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R Hermans

Publications and source records attributed to R Hermans.

At least 37 records · Page 2Linked to original sources
PubMed1999

Value of computed tomography as outcome predictor of supraglottic squamous cell carcinoma treated by definitive radiation therapy.

PURPOSE: To investigate the value of several CT-derived tumor parameters as predictors of local outcome of supraglottic squamous cell carcinoma treated by definitive radiation therapy. METHODS AND MATERIALS: The pretreatment CT studies of 103 patients with supraglottic squamous cell carcinoma were reviewed for tumoral involvement of specific laryngeal anatomic subsites and extralaryngeal tumor spread. After redigitizing the films, tumor volume was calculated with the summation-of-areas technique. Mean follow-up time was 3.4 years. Actuarial statistical analysis of local and locoregional outcome was done for each of the covariates; multivariate analysis was performed using Cox's proportional hazards model. RESULTS: In the actuarial analysis CT-determined primary tumor volume was significantly correlated with local recurrence rate (p < 0.001). Degree of involvement of the paraglottic space at the level of the true vocal cord (p < 0.05) and subglottic extension (p < 0.001) were also significantly correlated with local recurrence rate. In the multivariate analysis, only degree of involvement of the preepiglottic space (p < 0.01) and subglottic extension (p < 0.01) were found to be independent predictors of local recurrence. Total tumor volume was the strongest independent predictor of locoregional failure (p < 0.01). CONCLUSIONS: CT-determined tumor parameters are strong predictors of local and locoregional outcome of supraglottic carcinoma treated by definitive irradiation.

Adult↗
PubMed1999

Predicting the local outcome of glottic squamous cell carcinoma after definitive radiation therapy: value of computed tomography-determined tumour parameters.

BACKGROUND AND PURPOSE: The T-classification has shortcomings in the prediction of local outcome of glottic squamous cell carcinoma (SCC) treated by definitive radiation therapy. In this regard, the value of several CT-derived tumour parameters as predictors of local outcome was investigated. MATERIALS AND METHODS: The pretreatment CT studies of 119 patients with glottic SCC (T1, n=61; T2, n=40; T3, n=14; T4, n=4) treated with curative intent by radiation therapy were reviewed for tumoral involvement of specific laryngeal anatomic subsites (including laryngeal cartilages). Tumour volume was calculated with the summation-of-areas technique. Actuarial (life-table) statistical analysis was done for each of the covariates; multivariate analysis was performed using the Cox proportional hazards model. RESULTS: In the actuarial analysis tumour volume was significantly correlated with local recurrence rate (P=0.0062). Involvement of the cricoid cartilage (P=0.0052), anterior commissure (P=0.0203), subglottis (P=0.0481) and preepiglottic space (P=0.0134) and degree of involvement of the true vocal cord (P=0.0441) and paraglottic space at the level of the true vocal cord (P=0.0002) were also significantly correlated with local recurrence rate. In the multivariate analysis, only degree of involvement of the paraglottic space (at the level of the true vocal cord) (P=0.0001) and preepiglottic space (P=0.02) were found to be independent predictors of local recurrence. The T-category was significantly correlated with local outcome in the actuarial analysis (P=0.0001), but not in the multivariate analysis (P=0.5915). CONCLUSIONS: Several CT-derived parameters are powerful predictors of local outcome in glottic cancer treated with radiation therapy; some of these parameters are stronger linked to the local control rate than the T-classification.

Adult↗
PubMed1999

Tumoural perfusion as measured by dynamic computed tomography in head and neck carcinoma.

PURPOSE: To investigate the intra- and interobserver variability, as well as the intra- and interpatient variability of CT-determined tumour perfusion in head and neck tumours, and to evaluate the preliminary value of this parameter as predictive factor of local failure after treatment by definitive radiotherapy. MATERIALS AND METHODS: In 41 patients the perfusion of a primary head and neck squamous cell carcinoma was estimated using dynamic CT. A 40-ml intravenous bolus of a low-osmolar non-ionic contrast agent was rapidly injected over 5 s (8 ml/s), while a dynamic acquisition of image data was obtained during the first pass at the level of the largest axial tumour surface. A time-density curve was constructed for the primary tumour and the carotid artery. The perfusion in the selected tumour region of interest was calculated by dividing the slope of the tumour-time density curve by the maximal value in arterial density. Tumour volume was calculated on the CT-images and correlated with perfusion rate. RESULTS: The mean perfusion rate was 86.4 ml/min per 100 g (median, 80.6; SD, 43.05; range, 31.7-239.8 ml/min per 100 g). No systematic difference was found between the measurements performed by two independent observers. The intratumoural COV was 0.22, the intertumoural COV 0.37. No correlation was found with tumour volume. Ten out of 20 patients with a perfusion rate < 80 ml/min per 100 g were not locally controlled, while nine out of 21 patients with a value > 80 ml/min per 100 g did show a local failure (P = 0.19). CONCLUSIONS: CT-determined perfusion measurements of head and neck tumours are feasible. No correlation with tumour volume and a sufficiently large COV were found to consider this parameter as a possible prognostic factor for outcome after radiotherapy. More patients need to be investigated to test the hypothesis that tumours with a low CT determined perfusion rate have a higher risk of local failure.

