MR imaging of nonmalignant polyps and masses of the nasopharynx and sphenoid sinus after radiotherapy for nasopharyngeal carcinoma

Masses of the Paranasal Sinuses After Treatment of Nasopharyngeal Carcinoma: A Case Report

The development of a new mass in the field of irradiation of a previously treated Nasopharyngeal carcinoma is generally considered a sign of recurrence. We report a case of a 46-year-old male, with a past history of undifferentiated NPC, with an expansive lesion discovered during radiological follow-up that occupied nasal cavity and paranasal sinuses. The endoscopic sinuses surgery was necessary in order to analyze and remove the mass with intraoperative frozen sections to highlight mucosa free from disease. The presence of non-malignant masses in the paranasal sinuses are rare complications after radiotherapy at the skull base, but represent an eventuality that must be considered in the differential diagnosis of a suspected recurrence or with a secondary malignancies after radiation therapy. It is therefore required a final diagnosis based on biopsy, follow-up and an eventual endoscopic surgical treatment.

Mucocèles nasosinusiennes post-radiques à propos de trois cas

Nasosinusal mucoceles, although benign, are aggressive and sometimes destructive lesions. They may occur as a result of trauma, infection, sinus surgery and head and neck radiation. We describe three patients presenting mucocele, with the history of nasopharyngeal and temporal fossa cancers treated by radiotherapy.

Nasopharyngeal granulomatous mass after radiotherapy for nasopharyngeal carcinoma

OBJECTIVE

To evaluate the diagnosis, management and nasal endoscopic surgical outcome of nasopharyngeal granulomatous mass in post-radiation nasopharyngeal carcinoma (NPC) patients.

MATERIALS AND METHODS

A total of 23 cases of granulomatous mass after radiotherapy for NPC from 2008 to 2013 treated with nasal endoscopic surgery were retrospectively reviewed.

RESULTS

Radiotherapy dose (p=0.036) and chemotherapy (p<0.001) correlated with the latency period after the treatment against NPC. The symptoms of the 23 patients before the treatment were nonspecific including nasal obstruction, purulent discharge, headache, epistaxis, foreign body sensation and/or hearing impairment. 12 patients (52.2%) were misdiagnosed to be recurrence of NPC by imaging examination (CT/MRI). After the endoscopic surgery treatment, 18 patients were disease free while the other 5 patients had developed a recurrence. Four of those five recurrent patients were cured with the repeated treatment. Histologic findings of granulation tissue with fibrin and inflammatory cells were found in all of the patients.

CONCLUSIONS

In situ granulomatous masses in post-radiation NPC patients are very prone to be misdiagnosed as recurrence of nasopharyngeal carcinoma. Chemotherapy is a significant independent factor affecting latency period (p=0.029). The nasal endoscopic surgery is an effective therapy for post-radiation nasopharyngeal granuloma; surgery can not only alleviate symptoms, what is more important, but it also helps to confirm the diagnosis.

MRI and CT of nasopharyngeal carcinoma

OBJECTIVE

This article reviews the MRI and CT of nasopharyngeal carcinoma. Extension of nasopharyngeal tumors, especially into the skull base and the deep facial spaces, is well illustrated on imaging. Assessment of retropharyngeal and cervical lymphadenopathy is important for treatment planning. MRI is commonly used for monitoring patients after therapy.

CONCLUSION

Imaging can detect effect of radiation on surrounding structures. The imaging findings that help to differentiate nasopharyngeal carcinoma from simulating lesions are discussed.

Detecting plasma Epstein-Barr virus DNA to diagnose postradiation nasopharyngeal skull base lesions in nasopharyngeal carcinoma patients: a prospective study

The diagnosis of postradiation nasopharyngeal skull base lesions in petients with nasopharyngeal carcinoma (NPC) is still a tough problem in clinical practice. An early and accurate diagnosis is important for subsequent management. We prospectively evaluated the diagnostic value of plasma Epstein-Barr virus(EBV) DNA in detecting postradiation nasopharyngeal skull base lesions in NPC patients. From July 2006 to September 2010, 90 patients with postradiation NPC (34 women and 56 men; median age: 42 years) met the selection criteria and were recruited in this study. All postradiation nasopharyngeal skull base lesions were found in the latest magnetic resonance imaging (MRI) examinations before endoscopic surgery, and the nasopharyngeal cavity was normal under flexible nasopharyngoscopy. Plasma EBV DNA detection was performed within 2 weeks before endoscopic surgery. A total of 90 endoscopic operations were successfully performed without any postoperative complications. Recurrences confirmed by postoperative pathology were found in 30 patients. The specificity, positive and negative predictive values of plasma EBV DNA detection were better than those of MRI. In addition, combining plasma EBV DNA detection with MRI improved the specificity and positive predictive values of MRI. Plasma EBV DNA detection followed by MRI would help to diagnose recurrence whereas MRI was unable. These results indicate that plasma EBV DNA is an effective and feasible biomarker for detecting postradiation nasopharyngeal skull base lesions in NPC patients.

Recurrent nasopharyngeal carcinoma: current management approaches

OBJECTIVES

Providing the primary recurrence is localized, salvage treatment is possible for nasopharyngeal carcinoma (NPC). This is a review of the experience of retreatment of this malignancy highlighting the roles of surgery and repeat radiotherapy.

METHODS

The Tumor Registry of the Prince of Wales Cancer Centre was audited for patients with an initial diagnosis of squamous/nonsquamous cell NPC who had primary treatment with radiotherapy, and now presented for retreatment. Features relating to patient, disease and treatment factors were evaluated. The primary end point was subsequent local control, and secondary endpoints were overall and cancer-specific survival.

RESULTS

Over a 30-year period 39 patients were eligible, with 25 receiving both primary and retreatment at Prince of Wales Hospital. There were 25 males and 14 females with a median age of 50 years. Thirty-six patients had radiotherapy, 4 had stereotactic radiosurgery, 5 had brachytherapy, and the remainder had external treatment. Surgery was performed in 10 patients, of whom 3 had this as the only retreatment modality. Radiotherapy doses for retreatment ranged from 15 Gy (stereotactic radiosurgery) to 71.28 Gy (mean fractionated dose). Local control was achieved in 16 patients giving an overall rate of 41.0%, and the 5-year overall survival rate was 33.3%. Treatment modality was a significant prognostic factor for local control (P < 0.001) and cancer-specific survival (P < 0.05).

CONCLUSION

The presence of local recurrence after definitive treatment of NPC may still be salvageable. The best outcomes with reirradiation occur in the context of limited volume recurrence and a disease-free interval greater than 18 months.

MRI of radiation-induced tumors of the head and neck in post-radiation nasopharyngeal carcinoma

The aim of this study was to document the sites and MRI features of radiation-induced tumors (RITs) in the head and neck following treatment for nasopharyngeal carcinoma (NPC). The MRI examinations and clinical records of 20 patients with 21 RITs were reviewed retrospectively. RITs developed 3-30 years after radiotherapy and included eleven squamous cell carcinomas, six sarcomas, two neuroendocrine carcinomas, one mucoepidermoid carcinoma and one meningioma. RITs arose in the maxillary region (9), oro/hypopharynx and oral cavity (5), external auditory canal (4), nasopharynx and sphenoid sinus (2) and brain (1). Radiation-induced carcinoma and sarcoma had MRI features that were useful to distinguish them from recurrent NPC. To improve early detection of RITs, the check areas on an MRI of a patient with previous NPC treated by radiation should always include the maxillary region, tongue, and external auditory canal/temporal bone.