[Clinicopathological factors and clinical significance of No.12b lymph node metastasis in gastric antrum cancer]

Objective: To investigate the clinicopathological factors and clinical significance of (micro)metastasis in No.12b lymph node in patients with gastric antrum cancer. Methods: This was a retrospective cohort study of data of 242 patients with gastric adenocarcinoma without distant metastasis, complete follow-up data, and no preoperative anti-tumor therapy or history of other malignancies. All study patients had undergone radical gastrectomy (at least D2 radical range) + No.12b lymph node dissection in the Department of Gastric Surgery of Liaoning Cancer Hospital from January 2007 to December 2012. Immunohistochemical staining with antibody CK8/18 was used to detect micrometastasis to lymph nodes. Patients with positive findings on hematoxylin and eosin stained specimens and/or CK8/18 positivity in No.12b lymph node were diagnosed as having No.12b (micro)metastasis and included in the No.12b positive group. All other patients were classified as 12b negative. We investigated the impact of No.12b (micro)metastasis by comparing the clinicopathological characteristics and recurrence free survival (RFS) of these two groups of patients and subjecting possible risk factors to statistical analysis. Results: Traditional hematoxylin-eosin staining showed that 15/242 patients were positive for No.12b lymph nodes and 227 were negative. A total of 241 negative No. 12b lymph nodes were detected. Immunohistochemical testing revealed that seven of these 241 No.12b lymph nodes (2.9%) were positive for micrometastasis. A further seven positive nodes were identified among the 227 nodes (3.1%) that had been evaluated as negative on hematoxylin-eosin-stained sections. Thus, 22 /242 patients' (9.1%) No.12b nodes were positive for micrometastases, the remaining 220 (90.9%) being negative. Factor analysis showed that No.12b lymph node (micro) metastasis is associated with more severe invasion of the gastric serosa (HR=3.873, 95%CI: 1.676-21.643, P=0.006), T3 stage (HR=1.615, 95%CI: 1.113-1.867, P=0.045), higher N stage (HR=1.768, 95%CI: 1.187-5.654, P=0.019), phase III of TNM stage (HR=2.129, 95%CI: 1.102-3.475, P=0.046), and lymph node metastasis in the No.1/No.8a/No.12a groups (HR=0.451, 95%CI: 0.121-0.552, P=0.035; HR=0.645, 95%CI:0.071-0.886, P=0.032; HR=1.512, 95%CI: 1.381-2.100, P=0.029, respectively). Survival analysis showed that the 5-year RFS of patients in the No.12b positive group was worse than that of those in the No.12b negative group (18.2% vs. 34.5%, P<0.001). Independent predictors of RFS were poorer differentiation of the primary tumor (HR=0.528, 95%CI:0.288-0.969, P=0.039), more severe serous invasion (HR=1.262, 95%CI:1.039-1.534, P=0.019), higher T/N/TNM stage (HR=4.880, 95%CI: 1.909-12.476, P<0.001; HR=2.332, 95%CI: 1.640-3.317, P<0.001; HR=0.139, 95%CI: 0.027-0.713, P=0.018, respectively), and lymph node metastasis in the No.12a/No.12b group(HR=0.698, 95%CI:0.518-0.941, P=0.018; HR=0.341, 95%CI:0.154-0.758,P=0.008, respectively). Conclusion: Detection of micrometastasis can improve the rate of positive lymph nodes. In patients with gastric antrum cancer, dissection of group No.12b lymph nodes may improve the prognosis of those with intraoperative evidence of tumor invasion into the serosa, more than two lymph node metastases, and suspicious lymph nodes in groups No.1 / No.8a / 12a.

Screening Protein Prognostic Biomarkers for Stomach Adenocarcinoma Based on The Cancer Proteome Atlas

