Assessment of performance indicators of a radiotherapy department using an electronic medical record system.

AIM: To retrospectively assess the performance indicators of our radiotherapy department and their temporal trends, using a commercially available electronic-medical-record (EMR) system. BACKGROUND: A recent trend in healthcare quality is to define and evaluate performance indicators of the service provided. MATERIALS AND METHODS: Patient and external-beam-radiotherapy-treatments data were retrieved using the Mosaiq EMR system from 1-January-2012 till 31-December-2015. Annual performance indicators were evaluated as: productivity (number of new cases/year and diagnosis distribution); complexity (ratio of Volumetric-Modulated-Arc-Therapy (VMAT) courses, average number of imaging procedures/patient); and quality (average, median and 90th percentile waiting times from admission to first treatment). The temporal trends of all performance indicators were assessed by linear regression. RESULTS: Productivity: the number of new cases/year increased with an average rate of 4%. Diagnosis distribution showed that breast is the main pathology treated, followed by gastro-intestinal and head-and-neck. Complexity: the ratio of VMAT courses increased from 13% to 35%, with an average rate of 7% per year. The average number of imaging procedures/patient increased from 8 to 11. Quality: the waiting times from admission to treatment remained stable over time (R2 ≤ 0.1), with average, median and 90th percentile values around 20, 15, and 31 days, respectively. CONCLUSIONS: An EMR system can be used to: monitor the performance indicators of a radiotherapy department, identify workflow processes needing attention and improvement, estimate future demands of resources. Temporal analysis of our data showed an increasing trend in productivity and complexity paired with constant waiting times.

Optimization of Craniospinal Irradiation for Pediatric Medulloblastoma Using VMAT and IMRT.

PURPOSE: Intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) provide highly conformal target radiation doses, but also expose large volumes of healthy tissue to low-dose radiation. With improving survival, more children with medulloblastoma (MB) are at risk of late adverse effects of radiotherapy, including secondary cancers. We evaluated the characteristics of IMRT and VMAT craniospinal irradiation treatment plans in children with standard-risk MB to compare radiation dose delivery to target organs and organs at risk (OAR). PATIENTS AND METHODS: Each of 10 children with standard-risk MB underwent both IMRT and VMAT treatment planning. Dose calculations used inverse planning optimization with a craniospinal dose of 23.4 Gy followed by a posterior fossa boost to 55.8 Gy. Clinical and planning target volumes were demarcated on axial computed tomography images. Dose distributions to target organs and OAR for each planning technique were measured and compared with published dose-volume toxicity data for pediatric patients. RESULTS: All patients completed treatment planning for both techniques. Analyses and comparisons of dose distributions and dose-volume histograms for the planned target volumes, and dose delivery to the OAR for each technique demonstrated the following: (1) VMAT had a modest, but significantly better, planning target volume-dose coverage and homogeneity compared with IMRT; (2) there were different OAR dose-sparing profiles for IMRT versus VMAT; and (3) neither IMRT nor VMAT demonstrated dose reductions to the published pediatric dose limits for the eyes, the lens, the cochlea, the pituitary, and the brain. CONCLUSIONS: The use of both IMRT and VMAT provides good target tissue coverage and sparing of the adjacent tissue for MB. Both techniques resulted in OAR dose delivery within published pediatric dose guidelines, except those mentioned above. Pediatric patients with standard-risk MB remain at risk for late endocrinologic, sensory (auditory and visual), and brain functional impairments.

Knowledge- and Experience-Based Perceptions of Radiation Therapists during the COVID-19 Outbreak.

Objective: To assess the perceived risks and impact of the COVID-19 outbreak on radiation therapists in Saudi Arabia. Methods: A questionnaire was distributed to all radiation therapists in the country. The questionnaire contained questions about demographic characteristics, the extent of the pandemic's impact on hospital resources, risk perception, work-life, leadership, and immediate supervision. The questionnaire's reliability was assessed using Cronbach's alpha; >0.7 was considered adequate. Results: Out of the 127 registered radiation therapists, 77 (60.6%) responded; 49 (63.6%) females; and 28 (36.4%) males. The mean age was 36.8 ± 12.5 years. Nine (12%) of the participants had a past experience with pandemics or epidemics. Further, 46 (59.7%) respondents correctly identified the mode of transmission of COVID-19. Approximately, 69% of the respondents perceived COVID-19 as more than a minor risk to their families and 63% to themselves. COVID-19 had an overall negative impact on work at the personal and organizational levels. However, there was a positive attitude toward organizational management during the pandemic in general; positive responses ranged from 66.2% to 82.4%. Ninety-two percent considered protective resources and 70% considered the availability of supportive staff to be adequate. Demographic characteristics were not significantly associated with the perceived risk. Conclusions: Despite the high perception of risk and negative impact on their work, radiation therapists conveyed a positive overall perception regarding resource availability, supervision, and leadership. Efforts should be made to improve their knowledge and appreciate their efforts.

