Approximation of head and neck cancer volumes in contrast enhanced CT

Relative Tumour Volume in Canine Oral Melanoma Staging and Prognosis

Melanoma is one of the most common canine oral malignant tumours and is highly aggressive and metastatic, even at the early stages of development. Surgery relies on wide excision of the primary tumour and regional lymphadenectomy, with or without adjuvant therapy. Tumour location and size are important when considering staging, which ultimately affects the curative intent of surgery. Nevertheless, absolute tumour volume (TV) is not related to the vast phenotypic variability within canine breeds. This study aimed to determine the cutoff values of two ratios-tumour-to-head volume (THR) and tumour-to-body volume (TBR)-and assess whether they could be associated with the odds of finding metastasis at presentation and/or the likelihood of achieving tumour-free excision margins. A retrospective case series involving 51 dogs was used to evaluate the preoperative head/neck and chest computed tomography and histopathology of the primary mass and excised lymph nodes. Higher TV, THR% and TBR% values were associated with bone lysis and mitotic count (MC). The Ki67 index was significantly associated with local and distant metastases at presentation, whereas MC was associated with local metastasis alone. Tumour-infiltrated surgical margins were associated with caudally located tumours, regardless of the tumour size. Dogs with lymph node metastasis at presentation were seven times more prone to have local relapse. TV, THR% and TBR% values were positively associated with local lymph node metastasis at presentation. Cutoff values for both TV and TBR% were proposed to predict lymph node metastasis at presentation (TV = 6.423 cm3 and TBR% = 0.043), being supported by post-surgical survival analysis.

Accuracy of formula-based volume and image segmentation-based volume in calculation of preoperative cystic jaw lesions' volume

OBJECTIVE

The aim of this study was to assess the accuracy of formula-based volume measurements and the 3D volume analysis with different software packages in the calculation of preoperative cystic jaw lesions' volume. The secondary aim was to assess the reliability and the accuracy of 3 imaging software programs for measuring the cystic jaw lesions' volume in CBCT images.

MATERIALS AND METHODS

This study consisted of two parts: an in vitro part using 2 dry human mandibles that were used to create simulated osteolytic lesions to assess the accuracy of the volumetric analysis and formula-based volume. As a gold standard, the volume of each bone defect was determined by taking an impression using rapid soft silicone (Vinylight) and then quantifying the volume of the replica. Afterward, each tooth socket was scanned using a high-resolution CBCT. A retrospective part using archived CBCT radiographs that were taken from the database of the outpatient clinic of the oral and maxillofacial radiology department, Faculty of Dentistry, Minia University to assess the reliability of the 3 software packages. The volumetric data set was exported for volume quantification using the 3 software packages (MIMICS-OnDemand and InVesalius software). Also, the three greatest orthogonal diameters of the lesions were calculated, and the volume was assessed using the ellipsoid formula. Dunn's test was used for pair-wise comparisons when Friedman's test was significant. The inter-examiner agreement was assessed using Cronbach's alpha reliability coefficient and intra-class correlation coefficient.

RESULTS

Regarding the results of the retrospective part, there was a statistically significant difference between volumetric measurements by equation and different software (P value < 0.001, Effect size = 0.513). The inter-observer reliability of the measurements of the cystic lesions using the different software packages was very good. The highest inter-examiner agreement for volume measurement was found with InVesalius (Cronbach's alpha = 0.992). On the other hand, there was a statistically significant difference between dry mandible volumetric measurements and Gold Standard. All software showed statistically significantly lower dry mandible volumetric measurements than the gold standard.

CONCLUSION

Computer-aided assessment of cystic lesion volume using InVesalius, OnDemand, and MIMICS is a readily available, easy to use, non-invasive option. It confers an advantage over formula-based volume as it gives the exact morphology of the lesion so that potential problems can be detected before surgery. Volume analysis with InVesalius software was accurate in determining the volume of simulated periapical defects in a human cadaver mandible as compared to true volume. InVesalius software proved that open-source software can be robust yet user-friendly with the advantage of minimal cost to use.