Carcinoma, Squamous Cell↗
PubMed1999

Squamous cell carcinoma of the sinonasal cavities.

Squamous cell carcinoma of the sinonasal cavity is an uncommon neoplasm. The symptoms of this tumor are aspecific, and the diagnosis is often made in an advanced stage of disease. Imaging is necessary for evaluating paranasal extension and possible intracranial spread, orbital involvement, infratemporal extension, spread to the nasopharynx, oropharynx, or oral cavity, and spread along neurovascular bundles or perineural spread. Sinonasal cancers are studied with CT or MRI, and in many cases both modalities are used, as they often offer complementary information. The CT and MRI appearance of this kind of tumor is reviewed in this article.

Carcinoma, Squamous Cell↗
PubMed1999

Predictability of reformatted computed tomography for pre-operative planning of endosseous implants.

OBJECTIVES: To determine the reliability of reformatted 2D-CT for pre-operative planning of implant placement. METHODS: One hundred consecutive partially or fully edentate patients underwent 2-D reformatted CT pre-operative planning and subsequent implant placement. The number, site and size of the implants, the available bone height and anatomical complications were recorded. The pre-operative planning and the outcome at surgery were compared statistically using a percentage agreement and Kendall's correlation coefficient. RESULTS: Agreement between the pre- and intra-operative data was good for the number of implants (60%) and the selected sites (70%). From a total of 416 implants planned, 21 implants could not be placed because of intra-operative findings. Agreement was relatively poor for implant size (44%) and anatomical complications (46%). Kendall's correlation coefficient was highest for the number of implants (0.80) and implant sites (0.81). It was much lower for implant sizes (0.51) and did not reach significance for anatomical complications (0.09). CONCLUSIONS: Reformatted 2D-CT is reliable for the pre-operative assessment of the number and sites of implants in the jaws. It is less predictable for the implant size needed and poor for anatomical complications.

Adolescent↗
PubMed1999

Progress in larynx-sparing surgery for glottic cancer through tracheal transplantation.

The current surgical treatment for unilateral, advanced glottic cancer is a total laryngectomy. Usually, the noninvolved hemilarynx needs resection because the resulting laryngeal defect cannot be reconstructed after adequate tumor resection. Experimental findings suggest that segments of autologous trachea may restore extended laryngeal defects. The authors used tracheal transplantation to save laryngeal function after the removal of advanced glottic cancer. In this case series review, 10 patients were treated during a 1.5-year period, with an average follow-up of 8 months. Evaluated factors included survival of the tracheal transplant and functional outcome with regard to the onset and quality of the airway, speech, and deglutition. The authors showed that segments of cervical trachea may restore extended laryngeal defects after initial revascularization by a radial forearm fascial flap. The fascial flap served as a vascular carrier for the transplanted trachea. Follow-up showed the stability of the reconstruction. Compared with a total laryngectomy, a striking improvement in patient comfort and function was noticed. Transplantation of the trachea is a technique that may save laryngeal function after the treatment of advanced-stage glottic cancer. These findings may improve laryngeal preservation strategies in treating laryngeal cancer.

Arteries↗
PubMed1999

Autotransplantation of the trachea: experimental evaluation of a reconstructive technique for extended hemilaryngectomy defects.

Vascularized segments of trachea were used to repair extended hemilaryngectomy defects in a rabbit model. The cervical trachea was revascularized in a first stage by a fascia flap. In a second stage, the cervical trachea was isolated and transformed into a patch that could be autotransplanted on a vascular carrier. The patches were used for the reconstruction of hemilaryngectomy defects including half of the cricoid. Two months after transplantation, the vascular and morphologic characteristics of the tracheal patches were examined with silicone dye angiography and magnetic resonance imaging. The tracheal patches showed a reliable blood supply when wrapped in vascularized fascia. The patches provided a functional reconstruction of hemicricolaryngectomy defects. It is concluded that autotransplantation of the trachea should be further explored as a potential means for extending the limits of conservation laryngeal surgery.

Animals↗
PubMed1999

Preradiotherapy computed tomography as a predictor of local control in supraglottic carcinoma.