Scholarly Activity of Radiation Oncologists in High-Income Developing Countries: Saudi Arabia as an Example.

PURPOSE: To examine the trends and quality metrics of publications by radiation oncologists in Saudi Arabia. METHODS: PubMed was searched using names of all Saudi radiation oncologists to retrieve published articles between January 2010 and December 2019. International collaboration, journal impact factor and country of origin, and number of citations were collected. Each article was assessed for epidemiologic type and independently assigned a level of evidence (LOE) by two authors. The trend in publications was examined and compared in the first and second 5-year periods (2010-2014 and 2015-2019) using relevant parameters. RESULTS: A total of 186 publications were found and included. The most common type of research was cohort studies followed by case reports and case series in 24%, 14%, and 13% of all publications, respectively. Dosimetry, clinical, and preclinical studies formed 7%, 8.6%, and 7.5% of the total publications, respectively. The LOE was I, II, III, IV, and not applicable in 8.6%, 22%, 25.8%, 29%, and 14.5% of the included publications, respectively. Comparing the first and second 5-year periods, there was an increase in international collaboration (P < .001) in the second period. The number of citations (P < .001) and journal impact factor (P = .028) were lower in the second period. LOE and publications in international journals were not statistically different between the two periods. CONCLUSION: Although radiation oncology research activity in Saudi Arabia has gained momentum in terms of volume and international collaboration over time, the LOE has not improved. This calls for a national effort to make the contribution to the literature a priority, allocate adequate resources, and apply appropriate measures to enhance research productivity and quality.

Outcome of cervix uteri cancer patients: Clinical treatment results and toxicity profile in a retrospective study from Saudi Arabia.

AIM: This study evaluated the survival outcome, pattern of failure and prognostic factors in cervix uteri cancer patients. METHODS: We reviewed the data of 60 patients with stages IB-IVA cancer who were treated between January 2004 and December 2010. RESULTS: Most patients (n = 50; 83%) had squamous cell carcinoma. Stage IIB was the most common presentation (n = 41; 68%). Forty-seven patients (78%) received Cisplatin concurrent with radiotherapy (CRT). The 2- and 4-year overall survival (OS) was 82% and 79%, respectively. Prolongation of the overall treatment time (OAT) for greater than 56 days, advanced stage and pretreatment hemoglobin (Hb) levels (<10 g/dL) negatively predicted OS (P = 0.039, P = 0.044 and P = 0.008, respectively). The 2- and 4-year disease-free survival (DFS) rates were 80% and 69%, respectively. Vaginal infiltration and brachytherapy (orthogonal versus CT-based planning) were significant factors for the prediction of relapse (P = 0.048 and P = 0.049, respectively). The 2- and 4-year loco-regional control (LRC) rates were 78% and 70%, respectively, and the distant metastasis-free survival (DMFS) rates were 82% and 79%, respectively. Vaginal infiltration was the only negative predictive factor for LRC (P = 0.045), and pathological tumor grade was the only factor indicative of distant metastases (P = 0.037). Grade 3 or 4 late rectal reactions were reported in two patients (3%), and no patients developed grade 3 or 4 urinary reactions. CONCLUSION: The treatment results in our cervix uteri cancer patients and the prognostic factors are comparable to those of previous reports. Orthogonal brachytherapy planning and vaginal infiltration negatively predicted relapse.

Lung dose analysis in loco-regional hypofractionated radiotherapy of breast cancer.

OBJECTIVES: To report the ipsilateral lung dosimetry data of breast cancer (BC) patients treated with loco-regional hypofractionated radiotherapy (HFRT).  METHODS: Treatment plans of 150 patients treated in the Radiotherapy Unit, King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia between January 2012 and March 2015 by HFRT for BC were retrospectively reviewed. All patients received 42.4 Gy in 16 fractions by tangential and supra-clavicular fields with 6 MV, 18 MV, or mixed energies. Ipsilateral lung dosimetric data V20Gy and mean lung dose (MLD) were recorded. Correlations between lung dose, patient characteristics, and treatment delivery parameters were assessed by a logistic regression test. RESULTS: The mean ipsilateral lung V20Gy was 24.6% and mean MLD was 11.9 Gy. A weak, but statistically significant correlation was found between lung dose and lung volume (p=0.043). The lung dose was significantly decreasing with patient separation and depth of axillary lymph node (ALN) and supra-claviculary lymph nodes (SCLN) (p less than 0.0001), and increasing with ALN (p=0.001) and SCLN (p=0.003) dose coverage. Lung dose significantly decreased with beam energy (p less than 0.0001): mean V20Gy was 27.8%, 25.4% for 6 MV, mixed energy, and 21.2% for 18 MV. The use of a low breast-board angle correlates with low lung dose. CONCLUSION: Our data suggest that the use of high energy photon beams and low breast-board angulation can reduce the lung dose.