Radiomic Assessment of Radiation-Induced Alterations of Skeletal Muscle Composition in Head and Neck Squamous Cell Carcinoma within the Currently Clinically Defined Optimal Time Window for Salvage Surgery-A Pilot Study

Patients with locally advanced head and neck squamous cell carcinoma (HNSCC) frequently require primary radiochemotherapy (RCT). Despite intensity modulation, the desired radiation-induced effects observed in HNSCC may also be observed as side effects in healthy tissue, e.g., the sternocleidomastoid muscle (SCM). These side effects (e.g., tissue fibrosis) depend on the interval between the completion of RCT and restaging CT. For salvage surgery, the optimal time window for surgery is currently clinically postulated at between 6 and 12 weeks after completion of RCT. Thus, no extensive tissue fibrosis is to be expected. This interval is based on clinical studies exploring surgical complications. Studies directly exploring radiation-induced changes of the SCM in HNSCC patients are sparse. The present study quantified tissue alterations in the SCM and paravertebral musculature (PVM) after RCT, applying radiomics to determine the optimal time window for salvage surgery. Three radiomic key parameters, (1) volume, (2) mean positivity of pixels (MPP), and (3) uniformity, were extracted with mint LesionTM in the staging CTs and restaging CTs of 98 HNSCC patients. Of these, 25 were female, the mean age was 62 (±9.6) years, and 80.9% were UICC Stage IV. The mean restaging interval was 55 (±28; range 29-229) days. Only the mean volume significantly decreased after RCT, from 9.0 to 8.4 and 96.5 to 91.9 mL for the SCM and PVM, respectively (both p = 0.007, both Cohen's d = 0.28). In addition, the mean body mass index (BMI) decreased from 23.9 (±4.2) to 21.0 (±3.6) kg/m² (p < 0.001; Cohen's d = 0.9). The mean BMI decreased significantly and was correlated with the volume decrease for the SCM (r = 0.27; p = 0.007) and PVM (r = 0.41; p < 0.001). If t-test p-values were adjusted for the BMI decrease, no significant change in volumes for the SCM and PVM was observed (both p > 0.05). The present data support the clinically postulated optimal interval for salvage surgery of 6 to 12 weeks.

Tumor Volume Staging Provides a Comparable Stratifying for Laryngeal Squamous Cell Cancer According to T Stages

The prognostic significance of tumor volume (TV) in laryngeal squamous cell cancer (LSCC) has been demonstrated previously. Still, its clinical use is uncertain, and a method for accurate staging for TV is lacking. This study aimed to develop an objective staging and determine the effect of tumor volume on disease outcome after surgical treatment for LSCC. This study was designed retrospectively. Patients with LSCC who underwent laryngectomy were identified. Discretization for optimal scaling level of Tumor Volume (TV) was performed by Catreg Version 3.0. The rate of cancer recurrence, disease-free survival (DFS), and overall survival (OS) rate were calculated and compared between T stage and TV staging. Kaplan-Meier survival analysis was performed for comparison. 206 LSCC patients enrolled in the study. TV was found significantly higher in patients with cartilage invasion, contralateral nodal metastasis, and extranodal extension (p = 0.004, 0.010, and 0.021, respectively). TV and lymph node density LND showed a low significant positive correlation (p = 0.015, r = 0.169). TV was 7.25 + 7.53 ml on average, and TV above the mean value was found to be an independent risk factor for OS and DFS (p = 0.043, HR = 1.8; CI95% for HR: 1.02-3.44 and p < 0.001, HR = 3.7; CI95% for HR: 1.8-7.3, respectively). The optimal scaling level of TV was found in three-level; group 1: TV ≤ 7.07, group 2: 7.07 < TV ≤ 14.09, and group 3: TV ≥ 14.10. This categorization of TV has obtained significant discretization between patients for DFS and OS (Long-Rank = 0.038 and < 0.001). This classification may provide better performance in addition to helping the T stage in determining prognosis, especially in patients with advanced laryngeal SCC.

Is there a role for tumor volume in prediction of prognosis for oral cancer?

PURPOSE

New prognostic factors in oral squamous cell carcinoma (OSCC) (tumor-, host-, and environment-related) have been introduced recently to complete those traditionally considered. Among them, tumor volume (TV) could be the most interesting and applicable in clinical practice, considering the routine use of computed tomography in tumor staging. In this retrospective study we aimed to investigate whether a correlation exists among these new prognostic factors and survival outcomes.

