopy imaging. The lack of the radiation burden makes MRI suitable for a close follow-up of the patient, and the imaging with the use of new intravenous contrast material (such as ultrasmall iron oxide particles) seems superior to the conventional. In this article, we will focus on the lymph node MRI staging in HNC patients and the MR anatomy of the nodes, the necessary diagnostic workup, and the advantages of the method over computed tomography. The possibilities of the new imaging sequences and the treatment implications will be addressed as well.

Reduction rate of lymph node metastasis as a significant prognostic factor in esophageal cancer patients treated with neoadjuvant chemoradiation therapy

Tumor regression is used widely as a measure of tumor response following radiation therapy or chemoradiation therapy (CRT). In cases of esophageal cancer, a different pattern of tumor shrinkage is often observed between primary tumors and metastatic lymph nodes (MLNs). Regression of MLNs surrounded by normal tissue may be a more direct measure of the response to CRT than regression of a primary tumor as exfoliative mechanical clearance does not participate in shrinkage of MLNs. In this study we evaluated the significance of the reduction rate (RR) of MLNs as a prognostic factor in esophageal cancer patients treated with neoadjuvant CRT. Forty-two patients with marked MLNs were selected from 93 patients with esophageal carcinoma who had received neoadjuvant CRT. The RRs of the primary tumor and the MLNs were calculated from computed tomography scans. In 20 patients, surgical resection was carried out following CRT. Univariate analysis was used to determine which of the following variables were related to survival: size of the primary tumor and MLNs; RRs of both lesions; degree of lymph node (LN) metastasis; clinical stage; and surgical resection. Multivariate analysis was then performed to assess the prognostic relevance of each variable. The primary tumor was larger than the MLNs in 69% of patients before CRT and in 40% of patients after CRT. In 79% of the patients, the RR of the primary tumor was greater than the RR of the MLNs. The results of the univariate analyses showed that a high RR of the MLNs and surgical resection after CRT were associated with significantly improved survival. The multivariate analysis demonstrated that the RR of MLNs had the strongest influence on survival. The RR of LN metastasis should be evaluated as an important prognostic predictor in patients with marked LN metastasis of esophageal cancer treated with CRT.

Visualization of lymphatic basin from the tumor using magnetic resonance lymphography with superparamagnetic iron oxide in patients with thoracic esophageal cancer

OBJECTIVE

To evaluate magnetic resonance (MR) lymphography with submucosal injection of superparamagnetic iron oxide (SPIO) for imaging lymphatic pathways from thoracic esophageal cancer.

METHODS

In 24 patients with esophageal cancer, SPIO was injected into the submucosal layer of the peritumoral region endoscopically and MR lymphography was conducted. In study 1, fast spoiled gradient-recalled acquisition using a steady-state (FSPGR) sequence was performed from the neck to the upper abdomen before and at 20, 40, and 60 minutes after injection in 10 patients. In study 2, FSPGR and spin echo T1-weighted images were obtained after injection in 14 patients. Areas scanned were the neck to the upper mediastinum and the upper abdomen.

RESULTS

In study 1, at 20 minutes after injection, the signal of each lymph node appeared attenuated when compared with precontrast images. The signal-to-noise ratio in lymph nodes exhibiting influx of SPIO was significantly lower than that found on precontrast images (P < 0.0005). In study 2, influx to the neck lymph nodes was detected in 8 patients (64.3%), whereas influx to the upper abdominal lymph nodes was detected in 13 (92.9%).

CONCLUSIONS

Magnetic resonance lymphography with SPIO could visualize the lymphatic pathways draining from the injection site and the location of lymph nodes exhibiting influx of SPIO in patients with thoracic esophageal cancer.

Esophageal cancer staging with endoscopic MR imaging: pilot study

The authors defined esophageal anatomy and evaluated esophageal cancer staging in a pilot group by comparing endoscopic magnetic resonance (MR) imaging results with pathologic and endoscopic ultrasonographic (US) results when available. A porcine esophagus, one volunteer, and 23 patients suspected of having esophageal cancer were imaged at 0.5 T. MR imaging was successful in 21 patients. Eight of these patients underwent esophagectomy (one after chemotherapy, which invalidated comparison with MR imaging; another did not undergo lymphadenectomy) and one underwent laparoscopy and nodal staging only; eight underwent US. When verified with pathologic staging, endoscopic MR imaging was accurate in six of seven patients (T stage) and five of six patients (N stage; nodal areas too obscured by artifact for comparison in one case). MR imaging and US results concurred in seven of eight (T stage) and five of eight (N stage) patients. No complications were observed. Endoscopic MR imaging is safe and probably comparable to endoscopic US, but with a tendency to overstage the disease.

Prognostic significance of the size of cancer nests in metastatic lymph nodes in human esophageal cancers

BACKGROUND

Postoperative survival of patients with esophageal cancers after curative surgery is strongly affected by the presence of lymph node metastasis. The number and location of lymph node metastases have been evaluated and graded, but the clinical significance of their size has not been well investigated.

