3D in vivo dosimetry of HDR gynecological brachytherapy using micro silica bead TLDs.

PURPOSE: This study aimed to evaluate the feasibility of defining an in vivo dosimetry (IVD) protocol as a patient-specific quality assurance (PSQA) using the bead thermoluminescent dosimeters (TLDs) for point and 3D IVD during brachytherapy (BT) of gynecological (GYN) cancer using 60 Co high-dose-rate (HDR) source. METHODS: The 3D in vivo absorbed dose verification within the rectum and bladder as organs-at-risk was performed by bead TLDs for 30 GYN cancer patients. For rectal wall dosimetry, 80 TLDs were placed in axial arrangements around a rectal tube covered with a layer of gel. Ten beads were placed inside the Foley catheter to get the bladder-absorbed dose. Beads TLDs were localized and defined as control points in the treatment planning system (TPS) using CT images of the patients. Patients were planned and treated using the routine BT protocol. The experimentally obtained absorbed dose map of the rectal wall and the point dose of the bladder were compared to the TPSs predicted absorbed dose at these control points. RESULTS: Relative difference between TPS and TLDs results were -8.3% ± 19.5% and -7.2% ± 14.6% (1SD) for rectum- and bladder-absorbed dose, respectively. Gamma analysis was used to compare the calculated with the measured absorbed dose maps. Mean gamma passing rates of 84.1%, 90.8%, and 92.5% using the criteria of 3%/2 mm, 3%/3 mm, and 4%/2 mm were obtained, respectively. Eventually, a "considering level" of at least 85% as pass rate with 4%/2-mm criteria was recommended. CONCLUSIONS: A 3D IVD protocol employing bead TLDs was presented to measure absorbed doses delivered to the rectum and bladder during GYN HDR-BT as a reliable PSQA method. 3D rectal absorbed dose measurements were performed. Differences between experimentally measured and planned absorbed dose maps were presented in the form of a gamma index, which may be used as a warning for corrective action.

Plant Decellularization by Chemical and Physical Methods for Regenerative Medicine: A Review Article.

Fabricating three-dimensional (3D) scaffolds is attractive due to various advantages for tissue engineering, such as cell migration, proliferation, and adhesion. Since cell growth depends on transmitting nutrients and cell residues, naturally vascularized scaffolds are superior for tissue engineering. Vascular passages help the inflow and outflow of liquids, nutrients, and waste disposal from the scaffold and cell growth. Porous scaffolds can be prepared by plant tissue decellularization which allows for the cultivation of various cell lines depending on the intended application. To this end, researchers decellularize plant tissues by specific chemical and physical methods. Researchers use plant parts depending on their needs, for example, decellularizing the leaves, stems, and fruits. Plant tissue scaffolds are advantageous for regenerative medicine, wound healing, and bioprinting. Studies have examined various plants such as vegetables and fruits such as orchid, parsley, spinach, celery, carrot, and apple using various materials and techniques such as sodium dodecyl sulfate, Triton X-100, peracetic acid, deoxyribonuclease, and ribonuclease with varying percentages, as well as mechanical and physical techniques like freeze-thaw cycles. The process of data selection, retrieval, and extraction in this review relied on scholarly journal publications and other relevant papers related to the subject of decellularization, with a specific emphasis on plant-based research. The obtained results indicate that, owing to the cellulosic structure and vascular nature of the decellularized plants and their favorable hydrophilic and biological properties, they have the potential to serve as biological materials and natural scaffolds for the development of 3D-printing inks and scaffolds for tissue engineering.

Hypofractionated versus standard chemoradiotherapy in the definitive treatment of uterine cervix cancer: interim results of a randomized controlled clinical trial.

PURPOSE: Concurrent chemoradiation has been the mainstay of treatment for cervix cancer. We aimed to evaluate the non-inferiority of hypofractionated chemoradiation. METHODS: This study was designed as a phase 2, 1:1 randomized, investigator-blinded, controlled, non-inferiority trial and we report the interim results after 50% accrual. Cervical cancer patients with FIGO stages IIA-IIIC were recruited from April 2021 to September 2022. The intervention consisted of 40 Gy of 3D-conformal radiation therapy (RT) in 15 fractions over 3 weeks. In the control group, patients received standard chemoradiation of 45 Gy in 25 fractions over 5 weeks. Both groups received concurrent weekly cisplatin (40 mg/m2). Intravaginal brachytherapy of 28 Gy in 4 weekly fractions was delivered starting 1 week after the end of chemoradiation. The primary outcome was complete clinical response(CCR) at 3 months. Secondary outcomes included acute gastrointestinal (GI), genitourinary(GU), skin, and hematologic toxicities. A p value less than 0.05 was considered significant for analyses. RESULTS: 59 patients were randomized; 30 in the control group and 29 in the intervention group. 20/30 (66.7%) of the patients in the control group and 19/29 (65.5%) in the intervention group achieved a CCR (absolute difference of 0.011, 95% CI - 0.23 to 0.25, p value: 0.13). There was a significantly higher rate of acute grade ≥ 3 GI toxicity in the intervention group (27.6%) compared with the control group (6.7%) (p value 0.032). CONCLUSIONS: Despite an absolute difference of 1.1% in the 3-month CCR, our interim analysis failed to show the non-inferiority of the hypofractionated chemoradiation. Due to the higher GI toxicities, we will continue this trial using intensity-modulated radiation therapy. REGISTRATION NUMBER AND DATE: ClinicalTrials.gov: NCT04831437, 2021.4.1.