Radioactive seed localization (RSL) provides a precise and efficient method for removing non-palpable breast lesions. It has proven to be a valuable addition to breast surgery, improving perioperative logistics and patient satisfaction. This retrospective review examines the lessons learned from a high-volume cancer center’s RSL program after 10 years of practice and over 25 000 cases. We provide an updated model for assessing the patient’s radiation dose from RSL seed implantation and demonstrate the safety of RSL to staff members. Additionally, we emphasize the importance of various aspects of presurgical evaluation, surgical techniques, post-surgical management, and regulatory compliance for a successful RSL program. Notably, the program has reduced radiation exposure for patients and medical staff.

The goal of this study is to investigate the effect of the location and width of a single lead shield on the dose rate of staff and caregivers in a hospital room with an I-131 patient. The best orientation of the patient and caregiver relative to the shield was determined based on minimizing staff and caregiver radiation dose rates. Shielded and unshielded dose rates were simulated using a Monte Carlo computer simulation and validated using real-world ionisation chamber measurements. Based on a radiation transport analysis using an adult voxel phantom published by the International Commission on Radiological Protection, placing the shield near the caregiver yielded the lowest dose rates. However, this strategy reduced the dose rate in only a tiny area of the room. Furthermore, positioning the shield near the patient in the caudal direction provided a modest dose rate reduction while shielding a large room area. Finally, increased shield width was associated with decreasing dose rates, but only a four-fold dose-rate reduction was observed for standard width shields. The recommendations of this case study may be considered as potential candidate room configurations where radiation dose rates are minimized, however these findings must be weighed against additional clinical, safety, and comfort considerations.

Radiation therapy of cancer patients involves a trade-off between a sufficient tumour dose for a high probability of local control and dose to organs at risk that is low enough to lead to a clinically acceptable probability of toxicity. The International Commission on Radiological Protection (ICRP) reviewed epidemiological evidence and provided updated estimates of 'practical' threshold doses for tissue injury, as defined at the level of 1% incidence, in ICRP Publication 118. Particular attention was paid to cataracts and circulatory diseases. ICRP recommended nominal absorbed dose threshold for these outcomes as low as 0.5 Gy. Threshold doses for tissue reactions can be reached in some patients during radiation therapy. Modern treatment planning systems do not account for such low doses accurately, and doses to therapy patients from associated imaging procedures are not generally accounted for. While local control is paramount, the observations of ICRP Publication 118 suggest that radiation therapy plans and processes should be examined with particular care. The research needs are discussed in this paper.

PURPOSE:To measure radiation levels in treatment room due to activation after 15MV single fraction radiation treatment (SFRT) delivered to a solid water phantom.METHODS:We performed radiation surveys of two LINAC treatment rooms immediately after 15 MV SFRT. We delivered a sequence of two 15 MV single fraction IMRT treatments to a phantom at the end of a typical treatment day. The first treatment delivered was 6201MU (about 12 Gy) and the second one, 15 minutes later was 12711 MU (24 Gy). Both were delivered to the pelvic region of a solid water anthropomorphic phantom. In a second technique, a 15 MV VMAT SFRT (4326 MU) was delivered using the Varian TrueBeam LINAC. Radiation measurements were recorded repetitively at four locations using a thin windowed Geiger Muller detector, a sodium iodide photon spectrometer and a pressurized ionization chamber. The four locations surveyed were: the top of the collimator head, the collimator window surface, the isocenter, and the inferior end of the patient support assembly.RESULTS:Radiation levels at the isocenter at the end of the treatment day and before the two IMRT SFRTs varied from 0.06 to 0.1 mR/h. Within 2-3 minutes after finishing the second IMRT SFRT the radiation levels were approximately 10 and 1.4 mR/h at isocenter for the TrueBeam and Trilogy rooms respectively and around 0.6 mR/h for the TrueBeam VMAT SFRT. Closing the MLC and the jaws significantly reduces the radiation level at isocenter. The average half life of the mixture of radionuclides produced is about 10 minutes.CONCLUSIONS:High dose single fraction IMRT treatments with 15 MV photons produce elevated treatment room activation as compared to conventional IMRT. In addition, activation levels varied between the TrueBeam and Trilogy for similar SFRT schemes. There is no funding support, disclosures, or conflict of interest.

Purpose: Fluoroscopic examinations with cumulative dose exceeding 15 Gy to a single field is now considered as a ‘reviewable sentinel event’ according to Joint Commission standards. Guidance from the FDA suggests that the potential for injury be recorded in the patient's record for cumulative absorbed dose of 1 Gy or more. The purpose of this study was to estimate the peak radiation skin doses for interventional radiology procedures performed at a high patient volume cancer center. Method and Materials: A single-center, IRB-approved retrospective study was performed using data from an oncologic interventional radiology section. Peak skin doses were estimated from consecutive procedures performed during 2006 in three different fluoroscopic suites equipped for these studies. Of 6598 consecutive procedures, 3966 (60%) had dose-area-product (DAP) measurements recorded and were included in the study. Results: The mean estimated peak skin dose was 0.19 Gy (range 4.95 microGy to 8.65 Gy) with a maximum individual skin dose of 8.65 Gy. No procedures resulted in skin doses >15 Gy and over 95% of the procedures resulted in skin doses <1 Gy. Procedures with specific instances of skin doses >1 Gy included: embolization, biliary drain/stent, IVC filter, nephrostomy, arteriogram, abscess catheters, foreign body retrieval, catheter change, cholecystostomy, and gastronomy tube check. Embolizations, and biliary drain/stent procedures were most likely to result in skin doses >1 Gy. Significant variations in skin dose were noted for various instances of the same procedure (e.g. range 0.6 mGy to 8.65 Gy for hepatic embolizations). Conclusion: Even when potential errors in methodology are considered, it is unlikely that any typical case performed in an oncologic interventional radiology practice would exceed the Joint Commission ‘reviewable sentinel event’ level of 15 Gy. Identifying procedures that could have peak skin doses greater than 1 Gy can be useful for informed consent and clinical followup.