The objective was to construct a prognostic risk model of stomach adenocarcinoma (STAD) based on The Cancer Proteome Atlas (TCPA) to search for prognostic biomarkers. Protein data and clinical data on STAD were downloaded from the TCGA database, and differential expressions of proteins between carcinoma and para-carcinoma tissues were screened using the R package. The STAD data were randomly divided into a training set and a testing set in a 1:1 ratio. Subsequently, a linear prognostic risk model of proteins was constructed using Cox regression analysis based on training set data. Based on the scores of the prognostic model, sampled patients were categorized into two groups: a high-risk group and a low-risk group. Using the testing set and the full sample, ROC curves and K-M survival analysis were conducted to measure the predictive power of the prognostic model. The target genes of proteins in the prognostic model were predicted and their biological functions were analyzed. A total of 34 differentially expressed proteins were screened (19 up-regulated, 15 down-regulated). Based on 176 cases in the training set, a prognostic model consisting of three proteins (COLLAGEN VI, CD20, TIGAR) was constructed, with moderate prediction accuracy (AUC=0.719). As shown by the Kaplan-Meier and survival status charts, the overall survival rate of the low-risk group was better than that of the high-risk group. Moreover, a total of 48 target proteins were identified to have predictive power, and the level of proteins in hsa05200 (Pathways in cancer) was the highest. According to the results of the Univariate and multivariate COX analysis, tri-protein was identified as an independent prognostic factor. Therefore, the tri-protein prognostic risk model can be used to predict the likelihood of STAD and guide clinical treatment.

[The clinical application of mobile internet remote guidance platform for vestibular rehabilitation]

Objective: To guide the patients with vertigo who are suitable for vestibular rehabilitation therapy (VRT), and to evaluate the curative effect through a remote guidance platform based on mobile internet. Methods: Adult outpatients, who were diagnosed as vestibular disorders and required VRT, were selected and conducted baseline evaluation and formulated vestibular rehabilitation plan according to their symptoms, diagnosis and vestibular function examination results. These patients downloaded and installed the mobile internet remote guidance platform app for VRT, and then registered and uploaded medical records. According to the VRT plan formulated by clinicians for patients, the platform launched corresponding exercise guidance videos to guide them to complete 4-week VRT exercise at home. Before and after VRT, the patients were scored with Visual Analogue Scale (VAS), Activities-specific Balance Confidence (ABC), Dizziness Handicap Inventory (DHI) and Self-rating Anxiety Scale (SAS). The rehabilitation effects were statistically analyzed by SigmaStat 4.0 software. Results: From October 2019 to October 2021, 233 patients with vertigo completed the registration of vestibular rehabilitation guidance platform, of whom 187 patients insisted on 4-week rehabilitation training and completed the scale evaluation. Among 187 patients, 65 were male and 122 were female; Age was (49.8±16.0) years; The medical history ranged from one to 192 months, with a median of eight months. Compared with that before rehabilitation exercise, the subjective feeling of vertigo in 170 patients was improved, and the overall effective rate was 90.9% (170/187). The subjective symptoms of vertigo were basically improved after rehabilitation training in patients with unilateral vestibular dysfunction, vestibular neuritis, sudden deafness with vertigo, Hunt syndrome and acoustic neuroma. There were significant differences in ABC, DHI and SAS scores before and after VRT (P<0.05). Of those patients with Meniere's disease in the intermittent period and the patients with Meniere's disease who underwent surgical treatment, more than 90% of their subjective symptoms of vertigo or dizziness improved after VRT, and there were significant differences in the scores of ABC, DHI and SAS before and after VRT exercise (P<0.05). In patients with vestibular migraine, 36.7% (11/30) had no improvement or even aggravation of subjective symptoms of vertigo after VRT, however, the DHI score after rehabilitation exercise was lower than that before exercise, and the difference was statistically significant (P<0.05). In patients with bilateral vestibular dysfunction, although most (6/8) subjective symptom scores were improved compared with those before exercise, there was no significant difference in ABC, DHI and SAS scores before and after rehabilitation (P>0.05). Conclusion: VRT with the help of vestibular rehabilitation mobile internet remote guidance platform can effectively improve the subjective symptoms of vertigo, balance ability and anxiety in patients with unilateral vestibular lesions.

[A multi-center retrospective study of perioperative chemotherapy for gastric cancer based on real-world data]

