Management of the unknown primary carcinoma: long-term follow-up on a negative PET scan and negative panendoscopy.

BACKGROUND: The unknown primary carcinoma in the head and neck has been estimated to represent up to 7% of all head and neck carcinomas. In an attempt to identify the occult primary tumor the evaluation of this patient population has included a complete head and neck examination, flexible fiberoptic endoscopy, and imaging with CT/MRI. More recently, positron emission tomography (PET) has been advocated as a tool to detect primary tumors. METHODS: A cohort of 31 patients with fine-needle aspiration biopsy-confirmed squamous cell carcinoma were prospectively entered into a diagnostic protocol to identify the occult primary tumor. The diagnostic protocol included a comprehensive head and neck examination (including flexible endoscopy) and CT and/or MRI. If the initial diagnostic evaluation failed to identify a primary tumor, the patients then underwent whole body PET imaging followed by staging endoscopy with biopsy of the at-risk occult tumor sites. The outcome measures included the accuracy of the PET to predict the presence of occult tumor at staging endoscopy and the accuracy of the negative PET and negative panendoscopy in predicting the subsequent development of a primary tumor in the upper aerodigestive tract during follow-up. RESULTS: The PET detected 9 occult primary tumors in the 31 patients (detection rate, 29%). Five occult primary tumors (2 base of tongue and 3 palatine tonsil) were detected during panendoscopy despite a negative PET. The combination of PET and panendoscopy detected 45.2% of the unknown primary tumors. Seventeen patients (N1, n = 7; N2a, n = 4; N2b, n = 2; N3, n = 4) had no primary tumor detected and were treated as an unknown primary carcinoma with primary neck dissection +/- radiation therapy +/- chemotherapy. In this series of 17 patients, there were 3 neck recurrences (17.6%). In addition, only 1 patient (5.8%) developed a primary tumor of the upper aerodigestive tract with a mean follow-up of 31.1 months (range, 21-60 months). CONCLUSION: A negative PET study in patients with an occult primary head and neck carcinoma does not preclude the need for panendoscopy with biopsy to detect the occult primary tumor. The risk of subsequent primary tumor appears to be low in the patients with a negative PET and a negative panendoscopy (<6%).

The role of positron emission tomography scans in the management of the N-positive neck in head and neck squamous cell carcinoma after chemoradiotherapy.

OBJECTIVE: The objective of this study was to determine the sensitivity, specificity, and predictive value of 18-fluorodeoxyglucose positron emission tomography (PET) in predicting residual cervical metastatic disease in patients with N-positive necks undergoing curative radiotherapy and chemoradiotherapy for squamous cell carcinoma (SCC) of the upper aerodigestive tract. METHODS: The authors studied a prospective case series of patients (2003-2005) of patients undergoing radiotherapy and chemoradiotherapy for advanced head and neck SSC. Study entry criteria included N-positive neck disease, a complete response to treatment at the primary tumor site, posttreatment PET scan (8-12 weeks after completion of treatment), followed by salvage neck dissection. The posttreatment PET scan neck findings were correlated to the salvage neck dissection pathology report. The sensitivity, specificity, and predictive values of the PET scan to predict residual cervical metastatic disease after curative chemoradiotherapy were calculated. RESULTS: Twenty-one neck dissections (pretreatment N1 = 5, N2a = 2, N2b = 8, N3 = 6) were entered into the protocol. Four (19.0%) of the 21 neck specimens were positive for residual cervical metastatic disease, whereas the remaining 17 (80.9%) specimens demonstrated no residual carcinoma. The overall sensitivity and specificity were 75.0% and 64.7%, respectively. The positive predictive value was 33% and the negative predictive value was 91.7%. CONCLUSIONS: Although the role of posttreatment neck dissection remains controversial, the surgeon must rely on clinical examination and imaging studies. Our practice has been to perform planned staged neck dissections on all N2 and N3 necks, as well as N1 necks with an incomplete response to treatment. Based on this small prospective study, it appears that PET imaging lacks adequate sensitivity and specificity to reliably predict the presence of residual cervical metastatic disease after completion of chemoradiotherapy. With a negative predictive value of 91.7%, however, a negative PET scan appears to be a reliable predictor of the absence of residual tumor.

Indium-111-capromab pendetide radioimmunoscintigraphy and prognosis for durable biochemical response to salvage radiation therapy in men after failed prostatectomy.

PURPOSE: We evaluated the prognostic significance of indium-111 (111In)-capromab pendetide imaging for patients with prostate cancer who underwent salvage radiotherapy (RT) for recurrent disease after prostatectomy. PATIENTS AND METHODS: Records were reviewed for all men who underwent 111In-capromab pendetide imaging at a single institution from February 1997 through December 1999. We identified 30 eligible men who were radiographically negative for metastatic disease, who had increasing serum prostate-specific antigen (PSA) after primary radical prostatectomy, and who received salvage RT. Clinical interpretations of indium monoclonal antibody (In-mab) scan results were compared with postsalvage RT PSA response. RESULTS: Using an American Society of Therapeutic Radiation and Oncology definition of PSA failure, in men with a positive scan in at least one location (n = 14), the cumulative 2-year PSA control after salvage RT was 0.38 +/- 0.13 (+/- SE) compared with 0.31 +/- 0.13 for men with a normal antibody scan in and outside the prostate fossa (n = 15; proportional hazard ratio [PHR] = 1.32; 95% confidence interval [CI], 0.52 to 3.36). For men with a positive antibody scan limited to the prostate fossa (n = 9), PSA control at 2 years was 0.13 +/- 0.12 (PHR 1.77; 95% CI, 0.65 to 4.85). The 2-year probability of PSA control after salvage RT for men with positive scan results outside the prostate bed irrespective of In-mab findings in the prostate fossa (n = 5) was 0.60 +/- 0.22 (PHR 0.81; 95% CI, 0.17 to 3.78). CONCLUSION: In contrast to previous reports, for patients with postprostatectomy biochemical relapse who received salvage RT, presalvage RT In-mab scan findings outside the prostate fossa were not predictive of biochemical control after RT.

Intracranial ependymomas: an analysis of prognostic factors and patterns of failure.

From 1965 to 1997, 49 patients were diagnosed and treated for intracranial ependymoma at one institution. Tumor location was infratentorial in two thirds, and pathology was low grade in 38 patients (78%). Gross total resection of the primary tumor was achieved in 21 (43%). Thirty-six patients received adjuvant radiotherapy; the entire neuraxis was treated in 14, whole brain in 10, and local field only in 12. Median follow-up was 9.6 years (range, 2-33 years). The 5-, 10-, and 15-year overall survival rates were 71.4%, 63.5%, and 63.5% for craniospinal radiotherapy, 60.0%, 60.0%, and 40.0% for whole brain radiotherapy, and 80.8%, 64.6%, and 64.6% for local field radiotherapy (p = 0.88). The 5-, 10-, and 15-year local control rates were 60.3%, 54.4%, and 48.9%. The prognostic factors for a better local control rate were gross total resection (p = 0.021) and low grade histology (p = 0.031). Seventeen of 43 (39.5%) M0 patients did not respond to treatment; all had local failure and 4 also had a spinal relapse. Spinal relapse developed in 3 of 31 (10%) M0 patients who did not receive spinal radiotherapy, whereas 1 of 12 (8%) who had spinal radiotherapy did not respond to treatment in the spine. The results of this study indicate that local radiotherapy is sufficient for M0 patients with intracranial ependymoma.