Radiation Risks of Kidney during Abdominal CT Procedures in Morocco: A Multicentre Study

This study aimed to estimate renal effective dose during abdominal CT scans in order to assess the renal risks of cancer and heredity per procedure in Moroccan hospitals. It’s consisted of examining a total of 120 patients referred to three radiology departments for an abdominal CT scan at the rate of 40 per hospital. The data that collected for this diagnostic exam included scanner acquisition parameters, number of series, use of the contrast medium, and rotation time as well as slice thickness, the displayed CT dose index (CTDIvol) and the Dose Length Product (DLP). Renal dose, effective dose and biological risks were estimated using the International Commission on Radiological Protection (ICRP) conversion factor. The patients included in this study were an average age of the (46.49 ± 14.16) years and an average weight of (73.34 ± 7.58) kg. For the mean effective dose (E) and average kidney dose (DK) received per patient during an abdominal CT scan, it were respectively of (6.67 ± 2.73) and (18.26 ± 7.74) mSv. The distribution of these values according to the hospital variable shows a difference in mean effective dose of the order of 0.26, 0.38 and 1.45 mSv and a difference in the mean renal dose of the order of 8.76, 4.94 and 0.48 mSv respectively for H1, H2 and H3. The induction cancer risk of abdominal and kidney per 105 procedures was respectively of 3 and 10. The kidney cancer risk by procedure is two to three times more likely than abdominal. For hereditary risk of abdominal and renal exposure per 106 procedures, it is 14 and 21 respectively. The renal stochastic effect by procedure is also two to three times more likely than that of the abdomen. Our values are relatively higher than those of published in some previous studies. Cancer risk and heredity estimation highlights the need to limit radiation dose. This first ever survey confirmed the need to improved training of health professionals involved in computed tomography on factors affecting image quality, doses and protocols optimization.

Survey of current practices in the management of cervical cancer by Moroccan radiotherapists

Objective:To assess the applicability degree of the international guidelines by Moroccan radiotherapists,in order to improve the management of cervical cancer(CC),since CC is the second most common cancer for women in Morocco.Methods:This cross-sectional study was carried out using a questionnaire sent online to Moroccan radiotherapists.The questionnaire covered participants'characteristics,initial assessment and treatment preparation,techniques and indications for radiotherapy and brachytherapy,dose and indications,as well as on the protocol adopted in the intermediate stages and the location of adjuvant treatments and assessments'follow-up.Results:74 radiotherapists out of 300 have responded to the survey.Only 27.0%of practitioners reported discussing patient records systematically in a multidisciplinary consultation meeting(MCM).For the initial assessment,77.0%requested pelvic magnetic resonance imaging(MRI).It is significantly less requested in regional oncology centers(ROCs)than in university hospital centers(UHCs)or the private sector(P<0.001).Furthermore,Clinicians in ROCs do not have access to new techniques of radiotherapy.In 83.8%of cases,the most prescribed radiotherapy protocols were 45–46 Gy in 1.8–2 Gy per fraction.Three-dimensional gynaecological brachytherapy high-throughput dose guided by dosimetric scanner was available in 75.5%of structures while interstitial gynaecological brachytherapy was only available in 23%of centers.The two most prescribed dose protocols were 47 Gy and 37 Gy in 74.4%and 21.6%of cases,respectively.Finally,monitoring during the first two years was based mainly on pelvic MRI(82.2%)while PET/CT was recommended by only less than 10%.Conclusions:The findings obtained show that our radiotherapists generally comply with international guidelines for the cervical cancer management.However,they should still enhance their practices for the first staging evaluation,the use of systematic MCMs,the doses and treatment techniques used,and the follow-up evaluation.

