John S. Beatty

Incidental PET/CT findings in the cancer patient: How should they be managed?

BACKGROUND Despite a paucity of evidence-based guidelines, the use of PET/CT (positron emission tomography/computed tomography) in the management of cancer patients is increasing. As widespread clinical application increases, unexpected radiographic findings are occasionally identified. These incidental findings are often suspicious for a second primary malignancy. The purpose of this study was to determine the clinical impact of these incidental PET/CT findings. METHODS A query of our prospectively acquired Nuclear Medicine database was performed to identify patients with a known malignancy being staged or serially imaged with PET/CT. Patients with incidental findings suggestive of a second primary malignancy were selected. Statistical analysis was performed to determine the ability of PET/CT to identify a second primary malignancy. All PET/CT were interpreted by board certified nuclear radiologists. RESULTS Of 3,814 PET/CT scans performed on 2,219 cancer patients at our institution from January 1, 2005, to December 29, 2008, 272 patients (12% of all patients) had findings concerning for a second primary malignancy. An invasive work-up was performed on 49% (133/272) of these patients, while 15% (40/272) had no further evaluation due to an advanced primary malignancy. The remaining 36% (99/272) had no further evaluation secondary to a low clinical suspicion determined by the treating team, a clinical plan of observation, or patients lost to follow-up. Of the 133 patients evaluated further, clinicians identified a second primary malignancy in 41 patients (31%), benign disease in 62 patients (47%), and metastatic disease from their known malignancy in 30 patients (23%). The most common sites for a proven second primary malignancy were: lung (N = 10), breast (N = 7), and colon (N = 5). Investigation of these lesions was performed using several techniques, including 24 endoscopies (6 malignant). A surgical procedure was performed in 74 patients (29 malignant), and a percutaneous biopsy was performed on 34 patients (12 malignant). The overall positive predictive value for PET/CT to detect a second primary malignancy was 31% in this subgroup. At a median follow-up of 22 months, 9 of 41 patients with a second primary were dead of a malignancy, 20 were alive with disease, and 12 had no evidence of disease. CONCLUSION Incidental PET/CT findings consistent with a second primary are occasionally encountered in cancer patients. In our data, approximately half of these findings were benign, a third were consistent with a second primary malignancy or a metastatic focus, and the remainder were never evaluated due to physician and patient decision. Advanced primary tumors are unlikely to be impacted by a second primary tumor suggesting that this subset of patients will not benefit from further investigation. Our data suggests that, despite the high rate of false positivity, incidental PET/CT findings should be investigated when the results will impact treatment algorithms. The timing and route of investigation should be dictated by clinical judgment and the status of the primary tumor. Further investigation will need to be performed to determine the long-term clinical impact of incidentally identified second primary malignancies.

Nonoperative management of solid organ injury diminishes surgical resident operative experience: is it time for simulation training?

BACKGROUND Nonoperative management (NOM) of solid abdominal organ injury (SAOI) is increasing. Consequently, training programs are challenged to ensure essential operative trauma experience. We hypothesize that the increasing use and success of NOM for SAOI negatively impacts resident operative experience with these injuries and that curriculum-based simulation might be necessary to augment clinical experience. MATERIALS AND METHODS A retrospective cohort analysis of 1198 consecutive adults admitted to a Level I trauma center over 12 y diagnosed with spleen and/or liver injury was performed. Resident case logs were reviewed to determine operative experience (Cohort A: 1996-2001 versus Cohort B: 2002-2007). RESULTS Overall, 24% of patients underwent operation for SAOI. Fewer blunt than penetrating injuries required operation (20% versus 50%, P < 0.001). Of those managed operatively, 70% underwent a spleen procedure and 43% had a liver procedure. More patients in Cohort A received an operation compared with Cohort B (34% versus 16%, P < 0.001). Patient outcomes did not vary between cohorts. Over the study period, 55 residency graduates logged on average 27 ± 1 operative trauma cases, 3.4 ± 0.3 spleen procedures, and 2.4 ± 0.2 liver operations for trauma. Cohort A graduates recorded more operations for SAOI than Cohort B graduates (spleen 4.1 ± 0.4 versus 3.0 ± 0.2 cases, P = 0.020 and liver 3.2 ± 0.3 versus 1.8 ± 0.3 cases, P = 0.004). CONCLUSIONS Successful NOM, especially for blunt mechanisms, diminishes traditional opportunities for residents to garner adequate operative experience with SAOI. Fewer operative occasions may necessitate an increased role for standardized, curriculum-based simulation training.

The predictive value of incidental PET/CT findings suspicious for breast cancer in women with non-breast malignancies

BACKGROUND On occasion, patients followed with positron emission tomographic (PET)/computed tomographic (CT) imaging for nonbreast malignancies will have incidental breast findings concerning for second primary breast cancers. The aim of this study was to determine the predictive value of PET/CT imaging to identify breast cancers in these patients. METHODS Patients with primary nonbreast malignancies and findings concerning for second primary breast cancers were identified from a prospectively acquired nuclear medicine database from January 2005 to July 2008. Chart reviews were then performed. RESULTS Nine hundred two women underwent PET/CT imaging to evaluate nonbreast malignancies. Nine women (1%) had concerning breast findings, and 5 (56%) had subsequent breast cancer diagnoses. The positive predictive value of PET/CT imaging in these patients was 63%. Evidence of compliance with current screening guidelines was present in only 22% of these patients. CONCLUSIONS The data suggest that findings concerning for an additional primary breast cancer should be evaluated and that age-appropriate screening tools should not be abandoned.

Complications impair the usefulness and validity of the rat tail arteriovenous fistula model

To the Editor: We wish to follow up the report of a new rat tail model of the hemodialysis arteriovenous fistula (AVF).1 Such models are potentially important because maturation failure of AVFs is a major unsolved problem. Lin et al.1 reported 5/5 successful operations in which the lateral vein was anastomosed end-to-side to the ventral artery. We report our experience in creating 27 such AVFs.