METERIALS AND METHODS

We collected data about 140 patients affected by OSCC who underwent primary surgery. Prognostic factors were collected and Overall Survival (OS), Disease Specific Survival (DSS) and Disease Free Survival (DFS) were estimated using Kaplan-Meier method; the Log-Rank test (Mantel-Cox) and Cox regression models were applied to investigate predictors of survival.

RESULTS

The 5-year OS, DSS and DFS were 73.6 %, 89.2 % and 75.2 % respectively. Nodal metastasis (pN+), relapse and American Society of Anesthesiologists ASA-II were found independent prognostic factors for OS, and significantly associated to worst DSS (p < 0.001). TV significantly correlated with higher relapse occurrence (p = 0.03).

CONCLUSIONS

In our experience, lymph-node status, ASA classification and relapse significantly influenced DSS on univariate analysis. TV could represent an interesting additional parameter, since it significantly influenced DFS. However, prospective studies with standardized TV measurements and a greater number of patients are needed to validate this result.

Prognosticating Gross Tumor Volume in Head-and-Neck Cancer - Redefining Gross Tumor Volume Beyond Contouring

Purpose

Precision radiotherapy (RT) requires accurate delineation of gross tumor volumes (GTVs) for targeted dose delivery. Volumetric measurement of this GTV can predict the treatment outcomes. This volume has been limited for mere contouring and its potential as the prognostic factor is less explored.

Materials and Methods

The data of 150 patients with oropharynx, hypopharynx, and larynx cancer undergoing curative intensity-modulated RT and weekly cisplatin between April 2015 and December 2019 were retrospectively evaluated. GTV-P (primary), GTV-N (nodal), and GTV-P+N were defined, and volumetric parameters were generated. Volume thresholds were defined as per the receiver operating characteristics, and the prognostic value of these tumor volumes (TVs) with respect to treatment outcomes was analyzed.

Results

All patients completed 70 Gy, median chemotherapy cycles were six. Mean GTV-P, GTV-N, and GTV-P+N were 44.5 cc, 13.4 cc, and 57.9 cc, respectively. Oropharynx constituted 45% of cases. Forty-nine percent had Stage III disease. Sixty-six percent had complete response (CR). As per the defined cutoff values, GTV-P <30cc, GTV-N <4 cc, and GTV-P+N <50 cc had better CR rates with P < 0.05 (82.6% vs. 51.9%; 74% vs. 58.4% and 81.5% vs. 47.8%, respectively). At median follow-up of 21.4 months, overall survival (OS) was 60% and median OS was 32.3 months. The median OS in patients with GTV-P <30 cc, GTV-N <4 cc, and GTV-P+N <50 cc was better with P < 0.05 (59.2 vs. 21.4; 59.2 vs. 22.2, and 59.2 vs. 19.8 months, respectively).

Conclusion

GTV should not just be limited for contouring but its role as an important prognostic factor has to be recognized.

TGF-β-dependent lymphoid tissue residency of stem-like T cells limits response to tumor vaccine

TGF-β signaling is necessary for CD8+ T cell differentiation into tissue resident memory T cells (TRM). Although higher frequency of CD8+ TRM cells in the tumor microenvironment is associated with better prognosis, TGF-β-blockade typically improves rather than worsens outcomes. Here we show that in a mouse melanoma model, in the tumor-draining lymph nodes (TDLN) rather than in the tumors themselves, stem-like CD8+ T cells differentiate into TRMs in a TGF-β and tumor antigen dependent manner. Following vaccination against a melanoma-specific epitope, most tumour-specific CD8+ T cells are maintained in a stem-like state, but a proportion of cells lost TRM status and differentiate into CX3CR1+ effector CD8+ T cells in the TDLN, which are subsequently migrating into the tumours. Disruption of TGF-β signaling changes the dynamics of these developmental processes, with the net result of improving effector CD8+ T cell migration into the tumours. In summary, TDLN stem-like T cells transiently switch from a TGF-β-dependent TRM differentiation program to an anti-tumor migratory effector development upon vaccination, which transition can be facilitated by targeted TGF-β blockade.

