Brachytherapy Implant Patients

In cases where their tumors are close to accessible body cavities, oncology patients may undergo a procedure called brachytherapy, or implant therapy. Implant therapy is effective in some cases 

Work quickly, but effectively and courteously. Minimize your time in the room. 

Maintain the greatest distance possible from the patient consistent with effective care. Radiation exposure drops off drastically with increasing distance. 

Leave all trash, linens, and food trays in the room. Upon leaving the room, remove gloves and place them in the trash receptacles inside the room. The radiation safety department surveys all materials before they leave the room. 

After leaving the room, wash your hands. 

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The two commonly used methods for radiation therapy are external-beam radiotherapy and brachytherapy.26 In external-beam radiotherapy, doses of 70 to 75 Gy are delivered in 35 to 41 fractions in patient with low-grade prostate cancer and 75 to 80 Gy for those with intermediate- or high-grade prostate cancer. Brachytherapy involves the permanent implantation of radioactive beads of 145 Gy of 125I or 124 Gy of 103Pd and generally is reserved for individuals with low-risk cancers. 

Because resin microspheres carry less activity (50 Bq/ sphere) compared to glass microspheres, many more are used to deliver an adequate dose tumor. With upwards of 40 million-60 million delivered for a typical 2-GBq activity distributed in both lobes of the liver, many patients can experience temporary embolic side effects (pain, fever, nausea) which are similar but far less intense than is seen in TACE post-embolic symptoms. However, not all hepatic vascular beds can accept the number of microspheres desired from the pre-treatment planning formulae, and thus the delivery of microspheres discontinued prior to completely emptying the volume of microspheres planned. It is not the desire or plan to perform an embolic treatment, rather it is a brachyther-apy procedure and therefore it is recommended that the delivery of microspheres not cause stasis and/or reflux. Optimal implantation of microspheres is for the tumor only to have spheres, and the normal adjacent liver to be free of radiation. Once stasis has occurred, however, the normal liver arteries have also been filled with microspheres and the selectivity and therapeutic benefit to brachytherapy is lost. If the whole lobe or segment is receiving the same dose of radiation (tumor and normal liver) then external beam radiation could have been used instead. Also, many patients are selected for microsphere therapy specifically because an embolic treatment was not felt to be safe or in their best interests. 

From experimental beginnings, radiation therapy soon developed into a separate branch of medicine, with its own specialists, practices, and standards. X-rays had to be applied from an external machine, but radium could be introduced right into the patient. This approach, known as brachytherapy, was pioneered early in the century. The radium was put in gold needles that were inserted into cancerous tissue, in tubes that were placed in body cavities, or in moulds applied to the outside of the body. During tumour surgery, doctors permanently implanted gold capsules, or seeds, filled with short-lived radon to help kill residual cancerous cells. 

An important modality in cancer treatment is that of radiotherapy, either alone or in combination with chemotherapy. Indeed, the first treatment of cancer by X-rays followed within a year of their discovery by Rontgen [1] and it is estimated that today approximately half of all cancer patients receive radiation in some form. Conventional sources such as X-rays and Co-y rays are now supplemented with particles such as protons, neutrons and mesons [2] and also by internal delivery (brachytherapy) using various implanted isotopes [3]. 

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