Uterine perforation and its dosimetric implications in cervical cancer high-dose-rate brachytherapy.

PURPOSE: To retrospectively assess the incidence of sub-serosal and uterine perforation of intra-uterine tandem in intracavitary high-dose-rate (HDR) brachytherapy for cervical cancer, and to evaluate its dosimetric implications on computed tomography (CT)-based treatment planning. MATERIAL AND METHODS: Computed tomography images and brachytherapy plans of cervical cancer patients treated from February 2006 to December 2012 were reviewed for sub-optimal implants (sub-serosal and uterine perforation), and their correlation with cancer FIGO stage and patients' age. For each patient, the plans showing sub-optimal insertion of intra-uterine tandem were analyzed and compared to plans with adequate insertion. The difference in dose coverage of clinical-target-volume (CTV) and variation of the dose delivered to organs-at-risk (OARs) rectum and bladder were evaluated. RESULTS: A total of 231 brachytherapy plans for 82 patients were reviewed. We identified 12 (14.6%) patients and 14 (6%) applications with uterine perforation, and 12 (14.6%) patients and 20 (8.6%) applications with sub-serosal insertion of tandem. Data analysis showed that advanced stage correlates with higher incidence of sub-optimal implants (p = 0.005) but not the age (p = 0.18). Dose-volume-histograms (DVHs) analysis showed large variations for CTV dose coverage: D90 significantly decreased with average of -115.7% ± 134.9% for uterine perforation and -65.2% ± 82.8% for sub-serosal insertion (p = 0.025). The rectum and bladder dose assessed by D2cc increased up to 70.3% and 43.8%, respectively, when sub-optimal insertion of uterine tandem occurred. CONCLUSIONS: We report a low incidence of uterine perforation and sub-serosal insertion of uterine tandem in intracavitary HDR brachytherapy for cervical cancer. However, the effects on treatment plan dosimetry can be considerably detrimental. Therefore, we recommend image-guided insertion, at least for the challenging cases.

Single versus multichannel applicator in high-dose-rate vaginal brachytherapy optimized by inverse treatment planning.

PURPOSE: To retrospectively compare the potential dosimetric advantages of a multichannel vaginal applicator vs. a single channel one in intracavitary vaginal high-dose-rate (HDR) brachytherapy after hysterectomy, and evaluate the dosimetric advantage of fractional re-planning. MATERIAL AND METHODS: We randomly selected 12 patients with endometrial carcinoma, who received adjuvant vaginal cuff HDR brachytherapy using a multichannel applicator. For each brachytherapy fraction, two inverse treatment plans (for central channel and multichannel loadings) were performed and compared. The advantage of fractional re-planning was also investigated. RESULTS: Dose-volume-histogram (DVH) analysis showed limited, but statistically significant difference (p = 0.007) regarding clinical-target-volume dose coverage between single and multichannel approaches. For the organs-at-risk rectum and bladder, the use of multichannel applicator demonstrated a noticeable dose reduction, when compared to single channel, but statistically significant for rectum only (p = 0.0001). For D2cc of rectum, an average fractional dose of 6.1 ± 0.7 Gy resulted for single channel vs. 5.1 ± 0.6 Gy for multichannel. For D2cc of bladder, an average fractional dose of 5 ± 0.9 Gy occurred for single channel vs. 4.9 ± 0.8 Gy for multichannel. The dosimetric benefit of fractional re-planning was demonstrated: DVH analysis showed large, but not statistically significant differences between first fraction plan and fractional re-planning, due to large inter-fraction variations for rectum and bladder positioning and filling. CONCLUSIONS: Vaginal HDR brachytherapy using a multichannel vaginal applicator and inverse planning provides dosimetric advantages over single channel cylinder, by reducing the dose to organs at risk without compromising the target volume coverage, but at the expense of an increased vaginal mucosa dose. Due to large inter-fraction dose variations, we recommend individual fraction treatment plan optimization.

Assessment of air pockets in high-dose-rate vaginal cuff brachytherapy using cylindrical applicators.