Occurrence of hyperprogressive disease following administration of immune checkpoint inhibitors in lung squamous cell carcinoma: A case report

Immunotherapy through blocking programmed cell death 1, programmed death-ligand 1 and cytotoxic T lymphocyte antigen 4 is developing rapidly and has gained increasing attention as a treatment for malignant tumors. However, some patients experience varying degrees of immune-related side effects after undergoing immunotherapy, with hyperprogressive disease (HPD) occurring in severe cases which increases the risk of mortality. The present study discussed the risk factors for HPD following immunotherapy in a case of lung squamous cell carcinoma, after treatment with a combination of anti-angiogenic drugs and biological cytotoxic drugs, the mass was found to have become smaller than before, along with follow-up treatment options, to provide a reference for clinical treatment decisions.

Frequency and Consequences of Cervical Lymph Node Overstaging in Head and Neck Carcinoma

Clinical lymph node staging in head and neck carcinoma (HNC) is fraught with uncertainties. Established clinical algorithms are available for the problem of occult cervical metastases. Much less is known about clinical lymph node overstaging. We identified HNC patients clinically classified as lymph node positive (cN+), in whom surgical neck dissection (ND) specimens were histopathologically negative (pN0) and in addition the subgroup, in whom an originally planned postoperative radiotherapy (PORT) was omitted. We compared these patients with surgically treated patients with clinically and histopathologically negative neck (cN0/pN0), who had received selective ND. Using a fuzzy matching algorithm, we identified patients with closely similar patient and disease characteristics, who had received primary definitive radiotherapy (RT) with or without systemic therapy (RT ± ST). Of the 980 patients with HNC, 292 received a ND as part of primary treatment. In 128/292 patients with cN0 neck, ND was elective, and in 164 patients with clinically positive neck (cN+), ND was therapeutic. In 43/164 cN+ patients, ND was histopathologically negative (cN+/pN−). In 24 of these, initially planned PORT was omitted. Overall, survival did not differ from the cN0/pN0 and primary RT ± ST control groups. However, more RT ± ST patients had functional problems with nutrition (p = 0.002). Based on these data, it can be estimated that lymph node overstaging is 26% (95% CI: 20% to 34%). In 15% (95% CI: 10% to 21%) of surgically treated cN+ HNC patients, treatment can be de-escalated without the affection of survival.

Can Radiographic Tumor Volume of Oral Squamous Cell Carcinoma Help Predict Clinical and Pathological Tumor Features?

PURPOSE

Radiographic tumor volume (RTV) of oral squamous cell carcinoma (SCC) is seldom measured in practice. Aims of the study are to estimate RTV of SCC and to investigate its relationship with clinical and pathological stage, tumor margin status, recurrence, and need for chemo/radiation.

METHODS

The Design is a retrospective cohort study. The predictor variable is SCC RTV. The primary outcome variables are clinical and pathological tumor size. The secondary outcomes are margin status and postoperative chemo/radiation. Tumor dimensions were measured on preoperative maxillofacial or neck computer tomography images with contrast. Information on patient and tumor characteristics was obtained. Pearson correlation, t test, ANOVA and log rank test were used for statistical analysis. The significance level was set at .05.

RESULTS

Thirty-Six subjects aged 36 to 86 were included in the study. Positive association was found between clinical T stage and RTV (P = .0003) and between pathologic T stage and RTV (P = .002). Mean value of RTV was significantly higher in group with positive margins (P = .0004). RTV was significantly higher in cancers requiring adjuvant chemo/radiation (P = .033). Mean RTV for patients with recurrence was 1.86 cm³ as compared to 1.29 cm³ for patients with no recurrence. Higher tumor volumes were more likely to be associated with recurrence.

CONCLUSIONS

RTV is a variable that is readily available to head and neck surgeons. RTV is associated with clinical and pathological tumor sizes, margin status, need for adjuvant chemo/radiation and tumor recurrence.

A nomogram for predicting survival of head and neck mucosal melanoma

Objectives

We aimed to understand the clinical characteristics and better predict the prognosis of patients with mucosal melanoma of the head and neck (MMHN) using a nomogram.

Methods

Three hundred patients with nometastatic MMHN were included. Multivariable Cox regression was performed to analyze independent prognostic factors for overall survival (OS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS), and these factors were used to develop a nomogram. Concordance indexes (C-indexes), calibration plots, and receiver operating characteristic (ROC) analysis were performed to test the predictive performance of the nomogram in both the primary (n = 300) and validation cohorts (n = 182).