Evaluation of setup errors in conformal radiotherapy for pelvic tumours: Case of the Regional Center of Oncology, Agadir

Context:The errors made during repetitive patient placements affect significantly the accuracy of treatment and the results of radiotherapy.Objectives:To determine the total,systematic and random error in order to estimate the margin between the Clinical Target Volume(CTV)and the Planning Target Volume(PTV)in the pelvic region.Materials and methods:Set up errors was estimated by superimposing a digitally reconstructed radiograph(DRR)as a reference image with an electronic portal image device(EPID).The total errors in the Medio-Lateral(ML),Cranio-Caudal(CC)and Antero-Posterior(AP)directions were compared by t-test.For systematic and random errors,the ratio of variance(F statistic)was used.Margins were calculated using Van Herk formalis.Results:208 images(80 DRRs and 128 EPIDs)were assessed.The systematic error ranged from 1.93 to 2.01 mm,1.26 to 1.39 mm,and 1.20 to 2.94 mm in the x,y and z-axis,respectively.The random error ranged from 2.33 to 2.90 mm,1.25 to 1.66 mm,and 1.04 to 1.28 mm.The PTV margin according to the Van Herk equation in the x,y and z directions was estimated to be 7.11,4.64 and 3.90 mm for the cervix uteri and a 6.47,4.03,and 3.70 mm for the rectum.Conclusion:The use of weekly EPID/DRR allows estimating the setup of the planning target volume(PTV)expansion according to our configuration.In this study,the evaluated set up margin was approximately 8 mm in the X-axis,5 mm in Y and Z axis for pelvic conformal radiotherapy.

Physicians’knowledge about radiation protection of patients during prescription of CT scan procedures in Morocco

Objective:To evaluate the knowledge and practices of Moroccan physicians in terms of radioprotection of patients when prescribing computed tomography(CT)procedures.Methods:This is a cross-sectional study in which a questionnaire with 23 multiple-choice questions was sent to prescribers of CT examinations such as radiotherapists(RMs),other medical specialists(OMSs),general practitioners(GPs)and residents/interns(R/Is).The first eight questions asked about the demographics of the participants,while the remaining questions asked about knowledge of ionizing radiation examinations,doses received,relative risks,and patient radiation safety training.Results:A total of 223 physicians participated in this survey.Radiation therapists,considered as the reference group,had a better knowledge of irradiating and non-irradiating imaging compared to the other groups(P=0.003).Thus,67%of the reference group declared to take into account the number of scans performed by the patient during the last year,unlike the other groups(P=0.002).Furthermore,the knowledge of the different groups about the risks related to exposure to ionizing radiation was globally low(2%)(P=0.73).Regardless of their specialties and seniority,only 12%of the participants informed the patient at the time of prescription about the risks of X-rays.Finally,only 21%of the participants declared having had training in radiation protection,with no significant differences between the subgroups(P=0.832).Conclusions:The results obtained are similar to those reported in previous studies.They show that Moroccan prescribers have a low level of knowledge of the risks associated with CT examinations.Training on patient radiation protection should be included in the initial curriculum of interns and the continuing professional development of physicians should be reinforced.

Combination of immunotherapy-radiotherapy in non-small cell lung cancer: Reality and perspective

The aim of this review was to examine the theoretical,preclinical and clinical bases of the combination radiotherapy immunotherapy in the management of non-small cell lung cancer(NSCLC).Preclinical studies have shown that in addition to its well-established tumoricidal effects,radiotherapy can activate the host immune system and modify the tumor microenvironment.Immunotherapy is currently part of the therapeutic arsenal of the NSCLC given its capacity to restore the host's immune system's ability to recognize and destroy tumor cells.The combination of radiotherapy and immunotherapy seems to be synergistic,particularly with inhibitors of immune checkpoints.This association has become standard in the metastatic stages and especially in consolidation after radiochemotherapy in the locally advanced,unresectable and stable stages.Several questions remain unanswered including the optimal sequence of this combination,the type of radiotherapy(hypo-fractionated or normofractionated),the association of several immunotherapies and the cross-toxicity of the combination.The association of radiotherapy and immunotherapy is a promising treatment.