Abstract Postprandial lipemia test (PPLT) results are predictive of cardiovascular disease risk. However, their reproducibility must be established before they can be clinically useful. Therefore, we ...investigated PPLT reproducibility by testing 9 men and women (body mass index, 20-41 kg/m2 ; age, 21-40 years) on 4 separate occasions (n = 36 PPLTs total) separated by 1 week. Furthermore, because PPLTs are time consuming, we assessed the validity of an abbreviated PPLT. During the PPLT, venous blood was obtained before and every hour for 8 hours after a high-fat meal, which consisted of ice cream and heavy cream (∼800 kcal, 71% fat calories). Total and triglyceride-rich lipoprotein (TRL) triglyceride concentrations were measured in plasma. Total area under the curve (AUC) for total triglycerides was highly reproducible (within-subject coefficient of variation, 8%; intraclass correlation coefficient, 0.82); however, reproducibility was low for total triglyceride incremental AUC and both total and incremental TRL triglyceride AUCs (within-subject coefficients of variation, 20%-31%; intraclass correlation coefficients, 0.28-0.54). Four-hour lipemic responses were highly predictive of 8-hour responses ( R2 = 0.89-0.96, P ≤ .0001). In conclusion, PPLTs are highly reproducible when lipemic responses are determined as the total AUC for total triglycerides. However, large variability in incremental AUC and TRL triglyceride responses may preclude their clinical utility. Furthermore, abbreviated 4-hour PPLTs are a valid surrogate for longer tests and may make PPLTs more feasible in a clinical setting.
Prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) scan is the standard imaging procedure for biochemical recurrent prostate cancer postprostatectomy ...because of its high detection rate at low serum prostate-specific antigen levels. However, existing guidelines for clinical target volume (CTV) in prostate bed salvage external beam radiation therapy (sEBRT) are primarily based on experience-based clinical consensus and have been validated using conventional imaging modalities. Therefore, this study aimed to optimize CTV definition in sEBRT by using PSMA PET/CT-detected local recurrences (LRs).
Patients with suspected LR on PSMA PET/CT postprostatectomy were retrospectively enrolled in 9 Dutch centers. Anonymized scans were centrally reviewed by an expert nuclear medicine physician. Each boundary of the CTV guideline from the Groupe Francophone de Radiothérapie en Urologie (GFRU) was evaluated and adapted to improve the accuracy and coverage of the area at risk of LR (CTV) on PSMA PET/CT. The proposed CTV adaptation was discussed with the radiation oncologists of the participating centers, and final consensus was reached. To assess reproducibility, the participating centers were asked to delineate 3 new cases according to the new PERYTON-CTV, and the submitted contours were evaluated using the Dice similarity coefficient (DSC).
After central review, 93 LRs were identified on 83 PSMA PET/CTs. The proposed CTV definition improved the coverage of PSMA PET/CT-detected LRs from 67% to 96% compared with the GFRU-CTV, while reducing the GFRU-CTV by 25%. The new CTV was highly reproducible, with a mean DSC of 0.82 (range, 0.81-0.83).
This study contributes to the optimization of CTV definition in postprostatectomy sEBRT by using the pattern of LR detected on PSMA PET/CT. The PERYTON-CTV is highly reproducible across the participating centers and ensures coverage of 96% LRs while reducing the GFRU-CTV by 25%.
The PERYTON trial is a multicenter randomized controlled trial that will investigate whether the treatment outcome of salvage external beam radiation therapy (sEBRT) will be improved with ...hypofractionated radiation therapy. A pretrial quality assurance (QA) program was undertaken to ensure protocol compliance within the PERYTON trial and to assess variation in sEBRT treatment protocols between the participating centers.
Completion of the QA program was mandatory for each participating center (N = 8) to start patient inclusion. The pretrial QA program included (1) a questionnaire on the center-specific sEBRT protocol, (2) a delineation exercise of the clinical target volume (CTV) and organs at risk, and (3) a treatment planning exercise. All contours were analyzed using the pairwise dice similarity coefficient (DSC) and the 50th and 95th percentile Hausdorff distance (HD50 and HD95, respectively). The submitted treatment plans were reviewed for protocol compliance.
The results of the questionnaire showed that high-quality, state-of-the-art radiation therapy techniques were used in the participating centers and identified variations of the sEBRT protocols used concerning the position verification and preparation techniques. The submitted CTVs showed significant variation, with a range in volume of 29 cm3 to 167 cm3, a mean pairwise DSC of 0.52, and a mean HD50 and HD95 of 2.3 mm and 24.4 mm, respectively. Only in 1 center the treatment plan required adaptation before meeting all constraints of the PERYTON protocol.
The pretrial QA of the PERYTON trial demonstrated that high-quality, but variable, radiation techniques were used in the 8 participating centers. The treatment planning exercise confirmed that the dose constraints of the PERYTON protocol were feasible for all participating centers. The observed variation in CTV delineation led to agreement on a new (image-based) delineation guideline to be used by all participating centers within the PERYTON trial.
Bisphosphonates are the treatment of choice of Paget's disease of bone. For optimal patient care determinants of the induction and duration of remission of the disease after bisphosphonate therapy ...must be defined. We addressed these issues in a longitudinal study of 157 patients with biochemically active disease (serum alkaline phosphatase activity >120 U/L) treated with the bisphosphonate olpadronate and followed for a median period of 37 months (range 3–162, mean 46 ± 30). Two different total doses of olpadronate were used: an effective dose (40 mg intravenously given over 5 or 10 consecutive days) and a high dose consisting of the effective dose followed by oral olpadronate 200 mg/day for 15 days. Treatment induced biochemical remission, defined as normalization of serum alkaline phosphatase activity, in 89.2% of the patients. There were no differences between the two treatment regimens. The only independent determinants of induction of remission were baseline serum alkaline phosphatase activity and number of affected bones. In contrast, duration of remission depended on the dose of olpadronate given (high versus effective dose, RR of relapse 0.49, 95% CI 0.27–0.89). Additional independent determinants of relapse were nadir value of serum alkaline phosphatase activity after treatment, number of previous therapies, and number of affected bones. Pain scores decreased with therapy in 88% of patients with pain complaints. Pain scores were significantly related to the probability of relapse (RR1.54, 95% CI 1.04–2.27). In this long-term study of a large cohort of patients with Paget's disease we confirmed the efficacy of olpadronate therapy. In addition, we identified and quantified determinants of the response to bisphosphonate that can help in improving the management of patients with Paget's disease with bisphosphonates.
Samenvatting
Deze studie onderzocht het patroon van lokaal recidief (LR) na prostatectomie met behulp van prostaatspecifieke membraanantigeen (PSMA) positronemissietomografie/computertomografie ...(PET/CT)-scans. In totaal werden retrospectief 103 PSMA PET/CT-scans verzameld van patiënten met verdenking op LR in negen behandelcentra. Een ervaren nucleaire geneeskundige beoordeelde de geanonimiseerde scans opnieuw en identificeerde op 83 PSMA PET/CT-scans 93 laesies als verdacht voor LR. De meest voorkomende locatie van LR (56%) was binnen 2 cm craniaal van de bulbus. Daarnaast werden 24 LR (26%) waargenomen > 2 cm craniaal van de bulbus en caudaal van de top van de symfyse. Slechts 17 LR (18%) werden craniaal van de symfyse gezien. Deze bevindingen dragen bij aan de kennis van het patroon van LR na prostatectomie en kunnen in de toekomst leiden tot gerichtere bestraling van de prostaatloge.
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