COVID-19 Crisis in Jordan: Response, Scenarios, Strategies, and Recommendations

As of April 12, 2020, a total of 389 cases of coronavirus disease were confirmed in Jordan. To control this imminent threat, Jordan has enforced public health infection prevention and control measures, called for social distancing, seized all forms of inbound and outbound movement and international travel, and enacted the Defence Law that transferred the authority to the Minister of Defence to work and formulate orders according to the situation. In an effort to support the government in anticipating the requirements of the health system in the upcoming period, an in-depth reflection and examination of different scenarios of the disease spread were developed. This viewpoint suggests different strategies and measures for case detection and contact tracing, clinical management of cases, public health system functioning, and civil society organizations’ contribution. It is necessary to accelerate containment of the disease to protect the economy and to maintain the continuity of some activities to mitigate the subsequent social, economic, and financial impacts. This requires finding a coping mechanism for a period that may be prolonged until laboratories develop a vaccine. Specifically, it is strongly recommended to promote community health awareness toward public health prevention and control measures, increase the efficiency and comprehensiveness of the epidemiological investigation and active and passive surveillance, and employ technology and digital health solutions to track cases and contacts. It is also recommended to increase and expand resources of intensive care units including respirators, increase the capacity and the number of trained health staff in the area of public health and epidemiology, ensure continued provision of essential public health programs, and mobilize the resources of nongovernmental sectors and donors to provide services for refugees and vulnerable populations.

TU-E-BRB-03: Biological Dose Optimization for SBRT of Lung Cancer: One Size Does Not Fit All

PURPOSE

Given the differences in tumor size and location, encountered in lung SBRT, we hypothesize that 'one dose fractionation regimen does not fit all', i.e. that there is a role for patient-specific dose prescription based on optimization of biological models.

METHODS

Sixty one NSCLC patients (tumor volume 46.5+/-47.3 cc) treated with stereotactic body radiotherapy (48 Gy in 4fx) were retrospectively studied. Clinically treated plans were generated using Brainlab's Pencil Beam (PB-BL), and then recalculated with fixed MUs using Anisotropic Analytic Algorithm (AAA), Pencil Beam (PB-EC), Monte Carlo (MC) and Collapsed-Cone-Convolution (CCC). DVHs were exported to calculate TCP (Poisson) and NTCP (Lyman-Kutcher-Burman). TCP/NTCP model parameters were utilized from published data. For each dose distribution two dose response curves were generated by scaling the prescription dose and assuming a linear relationship between the prescription dose and entire 3D dose distribution. In addition, associations were assessed between changes in each algorithm's TCP relative to PB-BL, target diameter, and local density (density of the 70% isodose covering the PTV).

RESULTS

For PB-BL, mean TCP was 99.6%±0.9%, whereas for same MUs, mean TCP for PB-EC, AAA, CC and MC plans were 96.5±14.3%, 74.6±31.6%, 74.4±32.4% and 76.8±32.0%, respectively. With the same prescription dose for all plans, TCP values changed to 98.1±8.7%, 96.5±15.3%, 77.5±28.6%, 85.4±25.8% and 92.9±20.1% for PB-BL, PB-EC, AAA, and CCC, MC, respectively, indicating that AAA and CCC dose distributions are likely less homogeneous relative to MC. The TCP improvement was 12.3%, 8.9% and 4.4% for AAA, CCC and MC-based plans when the average NTCP before optimization was set as the upper limit for lung toxicity.

CONCLUSIONS

This work supports patient-specific dose prescription strategies, based on biological optimization, for lung SBRT. However, further investigation is warranted. Acknowledgement: supported in part by a grant from Varian Medical Systems.

SU-E-T-197: A Comprehensive Variance Reporting System and an Analysis of Variances Reported at Our Institution

PURPOSE

It is essential for radiation oncology departments to have comprehensive patient safety and quality programs. Two years ago we undertook a systematic review of our safety/QA program. Existing policies were updated and new policies created where necessary. One crucial component of any safety/QA program is continually updating it based on current information, the 'check' and 'act' portions of the Deming Cycle. We accomplished this with a transparent variance reporting system and a safety/QA committee reviewing and acting on reported variances.

METHODS

With 5 radiation oncology centers in our institution, we needed to devise a system that would allow anyone to report a variance and provide our QA committee the ability to review variances system-wide. We developed the system using web-based tools. The system allows individuals to report variances, anonymously or named, specify the nature of the variance and indicate the tools used to identify the variance.

RESULTS

In 2011, 285 variances were reported, 102 were reported by physicists, 86 anonymously, 71 by therapists and 26 by dosimetrists. We realized the need to develop clear classifications for variances. We added a high priority category, defined as variances which resulted in or had the potential to result in harm to a patient or when a policy is purposely overridden. Of the 285 variances reported, 5 were high priority. We created a process variance category, defined as variances where a specific clinical process is not followed. Of the 285 reported variances 155 were process variances.

CONCLUSIONS

Reporting of variances through a centralized database is central toward developing a robust patient safety/quality assurance program. Anonymous reporting fosters a non-punitive environment, and promotes the 'safety culture'. The goal of such a system is to review trends in clinical processes and ultimately to improve safety/quality by reducing variances associated with these processes.

TU-E-BRB-10: Dosimetric Consequences of Setup Errors Using CBCT for SBRT Localization

PURPOSE

Steep dose gradients and high dose per fraction in stereotactic ablative radiation therapy (SABR or SBRT) necessitate highly accurate tumor localization. This study evaluates inter-fraction shifts, as defined by couch correction analysis, and investigates the effect of tumor location and internal target volume (ITV) on these shifts. In addition, residual errors associated with post-CBCT correction and their dosimetric consequences were quantified.

METHODS

Daily free-breathing (FB) CBCT images used for daily localization of 78 patients with non-small cell lung cancer were retrospectively evaluated. Among the population, 39 patients also received pre-treatment kV images after CBCT alignment. ITV inter-fraction displacement was evaluated by matching the CBCT and the FB helical CT images, and setup errors were quantified using orthogonal kV images. Associations between ITV location and inter-fraction motion were studied by categorizing tumors into the following locations: chest-wall seated (CWS) and island, peripheral, central, or upper, middle and lower. Dosimetric consequences for the patient with the largest setup error were explored.

RESULTS

ITV inter-fraction motion included the mean of the systematic error, ?inter=(-1.4, 2.0, 1.6) mm, standard deviation (SD) of the systematic error, Σinter=(2.1, 4.2, 2.9) mm, and SD of random errors, sinter=(2.2, 3.2, 3.6) mm. No significant associations were observed between inter-fraction shifts and tumor location or volume. Using CBCT for image guidance reduced the observed errors to μsetup=(-0.3, 0.1, 0.0) mm, Σsetup=(0.6, 0.6, 0.4) mm and ssetup=(1.2, 0.7, 0.7) mm. Dosimetric consequences for the patient with the largest setup error were explored. It was shown that a 3.0 mm setup margin was sufficient to provide greater than 95% dose coverage to the ITV.

CONCLUSION

CBCT image guidance reduced setup errors significantly such that 2-3 mm, population-based, setup margins provided proper dose coverage to the ITV. Further investigation of inter-and intrafraction error classification by tumor location is warranted.