Results

The primary tumor site, T stage and N stage were independent risk factors for survival and were included in the nomogram to predict the 3- and 5-year OS, DFS, DMFS, and LRRFS in the primary cohort. The C-indexes (both > 0.700), well-fit calibration plots, and area under the ROC curve (both > 0.700) indicated the high diagnostic accuracy of the nomogram, in both the primary and validation cohorts. The patients were divided into three groups (high-risk, intermediate-risk, and low-risk groups) according to their nomogram scores. The survival curves of OS, DFS, DMFS, and LRRFS were well separated by the risk groups in both cohorts (all P < 0.001).

Conclusions

The nomogram can stratify MMHN patients into clinically meaningful taxonomies to provide individualized treatment.

Implications of limited exolaryngeal disease and cricoarytenoid joint involvement in organ conservation protocols for laryngopharyngeal cancers: Results from a prospective study

BACKGROUND

To identify clinicoradiological factors that determine functional outcomes in laryngopharyngeal cancers treated with chemoradiotherapy.

METHODS

One hundred patients of locally advanced laryngopharyngeal cancers who were treated with chemoradiotherapy were accrued in this prospective study. The coprimary endpoint of the study was local control (LC) and functional larynx preservation survival (FLPS).

RESULTS

The median follow-up was 39 months. Thirty-nine patients had a local failure of which 17 underwent a salvage laryngectomy. A dysfunctional larynx with clinic-radiologically disease was seen in only 1 patient. Factors significant for LC were thyroid cartilage erosion/lysis and cricoarytenoid joint involvement. Within the T4a subset, patients with exolaryngeal disease through the soft tissue framework had significantly better LC and FLPS than those with cartilage erosion/lysis.

CONCLUSIONS

Patients with limited exolaryngeal disease through the soft-tissue framework can be considered for functional organ preservation, while those with thyroid cartilage involvement and cricoarytenoid joint involvement are not suitable.

Response evaluation of cervical lymph nodes after chemoradiation in patients with head and neck cancer - does additional [18F]FDG-PET-CT help?

Background

Contrast-enhanced high-resolution computed tomography (contrast-CT) is a standard imaging modality following primary concurrent radiochemotherapy (RCT) for response evaluation in patients with head and neck squamous cell carcinoma (HNSCC). We investigated the additional benefit of Fluorine-18-fluorodeoxyglucose ([18F]FDG) - positron emission tomography with computed tomography (PET-CT), if complete response (CR) in the neck based on contrast-CT was considered unsafe by the interdisciplinary tumor board (ITB).

Methods

In a retrospective observational study, patients recorded in the institutional tumor registry with incident advanced HNSCC following first line treatment with RCT were eligible. If contrast-CT results of the neck were equivocal or positive at response evaluation, a neck dissection (ND) was scheduled. While waiting for the ND, a [18F]FDG-PET-CT was performed in addition. The histopathological outcome of ND served as reference criterion. Accuracy parameters including sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) for both, contrast-CT and PET-CT, served as main outcome parameters.

Results

A total of 41 HNSCC patients with positive or equivocal posttreatment contrast-CT were eligible for post-RCT-ND. Of these, 33 received an additional [18F]FDG-PET-CT prior to surgery. Median interval between completion of RCT and the ([18F]FDG)-PET-CT was 10 weeks. Vital persistent tumor in the neck was histopathologically found in 13 of 33 patients with positive or equivocal posttreatment contrast-CT. For contrast-CT and [18F]FDG-PET-CT, sensitivity was 92.3 and 69.2% and did not differ statistically significantly (p = 0.250) whereas specificity was significantly higher for [18F]FDG-PET-CT compared with contrast-CT (80% vs. 25%, p = 0.001). For contrast-CT and [18F]FDG-PET-CT accuracy, PPV and NPV was 31.7, 12.0,96.7 and 78.9, 27.8,95.0%, respectively.

