Tongue cancer treated with irradiation: assessment with MR imaging

T2-weighted MR imaging early after chemoradiotherapy to evaluate treatment response in head and neck squamous cell carcinoma

BACKGROUND AND PURPOSE

T2-weighted MRI shows potential in early posttreatment assessment of the primary tumor. Residual masses composed entirely of low T2-signal scar tissue suggest local control and those ≥1 cm of similar signal to untreated tumor suggest local failure. The purpose of this study was to investigate the diagnostic accuracy of T2-weighted MR imaging early after chemoradiotherapy for identifying primary tumor treatment failure in squamous cell carcinoma of the head and neck.

MATERIALS AND METHODS

At 6 weeks after treatment, T2-weighted MR images of 37 primary tumors in 37 patients were assessed. Residual masses were divided into 3 patterns: pattern 1 = scar tissue only (flat-edged/retracted mass of low T2 signal intensity); pattern 2 = mass without features described in pattern 1 or 3; and pattern 3 = any pattern that included an expansile mass ≥1 cm of intermediate T2 signal intensity (similar grade of signal intensity to the untreated tumor). T2 patterns were analyzed for local outcome (Fisher exact test) and time to local failure (univariate and multivariate analysis of T2 pattern, age, T stage, and tumor size by use of the Cox regression model).

RESULTS

Residual masses after treatment were present in 34 (92%) of 37 patients. Local failures occurred in residual masses with pattern 1 in 0 (0%) of 14 patients; pattern 2 in 6 (55%) of 11 patients; and pattern 3 in 9 (100%) of 9 patients. Significant associations were found between local control and pattern 1 (P = <.0001; sensitivity, 74%; specificity, 100%; PPV, 100%; NPV, 75%; accuracy, 85%), and between local failure and pattern 3 (P = <.0001; sensitivity, 60%; specificity, 100%; PPV, 100%; NPV, 76%; accuracy, 82%). Pattern 2 showed no significant associations with local outcome. Univariate analysis of time to local failure showed that the T2 pattern was significant (P < .0001) and remained significant on multivariate analysis.

CONCLUSIONS

T2-weighted MR imaging is a potential tool for early posttreatment assessment of primary HNSCC treatment response. Awareness of correlation of the T2 pattern of any residual mass with treatment outcome at the primary site may contribute to patient treatment.

Definitive chemoirradiation for resectable head and neck cancer: treatment outcome and prognostic significance of MRI findings

The aim of this study was to evaluate the outcome and prognosticators for patients with resectable head and neck cancer (RHNC) undergoing definitive concurrent chemotherapy and radiotherapy (CCRT). In total, 110 RHNC patients receiving definitive CCRT to defer radical surgery were enrolled. Radiotherapy was given as either 2 Gy once daily with 70 Gy, or 1.2 Gy twice daily with 74.4 Gy. Chemotherapy involved the administration of 5-fluorouracil and cisplatin in two concomitant and two post-radiotherapy adjuvant cycles. 3 months after CCRT, MRI was performed to evaluate the response and determine further treatment plans. Survival outcome was calculated by the Kaplan-Meier method. Log-rank test and Cox regression analyses were used to estimate the significance of prognosticators. 4-year local-regional control, distant metastasis-free survival, disease-free survival and overall survival rates were 76.1%, 85.6%, 67.5% and 53.2%, respectively. Local recurrence (odds ratio = 4.09; p < 0.0001) and T3/T4 stage (odds ratio = 2.34; p = 0.01) were the independent factors associated with poor survival. T stage (odds ratio = 3.29; p = 0.03) and/or remission status on post-CCRT MRI (odds ratio = 7.22; p < 0.0001) were significantly associated with local control, distant metastasis-free survival and disease-free survival. 13 of 20 patients with imaging residuum had local recurrence, compared with 12 of 89 with complete remission (4-year local control rate of 27% vs 86%; p < 0.0001). Post-CCRT MRI may thus be used to predict the chance of a successful non-surgical approach.

Imaging the treated oral cavity and oropharynx

Cross-sectional imaging has become essential in the evaluation of the treated oral cavity and oropharynx. The purpose of this paper is to review the imaging guidelines for the evaluation of this region and to detail the typical changes encountered on imaging following surgical and radiation treatment for cancer.

Head and neck tumors: imaging recurrent tumor and post-therapeutic changes with CT and MRI

OBJECTIVE

To evaluate criteria for detection of tumor recurrence and post-treatment changes in patients with head and neck malignancies in computed tomography (CT) and magnetic resonance imaging (MRI).

