SU-E-T-562: Reducing the Arc Span for CSA VMAT Delivery

PURPOSE

To dosimetrically evaluate advantages and disadvantages of using multiple, shorter, sub-arcs versus full arc deliveries for treatment of cranio-spinal axis (CSA) irradiation.

METHODS

Five (n=5) cranio-spinal axis irradiation patients were planned using 2 complete arcs, one superior and one inferior; with gantry rotations from 1 to 359 degrees. Due to supine patient setup, each original full arc was then replanned split into two sub arcs with gantry rotations from 1 to 100 and 260 to 359 degrees creating 4 smaller arcs. The PTV was normalized such that 95% received at least 23.4 Gy in 13 fractions. The PTV was evaluated based on conformity number and homogeneity index. The normal structures were evaluated based on maximum and mean doses. Beam on times and monitor units were compared.

RESULTS

Averaged over all patients, conformity number was calculated to be approximately 0.86 and 0.82 for full arc and sub arc plans respectively. The homogeneity index was approximately 1.07 and 1.06 for full arc and sub arc plans. This indicates better target conformity but less homogeneous dose distribution for full arc plans as compared with sub arc plans. With the exception of the eyes, each normal structure evaluated had lower maximum doses with subarc plans. All normal structures, with the exception of the left kidney, had lower mean doses using sub arc deliveries. Beam on times were shorter on average for full arcs, but the monitor units were lower on average for sub arcs.

CONCLUSIONS

Overall, CSA patients would benefit from the use of sub arc treatment deliveries versus full arc deliveries. Nearly all normal structure doses were lower for sub arcs, while the PTV was still adequately covered and beam on times and monitor units were similar.

WE-G-BRCD-05: Evaluation of Localization Errors for CSA Delivery Using VMAT

PURPOSE

To dosimetrically evaluate the effects of improper patient positioning in the junction area of a VMAT cranio-spinal axis irradiation technique consisting of one superior and one inferior arc.

METHODS

Five (n=5) cranio-spinal axis irradiation patients were planned with 2 arcs: one superior and one inferior. The plans were then recalculated with inferior isocenter shifted, in order to mimic patient setup errors, eight times: lmm, 2mm, 5mm, and 10mm superiorly, and 1mm, 2mm, 5mm, and 10mm inferiorly. Plans were then compared to the original, non-shifted arc plan based on target metrics of conformity number and homogeneity index, as well as several normal structure mean doses.

RESULTS

Percent differences were calculated in order to compare each of the eight shifted plans to the original arc plan without shifts, which would be the ideal setup of patient without error. The conformity number was on average 0.87%, 2.74%, 5.75%, and 9.10% lower for the 1mm, 2mm, 5mm, and 10mm inferiorly- shifted plans and 0.41%, 0.82%, 2.75%, and 5.99% lower for the respective superiorly-shifted plans. The homogeneity indices were, averaged among the five patients, 0.03%, 0.26%, 0.97%, and 2.84% for the inferior shifts and 0.23%, 1.17%, 6.31%, and 15.29% worse, or less homogenous for the superior shifts. Overall the mean doses to the organs at risk were less than 2% different for the 1mm, 2mm, and 5mm shifted plans. The 10mm shifted plans, however, showed percent differences from original plan of up to 5.6% on average.

CONCLUSIONS

Setup errors when shifting isocenters should be minimized in order to provide the patient with the best treatment possible. Errors of 1 to 2mm can negatively affect patient treatment, most notably in the arc junction area, but are not as problematic as larger errors of 5 to 10mm.

Use of complementary and alternative medicine in recurrent vulvovaginal candidiasis--results of a practitioner survey

BACKGROUND

The mainstream long term management of recurrent vulvovaginal candidiasis (RVVC) often results in poor outcomes. It is expensive and unacceptable for many women who therefore have incorporated complementary and alternative medicine (CAM) into their personal care plan.

OBJECTIVE

To ascertain clinicians' knowledge of CAM and their recommendations for the use of CAM and non-pharmacological management in women with RVVC.

DESIGN AND SETTING

Anonymous, single page, self completed survey using convenience sampling at a vulval disorders meeting in New South Wales, Australia in 2009.

PARTICIPANTS

Sixty six health professionals (medical practitioners, dermatologists, nurses and allied health professionals).

RESULTS

Most clinicians reported asking about their patients' use of CAM and non-pharmacological management of RVVC, although only around half reported recommending it. CAM management included lactobacillus, oral and vaginal yoghurt, vinegar, garlic, Chinese medicine and tea-tree oil. Non-pharmacological management included dietary changes and use of cotton undergarments. Lactobacillus was the most commonly recommended CAM.

CONCLUSION

CAM is popular with patients and many clinicians actively recommend its use in RVVC despite limited supporting evidence. Further research in the area of CAM and RVVC is long overdue.

Pericardial synovial sarcoma of the heart; is it always worth operating?

Synovial sarcoma is a rare malignant soft-tissue tumor that most commonly occurs in the extremities of young adults. Primary pericardial synovial sarcoma is extremely rare. We report the case of a 37 year old male patient who presented with intermittent fever, nocturnal sweating and asthenia. Chest X-ray revealed an enlarged cardiac silhouette. Echocardiography identified pericardial effusion and a mass compressing the right ventricle. After percutaneous drainage of the effusion, the mass was not visible and deemed to have been septations of the effusion. Chest computed tomography (CT) did not show the mass visible on the X-ray. At one month follow-up, the pericardial mass was again visible on echocardiography and confirmed by magnetic resonance imaging (MRI). CT-guided biopsy showed malignant mesenchymal cells. Complete resection was attempted, but not possible due to diffuse infiltration of the epicardium. Histological examination of the resected tissue revealed an undifferentiated primary pericardial synovial sarcoma. The patient refused adjuvant treatment and died 15 days later. Surgical resection is considered the cornerstone of treatment of this rare type of malignant tumor of the young; our patient presented with a diffusely infiltrating tumor which could not be resected and required reoperation for tamponade and left pericardectomy. We question whether the choice to attempt resection was beneficial.

