Overstaging of cartilage invasion by multidetector CT scan for laryngeal cancer and its potential effect on the use of organ preservation with chemoradiation

Abstract

Objective: The two currently acceptable treatment options for locally advanced laryngeal cancer are total laryngectomy and organ preservation using chemoradiation. To facilitate therapeutic decision making, the accurate pre-treatment evaluation of cartilage invasion is of paramount importance. The purpose of this study was to evaluate the positive predictive value (PPV) and negative predictive value (NPV) of detecting neoplastic cartilage invasion in laryngeal cancer patients using fast-speed multidetector CT (MDCT). Methods: 61 consecutive patients with clinically staged T3 or T4 squamous cell carcinoma of the larynx or hypopharynx who underwent total laryngectomy were analysed. All patients had MDCT of the neck within 2 weeks prior to surgery. Central radiographic and pathological review was performed in an attempt to correlate findings. MDCT invasion of cartilage was graded based on objective criteria. Results: MDCT scan was found to have a PPV of 78% and an NPV of 100% for detection of invasion through cartilage, with sensitivity being 100% and specificity 96%. For detection of any cartilage invasion (minor, major or through cartilage invasion), PPV and NPV were 63% and 92%, respectively. The sensitivity was 85% and specificity was 75%. For the detection of tumour invasion through cartilage or major cartilage invasion, MDCT scan had a PPV of 53% and an NPV of 95%. 47% (9/19) patients were down-staged from T4 to T3 after central pathology review. Conclusion: The low PPV for cartilage destruction using MDCT suggests that a significant proportion of patients who were treated by total laryngectomy could have been appropriately offered organ preservation if more accurately staged at initial diagnosis.

Primary staging of laryngeal and hypopharyngeal cancer: CT, MR imaging and dual-energy CT

“…The introduction of multi-slice CT has resulted in an increase of spatial and temporal resolution but has led to little progress in interpretation of cartilage invasion [43], which is still sometimes overestimated [9,10]. A fundamental problem of CT is that laryngeal non-ossified cartilage and tumors show similar CT values of about 100 HU, making them almost indistinguishable, especially when the tumor is located adjacent to non-ossified cartilage (Fig.…”

“…Both CT and MR imaging are routinely used to differentiate between limited and gross cartilage invasion. However, cartilage invasion is sometimes overestimated, resulting in unnecessary total laryngectomies in some patients [9,10].…”

Squamous Cell Carcinoma of the Upper Aerodigestive Tract

“…Although sclerosis of the cartilage, as seen on CT, is often cited as indicating tumoral invasion, it is nonspecific and can result from inflammation rather than invasion. 35,36 True erosion or frank lysis of cartilage is more specific. MR imaging is more sensitive and specific than CT for detection of thyroid cartilage invasion (Fig.…”

Current oncologic concepts and emerging techniques for imaging of head and neck squamous cell cancer

“…Many authors consider computed tomography to be the most sensitive tool for imaging the larynx with regard to inflammatory and malignant findings [26], [27]. Polyps of the vocal cords and laryngeal papillomas can be diagnosed by virtual, CT-assisted laryngoscopy with high sensitivity but little specificity [25].…”

“…Cancer of the vocal cords and the glottic and subglottic space can also be missed easily by endoscopic examination whereas MD-CT shows a sensitivity of up to 93% for lesion detection [26]. The diagnosis of cartilage invasion in laryngeal cancer can be performed sensitively with MD-CT and contributes towards surgery planning with regard to partial or radical laryngectomy [27], [28]. CT imaging criteria for cartilage invasion are lysis, sclerosis and erosions of the cartilage as well as extralaryngeal destruction.…”