Objective: To explore the effect of perioperative chemotherapy on the prognosis of gastric cancer patients under real-world condition. Methods: A retrospective cohort study was carried out. Real world data of gastric cancer patients receiving perioperative chemotherapy and surgery + adjuvant chemotherapy in 33 domestic hospitals from January 1, 2014 to January 31, 2016 were collected. Inclusion criteria: (1) gastric adenocarcinoma was confirmed by histopathology, and clinical stage was cT2-4aN0-3M0 (AJCC 8th edition); (2) D2 radical gastric cancer surgery was performed; (3) at least one cycle of neoadjuvant chemotherapy (NAC) was completed; (4) at least 4 cycles of adjuvant chemotherapy (AC) [SOX (S-1+oxaliplatin) or CapeOX (capecitabine + oxaliplatin)] were completed. Exclusion criteria: (1) complicated with other malignant tumors; (2) radiotherapy received; (3) patients with incomplete data. The enrolled patients who received neoadjuvant chemotherapy and adjuvant chemotherapy were included in the perioperative chemotherapy group, and those who received only postoperative adjuvant chemotherapy were included in the surgery + adjuvant chemotherapy group. Propensity score matching (PSM) method was used to control selection bias. The primary outcome were overall survival (OS) and progression-free survival (PFS) after PSM. OS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the last effective follow-up or death. PFS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the first imaging diagnosis of tumor progression or death. The Kaplan-Meier method was used to estimate the survival rate, and the Cox proportional hazards model was used to evaluate the independent effect of perioperative chemo therapy on OS and PFS. Results: 2 045 cases were included, including 1 293 cases in the surgery+adjuvant chemotherapy group and 752 cases in the perioperative chemotherapy group. After PSM, 492 pairs were included in the analysis. There were no statistically significant differences in gender, age, body mass index, tumor stage before treatment, and tumor location between the two groups (all P>0.05). Compared with the surgery + adjuvant chemotherapy group, patients in the perioperative chemotherapy group had higher proportion of total gastrectomy (χ(2)=40.526, P<0.001), smaller maximum tumor diameter (t=3.969, P<0.001), less number of metastatic lymph nodes (t=1.343, P<0.001), lower ratio of vessel invasion (χ(2)=11.897, P=0.001) and nerve invasion (χ(2)=12.338, P<0.001). In the perioperative chemotherapy group and surgery + adjuvant chemotherapy group, 24 cases (4.9%) and 17 cases (3.4%) developed postoperative complications, respectively, and no significant difference was found between two groups (χ(2)=0.815, P=0.367). The median OS of the perioperative chemotherapy group was longer than that of the surgery + adjuvant chemotherapy group (65 months vs. 45 months, HR: 0.74, 95% CI: 0.62-0.89, P=0.001); the median PFS of the perioperative chemotherapy group was also longer than that of the surgery+adjuvant chemotherapy group (56 months vs. 36 months, HR=0.72, 95% CI:0.61-0.85, P<0.001). The forest plot results of subgroup analysis showed that both men and women could benefit from perioperative chemotherapy (all P<0.05); patients over 45 years of age (P<0.05) and with normal body mass (P<0.01) could benefit significantly; patients with cTNM stage II and III presented a trend of benefit or could benefit significantly (P<0.05); patients with signet ring cell carcinoma benefited little (P>0.05); tumors in the gastric body and gastric antrum benefited more significantly (P<0.05). Conclusion: Perioperative chemotherapy can improve the prognosis of gastric cancer patients.

Surgical resection of esophagogastric junction stromal tumor: How to protect the cardiac function

BACKGROUND

Various surgical procedures have been described for gastrointestinal stromal tumors (GISTs) at the esophagogastric junction (EGJ) close to the Z-line. However, surgery for EGJ-GIST involving Z-line has been rarely reported.

AIM

To introduce a novel technique called conformal resection (CR) for open resection of EGJ-GIST involving Z-line.

METHODS

In this retrospective study, 43 patients having GISTs involving Z-line were included. The perioperative outcomes of patients receiving CR (n = 18) was compared with that of proximal gastrectomy (PG) (n = 25).

RESULTS

CR was successfully performed in all the patients with negative microscopic margins. The mean operative time, time to first passage of flatus, and postoperative hospital stay was significantly shorter in the CR group (P < 0.05), while the intraoperative blood loss was similar in the two groups. The postoperative gastroesophageal reflux as diagnosed by esophageal 24-h pH monitoring and quality of life at 3 mo were significantly in favor of CR compared to PG (both P < 0.001). The 5-year disease-free survival between the two groups was similar (P = 0.163). The cut- off value for the determination of CR or PG was 7.0 mm above the Z-line (83.33% sensitivity, 84.00% specificity, 83.72% accuracy).

CONCLUSION

CR is safe and feasible for EGJ-GIST located within 7.0 mm above the Z-line.