PURPOSE: To determine the utility of pretreatment computed tomography (CT) for predicting primary site control in patients with supraglottic squamous cell carcinoma (SCC) treated with definitive radiotherapy (RT). MATERIALS AND METHODS: Pretreatment CT studies in 63 patients were reviewed. Minimum length of follow-up was 2 years. Local recurrence and treatment complications resulting in permanent loss of laryngeal function were documented. Tumor volume was calculated using a computer digitizer, and pre-epiglottic space (PES) spread was estimated. The data were analyzed using a combination of Fisher's exact test, logistic regression modeling, and multivariate analyses. Five-year local control rates were calculated using the product-limit method. RESULTS: Local control rates were inversely and roughly linearly related to tumor volume, although there seemed to be a threshold volume at which primary site prognosis diminished. Local control was 89% in tumors less than 6 cm3 and 52% when volumes were > or =6 cm3 (P = .0012). The likelihood of maintaining laryngeal function also varied with tumor volume: 89% for tumors less than 6 cm3 and 40% for tumors > or =6 cm3 (P = .00004). Pre-epiglottic space involvement by tumor of > or =25% was associated with a reduced chance of saving the larynx (P = .0076). Multivariate analyses revealed that only tumor volume independently altered these end points. CONCLUSION: Pretreatment CT measurements of tumor volume permits stratification of patients with supraglottic SCC treated with RT alone (which allows preservation of laryngeal function) into groups in which local control is more likely and less likely. Pre-epiglottic space spread is not a contraindication to using RT as the primary treatment for supraglottic SCC.

Carcinoma, Squamous Cell↗
PubMed1999

Computed tomography and magnetic resonance imaging of laryngeal tumours.

The possibilities of CT and MR imaging in laryngeal tumours, focused on squamous cell carcinoma, are reviewed. As in other areas of the head and neck, the primary roll of laryngeal imaging studies is to define the extent of disease. Neither CT nor MRI show mucosal detail, but clarify the submucosal extent of disease. Both imaging modalities yield comparable results; in selected cases, they may be considered to be complementary to each other.

Carcinoma, Squamous Cell↗
PubMed1999

Imaging of the parapharyngeal space.

The parapharyngeal space is a deep space of the neck, always well visible on CT and MR imaging of the head and neck; in normal circumstances, this space should look symmetrical. The parapharyngeal space is often subdivided in compartments; such subdivision is helpful when considering the site of origin of a parapharyngeal space mass. Several concepts of compartmentalization of this space exist, sometimes leading to confusion; not the names but the anatomy is important to know. This manuscript reviews shortly the anatomy of the parapharyngeal space, the use of modern cross-sectional imaging methods in the evaluation of this region, and focuses somewhat more on imaging of primary parapharyngeal lesions.

Adipose Tissue↗
PubMed1999

The TNM classification revisited: role of anatomic and functional imaging in head and neck cancer.

Several imaging-derived parameters are powerful predictors of local and locoregional control in irradiated head and neck cancer, offering additional information to the TN-classification. Most information is available on the use of CT-determined parameters as predictor of local outcome of laryngeal cancer after curative radiation therapy. There is evidence that also functional imaging will provide complementary information on the prognosis of head and neck tumours. Such prognostic information is helpful in determining the relative value of surgery and radiation therapy, the selection of patients likely to benefit from neoadjuvant treatment, and identifying patients at high risk for recurrence to be followed more closely.

Head and Neck Neoplasms↗
PubMed1999

CT findings in laryngeal chondroradionecrosis.

The progressive CT features of the laryngeal framework and soft tissues in a case of laryngeal chondroradionecrosis are described. The differential diagnosis with tumor recurrence was at first uneasy, but the protracted history evolution of the tissue changes on CT eventually allowed correct diagnosis.

Aged↗
PubMed1998

Laryngeal tumor volume measurements determined with CT: a study on intra- and interobserver variability.

PURPOSE: To investigate the intra- and interobserver variability of computed tomography-based volume measurements of laryngeal tumors. METHODS AND MATERIALS: The volume of 13 laryngeal tumors was repeatedly measured by five independent observers in four different sessions, using the summation-of-areas technique. Mean tumor volume and its standard deviation were calculated for each tumor. Statistical analysis was done with analysis of variance, Spearman rank correlation, and linear regression. RESULTS: Both the effect of the observers (p < 0.0001) and the effect of the session (p < 0.01) on tumor volume was statistically significant. Interobserver variability was the most important component of total variability (89.3%). A significant rank correlation was found between mean volume and standard deviation (p < 0.01); the relationship between mean tumor volume and standard deviation can be described using linear regression [standard deviation = 0.28 volume + 0.35 (R = 0.79)]. CONCLUSION: Total variability in the computed tomography-based measurement of laryngeal tumor volume can be reduced by having the measurements done by a single trained observer.

Analysis of Variance↗
PubMed1998

Evaluation of pretreatment computed tomography as a predictor of local control in T1/T2 pyriform sinus carcinoma treated with definitive radiotherapy.

