The clinical efficacy of PSMA PET/MRI in biochemically recurrent prostate cancer compared with standard of care imaging modalities and confirmatory histopathology: results of a single-centre, prospective clinical trial.

Prospective evidence for the clinical role and efficacy of prostate specific membrane antigen (PSMA) positron emission tomography (PET)/magnetic resonance imaging (MRI) combining MRI characterization and localization of lesions with PET avidity in comparison to conventional imaging is limited. In a prospective clinical trial, we aimed to evaluate the diagnostic yield and therapeutic impact of PSMA PET/MRI in men with biochemical recurrence (BCR) following curative therapy. A single-centre, prospective clinical trial at the Princess Alexandra Hospital recruited 30 patients with BCR. Patients underwent PSMA PET/MRI and concurrent conventional CT chest, abdomen, pelvis and whole-body bone scan. Biopsy was performed when safety possible for histological correlation of identified lesions. Clinical efficacy and impact of PSMA PET findings were evaluated. 30 patients with BCR were recruited (median PSA 0.69 ng/ml). PSMA avid lesions were present in 21 patients (70%). 23 patients were previously treated with definitive surgery, 6 patients received external beam radiotherapy and 1 patient had low dose rate brachytherapy. A total of 8 of 9 lesions biopsied were positive (88.9% histological correlation). PSMA PET/MRI detected local recurrence (p = 0.005) and pelvic lesions (p = 0.06) more accurately than conventional imaging. PSMA PET/MRI may be useful in staging men with biochemical recurrence, especially when PSA is low. Our data demonstrates a high detection rate, especially for locally recurrent disease, and highlights the role of this modality when PSA is low. This modality has the potential to significantly improve prostate cancer detection and may have implications for earlier salvage treatment, avoidance of futile local therapy and change patient management to lead to improved outcomes.

Dermatofibrosarcoma protuberans, magnetic resonance imaging and pathological correlation.

Dermatofibrosarcoma protuberans (DFSP) is a rare slow-growing soft tissue tumour which characteristically occurs on the chest, head and neck regions. Typical histologic features include monomorphous spindle-shaped cells arranged in a storiform pattern on a background of fibrous stroma. The tumour has a propensity for local invasion and high recurrence rate. While the imaging features are not pathognomonic of the tumour, the characteristic location and shape should prompt inclusion in the differential diagnostic list.

New radiological typing system for rhinosinusitis and comparison with existing system: initial finding.

The objective of this study was to determine whether the proposed Malan radiological sinusitis typing (RST) system facilitated a level of agreement and ease of use comparable with the Lund-Mackay (LM) system for chronic rhinosinusitis. Ten observers (one otolaryngologist and nine radiologists), in two separate centres (regional and tertiary), blinded to all clinical data, used these two systems to independently and randomly score and type 15 sets of scans, recording the time to score each film. Using unweighted kappa scores, both methods facilitated a moderate level of agreement, slightly better with the LM system. The Malan system is more time efficient. Preliminarily, this study shows that the Malan RST system is easy to apply with a comparable level of agreement. The Malan RST system is a focused attempt at classifying disease extent radiologically and correlating it to a surgical approach. It emphasizes that scoring systems are vulnerable and proves to be superior to the LM system as a surgical planning tool. To score sinus disease, a Quality-of-Life questionnaire in association with this typing method is more appropriate.

Coaxial cutting needle biopsies: how important is it to rotate the cutting needle between passes?

AIM: To use an in-vitro model to measure the effect of turning the notch of the cutting needle between passes on the mass of core biopsy material obtained from a typical coaxial biopsy system when multiple passes are performed. METHODS: A coaxial guide needle was placed within tissue-equivalent agar cylinders and a cutting biopsy needle was used to take core biopsies. Two, three, or four sequential biopsies were performed on the same cylinder with the notch of the cutting needle either inserted facing in the same direction (no rotation) or placed in a sequence of different directions (rotation). The mass of the tissue core obtained at each biopsy pass was measured. A post hoc telephone questionnaire of radiologists across Australia was also undertaken to analyse current practice in the context of these results. RESULTS: There were statistically significant increases in the mass of tissue obtained using rotation compared with no rotation. Using rotation, the total mass of tissue obtained from three passes was increased by 32.8% (95% CI 23.9-41.7%) and from four passes was increased by 45% (95% CI 37.2-52.9%). The mass of the second pass cores was statistically significantly greater (p<0.001). Fifty-nine percent of Australian radiologists surveyed do not currently change the rotation of the biopsy needle between passes. CONCLUSION: This in-vitro model confirms that the notch of the cutting needle should be placed into different directions at each pass whenever a coaxial cutting biopsy system is being used to maximize the mass of tissue obtained.

CT-guided procedures: evaluation of a phantom system to teach accurate needle placement.