Conclusion

A negative [18F]FDG-PET-CT did not improve the exclusion of persistent vital tumor in the neck after primary RCT in comparison with contrast-CT alone. However, a positive [18F]FDG-PET-CT was a considerably better indicator of persistent, vital tumor in the neck than contrast-CT. If, based on the [18F]FDG-PET-CT result, the ND in patients with an uncertain or positive neck response in contrast CT had been omitted, the treatment of persistent nodal disease would have been delayed in 3 of 13 patients. On the other hand, if ND would have only been performed in [18F]FDG-PET-CT positive patients, an unnecessary ND would have been avoided in 11 of 20 patients.

Primary tumor volume as a predictor of distant metastases and survival in patients with sinonasal mucosal melanoma

BACKGROUND

Sinonasal mucosal melanoma (SNMM) is an aggressive cancer with high mortality. Identifying patients at risk of distant metastasis assists with management and prognostication. We aimed to define the relationship between volume, survival, and risk of distant metastases.

METHODS

A retrospective review of all patients with SNMM treated at a single institution over a 21-year period was conducted. Tumor volume was calculated using cross-sectional imaging and survival analysis was performed.

RESULTS

Sixty-one patients were included. Tumor volume was predictive of local progression-free survival (P = .03), distant metastases-free survival (DMFS) (P = .002), and overall survival (OS) (P = .02). It was a better predictor than AJCC stage and T-classification. Tumor volume equal to or greater than 5 cm³ was associated with a significantly worse DMFS and OS (P = .02 and .009, respectively).

CONCLUSION

Calculation of tumor volume assists in quantifying the risk of distant metastases and death in SNMM.

Specific growth rates calculated from CTs in patients with head and neck squamous cell carcinoma: a retrospective study performed in Austria

OBJECTIVE

To provide data on specific growth rates (SGRs) of primary tumours (PT-SGR) and largest pathological cervical lymph nodes (LN-SGR) for head and neck squamous cell carcinoma (HNSCC). To explore PT-SGR's and LN-SGR's correlation with selected biomarkers epidermal growth factor receptor (EGFR), Ki67 and CD44.

DESIGN AND SETTING

Retrospective study performed at a tertiary oncological referral centre in Innsbruck, Austria.

PARTICIPANTS

Adult patients with incident HNSCC treated with primary radiotherapy (RT) or radiochemotherapy (RCT).

OUTCOME MEASURES

Volumes of the primary tumour (PT-volume) and largest pathological cervical lymph node (LN-volume) were measured in CT scans obtained at time of diagnosis and subsequent planning CTs immediately prior to RT or RCT. SGRs were calculated assuming an exponential growth function. PT-SGR's and LN-SGR's correlation with EGFR, Ki67 and CD44 were explored.

RESULTS

In 123 patients, mean interval between diagnostic and planning CT was 29±21 days. PT-SGR was 1.8±1.8% (mean±SD) per day and was positively correlated with EGFR, Ki67 and CD44 expression (p=0.02; p=0.02; p=0.03). LN-SGR was 1.7±2.0% per day and increased with larger initial LN-volume, was lower in laryngeal cancer (p=0.003) and slowed down with time. LN-SGR was not correlated with EGFR, Ki67 or CD44 expression in primary tumours (p>0.12). New cartilage or bone infiltration occurred in 10 patients and new central lymph node necrosis in 8 patients.

CONCLUSIONS

HNSCCs are fast-growing tumours for which treatment must not be delayed. Clinical tumour growth rates are influences by EGFR, KI67 and CD44 expression.

The Association of 3-D Volume and 2-D Area of Post-swallow Pharyngeal Residue on CT Imaging

Pharyngeal residue, the material that remains in the pharynx after swallowing, is an important marker of impairments in swallowing and prandial aspiration risk. The goals of this study were to determine whether the 2D area of post-swallow residue accurately represents its 3D volume, and if the laterality of residue would affect this association. Thirteen patients with dysphagia due to brainstem stroke completed dynamic 320-detector row computed tomography while swallowing a trial of 10 ml honey-thick barium. 3D volumes of pharyngeal residue were compared to 2D lateral and anterior-posterior areas, and a laterality index for residue location was computed. Although the anteroposterior area of residue was larger than the lateral area, the two measures were positively correlated with one another and with residue volume. On separate bivariate regression analyses, residue volume was accurately predicted by both lateral (R² = 0.91) and anteroposterior (R² = 0.88) residue areas, with limited incidence of high residuals. Half of the sample demonstrated a majority of pharyngeal residue lateralized to one side of the pharynx, with no effect of laterality on the association between areas and volume. In conclusion, the area of post-swallow pharyngeal residue was associated with volume, with limitations in specific cases. Direct measurement of pharyngeal residue volume and swallowing physiology with 3D-CT can be used to validate results from standard 2D instrumentation.

