Nat E. Watson

A comparative diagnostic study of head and neck nodal metastases using positron emission tomography

A prospective study was conducted to compare the accuracy of clinical examination, computed tomography (CT), and positron emission tomography (PET) in identifying head and neck squamous cell carcinoma metastatic to cervical lymph nodes. The findings in the necks of 49 patients evaluated by clinical examination and CT were compared to the findings in the same necks by PET, a newly available metabolic imaging modality. Pathology specimens were available for 45 of the necks. The findings of PET and CT correlated in 84% of cases. In the cases that did not correlate, CT proved correct in four of five cases. PET (82%) and CT (84%) were comparable and were both better than clinical examination (71%) in correctly identifying the presence or absence of metastatic disease.

Pet scanning in head and neck oncology: A review

The objective of this study was to review and describe the usage of fluorine‐labeled deoxyglucose (FDG) and positron emission tomography (PET) in the diagnosis and management of head and neck cancer.

Can post RT neck dissection be omitted for patients with head and neck cancer who have a negative PET scan after definitive radiation therapy

PURPOSE A prospective, single institution study was conducted to evaluate the role of positron emission tomography with fluoro-deoxyglucose (FDG) before and after definitive radiation therapy for patients with head-and-neck cancer. Correlation with CT or MRI imaging and pathologic findings at the time of planned neck dissection was made. METHODS AND MATERIALS Twelve patients with AJCC Stages III-IV cancer of the head and neck received CT or MRI and PET imaging before treatment with definitive radiation therapy. One month after completion of treatment, repeat CT or MRI and PET imaging was obtained. All images were reviewed independently by radiologists who were blind to the results of the other modality. Patients then underwent planned neck dissection. Pathologic correlation with posttreatment scans allowed calculation of the sensitivity, specificity, negative predictive value, and the positive predictive value for both CT/MRI and PET. RESULTS Comparison of CT/MRI to PET obtained before definitive RT revealed both primary tumor and nodal disease were detected by both modalities in all cases where primary tumor was known. After RT, comparison of CT/MRI imaging to findings of neck dissection revealed a sensitivity of 90%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 50%. Comparison of PET imaging with pathologic findings demonstrated sensitivity of 45%, specificity of 100%, positive predictive value of 100%, and a negative predictive value of 14%. CONCLUSIONS In this small series of patients, the presence of a positive PET 1 month after RT accurately indicated the presence of residual disease in all cases; however, a negative PET indicated absence of disease in only 14%. Further investigation is warranted before FDG-PET should be used to determine whether post-RT neck dissection should be omitted.

Distinguishing tumor recurrence from irradiation sequelae with positron emission tomography in patients treated for larynx cancer.

PURPOSE Distinguishing persistent or recurrent tumor from postradiation edema, or soft tissue/cartilage necrosis in patients treated for carcinoma of the larynx can be difficult. Because recurrent tumor is often submucosal, multiple deep biopsies may be necessary before a diagnosis can be established. Positron emission tomography with 18F-2fluoro-2deoxyglucose (FDG) was studied for its ability to aid in this problem. METHODS AND MATERIALS Positron emission tomography (18FDG) scans were performed on 11 patients who were suspected of having persistent or recurrent tumor after radiation treatment for carcinoma of the larynx. Patients underwent thorough history and physical examinations, scans with computerized tomography, and pathologic evaluation when indicated. Standard uptake values were used to quantitate the FDG uptake in the larynx. RESULTS The time between completion of radiation treatment and positron emission tomography examination ranged from 2 to 26 months with a median of 6 months. Ten patients underwent computed tomography (CT) of the larynx, which revealed edema of the larynx (six patients), glottic mass (four patients), and cervical nodes (one patient). Positron emission tomography scans revealed increased FDG uptake in the larynx in five patients and laryngectomy confirmed the presence of carcinoma in these patients. Five patients had positron emission tomography results consistent with normal tissue changes in the larynx, and one patient had increased FDG uptake in neck nodes. This patient underwent laryngectomy, and no cancer was found in the primary site, but nodes were pathologically positive. One patient had slightly elevated FDG uptake and negative biopsy results. The remaining patients have been followed for 11 to 14 months since their positron emission studies and their examinations have remained stable. In patients without tumor, average standard uptake values of the larynx ranged from 2.4 to 4.7, and in patients with tumor, the range was 4.9 to 10.7. CONCLUSION Positron emission tomography with labeled FDG appears to be useful in distinguishing benign from malignant changes in the larynx after radiation treatment. This noninvasive technique may be preferable to biopsy, which could traumatize radiation-damaged tissues and precipitate necrosis.