[Clinical value of endoscopicultrsaonography and multi-slice spiral CT in Siewert Ⅱand Ⅲ type adenocarcinoma of esophagogastric junction]

Objective: To investigate the clinical value of endoscopic ultrasonography (EUS) and Multi-slice Spiral CT (MSCT) in the preoperativestaging of tumor(T) and lymph node (N) metastasis in patients with SiewertⅡand Ⅲ typeadenocarcinoma of esophagogastric junction(AEG). Methods: Clinical data of 145 Siewert Ⅱ and Ⅲ type AEG patientswithout preoperative chemoradiotherapy were retrospectively reviewed. Theyall received preoperative EUS and MSCT examination and underwent surgical resection, and the results of EUS and MSCT were compared with their postoperative pathologic staging. Results: The sensitivity, specificity, and accuracy of EUS for T stage in Siewert Ⅱ and Ⅲ type AEG were higher than those of MSCT. The total accuracy of EUS and MSCT were 90.3% and 63.5%, respectively, and the difference was statistically significant (χ(2)=29.52, P<0.01). The sensitivity of EUS for T1, T2 and T3 were 89.5%, 91.1% and 85.2%, respectively, which were significantly higher than 42.1%, 66.7% and 29.6% of MSCT (χ(2)=9.47, P<0.01 for T1; χ(2)=8.07, P<0.01 for T2; χ(2)=17.40, P<0.01 for T3). In addition, the total accuracy of EUS and MSCT for lymph node metastasis status of Siewert Ⅱ and Ⅲ type AEG were 75.9% and 64.8%, respectively, showing a statistically significant difference(χ(2)=4.23, P=0.04). The sensitivity of EUS for N1 and N2 were 82.1% and 79.2%, respectively, which were significantly higher than 53.6% and 60.4% of MSCT (χ(2)=5.24, P=0.02; χ(2)=4.48, P=0.03). There was no statistical significance for sensitivity of EUS and MSCT in N0 and N3 (P>0.05). Conclusion: EUS diagnosis of T and N staging in Siewert Ⅱ/Ⅲ type AEG showed significantly greater performance than MSCT.

Celiac Artery Compression Syndrome Evaluated with 3-D Contrast-Enhanced Ultrasonography: a New Approach

This study was performed to estimate the value of 3-D contrast-enhanced ultrasonography (3-D-CEUS) in the diagnosis of celiac artery compression syndrome (CACS). Patients suspected of having CACS were assessed with 3-D-CEUS and contrasted with computed tomography angiography. Diagnostic accuracy was evaluated with a receiver operating characteristic curve. Three-dimensional CEUS revealed 19 positive and 9 negative cases. In the negative group, the contrast agent did not change with respiration. In the positive group, the contrast agent exhibited a hook-shaped stenosis on expiration and returned to normal on inspiration. Computed tomography angiography indicated 1 false-positive case and 1 false-negative case. The sensitivity and specificity of 3-D-CEUS were 95% and 89%, respectively. The area under the receiver operating characteristic curve was 0.982 (p <0.01). In conclusion, 3-D-CEUS can accurately reveal the characteristic hooked appearance and dynamic nature of CACS with respiration, and thus, it represents a new, non-invasive approach to CACS diagnosis.

Disruption of the Accidental Dirac Semimetal State in ZrTe_{5} under Hydrostatic Pressure

We study the effect of hydrostatic pressure on the magnetotransport properties of zirconium pentatelluride. The magnitude of resistivity anomaly gets enhanced with increasing pressure, but the transition temperature T^{*} is insensitive to it up to 2.5 GPa. In the case of H∥b, the quasilinear magnetoresistance decreases drastically from 3300% (9 T) at ambient pressure to 230% (9 T) at 2.5 GPa. Besides, the change of the quantum oscillation phase from topological nontrivial to trivial is revealed around 2 GPa. Both demonstrate that the pressure breaks the accidental Dirac node in ZrTe_{5}. For H∥c, in contrast, subtle changes can be seen in the magnetoresistance and quantum oscillations. In the presence of pressure, ZrTe_{5} evolves from a highly anisotropic to a nearly isotropic electronic system, which accompanies the disruption of the accidental Dirac semimetal state. It supports the assumption that ZrTe_{5} is a semi-3D Dirac system with linear dispersion along two directions and a quadratic one along the third.

[Analysis of the therapeutic efficacy of radical gastrectomy in Siewert type Ⅱ and Ⅲ adenocarcinoma of the esophagogastric junction]

OBJECTIVE

To conduct a retrospective analysis of clinicopathological data of patients with Siewert type Ⅱand Ⅲ adenocarcinoma of the esophagogastric junction (AEG), who underwent total gastrectomy (TG) or proximal gastrectomy (PG), to discuss the differences between the two groups in 3-year and 5-year survival rates, postoperative complications and so forth, and to provide theoretical and clinical basis for choosing an ideal surgical approach for patients with Siewert typeⅡ and ⅢAEG.

