Effect of androgen deprivation therapy on intraprostatic tumour volume identified on 18F choline PET/CT for prostate dose painting radiotherapy.

OBJECTIVE: Prostate dose painting radiotherapy requires the accurate identification of dominant intraprostatic lesions (DILs) to be used as boost volumes; these can be identified on multiparametric MRI (mpMRI) or choline positron emission tomography (PET)/CT. Planning scans are usually performed after 2-3 months of androgen deprivation therapy (ADT). We examine the effect of ADT on choline tracer uptake and boost volumes identified on choline PET/CT. METHODS: Fluoroethylcholine (18F choline) PET/CT was performed for dose painting radiotherapy planning in patients with intermediate- to high-risk prostate cancer. Initially, they were performed at planning. Owing to low visual tracer uptake, PET/CT for subsequent patients was performed at staging. We compared these two approaches on intraprostatic lesions obtained on PET using both visual and automatic threshold methods [prostate maximum standardized uptake value (SUVmax) 60%] when compared with mpMRI. RESULTS: PET/CT was performed during ADT in 11 patients (median duration of 85 days) and before ADT in 29 patients. ADT significantly reduced overall prostate volume by 17%. During ADT, prostate SUVmax was lower although it did not reach statistical significance (4.2 vs 6.6, p = 0.06); three patients had no visually identifiable PET DIL; and visually defined PET DILs were significantly smaller than corresponding mpMRI DILs (p = 0.03). However, all patients scanned before ADT had at least one visually identifiable PET DIL, with no significant size difference between MRI and visually defined PET DILs. In both groups, threshold PET produced larger DILs than visual PET. Both PET methods have moderate sensitivity (0.50-0.68) and high specificity (0.85-0.98) for identifying MRI-defined disease. CONCLUSION: For visual contouring of boost volumes in prostate dose painting radiotherapy, 18F choline PET/CT should be performed before ADT. For threshold contouring of boost volumes using our PET/CT scanning protocol, threshold levels of above 60% prostate SUVmax may be more suitable. Additional use of PET with MRI for radiotherapy planning can significantly change the overall boost volumes compared with using MRI alone. Advances in knowledge: For prostate dose painting radiotherapy, the additional use of 18F choline PET with MRI can significantly change the overall boost volumes, and PET should be performed before hormone therapy, especially if boost volumes are visually identified.

Angiographic progression of coronary atherosclerosis in patients with familial hypercholesterolaemia treated with non-statin therapy: Impact of a fat-modified diet and a resin.

BACKGROUND AND AIMS: Familial hypercholesterolaemia (FH) profoundly increases the risk of coronary artery disease (CAD). We investigated whether diet and a bile-acid sequestrant decrease coronary atherosclerosis in patients with FH. METHODS: We identified 26 men with FH and CAD, participating in the St Thomas' Atherosclerosis Regression Study, who had been randomized to receive a fat-modified diet plus cholestyramine (8 g twice daily) (DC, n = 12) or usual care (UC, n = 14), and investigated the relative effects of these treatments on the angiographic progression of coronary atherosclerosis over 39 months. FH was defined as probable/definite according to Dutch Lipid Clinic Network criteria; mean FH score was 8.7 (range 6-15) and mean baseline low-density lipoprotein cholesterol (LDL-Ch) concentration was 5.4 (SD 1.4) mmol/L. Coronary atherosclerosis was assessed by serial quantitative angiography as the global changes in mean and minimum absolute width of segments (MAWS and MinAWS, respectively). RESULTS: Mean plasma LDL-Ch concentration fell by 35% with DC and remained significantly (p < 0.001) lower during the trial at 3.78 (SD 0.98) mmol/L compared with UC at 4.89 (1.04). MAWS decreased by 0.252 (SEM 0.072) mm in the UC group and by 0.001 (0.065) mm in the DC group (p = 0.007), with corresponding reductions in MinAWS of 0.290 (0.087) mm and 0.013 (0.058) mm (p = 0.009); these changes were significant after adjusting for baseline variables, including coronary luminal dimensions and lipoprotein(a). Progression was observed in 7 patients (50%) on UC and 3 (25%) on DC (p = 0.19), with regression in no patients (0%) and 3 patients (25%) (p < 0.05), respectively. CONCLUSIONS: This investigation, carried out in the pre-statin era, demonstrates that a prudent diet and cholestyramine could improve the course of coronary atherosclerosis in men with phenotypic FH through sustained reductions in LDL-Ch.

Volumetric modulated arc therapy in prostate cancer patients with metallic hip prostheses in a UK centre.

AIM: This study aimed to investigate whether IMRT using VMAT is a viable and safe solution in dose escalated RT in these patients. BACKGROUND: An increasing number of prostate cancer patients are elderly and have hip prostheses. These implants pose challenges in radiotherapy treatment planning. Although intensity modulated radiotherapy (IMRT) is commonly used, there is a lack of clinical studies documenting its efficacy and toxicities in this subgroup of patients. MATERIALS AND METHODS: The data from 23 patients with hip prostheses and non-metastatic prostate cancer treated with VMAT (volumetric modulated arc therapy) between 2009 and 2011, were retrospectively analyzed. Baseline characteristics, treatment details and outcome data were collected on all patients. The median follow up was 40.9 months. MRI-CT image fusion was performed and the treatment plans were created using RapidArc™ (RA) techniques utilizing 1 or 2 arcs and 10 MV photon beams. RESULTS: 96% of patients were treated with a dose of 72 Gy/32 fractions over 44 days. 21/23 plans met the PTV targets. The mean homogeneity index was 1.07. 20/23 plans met all OAR constraints (rectum, bladder). Two plans deviated from rectal constraints, four from bladder constraints; all were classed as minor deviations. One patient experienced late grade 3 genitourinary toxicity. Three other patients experienced late grade 2 or lower gastrointestinal toxicity. One patient had biochemical failure and one had a non-prostate cancer related death. CONCLUSIONS: VMAT provides an elegant solution to deliver dose escalated RT in patients with unilateral and bilateral hip replacements with minimal acute and late toxicities.

Cytogenetic and molecular characterization of complex three-way translocations in acute promyelocytic leukemia.

The most frequent chromosomal rearrangement reported in acute promyelocytic leukemia (APL) is t(15; 17) (q22; q21). The t(15; 17) generates the PML/RARA fusion gene that blocks the transcription of genes involved in myeloid cell differentiation. A small number of simple and complex variants of the classical t(15; 17) have been reported. We report two complex three-way translocation variants, t(3; 17; 15) (q27; q21; q22) and t(8; 17; 15) (q24.3; q12; q22) in which the PML/RARA fusion gene has been created on the derivative 15 chromosomes. Many of these variant translocations are suspected by conventional cytogenetics but need to be confirmed with additional molecular testing. We discuss the importance of supplementing conventional cytogenetic testing with FISH and RT-PCR to accurately diagnose APL variant patients.