Novel approach to mitral valve repair in childhood dilated cardiomyopathy

Evidence is mounting that mitral valve repair can improve symptoms in adults with dilated cardiomyopathy. Data is currently lacking for children with dilated cardiomyopathy and options for annuloplasty are limited in children. We report on the successful management of a 21 month-old child in heart failure from dilated cardiomyopathy and severe mitral regurgitation. The echocardiogram showed severely dilated left heart cavities, severe mitral regurgitation from a dilated annulus (23 mm, Z-score 1.74) with discrete anterior leaflet tethering, and moderate systolic dysfunction. The mitral valve was repaired using a 16 mm Bioring Kalangos biodegradable annuloplasty ring. The patient was extubated on the third postoperative hour and discharged on the fifth postoperative day with trivial mitral regurgitation and a 5 mmHg mean transvalvular gradient. At 12 months, the patient is in NYHA class I and presents trivial central mitral regurgitation without any transmitral gradient. This represents the first report in successfully managing a child with dilated cardiomyopathy with mitral regurgitation using a novel biodegradable annuloplasty ring, which has the potential to durably remodel the mitral annulus and grow with the patient.

A microfabricated graphitic carbon column for high performance liquid chromatography

We report the first development of a novel, planar, microfluidic, graphitic carbon separations column utilizing an array of graphitic micropillars of diamond cross-section as the chromatographic stationary phase. 795 nm femtosecond laser ablation was employed to subtractively machine fluidic architectures and a micropillared array in a planar, graphitic substrate as a monolithic structure. A sample injector was integrated on-chip, together with fluid-flow distribution architectures to minimize band-broadening and ensure sample equi-distribution across the micro-pillared column width. The separations chip was interfaced directly to the ESI probe of a Thermofisher Surveyor mass spectrometer, enabling the detection of test-mixture analytes following their differential retention on the micro-pillared graphitic column, thus demonstrating the exciting potential of this novel separations format. Importantly, unlike porous, graphitic microspheres, the temperature and pressure resilience of the microfluidic device potentially enables use in subcritical H(2)O chromatography.

Repair of radial tears and posterior horn detachments of the lateral meniscus: minimum 2-year follow-up

PURPOSE

The aim of this study was to show that repair of posterior radial tears and horn detachments of the lateral meniscus is possible and to assess the outcomes.

METHODS

A retrospective review of 24 patients who had repair of a posterior defunctioning tear of the lateral meniscus combined with anterior cruciate ligament reconstruction was undertaken. Patients completed a follow-up postal questionnaire that included Lysholm, subjective International Knee Documentation Committee (IKDC), and Tegner scoring systems.

RESULTS

Eight patients had suture repair of a lateral meniscal radial tear. The mean Lysholm, IKDC, and Tegner scores were 86.9 (SD, 11.6), 81.6 (SD, 13.9), and 5.8 (SD, 2.7), respectively, at a mean follow-up of 70.5 months (range, 29.0 to 168.0 months). Subsequent arthroscopy in 2 patients confirmed meniscal healing. Sixteen patients underwent a posterior horn reattachment. The mean Lysholm, subjective IKDC, and Tegner scores were 86.1 (SD, 13.3), 84.3 (SD, 17.0), and 6.5 (SD, 2.1), respectively, at a mean follow-up of 53.6 months (range, 26.0 to 116.0 months). Three patients had subsequent magnetic resonance imaging and/or arthroscopy that indicated meniscal healing. Two further patients had reinjury, and magnetic resonance imaging and/or arthroscopy showed that their repairs had failed.

CONCLUSIONS

Posterior radial tears that extend to the capsule and posterior horn detachments of the lateral meniscus are frequently amenable to repair. In this study 22 of 24 repairs functioned successfully over a mean follow-up of 58.6 months (range, 26.0 to 168.0 months).

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Porous silica spheres in macroporous structures and on nanofibres

Porous nanospheres have a wide range of applications such as in catalysis, separation and controlled delivery. Among these nanospheres, syntheses and applications of porous silica nanospheres have been investigated extensively. Uniform porous silica nanospheres can be synthesized using a modified Stöber method. In the present study, porous silica spheres were prepared in the pre-formed emulsion-templated porous polyacrylamide (PAM). A hierarchical hybrid structure of mesoporous silica spheres was formed in the highly interconnected macroporous polymer. The polymer scaffold could be removed by calcination with porous silica spheres and the macroporous structures retained. This resulted from the close packing or aggregation of small silica nanospheres in the pores and on the surface of pores of PAM. The modified Stöber synthesis was further carried out in pre-formed polymer nanofibres (chitosan and sodium carboxymethyl cellulose). The structure of porous silica spheres on nanofibres was produced in the presence of the polymer or composite fibres. The corresponding inorganic structures were successfully obtained after calcination. The hierarchical structures of porous nanospheres within macroporous structures or on nanofibres are of potential interest to researchers in nanomaterials, porous polymers, supported catalysis and controlled delivery.