Clinical implementation of the first Cherenkov imaging system in a community-based hospital.

Purpose: To document experiences with one year of clinical implementation of the first Cherenkov imaging system and share the methods that we developed to utilize Cherenkov imaging to improve treatment delivery accuracy in real-time. Methods: A Cherenkov imaging system was installed commissioned and calibrated for clinical use. The optimal room lighting conditions and imaging setup protocols were developed to optimize both image quality and patient experience. The Cherenkov images were analyzed for treatment setup and beam delivery verification. Results: We have successfully implemented a clinical Cherenkov imaging system in a community-based hospital. Several radiation therapy patient setup anomalies were found in 1) exit dose to the contralateral breast, 2) dose to the chin due to head rotation for a supraclavicular field, 3) intrafractional patient motion during beam delivery, and 4) large variability (0.5 cm to 5 cm) in arm position between fractions. The system was used to deliver deep inspiration breath hold (DIBH) treatment delivery of an electron treatment beam. Clinical process and procedures were improved to mitigate the identified issues to ensure treatment delivery safety and to improve treatment accuracy. Conclusion: The Cherenkov imaging system has proven to be a valuable clinical tool for the improvement of treatment delivery safety and accuracy at our hospital. With only minimal training the therapists were able to adjust or correct treatment positions during treatment delivery as needed. With future Cherenkov software developments Cherenkov imaging systems could provide daily surface guided radiotherapy (SGRT) and real time treatment delivery quality control for all 3D and clinical setup patients without adding additional radiation image dose as in standard kV, MV and CBCT image verifications. Cherenkov imaging can greatly improve clinical efficiency and accuracy, making real time dose delivery consistency verification and SGRT a reality.

Pathologic comparison of asymmetric or sulcus fixation of 3-piece intraocular lenses with square versus round anterior optic edges.

OBJECTIVE: To evaluate the pathologic findings of 3-piece intraocular lenses (IOLs) with asymmetric or sulcus fixation in pseudophakic cadaver eyes, comparing IOLs with square or round edges on the anterior optic surface. DESIGN: Comparative case series with pathology. PARTICIPANTS: A total of 661 pseudophakic cadaver eyes, obtained from eye banks within the United States, implanted with different IOLs. METHODS: Anterior segment scanning of whole eyes with a high-frequency ultrasound system or high-resolution anterior segment magnetic resonance imaging followed by gross examination. Selected eyes were processed for complete histopathologic analysis. MAIN OUTCOME MEASURES: Findings from imaging, gross, and histopathologic evaluation that could be related to out-of-the-bag fixation of the lenses. RESULTS: Of 661 pseudophakic cadaver eyes obtained, 13 had 3-piece hydrophobic acrylic IOLs with anterior and posterior square optic edges, and 14 had 3-piece lenses with anterior round edges (13 silicone lenses and 1 hydrophobic acrylic lens) without symmetric in-the-bag fixation. These 27 selected eyes were processed for complete histopathologic analysis. Gross findings in both groups were composed of IOL decentration and tilt, pigmentary dispersion within the anterior segment and on the IOL surface, and iris transillumination defects. Histopathology of the 14 eyes with 3-piece IOLs with round anterior optic edges showed mild focal disruption of the iris pigmented layer and loop protrusion/erosion in the ciliary sulcus. Additional changes observed in the 13 eyes with square anterior optic edge IOLs included iris changes, such as vacuolization, disruption and loss of the pigmented epithelial layers, iris thinning and atrophy, synechiae, and pigmentary dispersion within the trabecular meshwork. One eye also exhibited initial signs of optic nerve disc cupping. CONCLUSIONS: In this series, pathologic findings were more severe in eyes implanted with 3-piece IOLs with square anterior optic edges, suggesting that IOLs with round anterior edges are more suitable for sulcus fixation. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Light scattering and light transmittance in intraocular lenses explanted because of optic opacification.

PURPOSE: To assess light scattering and light transmittance in intraocular lenses (IOLs) explanted because of optic opacification. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Poly(methyl methacrylate) (PMMA) IOLs with snowflake degeneration, hydrophilic acrylic IOLs with different calcification patterns, and 1 calcified silicone IOL explanted from an eye with asteroid hyalosis were studied with gross and light microscopy. Light scattering was measured with an EAS-1000 Scheimpflug camera. Light transmittance was measured with a Lambda 35 UV/Vis spectrophotometer (single-beam configuration with RSA-PE-20 integrating sphere). Analyses were performed at room temperature in the hydrated state and compared with controls. RESULTS: The study evaluated 8 PMMA IOLs, 22 hydrophilic acrylic IOLs, and 1 silicone IOL. Light scattering was as follows: 208 to 223 computer-compatible tapes (CCTs) for PMMA IOLs with snowflake degeneration (control = 9 CCTs); 90 to 227 CCTs for calcified hydrophilic acrylic IOLs (controls = 12 to 23 CCTs); 223 CCTs for the calcified silicone IOL (control = 5 CCTs). The mean light transmittance in the visible light spectrum was 81.08% to 97.10% for PMMA IOLs (control = 98.80%); 78.94% to 97.32% for hydrophilic acrylic IOLs (controls = 97.32% to 98.66%); 94.68% for the silicone IOL (control = 97.74%). CONCLUSION: Intraocular lens opacification led to very high levels of light scattering and a potential for decreased light transmittance, which play a role in the development of symptoms such as glare and halos, decreased contrast sensitivity, and eventually decreased visual acuity. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Prevention of capsular bag opacification with a modified hydrophilic acrylic disk-shaped intraocular lens.

