2D and 3D scintillation dosimetry for brachytherapy
Sam Beddar, Luc Beaulieu in Scintillation Dosimetry, 2018
Brachytherapy is a method for treating tumors with radiation by placing a radioactive source inside or adjacent to them. Since the irradiation of tumors on or within the eye with radioactive applicators was introduced in the early 1960 s, this eye-salvaging brachytherapy modality has become a clinical standard. These applicators, often called ophthalmic plaques, typically consist of a metal calotte as a carrier adapted to the curvature of the eye surface, with varying shapes and sizes (cf. Figure 14.1, for example). The sealed radioactive sources are attached at the concave side of the calotte. The applicator emits radiation mainly into the target volume adjacent to the applicator. The metal carrier absorbs most of the radiation emitted in other directions, thus reducing side effects and problems with radiation protection. The methods described in this chapter were developed and tested specifically for ophthalmic plaques, but with some modifications they can be applied also for other brachytherapy sources.
Premalignant and malignant disease of the lower genital tract
Helen Bickerstaff, Louise C Kenny in Gynaecology, 2017
The aim of radiotherapy is to deliver a lethal dose of radiation to the tumour and minimize damage to the surrounding tissues. Treatment is overseen by a radiotherapist and team. Treatment is delivered in two ways: external beam radiotherapy (as teletherapy) and internal radiotherapy (brachytherapy). In external beam radiotherapy, the source of the radiation is from a machine called a linear accelerator, and radiation is delivered to the pelvis a distance from the patient (Figure 16.10). The dose of radiotherapy is carefully calculated according to the patient and the tumour, and is usually administered as 45 Gy in total. This is given in several treatments or ‘fractions’ as an outpatient over 4 weeks. Although this treatment is given daily, the time of each fraction is no more than 10 minutes. Brachytherapy is a radiotherapy technique where the radiation is delivered internally to the patient. The source of the radiation is usually selenium and patients generally have to undergo an examination under anaesthetic to insert the rods into the uterus. These rods are then attached to the radiotherapy source; the patient receives this internal treatment in isolation to protect the staff. Brachytherapy delivers a high dose of radiation to the tumour source and its harmful effects on the bladder and bowel are minimized as its effects are targeted only 5 mm from the rod.
Eckert & Ziegler BEBIG
William Y. Song, Kari Tanderup, Bradley R. Pieters in Emerging Technologies in Brachytherapy, 2017
Since its first use over a century ago, brachytherapy has allowed high radiation doses to be delivered to clinical targets while sparing adjacent healthy tissues. Many technological developments have enabled the range and complexity of treatments to enhance, from simple skin treatments and manual gynecological insertions, to sophisticated image-guided implants. The pace of change has never been greater than it is today. Brachytherapy plays an important role both as a monotherapy and in multimodal settings and a range of radionuclides are available to provide low-dose rate (LDR) or high-dose rate (HDR) treatment. Eckert & Ziegler BEBIG were the first to introduce 60Co miniaturized HDR sources in 2003, and continue to innovate and contribute to the further advancement of brachytherapy (e.g., see Figure 31.1), with promising new technologies emerging in the near future. Faster computing, smaller detectors, and individual 3D printing solutions will update imaging and treatment planning, refine dose delivery verification, and bring individualization of therapy to a higher level. The introduction of nanoparticles might have the potential to further improve the clinical effectiveness of brachytherapy.
Radiation therapy techniques in the treatment of skin cancer: an overview of the current status and outlook
Published in Journal of Dermatological Treatment, 2019
Ali Pashazadeh, Axel Boese, Michael Friebe
Brachytherapy refers to the therapeutic application of a small source of radiation in close contact with the target volume. Immediately after the discovery of radioactivity in the late 1900, brachytherapy was introduced in oncology practices to manage cancer. However, the risk of radionuclide handling in brachytherapy practices together with the advancement in external beam radiation therapy (EBRT) in that time postponed its popularity until the 1960s when after-loading treatment delivery was introduced in brachytherapy (13). Afterloading made it possible to use the radioactive source in a safer mode by guiding the source from the shielded housing to the site of the tumor after the applicator is fixed on the patient. This technique leads to less radiation exposure to the staff and reduced risk of contamination, increasing the acceptance of brachytherapy in the RT community. Currently, 10–20% of all procedures done in RT clinics are brachytherapy-based treatments (14). Figure 1
Stereotactic Body Radiation Therapy (SBRT) in Pelvic Lymph Node Oligometastases
Published in Cancer Investigation, 2020
Leonid B. Reshko, Martin K. Richardson, Kelly Spencer, Charles R. Kersh
For patients who are not good surgical candidates or who desire a less invasive approach, radiotherapy may offer another option. Treating pelvic lymph node metastases with radiotherapy presents a unique challenge in a setting of oligometastatic disease. In this location, avoiding radiation toxicities including cystitis, proctitis, colitis, bowel perforation, fistula formation, pelvic insufficiency fractures, and chronic pain is important (8,9). Conventionally fractioned radiotherapy has a well-recognized role in managing pelvic pain, hematuria, and obstruction from pelvic metastases not amenable to surgery (4–6). However, this approach is unlikely to provide durable disease control (10). Brachytherapy is another radiation treatment technique that allows for delivering a higher dose of radiation to the tumor directly with the goal of sparing normal tissues. This has been successfully used in recurrent pelvic tumors (11). The downside of this approach is the need for general anesthesia, the invasive nature of the procedure and the unique toxicity profile (11).
Capacitive hyperthermia as an alternative to brachytherapy in DNA damages of human prostate cancer cell line (DU-145)
Published in International Journal of Radiation Biology, 2019
Seied Rabi Mahdavi, Azam Janati Esfahani, Samideh Khoei, Mohsen Bakhshandeh, Ali Rajabi
It was found that some regimens of hyperthermia in combination with teletherapy has the potential to produce similar DNA damages on prostate cancer cells to EBRT + BR. Substitution of brachytherapy with hyperthermia for prostate cancer treatment needs more investigation in terms of thermal dose and fractionation and may be at this stage, it is better to say that hyperthermia can enhance the radiation effect of EBRT and in some instances, it may create the effect of brachytherapy doses. So we could create the same radiobiological effect also not undesirable effects of brachytherapy. Brachytherapy plays a key role in the treatment of many cancers. However, some patients cannot tolerate brachytherapy. For these patients, hyperthermia added to teletherapy might be offered as an alternative treatment, which requires more research.
Related Knowledge Centers
- Cervical Cancer
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- Radionuclide Therapy