Frank A. Pameijer

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 Fishers 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.

The potential impact of CT-MRI matching on tumor volume delineation in advanced head and neck cancer

PURPOSE To study the potential impact of the combined use of CT and MRI scans on the Gross Tumor Volume (GTV) estimation and interobserver variation. METHODS AND MATERIALS Four observers outlined the GTV in six patients with advanced head and neck cancer on CT, axial MRI, and coronal or sagittal MRI. The MRI scans were subsequently matched to the CT scan. The interobserver and interscan set variation were assessed in three dimensions. RESULTS The mean CT derived volume was a factor of 1.3 larger than the mean axial MRI volume. The range in volumes was larger for the CT than for the axial MRI volumes in five of the six cases. The ratio of the scan set common (i.e., the volume common to all GTVs) and the scan set encompassing volume (i.e., the smallest volume encompassing all GTVs) was closer to one in MRI (0.3-0.6) than in CT (0.1-0.5). The rest volumes (i.e., the volume defined by one observer as GTV in one data set but not in the other data set) were never zero for CT vs. MRI nor for MRI vs. CT. In two cases the craniocaudal border was poorly recognized on the axial MRI but could be delineated with a good agreement between the observers in the coronal/sagittal MRI. CONCLUSIONS MRI-derived GTVs are smaller and have less interobserver variation than CT-derived GTVs. CT and MRI are complementary in delineating the GTV. A coronal or sagittal MRI adds to a better GTV definition in the craniocaudal direction.

Can pretreatment computed tomography predict local control in T3 squamous cell carcinoma of the glottic larynx treated with definitive radiotherapy

PURPOSE To determine if pretreatment computed tomography (CT) can predict local control in T3 squamous cell carcinoma of the glottic larynx treated with definitive radiotherapy (RT). METHODS AND MATERIALS Forty-two patients with previously untreated T3 squamous cell carcinoma of the glottic larynx were treated for cure with RT alone; all had a minimum 2-year follow-up. Tumor volumes and extent were determined by consensus of two head and neck radiologists on pretreatment CT studies. A tumor score was calculated and assigned to each primary lesion depending on the extent of laryngeal spread. Sclerosis of any laryngeal cartilage was recorded. The specific CT parameters assessed were correlated with local control. RESULTS Tumor volume was a significant predictor of local control. For tumors measuring < 3.5 cm3, local control was achieved in 22 of 26 patients (85%), whereas for tumors > or = 3.5 cm3, local control was achieved in 4 of 16 patients (25%) (p = 0.0002). Sensitivity and specificity using this cutpoint were 85% and 75%, respectively. Tumor score as a measure of anatomic extent was also found to be a significant predictor of local control. The local control rate for tumors assigned a low tumor score (< or = 5) was 78% (21 of 27) compared to 33% (5 of 15) for tumors assigned a high tumor score (6, 7, or 8) (p = 0.008). A significant decrease in the local control rate was observed for cancers involving the paraglottic space at the false vocal cord level (14 of 16 [88%] vs. 12/26 [46%]) (p = 0.010), cancers involving the face of the arytenoid (15 of 18 [83%] vs. 11 of 24 [46%]) (p = 0.024), and tumors involving the interarytenoid region (25 of 36 [69%] vs. 1 of 6 [17%]; p = 0.020). There were 12 patients with sclerosis of both the ipsilateral arytenoid and the adjacent cricoid cartilage. These patients showed a significant decrease in local control (4 of 12 [33%]). CONCLUSION Pretreatment CT can stratify patients with T3 glottic carcinoma into groups more or less likely to be locally controlled with definitive RT. The local control rate for these tumors can be improved using a CT-based tumor profile; the ideal CT profile for a radiocurable T3 glottic larynx carcinoma is volume < 3.5 cm3 and no or single laryngeal cartilage sclerosis.

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

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).

Pretreatment probability model for predicting outcome after intraarterial chemoradiation for advanced head and neck carcinoma

Concurrent chemoradiation is being used increasingly to treat patients with advanced‐stage head and neck carcinoma. In the current study, a clinical nomogram was developed to predict local control and overall survival rates for individual patients who will undergo chemoradiation.

Variability of tumor volumes in T3-staged head and neck tumors

The Tumor Node Metastasis (TNM) classification system describes head and neck tumors using anatomic or unidimensional criteria and may therefore fail to define the actual three‐dimensional tumor bulk. To investigate this we measured variability of tumor volumes (Vvol) in T3‐staged head and neck tumors.