Ultrasonographic diagnosis of varicoceles

OBJECTIVE To assess the ability of color duplex scrotal ultrasonography to detect subclinical varicoceles and confirm the diagnosis of clinical varicoceles. DESIGN Physical examination, color duplex scrotal ultrasonography and internal spermatic venography was performed on 64 testicular units in 33 men. SETTING Male fertility center. PATIENTS Two hundred sixty-two consecutive men being evaluated for male factor infertility of whom 33 agreed to undergo venography. MAIN OUTCOME MEASURES Ultrasonographic measurement of scrotal vein diameter of patients in the supine and upright position, before and during valsalva maneuver, and scrotal vein blood flow reversal with valsalva maneuver was compared with the findings of varicocele by physical examination and venography. RESULTS The best predictor of a varicocele was internal spermatic vein diameter, and the best overall performance of ultrasonography was achieved with the patient at rest in the supine position. The best cutoff point for venous diameter for a clinical varicocele was 3.6 mm and 2.7 mm for a subclinical varicocele, but the overall accuracy was only 63%. CONCLUSIONS Confirmatory studies are needed to support the ultrasonographic diagnosis of varicoceles before considering surgical repair.

Preoperative identification of benign versus malignant parotid masses: A comparative study including positron emission tomography

Various diagnostic tools were used in 26 patients with parotid masses to determine their value in preoperative malignant or benign categorization. These tools were positron emission tomography (PET), clinical examination, fine‐needle aspiration biopsy (FNAB), computed tomography (CT), and magnetic resonance imaging (MRI). PET identified all 26 lesions and all 12 malignant lesions, but made the correct categorization in only 69% of cases. Thus, it was not as good as the more conventional diagnostic methods, their correct categorizations being 85% (clinical), 87% (CT/MRI), and 78% (FNAB) in the same patients.

Positron emission tomography in the evaluation of laryngeal carcinoma.

Positron emission tomography (PET) is a relatively new radiologic imaging technique based on glucose analog uptake and metabolism in tumor tissue. In this study, PET was used in evaluating 38 patients with laryngeal cancer. Twenty-five patients were examined with PET prior to treatment to study the reliability of PET in identifying the primary tumor and assessing regional nodal status; 13 patients who had previously received irradiation with curative intent and who represented differential diagnostic problems were imaged to differentiate between irradiation effects and recurrent or residual cancer. Findings for both groups were compared to results of clinical evaluation and those of computed tomography (CT) and magnetic resonance imaging (MRI). The PET results were essentially identical to those of CT, MRI, and clinical evaluation in identifying metastatic lesions (82% correct), and were as reliable as CT and MRI for correctly identifying primary tumors (88%). Positron emission tomography was most helpful in differentiating recurrent tumor from postirradiation tissue sequelae. However, its lack of anatomic detail made PET less valuable for primary staging and therapeutic planning. It may enhance the diagnostic accuracy of CT and MRI where anatomic distortions occur or where diagnostic criteria for CT and MRI are ambiguous.

FDG pet evaluation of head and neck cancer: Value of imaging the thorax

Patients with primary tumors of the head and neck have been reported to have a high rate of synchronous primary tumors of the upper aerodigestive tract. This study was performed to determine whether inclusion of the thorax in the scan volume would be diagnostically useful for positron emission tomography (PET) with [F‐18] fluorodeoxy‐D‐glucose (FDG) in patients with primary tumors of the head and neck.

Laryngeal radionecrosis versus recurrent cancer: a clinical approach.

A group of 38 patients was studied by positron emission tomography utilizing fluorine18-labeled deoxyglucose (FDG-PET) scanning to examine the ability to differentiate postirradiation laryngeal recurrent cancer from radionecrosis. The resulting 79% correct diagnosis showed the technique to be far superior to conventional computed tomography scanning (61%) and clinical examination (43%). An algorithmic approach to evaluating and treating patients with radionecrosis and/or recurrent cancer by utilizing FDG-PET scanning is presented.

The effect of varicoceles on testicularblood flow in man

Abstract Objectives. To assess the effect of varicoceles on testicular blood flow in man. Methods. Testicular blood flow was measured in 248 consecutive men attending an infertilityclinic and 34 fertile volunteers using color duplex ultrasonography. Results. The testicular blood flow of men with either clinical and/or subdinical varicoceles was not significantly different from controls without varicoceles. Conclusions. Varicoceles do not significantly alter testicular blood flow in man.