Maximizing rectal dose sparing with hydrogel: A retrospective planning study.

Maximizing rectal dose sparing with hydrogel: A retrospective planning study. J Appl Clin Med Phys. 2019 Mar 19;: Authors: Paetkau O, Gagne IM, Pai HH, Lam J, Goulart J, Alexander A Abstract External beam radiation therapy for prostate cancer can result in urinary, sexual, and rectal side effects, often impairing quality of life. A polyethylene glycol-based product, SpaceOAR© hydrogel (SOH), implanted into the connective tissue between the prostate gland and rectum can significantly reduce the dose received by the rectum and hence risk of rectal toxicity. The optimal way to manage the hydrogel and rectal structures for plan optimization is therefore of interest. In 13 patients, computerized tomography (CT) scans were taken pre- and post-SpaceOAR© implant. A prescription of 60 Gy in 20 fractions was planned on both scans. Six treatment plans were produced per anonymized dataset using either a structure of rectum plus the hydrogel, termed composite rectum wall (CRW), or rectal wall (RW) as an inverse optimization structure and intensity modulated radiotherapy (IMRT) or volumetric modulated arc therapy (VMAT) as a treatment technique. Dose-volume histogram metrics were compared between plans to determine which optimization structure and treatment technique offered the maximum rectal dose sparing. RW structures offered a statistically significant decrease in rectal dose over CRW structures, whereas the treatment technique (IMRT vs VMAT) did no...
Source: Journal of Applied Clinical Medical Physics - Category: Physics Authors: Tags: J Appl Clin Med Phys Source Type: research

Related Links:

Stereotactic body radiation therapy (SBRT) is capable of delivering very large and precise dose of radiation, and has emerged as a primary treatment for low and intermediate risk prostate cancer [1,2]. Accurate imaging and tracking of the target regions allows clinicians to reduce treatment margins and maximally spare rectum, bladder, urethra and penile bulb [3]. However, very sharp dose gradients and the proximity of critical structures to prostate requires precise verification of treatment plans [4,5].
Source: Physica Medica: European Journal of Medical Physics - Category: General Medicine Authors: Tags: Original paper Source Type: research
Abstract While radiotherapy is widely used in cancer treatment, the benefits can be limited by radiation-induced damage to neighboring healthy tissues. We previously demonstrated that the anti-inflammatory compound dimethylaminoparthenolide (DMAPT) selectively induces radiosensitivity in prostate tumor tissue from transgenic adenocarcinoma of mouse prostate (TRAMP), while simultaneously protecting healthy tissues from 6 Gy whole-body radiation-induced apoptosis. Here, we examined the radioprotective effect of DMAPT on fibrosis in normal tissues after a partial-body fractionated radiation protocol that more closely...
Source: Radiation Research - Category: Physics Authors: Tags: Radiat Res Source Type: research
Conclusions: Insertion of HS in prostate cancer patients receiving combined HDR and EBRT is safe and has resulted in a significant radiation dose reduction to the rectum, resulting in significantly less acute GI toxicity and a trend towards less late GI toxicity. PMID: 30911304 [PubMed]
Source: Journal of Contemporary Brachytherapy - Category: Cancer & Oncology Tags: J Contemp Brachytherapy Source Type: research
ConclusionsInter ‐observer contouring variation was significant for multiple pelvic structures contoured on MR.
Source: Journal of Medical Imaging and Radiation Oncology - Category: Radiology Authors: Tags: Radiation Oncology —Original Article Source Type: research
This study seeks to evaluate the quality of the delineation of volumes according to HAS recommendations [1] by showing the existence or not of discrepancies in terms of volumes and the influence on the doses delivered with different treatment planning techniques.
Source: Physica Medica: European Journal of Medical Physics - Category: General Medicine Authors: Source Type: research
ConclusionsDVH parameters and post-radiotherapy HRQoL appear to be closely correlated, underscoring the importance of assessing DVH values prior to initiating EBRT to determine the risk of developing HRQoL related adverse effects. Advanced treatment modalities may be appropriate in high risk cases to minimize treatment-related toxicity and to improve treatment outcomes and HRQoL. Future studies are needed to better elucidate the association between pre-treatment DVH parameters in organs at risk and subsequent HRQoL.
Source: Reports of Practical Oncology and Radiotherapy - Category: Cancer & Oncology Source Type: research
This article investigates dose-volume prediction improvements in a common knowledge-based planning (KBP) method using a Pareto plan database compared with using a conventional, clinical plan database.Methods and materialsTwo plan databases were created using retrospective, anonymized data of 124 volumetric modulated arc therapy (VMAT) prostate cancer patients. The clinical plan database (CPD) contained planning data from each patient’s clinically treated VMAT plan, which were manually optimized by various planners. The multicriteria optimization database (MCOD) contained Pareto-optimal plan data from VMAT plans creat...
Source: Practical Radiation Oncology - Category: Cancer & Oncology Source Type: research
CONCLUSION: Compared to CyberKnife, the RapidArc, volumetric-modulated arc therapy, and noncoplanar intensity-modulated radiotherapy produced treatment plans with similar dosimetric quality, with RapidArc achieving the highest dose conformity. Overall, the dosimetric differences between the studied techniques were marginal, and thus, the choice of the technique should rather focus on the delivery accuracies and dose delivery times. PMID: 28279147 [PubMed - in process]
Source: Technology in Cancer Research and Treatment - Category: Cancer & Oncology Authors: Tags: Technol Cancer Res Treat Source Type: research
Conclusion: Including information from 18F-fluciclovine PET in the treatment-planning process led to significant differences in the defined target volume, with higher doses to the penile bulb but no significant differences in rectal or bladder dose or in acute genitourinary or gastrointestinal toxicity. Longer follow-up is needed to determine the impact of 18F-fluciclovine PET on cancer control and late toxicity endpoints.
Source: Journal of Nuclear Medicine - Category: Nuclear Medicine Authors: Tags: Clinical Source Type: research
This study only looked at the effect of dietary or food sources of zinc and not at zinc supplements. Some dietary sources of zinc include the following: • Beef steak - 3 oz contains 4.9 mg • Oysters - 3 oz contains 67 mg • Shrimp - 3 oz contains 1.5 mg • Pork chop - 3 oz contains 2.8 mg • Yogurt - 1 cup contains 2.2 mg • Enriched cereal - ¾ cup contains 15 mg • Red kidney beans - ½ cup contains 2 mg Zinc coming from meat sources is more readily bioavailable than zinc from vegetarian sources. Legumes and whole grains contain phytic acid inhibiting zinc's bioavailability. Co...
Source: Healthy Living - The Huffington Post - Category: Consumer Health News Source Type: news
More News: Bladder Cancer | Cancer | Cancer & Oncology | Colorectal Cancer | Computers | CT Scan | External Beam Therapy | Intensity-Modulated Radiation Therapy | Penile Cancer | PET Scan | Physics | Polyethylene Glycol | Prostate Cancer | Radiation Therapy | Statistics | Study | Toxicology