METHODS

The clinical data of 163 patients who underwent radical gastrectomy from January 2006 to December 2008 were analyzed retrospectively. Among them, 85 patients received total gastrectomy (group TG) and 78 patients received proximal gastrectomy (group PG). The 3-year and 5-year survival rates, and postoperative complication rate and mortality rate in the two groups were followed up and compared.

RESULTS

The 3-year and 5-year survival rates of the group TG were 71.4% and 47.6%, and those of the group PG were 56.6% and 34.7%, showing a statistically significant difference (χ(2)=4.67, P=0.031;χ(2)=5.17, P=0.023). The postoperative complication rate and mortality rate of the group TG were 12.9% and 4.7% and those of the group PG were 19.2% and 2.6%, with a nonsignificant difference between the two groups (P>0.05). The incidence of reflux esophagitis in the group TG was 1.2%, significantly lower than that of 7.7% in the group PG (P<0.05).

CONCLUSIONS

To improve the long-term therapeutic effects, total gastrectomy should be recommended for patients with Siewert type Ⅱ and Ⅲ AEG having high risk factors such as tumor size >3.0 cm, subserosal or serosal invasion, N3 lymph node metastasis and stage Ⅲ tumor. The postoperative complication rate and mortality rate should not be increased, and reflux esophagitis can be effectively avoided in the patients treated with total gastrectomy.

Antibody detection tests for early diagnosis in tuberculous meningitis

BACKGROUND

Tuberculous meningitis (TBM) is the most severe form of tuberculosis. Microbiological confirmation is rare and treatment is often delayed. Early diagnosis and immediate initiation of treatment are essential for effective TBM control. A systematic review was performed in this study to assess the diagnostic accuracy of detecting antibodies against Mycobacterium tuberculosis in the cerebrospinal fluid (CSF), according to standard methods. Test performance was summarized using a bivariate random-effects meta-analysis.

METHODS

Studies were identified by a search of the literature, up to July 25, 2015, in the EMBASE and MEDLINE databases via Ovid SP and PubMed. The Cochrane Library was also searched for original, peer-reviewed molecular epidemiology studies that reported the diagnosis of TBM based on antibody detection in the CSF.

RESULTS

Thirty-six articles (58 studies) were identified. The sensitivity of antibody detection was 0.75 (95% confidence interval (CI) 0.66-0.82), specificity was 0.98 (95% CI 0.96-0.99), and the area under the receiver operating characteristic curve (AUROC) was 0.97 (95% CI 0.95-0.98). By subgroup analysis, the detection of anti-M37Ra was the highest (AUROC 0.99, 95% CI 0.98-1.00), followed by anti-antigen 5 (AUROC 0.99, 95% CI 0.97-0.99) and anti-M37Rv (AUROC 0.97, 95% CI 0.95-0.98).

CONCLUSIONS

For the early diagnosis of TBM based on antibodies in the CSF, the detection of anti-M37Ra, anti-antigen 5, or anti-M37Rv provides the greatest sensitivity and specificity.

[CT morphology of hepatocellular carcinoma lesions]

The preoperative CT appearances of hepatocellular carcinoma (HCC) lesions in 232 cases were analyzed. According to the CT features in shape, outline and boundary of the tumors, the HCC was divided into 3 Types: Type I--roundish expansive growth type (REG TYPE), Type II--irregular expansive growth type (IREG TYPE), and type III--irregular infiltration growth type (IIG TYPE). Comparing different CT types with findings at laparotomy or pathological specimens, it showed that the intrahepatic tumor dissemination rates of type I, II and III were 18.6%, 37.7%, and 47.8%, respectively. The lymph node metastasis rates were 0, 7.7% and 23.1%, respectively. The portal vein tumor thrombus formation rates were 2.3%, 20.8% and 46.4%, respectively. The proportion of encapsulation (67.4%, 27.3% and 5.28%, respectively) apparently decreased from type I to type III in turn. The differences were statistically significant. From type I to III the resection rate of large sized tumor decreased, and the prognosis was from bad to worse. Survival analysis (Cox's mode) showed significant differences from type I to type III. Therefore, CT classification may be used to evaluate the gross biological behavior of HCC lesions and may be of pathological and clinical relevance.