METHODS AND MATERIALS

Thirty-nine patients with head and neck carcinoma receiving radiochemotherapy were examined before, during and after therapy with MRI. Changes in signal intensity were correlated to histology or clinical course. Three hundred and thirty-one patients with head and neck malignancies were examined with CT after therapy. CT diagnoses were correlated with histology or clinical course.

RESULTS

Main criteria for recurrent/residual tumor in MRI was infiltrative mass with high signal intensity in T2-weighted images and enhancement after Gd-DTPA in T1-weighted images. Radiation-induced changes led to false positive diagnosis in 46% in the interval up to 3 months after therapy and in 58% in the interval 3-6 months after therapy. The combination of a circumscribed, infiltrative mass with contrast enhancement in CT had a sensitivity of 86% and a specificity of 80%.

CONCLUSION

CT could accurately demonstrate postoperative changes and tumor recurrence. MRI had advantages in differentiation of tumor and scar, but edema after radiation therapy can spoil diagnosis.

Squamous carcinoma of the tongue: review

Carcinoma of the tongue is a common condition treated by oral and maxillofacial surgeons. The tongue is a complex anatomical site at the entrance of the oropharynx, bounded by the floor of mouth and lingual mandibular cortex; its form and mobility are crucial for efficient swallowing; speech, and the appreciation of taste. Single and multiple treatments have been used, but the tongue remains a difficult area to assess and treat. In this paper, we have attempted to review some of the papers published over the last 20 years with particular reference to prognosis and functional outcome. We have dealt exclusively with squamous cell carcinoma of the tongue and its management by surgery, radiotherapy, brachytherapy, photodynamic therapy, and chemotherapy.

Staging of squamous cell carcinoma of the oral cavity and oropharynx: a comparison of MRI and CT in T- and N-staging

PURPOSE

Our purpose was to assess the accuracy of CT and MRI in staging of squamous cell carcinoma (SCC) of the oral cavity and oropharynx.

METHOD

Fifty-one episodes of primary and recurrent SCC were assessed with CT and MRI. The results were compared with pathological staging.

RESULTS

For staging primary tumours, the accuracy of MR was 77% and that of CT was 67%. For detecting recurrent tumour, the accuracy of MR was 89% and that of CT was 100%. For N-staging, nodal sites were divided, according to the site of the primary tumour, into high and low risk. Sensitivity for high risk sites was 60% for clinical assessment, 35% for CT, and 75% for MR. Negative predictive value (NPV) was < or = 50% for all methods. For low risk sites, the NPV was > or = 95% for all methods.

CONCLUSION

For T-staging, MR scanning is overall more accurate than CT. If degraded images and T1 tumours are excluded, the techniques are comparable. MR scanning is oversensitive for recurrent disease. For N-staging, all methods failed to detect small metastatic deposits.

The impact of surgical margin status and use of an interstitial implant on T1, T2 oral tongue cancers after surgery

PURPOSE

In patients with T1,T2 oral tongue carcinoma treated with surgical resection, postoperative radiation therapy (RT) is required especially when surgical margins contain tumors. Irradiation techniques include external beam, interstitial implants, or a combination of the two modalities. We investigated whether positive surgical margin remains a poor prognostic factor after radiation therapy, and the contribution of interstitial implants to disease control.

METHODS AND MATERIALS

Between 1972 and 1989, 55 patients were treated postoperatively at the Mallinckrodt Institute of Radiology for T1,T2 squamous cell carcinomas of the oral tongue. Surgeries included 26 wide excisions or excisional biopsies and 29 composite resections or hemiglossectomies. Thirty-nine patients received external radiation therapy alone and 16 patients had an interstitial implant (ISI) as part of the treatment. The minimum follow-up is 4 years.

RESULTS

At 2 and 5 years, the overall survivals for all patients were 82 and 68%. The disease-free survivals (DFS) were 82 and 70%, respectively. There was no significant difference in the pattern of failure and DFS when stratified by the status of surgical margins and the type of the surgical procedure. Local control was achieved in 15 of 18 patients when surgical margins were involved by tumor and in 29 of 37 patients without tumor involving margins (p > 0.05). Ten of 18 (56%) patients with tumor involving resection margins were treated with ISI, whereas only 3 of 33 (9%) of those with negative margins received ISI. Local control was achieved in 32 of 39 patients treated with external beam RT alone, and 13 of 16 patients who received interstitial implant (p > 0.05). Four patients treated with ISI developed persistent soft tissue ulceration and mandibular bone exposures.

CONCLUSIONS

Postoperative radiation therapy converted the ominous outcome of patients with tumor involving surgical margins. Patients with positive surgical margins were often selected to be treated with interstitial implants. We found that the local control was as good as in those with a more favorable pathology (negative margins) and treated with external RT alone. Further investigation is needed to optimize the implant treatment to minimize the complications.