BACKGROUND: This study was undertaken to determine whether pretreatment computed tomography (CT) findings can predict local control in pyriform sinus carcinoma treated with definitive radiotherapy (RT). METHODS: Twenty-three patients with pyriform sinus carcinoma (T1: n = 5; T2: n = 18) were treated with high-dose RT and followed for a minimum of 2 years. Tumor volumes and extent were determined on pretreatment CT studies. The specific CT parameters assessed were analyzed as predictors of local control. RESULTS: There was a significant decrease in local control rate for tumors over 6.5 mL (1 of 4 [25%]) relative to tumors under 6.5 mL (17 of 19 [89%]; p = .021). Sensitivity and specificity for local control using this cutoff were 94% and 60%, respectively. Tumor score, as a measure of anatomic extent, was also found to be a significant predictor of local control (p = .033). The local control rate was not influenced significantly by the presence of "minimal" apex disease (< 10 mm in greatest dimensions as measured on CT) but decreased significantly when "bulk" apex disease (> OR = 10 mm) was present (p = .027). Laryngeal cartilage sclerosis was not a significant predictor of outcome. CONCLUSION: Computed tomography can stratify pyriform sinus carcinomas into groups more or less likely to be locally controlled with definitive RT.

Carcinoma, Squamous Cell↗
PubMed1998

Imaging of laryngeal cancer.

CT and MRI are the main modalities for examination of laryngeal pathology. Generally, MRI seems to be the optimal method of examination in cooperative patients, especially for evaluation of their larynx before an attempted partial laryngectomy. The choice between the two modalities will also be determined by one's experience with these modalities. The possibilities of CT and MRI vary clearly from each other regarding detection of cartilage invasion. MRI seems to be more sensitive than CT in detection of neoplastic cartilage invasion, but seems to have a somewhat lower specificity, especially for thyroid cartilage involvement. There are increasing indications for imaging regarding tumor volume, and signs of cartilage involvement may have prognostic significance for the risk of tumor recurrence.

Carcinoma, Squamous Cell↗
PubMed1998

Laryngotracheal reconstruction with tracheal patch allografts.

The capacity of tracheal allotransplants in providing optimal tissues for laryngotracheal repair was studied in an animal model. Segments of cervical trachea could be revascularized completely when wrapped in a receptor fascia flap in immunosuppressed rabbits. In phase I the revascularized tracheas were incised longitudinally and transformed into four different patches after a 14-day revascularization period. The blood supply toward the four patch designs was examined with angiography. The patch designs that showed a vascularization over at least 75% of their mucosal surface area were used in phase II to reconstruct extended anterior laryngotracheal defects. The morphologic characteristics of the tracheal patches when used inside laryngotracheal defects were studied using radiographic, angiographic, and histologic techniques. The revascularized allograft patches that were fully supported by tracheal cartilage were most suitable to repair anterior laryngotracheal defects in this animal study. This model allowed us to define the tissue characteristics necessary for obtaining a combination of primary healing and optimal luminal support in the repair of laryngotracheal defects.

Animals↗
PubMed1998

Tracheal autotransplantation: a reliable reconstructive technique for extended hemilaryngectomy defects.

OBJECTIVES: Current surgical treatment for a glottic cancer with significant subglottic extension is a total laryngectomy. The objective of this study was to expand laryngeal conservation procedures by using a reconstructive technique that allows for the repair of hemicricolaryngectomy defects. STUDY DESIGN: After resection of the ipsilateral thyroid, cricoid, and arytenoid for advanced T3 glottic cancer, the laryngeal defect was reconstructed by means of an autotransplanted segment of trachea in four patients. The reconstruction consisted of a transferable patch that was constructed from a segment of revascularized cervical trachea. METHODS: During a 14-day period, a 4-cm segment of cervical trachea was wrapped by a free radial forearm fascial flap. In the second stage, the glottic cancer was removed and the cervical trachea was isolated on its fascial blood supply and transformed into a patch that was used to repair the extended hemilaryngectomy defect. Two different patch designs were used. Two patients underwent reconstruction with a patch augmented at the glottic level (group A); two patients underwent reconstruction without glottic augmentation on the patch (group B). Tracheal continuity was restored by an end-to-end reanastomosis. The postreconstruction morphology of the two patch designs was compared with the preoperative laryngeal morphology. RESULTS: The autotransplantation technique led to complete restoration of the subglottic airway lumen in all four patients. Although the anterior-posterior glottic diameter was reduced by 36% in group A patients and by 43.5% in group B patients, a sufficient glottic airway lumen was obtained. The glottic sphincteric function was restored in both groups. CONCLUSIONS: Tracheal autotransplantation may be used reliably to repair hemicricolaryngectomy defects. Augmentation of the patch at the level of the glottis is not essential for successful rehabilitation.

Humans↗