MRI-T2 values in the differentiation of recurrence and fibrosis after radiation of nasopharyngeal carcinoma

The possibility of T2 values in the differentiation of local recurrence and irradiation fibrosis was studied prospectively in 36 patients with nasopharyngeal carcinoma (NPC) after radiotherapy. All the patients had a soft-tissue mass in the nasopharynx demonstrated by CT. Fourteen patients had tumor recurrence, 20 radiation fibrosis, 1 postradiation edema, and 1 inflammatory change. The control group consisted of 8 patients with untreated NPC. It was found that T2 was longer in patients with tumor than in patients with radiation fibrosis. We conclude that MRI may be used as a noninvasive method for differentiating radiation fibrosis from local recurrent NPC, but the prolonged T2 value of tumor is not specific and may be seen in radiation edema and infection.

MRI differentiation of recurrent nasopharyngeal carcinoma from postradiation fibrosis

A prospective study was performed to determine the usefulness of magnetic imaging (MRI) in differentiating local recurrence versus post-irradiation fibrosis in 72 patients after radiotherapy of nasopharyngeal carcinoma (NPC). All patients had a soft-tissue mass in the nasopharynx demonstrated by computed tomography. A total of 29 patients had tumor recurrence; 40 patients had only radiation fibrosis; 1 patient had postradiation edema and 2 patients had inflammatory changes. Based on the differences in signal intensity on T2-weighted images, MRI may be promising as a noninvasive method for differentiating radiation fibrosis from local recurrent NPC. However, the signal intensity pattern of the tumor is not specific and may be seen in radiation edema and infection.

Computed tomography in the management of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is one of the common cancers in China. According to mass surveys, the incidence of NPC in some areas of Guangdong is 39.84/100,000. Due to its high contrast resolution CT has the ability to show not only superficial abnormality but also deep infiltration of the fasciae and muscles of the parapharyngeal region. Computed tomography scanning was performed on more than 1000 patients with NPC in the Tumour Hospital in the 2 years from 1984 to 1986. The role of CT scanning in NPC can be summarised as: (1) detection of primary lesions not accessible to pharyngoscopy; (2) determination of the extent of disease; (3) clinical staging; (4) radiotherapy planning; (5) follow up evaluation; (6) the differentiation of recurrence and radiation damage to the brain; and (7) the demonstration of distant metastasis. In contrast to the concept of jugular chain metastasis via the postero-lateral pharyngeal lymph nodes, our material has demonstrated that the lesion most probably spreads to the carotid sheath area directly from the pharyngeal lesion. The tendency of submucosal spread of NPC is emphasised.

[Mode of spread in nasopharyngeal carcinoma as seen on CT scan]

From April 1984 to April 1986, 993 NPC patients were scanned with an 8800 CT scanner in our hospital. 200 consecutive cases who had CT scan before treatment were selected for analysis. CT features of local invasion, incidence of involvement of the parapharyngeal spaces and the adjacent structures, and bone destruction of the base of the skull were analysed. The results showed that the mode of local spread of nasopharyngeal carcinoma is direct infiltration. It tends to spread posterolaterally. According to the relation of the carotid sheath area and lymph nodes in the neck, it is most likely that metastasis in the cervical lymph nodes is the result of direct spread of the disease via the carotid sheath area. CT could detect more bone destruction of the skull base than the conventional submental view. The relationship of neck lymph node metastasis and bone destruction is discussed.

The removal of a "cupping" artefact from brain images produced by the EMI 7070 CT scanner

Brain images produced on the EMI 7070 scanner exhibit a "cupping" artefact due to a combination of beam hardening and scatter effects. The magnitude of the artefact is assessed by statistically analysing a series of concentric regions of interest in the final image. Once the magnitude has been determined it can be subtracted from the image. While the result of the technique does not modify the clinical analysis of images it does increase the observer's appreciation of the image. Both the technique and clinical results are presented, and the implications of this type of reconstruction artefact removal discussed.

Prognostic factors in locally recurrent rectal carcinoma treated by radiotherapy

An analysis has been made of the symptomatic response and survival of 143 patients following radiotherapy for locally recurrent rectal cancer. Computerized tomography (CAT) was performed on 45 patients. Of 119 evaluable patients, 54 had a good response to radiotherapy, 29 a moderate response and 36 no apparent response. Median response was 9 and 3 months respectively in the good and moderate groups. Median survival was 15, 9 and 5 months for the three groups. Latent interval between surgery and radiotherapy appeared to be of prognostic importance. When this exceeded 2 yr median survival was 12 months compared with 7 months for patients with a latent interval of less than 2 yr. Tumour volume measured by computed tomography may have prognostic importance. Radiotherapy should be considered for most patients with symptomatic recurrence. Surgery might be combined with radiotherapy for selected groups of patients with good prognosis.