PURPOSE: To evaluate the stability and capsular bag opacification with a modified disk-shaped 1-piece hydrophilic acrylic intraocular lens (IOL) suspended between 2 complete haptic rings connected by a pillar of the haptic material and with a commercially available 1-piece hydrophilic acrylic IOL. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Study and control IOLs were implanted into the left eyes and right eyes of 5 New Zealand rabbits. Eyes were examined at the slitlamp from 1 through 4 weeks. At 4 weeks, the globes were enucleated and evaluated under a very-high-frequency ultrasound. Photographs were taken and capsular bag opacification scored from the posterior aspect (Miyake-Apple view), and the eyes were processed for complete histopathology. RESULTS: At 4 weeks, the posterior capsule opacification score was 0.0 in the study group and 1.75 ± 0.5 (SD) in the control group (P=.005, paired t test). Ultrasound examination showed that 2 of the study IOLs had no contact between the posterior optic surface and the posterior capsule. Minimal proliferative cortical material was confined to the peripheral space between anterior and posterior rings of the study IOL haptics in localized areas at the equatorial region of the capsular bag. Anterior capsule opacification was absent in all eyes. CONCLUSIONS: The study IOL is a modification of a previous design, incorporating haptic perforations between the peripheral rings. By maintaining an open capsular bag and enhancing endocapsular inflow of aqueous, this modified design appears to prevent capsular bag opacification.

Anterior segment optical coherence tomography in the assessment of postoperative intraocular lens optic changes.

PURPOSE: To evaluate the use of anterior segment optical coherence tomography (AS-OCT) to assess postoperative intraocular lens (IOL) optic changes. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Intraocular lenses explanted because of various complications were used, including poly(methyl methacrylate) (PMMA) IOLs with snowflake degeneration, hydrophilic acrylic IOLs with calcification, a silicone IOL with calcification from an eye with asteroid hyalosis, and hydrophobic acrylic IOLs explanted because of decentration, subluxation, or uveitis-glaucoma-hyphema syndrome. After gross and light microscopy, the IOLs were examined in the dry and hydrated states using AS-OCT. Selected hydrophilic acrylic IOLs were stained for calcium. In-the-bag IOLs in pseudophakic cadaver eyes were also evaluated by AS-OCT before and after explantation to confirm correspondence with the clinical situation. RESULTS: Intraoptic changes, such as snowflake lesions in PMMA IOLs, calcification in hydrophilic acrylic IOLs, and glistenings in hydrophobic acrylic IOLs, could be imaged by AS-OCT. The method was also helpful in analyzing the location and density. However, in cases of more superficial changes, unless the lesions/deposits were present on the optic surface with an extension to the optic substance of at least 0.1 mm, they could not be clearly differentiated from the overall outline of the IOL surface. CONCLUSIONS: Anterior segment OCT may be helpful in assessing the presence, location, and density of intraoptic changes, avoiding a misdiagnosis of IOL opacification and the performance of unnecessary procedures, such as posterior capsulotomy or vitrectomy.

The transverse genicular ligament: anatomical study and review of the literature.

There is scant information in the literature regarding the transverse genicular ligament. In order to elucidate further the anatomy and controversial function of this structure, we dissected 28 cadavers. This ligament was identified in 55% of knee joints. Morphometrically, we found a mean length and width of this ligament of 35.4 and 2.5 mm, respectively. Two (3.7%) specimens were found to have a duplicated ligament. The mean distance between the anterior attachment site of the anterior cruciate ligament onto the tibia to the transverse genicular ligament was 2.5 mm and the mean distance to this ligament to a midpoint of the tibial tuberosity was 40.5 mm The transverse genicular ligament was found to be slightly taut in extension and lax in flexion of the knee joint. Lateral and medial forces applied manually to the knee had no effect on this ligament. No tension was noted of the transverse genicular ligament with rotation of the knee. With transection of the ligament, no discernable difference in the integrity of the knee joint was observed. The mean tensile strength of this ligament was 67 N. Based on our study, the transverse genicular ligament plays a minimal part in the proper function of the knee joint. Moreover, with only approximately one-half of the knees in our study harboring this structure, one would expect a significant portion of the population to exhibit signs of biomechanical dysfunction of the knee joint which is not the case. This structure may represent a vestigal/insular part of the mesenchyme forming the menisci.

Protocols for managing chemotherapy-induced neutropenia in clinical oncology practices.

Chemotherapy-induced neutropenia is managed in different ways in clinical practice. Chemotherapy dose reductions and delays are used more often than proactive, first-cycle use of colony-stimulating factors, but such dose modifications can result in suboptimal treatment outcomes. This article reviews how 3 oncology practices have used practice pattern studies to assess and improve their quality of care, particularly in the management of neutropenia. These practices analyzed their records for the occurrence of neutropenia and for delays or reductions in chemotherapy doses. Once baseline measurements of quality of care were established, the practices developed guidelines to optimize their management of neutropenia. The practice patterns were assessed again after the guidelines had been implemented, to determine the effect of these guidelines on clinical outcomes. All 3 practices had fewer delays and reductions of chemotherapy doses after the guidelines were used. These differences were both clinically and statistically significant. Clinical experience shows that nurses are well positioned to assess which patients may be at the greatest risk for neutropenia and its complications and therefore should be treated with colony-stimulating factors. Practice guidelines for the use of colony-stimulating factors are being developed, but broader acceptance of these guidelines is needed to support nurses' recommendations.