Alphons C.M. van den Bergh

Detection of Local, Regional, and Distant Recurrence in Patients With PSA Relapse After External-Beam Radiotherapy Using 11C-Choline Positron Emission Tomography

PURPOSE An elevated serum prostate-specific antigen (PSA) level cannot distinguish between local-regional recurrences and the presence of distant metastases after treatment with curative intent for prostate cancer. With the advent of salvage treatment such as cryotherapy, it has become important to localize the site of recurrence (local or distant). In this study, the potential of (11)C-choline positron emission tomography (PET) to identify site of recurrence was investigated in patients with rising PSA after external-beam radiotherapy (EBRT). METHODS AND MATERIALS Seventy patients with histologically proven prostate cancer treated with EBRT and showing biochemical recurrence as defined by American Society for Therapeutic Radiology and Oncology consensus statement and 10 patients without recurrence underwent a PET scan using 400 MBq (11)C-choline intravenously. Biopsy-proven histology from the site of suspicion, findings with other imaging modalities, clinical follow-up and/or response to adjuvant therapy were used as comparative references. RESULTS None of the 10 patients without biochemical recurrence had a positive PET scan. Fifty-seven of 70 patients with biochemical recurrence (median PSA 9.1 ng/mL; mean PSA 12.3 ng/mL) showed an abnormal uptake pattern (sensitivity 81%). The site of recurrence was only local in 41 of 57 patients (mean PSA 11.1 ng/mL at scan), locoregionally and/or distant in 16 of 57 patients (mean PSA 17.7 ng/mL). Overall the positive predictive value and negative predictive value for (11)C-choline PET scan were 1.0 and 0.44 respectively. Accuracy was 84%. CONCLUSIONS (11)C-choline PET scan is a sensitive technique to identify the site of recurrence in patients with PSA relapse after EBRT for prostate cancer.

The incidence of second tumours and mortality in pituitary adenoma patients treated with postoperative radiotherapy versus surgery alone

BACKGROUND AND PURPOSE To assess and compare the incidence of intra- and extracranial tumours and mortality in pituitary adenoma patients treated with postoperative radiotherapy and surgery alone. PATIENTS AND METHODS A total of 462 pituitary adenoma patients were treated between 1959 and 2008 at the University Medical Center Groningen in The Netherlands. Postoperative radiotherapy was administered on indication in 236 patients. RESULTS The median follow-up time was 14 (range 1-49) years in patients treated with radiotherapy and 6 (range 1-34) years in patients treated with surgery alone. Three radiotherapy patients developed an intracranial tumour compared to one patient treated with surgery alone. The numbers of extracranial tumours per follow-up year were 6.5 (95% CI 2.5-10.5) and 5.1 (95% CI 1.9-8.2) in patients treated with and without a technique with vertex field and central body axis irradiation and 7.1 (CI 95% 2.9-11.2) in surgery alone patients. Forty-five patients treated with radiotherapy died compared to twenty-four patients treated with surgery alone (log-rank test RR 1.26, 95% CI 0.77-2.08, p=0.36). CONCLUSION In this study postoperative radiotherapy and a radiotherapy treatment technique with vertex field and central body axis irradiation were not associated with an increased incidence of second tumours and mortality in pituitary adenoma patients.

Incidence, causative mechanisms, and anatomic localization of stroke in pituitary adenoma patients treated with postoperative radiation therapy versus surgery alone

PURPOSE To assess and compare the incidence of stroke and stroke subtype in pituitary adenoma patients treated with postoperative radiation therapy (RT) and surgery alone. METHODS AND MATERIALS A cohort of 462 pituitary adenoma patients treated between 1959 and 2008 at the University Medical Center Groningen in The Netherlands was studied. Radiation therapy was administered in 236 patients. The TOAST (Trial of ORG 10172 in Acute Stroke Treatment) and the Oxfordshire Community Stroke Project classification methods were used to determine causative mechanism and anatomic localization of stroke. Stroke incidences in patients treated with RT were compared with that observed after surgery alone. Risk factors for stroke incidence were studied by log-rank test, without and with stratification for other significant risk factors. In addition, the stroke incidence was compared with the incidence rate in the general Dutch population. RESULTS Thirteen RT patients were diagnosed with stroke, compared with 12 surgery-alone patients. The relative risk (RR) for stroke in patients treated with postoperative RT was not significantly different compared with surgery-alone patients (univariate RR 0.62, 95% confidence interval [CI] 0.28-1.35, P=.23). Stroke risk factors were coronary or peripheral artery disease (univariate and multivariate RR 10.4, 95% CI 4.7-22.8, P<.001) and hypertension (univariate RR 3.9, 95% CI 1.6-9.8, P=.002). There was no difference in TOAST and Oxfordshire classification of stroke. In this pituitary adenoma cohort 25 strokes were observed, compared with 16.91 expected (standard incidence ratio 1.48, 95% CI 1.00-1.96, P=.049). CONCLUSIONS In pituitary adenoma patients, an increased incidence of stroke was observed compared with the general population. However, postoperative RT was not associated with an increased incidence of stroke or differences in causative mechanism or anatomic localization of stroke compared with surgery alone. The primary stroke risk factor was pre-existent coronary or peripheral artery disease.

Brain abnormalities on MRI in non-functioning pituitary adenoma patients treated with or without postoperative radiotherapy

BACKGROUND AND PURPOSE To assess and compare brain abnormalities on Magnetic Resonance Imaging (MRI) in non-functioning pituitary macro-adenoma (NFA) patients treated with or without postoperative radiotherapy (RT). MATERIAL AND METHODS In 86 NFA patients, treated between 1987 and 2008 at the University Medical Center Groningen, white-matter lesions (WMLs), cerebral atrophy, brain infarctions and abnormalities of the temporal lobes and hippocampi were assessed on pre- and post-treatment MRI scans in patients treated with (n=47) or without RT. RESULTS The median MRI follow-up time for RT patients was 10 (range 1-22) years and 5 (range 1-21) years in patients treated without RT. In RT patients the cumulative incidence of WMLs was significantly lower compared to patients treated without RT (log-rank test RR 0.49, 95% CI 0.25-0.97, p=.042). The cumulative incidences of cerebral atrophy, brain infarctions, abnormalities of the temporal lobes and hippocampi, and the severity of WMLs and cerebral atrophy ratings were not significantly different between the two treatment groups. CONCLUSIONS Brain abnormalities on MRI are not observed more frequently in NFA patients treated with RT compared to patients treated with surgery-alone. Furthermore, RT was not associated with an increased severity of WMLs and cerebral atrophy ratings in this cohort of NFA patients.