Image segmentation-based volume approximation-volume as a factor in the clinical management of osteolytic jaw lesions

OBJECTIVE

Size characterization of osteolytic jaw lesions (OJL), in particular of neoplastic nature, is heterogeneously performed and lacks standardization in the medical literature and clinical practice. An OJL's volume holds promise as a surrogate for treatment response and prognosis. We comparatively evaluate various methods for size characterization of odontogenic OJLs.

METHODS

We retrospectively performed semiautomatic image segmentation of CBCT data sets for volume approximation of neoplastic (51) and non-neoplastic odontogenic OJLs (100). We assessed the three greatest orthogonal diameters and calculated the volume using the cuboid- and ellipsoid-formula. Image segmentation was carried out using ITK-SNAP. Image segmentation-based volume approximation served as reference. Intra- and inter-rater variability were evaluated at hand of Bland-Altman-Analysis and dice similarity coefficient (DSC).

RESULTS

Concerning the intrarater variability, we found the DSC to be highest for image segmentation-based volume approximation, simultaneously showing the tightest limits of agreement and greatest reliability. The cuboid formula showed consistent overestimation of the lesion's volume with a percent mean difference of -52 % (upper and lower limits of agreement +8.57 %  and -112.63%, respectively). In mean, the ellipsoid formula underestimated the lesion's volume by 10.1% (upper and lower limits of agreement +76.8%  and -56.6%, respectively). Inter rater variability was higher for formula-based volume approximation. Volume and multilocularity (p = 0.001) correlate with aggressiveness and growth potential.

CONCLUSIONS

Segmentation-based volume approximation holds great promise for patient individualized treatment planning and clinical management. The data suggest that maximum tumour diameter-based size characterization, especially the cuboid-formula and the maximum diameter alone, should not be recommended.

Volumetric MRI Analysis of Plexiform Neurofibromas in Neurofibromatosis Type 1: Comparison of Two Methods

OBJECTIVES

Plexiform neurofibromas (PNs) are complex, histologically benign peripheral nerve sheath tumors that are challenging to measure by simple line measurements. Computer-aided volumetric segmentation of PN has become the recommended method to assess response in clinical trials directed at PN. Different methods for volumetric analysis of PN have been developed. The goal of this study is to test the level of agreement in volume measurements and in interval changes using two separate methods of volumetric magnetic resonance imaging analysis.

METHODS

Three independent volume measurements were performed on 15 PN imaged at three time-points using 3DQI software at Massachusetts General Hospital (MGH) and National Cancer Institute (NCI) and MEDx software at NCI.

RESULTS

Median volume differences at each time-point comparing MGH-3DQI and NCI-3DQI were -0.5, -4.2, and -19.9 mL; comparing NCI-3DQI and NCI-MEDx were -21.0, -47.0, and -21.0 mL; comparing MGH-3DQI and NCI-MEDx were -10.0, -70.3, and -29.9 mL. Median differences in percentage change over time comparing MGH-3DQI and NCI-3DQI were -1.7, 1.1, and -1.0%; comparing NCI-3DQI and NCI-MEDx were -2.3, 3.3, and -1.1%; comparing MGH-3DQI and NCI-MEDx were -0.4, 2.0, and -1.5%. Volume differences were <20% of the mean of the two measurements in 117 of 135 comparisons (86.7%). Difference in interval change was <20% in 120 of the 135 comparisons (88.9%), while disease status classification was concordant in 115 of 135 comparisons (85.2%).

CONCLUSIONS

The volumes, interval changes, and progression status classifications were in good agreement. The comparison of two volumetric analysis methods suggests no systematic differences in tumor assessment. A prospective comparison of the two methods is planned.

Prognostic value of tumor volume in patients with head and neck squamous cell carcinoma treated with primary surgery

BACKGROUND

Tumor volume in head and neck squamous cell carcinoma (HNSCC) was mainly measured in nonsurgically treated patients. We analyzed the influence of tumor volume on complete response (CR), overall survival (OS), and clear surgical margins also in primarily surgically treated patients.

