Biomedical subjects

Peter D Lacy

Publications and source records attributed to Peter D Lacy.

4 recordsLinked to original sources

PubMed2006

Evaluation of the impact of addition of PET to CT and MR scanning in the staging of patients with head and neck carcinomas.

The addition of whole body positron emission tomography (PET) to the investigation of patients with newly diagnosed head and neck squamous cell carcinoma (HNSCC) was assessed over a 6-month period. Staging investigations included laryngoscopy, oesophagoscopy, CXR, CT and MRI. In addition, all patients had an extended-field (whole body) FDG-PET scan and were restaged. Standardised Uptake Values (SUV) were used to measure FDG uptake. SUV levels above 5 were considered indicative of the presence of tumour, values below 3 indicative of benign aetiology and values equal to and between 3 and 5 were considered equivocal. Forty-eight consecutive patients with biopsy proven HNSCC were included for study. Three patients presenting with neck disease had unknown primary tumours. Of the remaining 45 patients, CT scan correctly identified 40 of the primary tumours (89%). MRI and PET both identified 41 primary tumours (91%). Thirty-two patients underwent neck dissection. Of these patients 12 had pathologically N0 necks and 20 had positive nodal disease. CT scan and MRI each correctly staged pN0 necks in 10 of 12 patients (83%) whereas PET alone had a lower true negative rate of 8 out of 12 patients (67%). PET correctly staged the N+ necks in 14/20 patients (70%) versus 12/20 (60%) for MRI, and 8/20 (40%) for CT alone. All four patients who were judged to have distant metastases by PET had these metastases deemed negative by other investigation. None of the three imaging modalities was able to identify the tumour site in the three patients with unknown primaries. In conclusion, although PET has got a higher sensitivity in detecting nodal disease, it has only slightly improved the classification of N+ necks. The findings of this study cast doubt on the merit of routine addition of PET to the current investigative protocols for HNSCC patients.

Adult↗

PubMed2006

Telephony-based voice pathology assessment using automated speech analysis.

A system for remotely detecting vocal fold pathologies using telephone-quality speech is presented. The system uses a linear classifier, processing measurements of pitch perturbation, amplitude perturbation and harmonic-to-noise ratio derived from digitized speech recordings. Voice recordings from the Disordered Voice Database Model 4337 system were used to develop and validate the system. Results show that while a sustained phonation, recorded in a controlled environment, can be classified as normal or pathologic with accuracy of 89.1%, telephone-quality speech can be classified as normal or pathologic with an accuracy of 74.2%, using the same scheme. Amplitude perturbation features prove most robust for telephone-quality speech. The pathologic recordings were then subcategorized into four groups, comprising normal, neuromuscular pathologic, physical pathologic and mixed (neuromuscular with physical) pathologic. A separate classifier was developed for classifying the normal group from each pathologic subcategory. Results show that neuromuscular disorders could be detected remotely with an accuracy of 87%, physical abnormalities with an accuracy of 78% and mixed pathology voice with an accuracy of 61%. This study highlights the real possibility for remote detection and diagnosis of voice pathology.

Algorithms↗

PubMed2004

Validation of the Composite Laryngeal Recurrence Staging System.

BACKGROUND: The Composite Laryngeal Recurrence Staging System (CLRSS) has been described recently as an improved alternative to the retreatment TNM system (rTNM) for staging patients with recurrent laryngeal squamous cell carcinoma. The objectives of this study were to validate the CLRSS and compare its use with the rTNM system. METHODS: A retrospective chart review was conducted of 67 patients with recurrent laryngeal squamous cell carcinoma who had their initial treatment between 1980 and 1992. The external validity of the CLRSS was assessed, and its ability to stage patients and to predict survival was compared with the rTNM system. RESULTS: The overall 2-year survival rate was 51% (34 of 67 patients). The rTNM system was unable to stage 12 patients (18%), whereas all patients could be staged using the CLRSS. The CLRSS predicted survival better than the rTNM system (c-statistic = 0.79). CONCLUSIONS: The newer CLRSS staging system for recurrent laryngeal carcinoma outperformed the rTNM system in its ability to stage more patients and to predict survival.

Adult↗

PubMed2002

Development of a new head and neck cancer-specific comorbidity index.

BACKGROUND: Most patients with head and neck squamous cell carcinoma are older and may have coexistent or comorbid diseases. OBJECTIVES: To determine the prognostic impact of individual comorbid conditions in patients with head and neck cancer, to combine the individual comorbid conditions to form a new a head and neck-specific comorbidity instrument, and to compare it with the Modified Kaplan-Feinstein Index to determine if the new disease-specific instrument offers any improvement in survival prediction over a general comorbidity index. DESIGN: Retrospective review of medical records. POPULATION: The study population comprised 1153 patients with biopsy-proven, newly diagnosed squamous cell carcinoma of the oral cavity, oropharynx, or larynx. RESULTS: Seven comorbid conditions (congestive heart disease, cardiac arrhythmia, peripheral vascular disease, pulmonary disease, renal disease, cancer controlled, and cancer uncontrolled) were significantly related to survival. These comorbid conditions were assigned integer weights to reflect their relative prognostic importance and combined to create the new Washington University Head and Neck Comorbidity Index (WUHNCI). Survival was significantly related to levels of comorbidity severity as defined by the WUHNCI. The WUHNCI predicted survival better than the Modified Kaplan-Feinstein Index despite containing far fewer ailments. CONCLUSIONS: Comorbidity is an important feature of the patient with head and neck cancer. The WUHNCI can be used for retrospective review or prospective outcomes research.

Adolescent↗