AIM: To evaluate the use of a phantom system to help teach the basic techniques of accurate CT-guided needle placement, thereby avoiding the risks associated with teaching on patients. MATERIALS AND METHODS: Gelatine phantoms with five, 1.9 cm embedded spherical wooden targets were constructed. Four trainee operators performed 15 simulated biopsy procedures on the targets (series one) and repeated identical procedures 2 weeks later (series two). Statistical analysis of accuracy of needle placement and subject confidence were performed. RESULTS: Significant sequential improvement in axial plane angular error was noted with the average error decreasing by 0.33 degrees after every five procedures performed (95% CI: -0.58 to -0.08, p=0.01). Operator confidence indicated significant improvement both within each series and from series one to series two (95% CI: 0.08 to 1.17, p=0.025 and 95% CI: 0.00 to 0.58, p=0.05) respectively. However, variability in operator performance made statistically significant improvement in other variables unproven. CONCLUSION: Despite the study comprising a relatively small number of participants and procedures, it clearly demonstrated the effectiveness of teaching operators to perform CT-guided procedures using a phantom system. Needle placement accuracy significantly improved, with a reduction in axial angular error, and improved operator confidence without the risks associated with training on patients. Three of the operators in this study had never performed a CT-guided procedure previously, and their proficiency, after a relatively short but intense period of training, was impressive. The use of phantoms should be considered routinely for basic training of CT-guided needle placement.

The imaginary line method is not reliable for identification of prosthetic heart valves on AP chest radiographs.

OBJECTIVE: To examine the utility of four criteria for distinguishing aortic from mitral valve prostheses on supine anteroposterior (AP) chest x rays in critically ill patients. MATERIALS AND METHODS: Two reviewers independently examined the post operative chest X-rays (CXR) of all patients undergoing either an aortic or mitral valve replacement over a 32 month period, in a blinded fashion. They applied four criteria to each film. For each criterion a sensitivity and specificity of differentiating the valve positions correctly was calculated for each reviewer, as well as a kappa statistic for inter-observer agreement between the two reviewers. RESULTS: Two hundred and twenty seven CXR's were evaluated by each of the reviewers. There were 174 aortic and 53 mitral valve replacements. There was a high level of inter-observer agreement for all four criteria applied (kappa values 0.785 to 0.966). Criterion one (imaginary line method) could be applied by both reviewers to less than 50% of CXR's, and when applied was specific but not sensitive. The other three criteria could be applied by both reviewers to approximately 80% of films. Criterion 2 (orientation method) was sensitive but not specific. Criteria 3 (valve orifice method) and 4 (perceived direction of blood flow method) were both highly sensitive and specific and are therefore the best methods. CONCLUSIONS: The well known imaginary line method is of limited value when identifying prosthetic valve positions on supine AP CXR's. We advocate the use of the "valve orifice" method or the "perceived direction of blood flow" method to gain valuable information regarding the presence and position of prosthetic heart valves.

Percutaneous coaxial needle biopsy using the spacer technique: a novel and easy modification to increase procedure safety.

We describe a novel but easy modification to percutaneous coaxial needle biopsy technique using readily available standard equipment to enable a predefined variable sampling length to be achieved. This technique involves the insertion of a carefully measured spacer between the coaxial cutting needle and guide needle. This can minimise the sampling length required to biopsy any given lesion, minimising the volume of traumatised tissue and preventing unnecessary penetration of tissues deep to smaller lesions, thus increasing procedure safety.

Effect of a full and empty bladder on radiation dose to the uterus, ovaries and bladder from lumbar spine CT and X-ray examinations.

This is a quantitative study of the effect of a full and empty bladder on the position of the uterus, ovaries and bladder relative to the lumbar spine. Data are used to estimate the difference in radiation dose to these organs from performing a lumbar spine CT investigation or a lateral lumbar spine radiograph with a full bladder compared with an empty bladder. 12 women of child-bearing age underwent pelvic magnetic resonance scans with full and empty bladders. The positions of the uterus, ovaries and bladder were matched with the radiation dose distribution that would have occurred either side of the inferior boundary of the CT scan volume and the lateral lumbar spine radiograph. These radiation dose profiles were measured on phantoms using a combination of ionization chambers and thermoluminescent dosemeters. When the bladder was emptied, the mean position of the endometrial cavity fundal tip moved from 4.1 cm to 6.1 cm inferior to the centre of the L5/S1 disc space, and from 0.87 cm to 1.12 cm anterior to the centre of the L5/S1 disc space. This movement on micturation would have reduced the mean dose to the uterine internal fundal tip during a pelvic CT scan from 6.8 mGy to 3.9 mGy, which represents a mean reduction of 43% (range 12-67%). The mean dose from a lateral lumbar spine examination would have been reduced from 197 microGy to 126 microGy. The change in ovary position results in the mean ovary dose being reduced by 48% for the lumbar spine CT scan and by 43%) for a lateral lumbar spine radiograph. When the bladder was emptied, the average position of the bladder wall moved from 7.2 cm to 10.3 cm inferior to the L5/S1 disc space. This change in bladder position reduces the mean dose to the wall of a full bladder from 5.7 mGy for a CT scan and 114 microGy for a lumbar spine radiograph to 2.2 mGy and 42 microGy, respectively, for an empty bladder.

Expression of intercellular adhesion molecule-1 in atherosclerotic plaques.

Immunohistochemistry of human atherosclerotic arteries demonstrates expression of the intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, macrophages, and smooth muscle cells of the plaques. Normal arterial endothelial cells and intimal smooth muscle outside plaques give weaker or negative reactions; these differ from the strong endothelial expression in small vessels. Quantitative color-image analysis of the endothelial layer shows increased expression of ICAM-1 in all subtypes of atherosclerotic lesions, except fibrous plaques. Endothelial expression of ICAM-1 may be involved in the recruitment of monocytes to the lesion, as suggested by its role in the entry of leukocytes, including monocytes, into foci of inflammation. Collaboration with other mechanisms, particularly chemoattractant factors, may be important for this effect. ICAM-1 enhanced monocyte recruitment is a potential mechanism for the growth of an atherosclerotic plaque.