Photodiagnosis and photodynamic therapy最新文献

Objective: This study aimed to evaluate the clinical efficacy of combining 5-aminolevulinic acid (5-ALA) fluorescence with intraoperative ultrasound (ioUS) for microsurgical resection of high-grade gliomas (HGGs).

Methods: In this single-centre retrospective cohort study, 228 patients with HGG were grouped based on the surgical approach: 122 underwent 5-ALA + ioUS-guided resection, whereas 106 received conventional microsurgery (control). Outcomes included gross total resection (GTR) rates, tumour recurrence at 3-6 months, postoperative Karnofsky Performance Status (KPS) scores, intraoperative haemorrhage value and operation time, length of hospital stay and complications.

Results: The 5-ALA + ioUS group achieved significantly higher GTR rates (91.0% vs 74.5%; P < 0.001) and lower recurrence rates at both 3 months (4.1% vs 12.3%; P = 0.027) and 6 months (9.0% vs 23.6%; P = 0.002) than the control group. Functional recovery (the KPS) improved more substantially in the 5-ALA + ioUS group at 1 month (85.9 vs 77.6; P < 0.001) and 6 months (90.9 vs 82.5; P < 0.001) postoperatively. Intraoperative haemorrhage (255.9 vs 338.5 mL), operation time (2.6 vs 3.4 h) and hospital stay (14.8 vs 20.4 days) were significantly reduced (P < 0.001 for all) in the 5-ALA + ioUS group compared with the control group. Complication rates did not differ significantly between the groups (P = 0.104).

Conclusion: This retrospective study suggests that the combination of 5-ALA and ioUS may improve GTR, reduce early recurrence, enhance functional recovery and optimise surgical efficiency in HGG resection. Prospective studies are warranted to confirm these results.

The preservation of the anus in ultra-low rectal cancer (ULRC) surgery presents considerable clinical challenges. While combined neoadjuvant therapy is considered a pivotal treatment strategy, its effectiveness is constrained by factors such as anatomical location, postoperative complications, systemic toxic reactions, and tumor drug resistance. Photodynamic therapy (PDT), as a localized treatment modality, operates through multiple mechanisms, including the targeted eradication of tumor cells, disruption of the tumor vascular system, enhancement of drug resistance, and activation of anti-tumor immune responses. This article presents a case study of a patient with stage IIIb (cT4N1Mx), microsatellite stable (MSS) ULRC, who successfully achieved tumor downstaging and underwent anus-preserving surgery following a comprehensive treatment regimen. This regimen included PDT, systemic therapy, Da Vinci robot-assisted anus-preserving surgery, and anastomotic stent implantation. The patient has achieved a progression-free survival (PFS) exceeding 14 months. At present, the patient exhibits satisfactory defecation function, and no complications, such as anastomotic fistula, have been observed.

Purpose: To compare the corneal biomechanical differences of eyes with and without posterior staphyloma (PS) using Corneal Visualization Scheimpflug Technology (Corvis ST).

Methods: This is a cross-sectional study. The patients were classified into the PS group and control group. Corneal biomechanical parameters were measured by Corvis ST and compared between the two groups and among different PS subtypes.

Results: This study included 40 patients in the PS group and the control group respectively. The deformation amplitude at the highest concavity (HCDA), deflection amplitude at the highest concavity, max deflection amplitude (DLA max) and deformation amplitude ratio max at 2mm were significant higher in the PS group after adjusting the axial length (AL). After matching the AL, only the HCDA and DLA max were significantly greater in the PS group. There was no significant difference in corneal biomechanical parameters among the subtype PS. The A2 V, PD, Radius, HCDA, HCDLL, HCDLA, A2DLA, DLAmax, HC dArc Length, A2 dArc Length, dArc Length Max, DA Ratio Max, Integrated Radius are significantly correlated with PS. In distinguishing PS, DLA Max achieved the highest diagnostic performance, with an area under the receiver operating characteristic curve (AUROC) of 0.79 (95% CI,0.71-0.85), meanwhile, the area under the ROC curve of all data after the combination of gender and age was 0.813(95%CI:0.74-0.88).

Conclusion: Eyes with posterior staphyloma (PS) exhibit greater corneal deformability, elasticity, and viscoelasticity than controls, independent of PS location. These findings suggest PS impacts the anterior ocular wall, offering insights into PS pathogenesis.

Background: Accurate light dosimetry is a complex remaining challenge in interstitial photodynamic therapy (iPDT) for malignant gliomas. The light dosimetry should ideally be based on the tissue morphology and the individual optical tissue properties of each tissue type in the target region. First investigations are reported on using NMR information to estimate changes of individual optical tissue properties.

Methods: Porcine brain tissue and optical tissue phantoms were investigated. To the porcine brain, supplements were added to simulate an edema or high blood content. The tissue phantoms were based on agar, Lipoveneous, ink, blood and gadobutrol (Gd-based MRI contrast agent). The concentrations of phantom ingredients and tissue additives are varied to compare concentration-dependent effects on optical and NMR properties. A 3-tesla whole-body MRI system was used to determine T₁ and T₂ relaxation times. Optical tissue properties, i.e., the spectrally resolved absorption and reduced scattering coefficient, were obtained using a single integrating sphere setup. The observed changes of NMR and optical properties were compared to each other.

Results: By adjusting the NMR relaxation times and optical tissue properties of the tissue phantoms to literature values, recipes for human brain tumor, white matter and grey matter tissue phantoms were obtained that mimic these brain tissues simultaneously in both properties. For porcine brain tissue, it was observed that with increasing water concentration in the tissue, both NMR-relaxation times increased, while µ_a decreased and µ_s' increased at 635 nm. The addition of blood to porcine brain samples showed a constant T₁, while T₂ shortened and the absorption coefficient at 635 nm increased.

Conclusions: In this investigation, by changing sample contents, notable changes of both NMR relaxation times and optical tissue properties have been observed and their relations examined. The developed dual NMR/optical tissue phantoms can be used in iPDT research, clinical training and demonstrations.

Background: The study is aimed at developing a method for monitoring photodynamic therapy (PDT) of a tumor using chlorin-type photosensitizers (PSs). Lack of monitoring of chlorin e6 (Cе6) photobleaching, hemoglobin oxygenation and blood flow during light exposure can limit the PDT effectiveness.

Materials and methods: Phototheranostics includes spectral-fluorescence diagnostics of Ce6 distribution in the NIR range and PDT with simultaneous assessment of hemoglobin oxygenation and tumor blood flow. Fluorescence diagnostics and PDT were performed using the single laser λ_exc=660 ± 5 nm.

Results: Combined spectroscopic PDT monitoring method allowed simultaneous estimation of Ce6 photobleaching, hemoglobin oxygenation and tumor vascular thrombosis during PDT without interrupting the therapeutic light exposure.

Conclusion: The developed method of tumor phototheranostics using chlorin-type PSs may make it possible to personalize the duration of therapeutic light exposure during PDT.