METHODS

In contrast-enhanced CTs, the tumor volumes of patients with incident HNSCC were measured.

RESULTS

The tumor volumes of 259 patients were measured, of which 125 patients (48%) underwent primary surgery and 102 patients (84%) had clear margins. The tumor volume was not an independent factor for CR at the primary tumor site. Risk of death increased by 1.4% per mL of tumor volume (95% confidence interval [CI] 0.8%-2.0%; P < .001). The OS was better in patients treated with primary surgery, if the tumor volume was ≤12 mL (P < .001). Risk of involved margins increased by 4.5% per mL of tumor volume (95% CI 0.9%-8.3%; P = .003). The predicted probability of clear margins was ≥80% in tumor volumes ≤ 16 mL.

CONCLUSION

The tumor volume had an impact on CR, OS, and clear margins. The tumor volume may also aid in selecting HNSCC treatment.

Volumetric analysis of keratocystic odontogenic tumors and non-neoplastic jaw cysts - Comparison and its clinical relevance

The keratocystic odontogenic tumor (KCOT) is capable of causing vast osseous destruction. Histopathological examination is pivotal for diagnosis. The diagnostic process can sometimes be hindered by tissue inflammation of KCOTs with loss of defining criteria, resulting in misdiagnosis as an odontogenic jaw cyst. We discuss the possible merits of volumetric analysis when facing this particular diagnostic dilemma and for pathophysiological characterization of KCOTs. We included 114 patients, of whom 27 were histopathologically diagnosed with a KCOT and 87 with dentigerous (n = 41) and periapical cyst (n = 46). Semiautomatic segmentation and radiological analysis of preoperative cone beam computed tomography (CBCT) image data was carried out using ITK-SNAP. The mean volumetric extent of KCOTs is significantly higher compared to non-neoplastic odontogenic jaw cysts (p = 0.001). The mean volume and standard deviation for KCOTs and non-neoplastic odontogenic jaw cysts was 10381 mm³ ± 6410 and 5813 mm³ ± 4425, respectively. Volumetric analysis reveals that KCOTs significantly exceed the mean size of non-neoplastic odontogenic jaw cysts, adding an argument in favor of the neoplastic nature of KCOTs. In the case of difficult histopathological examination, lesions with a size exceeding a value of about 3000 mm³ could be considered for close clinico-radiologic follow-up.

Size distribution and clinicoradiological signs of aggressiveness in odontogenic myxoma-three-dimensional analysis and systematic review

OBJECTIVES

Therapeutic assessment of odontogenic myxoma (OM) is poorly standardized. Unidimensional size criteria have shown to be unreliable in therapeutic decision-making. We evaluate the size distribution of OM and scan for associated clinicoradiological signs of aggressiveness. Additionally, we evaluate three-dimensional size delineation of OM aiming to improve future therapeutic assessment of this destructive neoplasm.

METHODS

Primarily, we reviewed the database "PubMed" for data concerning the size of OMs as radiologically determined. Afterwards, the impact of age, sex, locularity and location on the size was investigated by χ² test, Student's t-test and regression analysis. Furthermore, we statistically evaluated the impact of size on the occurrence of clinicoradiological signs of aggressiveness. Secondly, we approximated the volume of five unpublished cases of OM by semi-automatic image segmentation of cone-beam CT images.

RESULTS

Multilocular OMs were significantly larger than unilocular ones (p < 0.002). Age (0.042) and multilocularity (<0.002) significantly impacted size. Size was significantly associated with cortical perforation (0.032) and multilocularity (<0.002), further regression analysis revealed tooth resorption (0.019), cortical perforation (0.005) and multilocularity (<0.002) as significant predictors of size. Employing the volume as a mean of comparison, we found that the biggest OM (38.42 ml; multilocular) was 124 times larger than the smallest (0.31 ml; unilocular). However, using the maximum diameter (cm) as a surrogate for size, the biggest lesion (6.3) was only 5.25 times larger than the smallest (1.2).

CONCLUSIONS

Locularity and volumetric size characterization might help in therapeutic decision-making and could help to improve our understanding of OM.