METHODS

Of 322 esophageal cancer patients who underwent curative operations with radical lymph node dissection, 170 (53%) had lymph node metastasis. A total of 784 metastatic lymph nodes were obtained, and the area of the cancer nests was measured microscopically in the cross section. The data from each patient included the area of the largest cancer nest in the positive nodes (Nmax), classified as Na (<4 mm2), Nb (4-25 mm2), Nc (25-100 mm2), or Nd (>100 mm2).

RESULTS

The 170 patients were classified according to the Nmax value: Na, 31 (18.2%); Nb, 35 (20.5%); Nc, 49 (28.8%); and Nd, 55 (32.4%). The 5-year survival rate was 77.7% in patients without lymph node metastasis and 35.4% in those with lymph node metastasis. When classified by Nmax, the 5-year survival rate was 77.8% for Na, 63.9% for Nb, 18.8% for Nc, and 12.8% for Nd. There was no significant difference in the survival rate between Na patients and those without lymph node metastasis. Nmax showed significant correlation with the primary tumor size, depth of tumor invasion, and number and location of metastatic lymph nodes, but not with histologic type or primary tumor location. In multivariate analysis, the Nmax value, the number of lymph node metastases and depth of tumor invasion were independent prognostic factors, while the location of the lymph node metastases was not statistically significant.

CONCLUSIONS

The area of the largest cancer nest in the lymph nodes was one of the most significant prognostic factors for esophageal cancers. This estimation is objective and reproducible and may be of great importance when deciding the therapeutic modality for patients with esophageal cancers.

A surface-modified chylomicron remnant-like emulsion for percutaneous computed tomography lymphography: synthesis and preliminary imaging findings

RATIONALE AND OBJECTIVES

To assess a surface-modified emulsion as a percutaneous CT lymphographic agent in normal dogs.

METHODS

An iodinated chylomicron remnant-like microemulsion was formulated with a mean particle size of 91.3 nm and an iodine concentration of 91 mg I/mL. Contrast material (2 mL) was injected into the subcutaneous tissues of the metatarsus and metacarpus of six normal dogs to enhance popliteal and cervical lymph nodes, respectively. CT images were acquired at 0, 15, 30, 45, 60, 240, 480, and 1440 minutes.

RESULTS

Significant lymph node enhancement occurred in as little as 15 minutes after injection and persisted at least 8 hours. Node opacification was most pronounced at 1 to 4 hours postinjection and exceeded 200 HU in some nodes (precontrast attenuation = 45 HU). Marked enhancement of popliteal efferent lymphatics and of iliac and sacral node groups also occurred indicating distribution to second order nodes. Attenuation of enhanced nodes reverted to precontrast levels by 24 hours.

CONCLUSION

The new surface-modified, chylomicron remnant-like emulsion provided marked, selective enhancement of targeted lymph nodes after subcutaneous administration. Moreover, the formulation produced significant opacification of more distant node groups from a single injection.

Variability of target volume delineation in cervical esophageal cancer

PURPOSE

Three-dimensional (3D) conformal radiation therapy (CRT) assumes and requires the precise delineation of the target volume. To assess the consistency of target volume delineation by radiation oncologists, who treat esophageal cancers, we have performed a transCanada survey.

MATERIALS AND METHODS

One of three case presentations, including CT scan images, of different stages of cervical esophageal cancer was randomly chosen and sent by mail. Respondents were asked to fill in questionnaires regarding treatment techniques and to outline boost target volumes for the primary tumor on CT scans, using ICRU-50 definitions.

RESULTS

Of 58 radiation oncologists who agreed to participate, 48 (83%) responded. The external beam techniques used were mostly anterior-posterior fields, followed by a multifield boost technique. Brachytherapy was employed by 21% of the oncologists, and concurrent chemotherapy by 88%. For a given case, and the three volumes defined by ICRU-50 (i.e., gross tumor volume [GTV], clinical target volume [CTV], and planning target volume [PTV]) we determined: 1. The total length in the cranio-caudal dimension; 2. the mean diameter in the transverse slice that was located in a CT slice that was common to all participants; 3. the total volume for each ICRU volume; and 4. the (5, 95) percentiles for each parameter. The PTV showed a mean length of 14.4 (9.6, 18.0) cm for Case A, 9.4 (5.0, 15.0) cm for Case B, 11.8 (6.0, 16.0) cm for Case C, a mean diameter of 6.4 (5.0, 9.4) cm for Case A, 4.4 (0.0, 7.3) cm for Case B, 5.2 (3.9, 7.3) cm for Case C, and a mean volume of 320 (167, 840) cm3 for Case A and 176 (60, 362) cm3 for Case C. The results indicate variability factors (95 percentile divided by 5 percentile values) in target diameters of 1.5 to 2.6, and in target lengths of 1.9 to 5.0.

CONCLUSION

There was a substantial inconsistency in defining the planning target volume, both transversely and longitudinally, among radiation oncologists. The potential benefits of 3D treatment planning with high-precision dose delivery could be offset by this inconsistency in target-volume delineation by radiation oncologists. This may be particularly important for multicenter clinical trials, for which quality assurance of this step will be essential to the interpretation of results.