Diffusion-weighted MR Imaging in Laryngeal and Hypopharyngeal Carcinoma: Association between Apparent Diffusion Coefficient and Histologic Findings

PURPOSE To investigate the relationship between the histologic characteristics of head and neck squamous cell carcinoma and apparent diffusion coefficient (ADC) at diffusion-weighted magnetic resonance (MR) imaging. MATERIALS AND METHODS The institutional ethics committee approved this study and waived informed consent. In head and neck squamous cell carcinoma, local failure after chemotherapy and/or radiation therapy correlates with pretreatment ADC. However, the histopathologic basis of this correlation remains unclear. In this study, 16 patients with head and neck squamous cell carcinoma were enrolled (median age, 60 years; range, 49-78 years). Before undergoing total laryngectomy, patients underwent 1.5-T diffusion-weighted MR imaging. After resection, whole-mount hematoxylin-eosin-stained sections were registered to the MR images. Cellular density; nuclear, cytoplasmic, and stromal area; and nuclear-cytoplasmic ratio within the tumor were calculated by using image-based segmentation on four consecutive slices. Mean ADC of the corresponding tumor region was calculated. Spearman correlations between ADC and histologic characteristics were calculated. RESULTS ADC was significantly and inversely correlated with cell density (n = 16, r = -0.57, P = .02), nuclear area (n = 12, r = -0.64, P = .03), and nuclear-cytoplasmic ratio (n = 12, r = -0.77, P ≤ .01). ADC was significantly and positively correlated with percentage area of stroma (n = 12, r = 0.69, P = .01). Additionally, the percentage area of stroma was strongly interdependent with the percentage area of nuclei (n = 12, r = -0.97, P ≤ .01). CONCLUSION ADC was significantly correlated with cellularity, stromal component, and nuclear-cytoplasmic ratio. The positive correlation of ADC and stromal component suggests that the poor prognostic value of high pretreatment ADC might partly be attributed to the tumor-stroma component, a known predictor of local failure.

Decreased 3D observer variation with matched CT-MRI, for target delineation in Nasopharynx cancer

PurposeTo determine the variation in target delineation of nasopharyngeal carcinoma and the impact of measures to minimize this variation.Materials and methodsFor ten nasopharyngeal cancer patients, ten observers each delineated the Clinical Target Volume (CTV) and the CTV elective. After 3D analysis of the delineated volumes, a second delineation was performed. This implied improved delineation instructions, a combined delineation on CT and co-registered MRI, forced use of sagittal reconstructions, and an on-line anatomical atlas.ResultsBoth for the CTV and the CTV elective delineations, the 3D SD decreased from Phase 1 to Phase 2, from 4.4 to 3.3 mm for the CTV and from 5.9 to 4.9 mm for the elective. There was an increase agreement, where the observers intended to delineate the same structure, from 36 to 64 surface % (p = 0.003) for the CTV and from 17 to 59% (p = 0.004) for the elective. The largest variations were at the caudal border of the delineations but these were smaller when an observer utilized the sagittal window. Hence, the use of sagittal side windows was enforced in the second phase and resulted in a decreased standard deviation for this area from 7.7 to 3.3 mm (p = 0.001) for the CTV and 7.9 to 5.6 mm (p = 0.03) for the CTV elective.DiscussionAttempts to decrease the variation need to be tailored to the specific causes of the variation. Use of delineation instructions multimodality imaging, the use of sagittal windows and an on-line atlas result in a higher agreement on the intended target.

Tumor volume as prognostic factor in chemoradiation for advanced head and neck cancer

Tumor volume is an important predictor of outcome in radiotherapy alone. Its significance in concomitant chemoradiation (CCRT) is much less clear. We analyzed the prognostic value of primary tumor volume for advanced head and neck squamous cell carcinoma (HNSCC) treated with CCRT.

Pre- and post-radiotherapy computed tomography in laryngeal cancer: imaging-based prediction of local failure.

PURPOSE To determine if pre-radiotherapy (RT) and/or post-radiotherapy computed tomography (CT) can predict local failure in patients with laryngeal carcinoma treated with definitive RT. METHODS AND MATERIALS The pre- and post-RT CT examinations of 59 patients (T3 glottic carcinoma [n = 30] and T1-T4 supraglottic carcinoma [n = 29]) were reviewed. For each patient, the first post-RT CT study between 1 and 6 months after irradiation was used. All patients were treated with definitive hyperfractionated twice-daily continuous-course irradiation to a total dose of 6,720-7,920 cGy, and followed-up clinically for at least 2 years after completion of RT. Local control was defined as absence of primary tumor recurrence and a functioning larynx. On the pre-treatment CT study, each tumor was assigned a high-or low-risk profile for local failure after RT. The post-RT CT examinations were evaluated for post-treatment changes using a three-point post-RT CT-score: 1 = expected post-RT changes; 2 = focal mass with a maximal diameter of < 1 cm and/or asymmetric obliteration of laryngeal tissue planes; 3 = focal mass with a maximal diameter of > 1 cm, or < 50% estimated tumor volume reduction. RESULTS The local control rates at 2 years post-RT based on pre-treatment CT evaluation were 88% for low pre-treatment risk profile patients (95% CI: 66-96%) and 34% (95% CI: 19-50%) for high pre-treatment risk profile patients (risk ratio 6.583; 95% CI: 2.265-9.129;p = 0.0001). Based on post-treatment CT, the local control rates at 2 years post-RT were 94% for score 1, 67% for score 2, and 10% for score 3 (risk ratio 4.760; 95% CI: 2.278-9.950 p = 0.0001). Post-RT CT scores added significant information to the pre-treatment risk profiles on prognosis. CONCLUSIONS Pre-treatment CT risk profiles, as well as post-RT CT evaluation can identify patients, irradiated for laryngeal carcinomas, at high risk for developing local failure. When the post-RT CT score is available, it proves to be an even better prognosticator than the pre-treatment CT-risk profile.