PURPOSE: To retrospectively assess the incidence and magnitude of air pockets around vaginal cylinders and its impact on dose distribution in vaginal cuff image-guided high-dose-rate (HDR) brachytherapy. MATERIAL AND METHODS: Fifty endometrial carcinoma patients treated by postoperative HDR vaginal cuff brachytherapy were included in the study. The average age of patients was 58.3 ± 11.8 years (range: 31-87 years). Brachytherapy was performed using cylindrical applicators, and the dose prescribed to 0.5 cm from the applicator's surface, over a length of 5 cm from the applicator's tip. Computed tomography (CT) simulation was used for each brachytherapy fraction. The incidence, vaginal mucosa displacement, volume, and dosimetric effect of air pockets around the vaginal cylinder were evaluated. RESULTS: A total of 78 air pockets were found in 29/50 patients (58%) and 45/135 (33%) brachytherapy plans. They were located at the apex: 16/78 (20%) and lateral to the applicator: 62/78 (80%). The volume of air pockets ranged between 0.01 and 2.1 cm(3) (mean: 0.15 cm(3) ± 0.36 cm(3)), and the maximum displacement of vaginal mucosa from cylinder surface was between 0.1 and 1.09 cm (mean: 0.34 cm ± 0.2 cm). The dose reduction to the vaginal mucosa generated by the air pockets ranged from 0.5 to 66% (mean: 26.4% ± 13.9%). CONCLUSIONS: The presence of air pockets around vaginal cylinder applicators is frequently noticed in post-operative vaginal cuff brachytherapy. The dose to the vaginal mucosa is reduced, as a result of displacement generated by air pockets. The effect on the clinical outcome of this dose reduction is yet to be determined.

Phase II study on the use of intraoperative radiotherapy in early breast cancer.

OBJECTIVE: To report our early experience using the Intrabeam radiotherapy delivery system for intraoperative radiotherapy (IORT) in early breast cancer. METHODS: This is a prospective phase 2 study carried out at the Department of Surgery and Radiology, King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia from December 2010 to November 2012. Females eligible for breast-conserving surgery with biopsy-proven invasive duct carcinoma, and with a mass of 3 cm, with lymphovascular invasion, multifocal lesion, extensive intraductal carcinoma, and positive nodes. Early and late toxicity were recorded using the Radiation Therapy Oncology Group (RTOG) criteria. RESULTS: Forty-five patients were included with a median age of 54 (range: 27-79 years). Thirty-six cases (80%) had tumor <3 cm in diameter, and 36 (67%) have pathologically negative axillary lymph node metastases. None of the patients developed delayed wound healing, postoperative infection requiring intravenous antibiotic, or breast seroma requiring aspiration. Sixteen (36%) received EBRT after IORT. Twelve patients developed radiologically proved fat necrosis. CONCLUSION: The IORT for early stage breast cancer patients using the Intrabeam delivery system was easily implemented in our center with an acceptable toxicity profile and cosmetic outcome.

Tumor bed boost radiotherapy in breast cancer. A review of current techniques.

Various breast boost irradiation techniques were studied and compared. The most commonly used techniques are external beam radiation therapy (EBRT) (photons or electrons) and high dose rate (HDR) interstitial brachytherapy, but recent studies have also revealed the use of advanced radiotherapy techniques, such as intensity modulated radiation therapy (IMRT), intra-operative radiation therapy (IORT), tomotherapy, and protons. The purpose of this study is to systematically review the literature concerning breast boost radiotherapy techniques, and suggest evidence based guidelines for each. A search for literature was performed in the National Library of Medicine's (PubMed) database for English-language articles published from 1st January 1990 to 5th April 2011. The key words were `breast boost radiotherapy`, `breast boost irradiation`, and `breast boost irradiation AND techniques`. Randomized trials comparing the long-term results of boost irradiation techniques, balancing the local control, and cosmesis against logistic resources, and including cost-benefit analysis are further needed.

Three-dimension anatomy-based planning optimization for high dose rate vaginal vault brachytherapy.

OBJECTIVE: To retrospectively compare 3-dimension (3D)-inverse planning optimization with 2 conventional planning methods in vaginal vault high-dose-rate brachytherapy. METHODS: We randomly selected 26 patients with endometrium cancer, treated with external beam radiotherapy followed by intracavitary high-dose-rate brachytherapy. The study was carried out in the Radiotherapy Unit of King Abdulaziz University Hospital, Jeddah, Saudi Arabia between July 2010 and October 2011. For each brachytherapy fraction, dose-volume-histograms were analyzed for 3 different dose prescription protocols: 0.5 cm from the applicator's tip, 0.5 cm along the applicator's surface, and inverse planning. RESULTS: Dose-volume-histogram analysis showed a significant difference (p<0.001) between the 3 treatment planning methods regarding clinical-target-volume prescribed dose coverage: 26.7%+/-5.4% versus 48.5%+/-6.7% versus 68.6%+/-7.5%. The doses received by the volumes of 2 cm3 of organs-at-risk were (p<0.001): rectum: 4.6+/-1.1 Gy versus 2.8+/-0.5 Gy versus 3.3+/-0.5 Gy; sigmoid: 1.4+/-0.8 Gy versus 0.7+/-0.3 Gy versus 0.9+/-0.5 Gy; and bladder: 3.7+/-1.0 Gy versus 2.3+/-0.5 Gy, versus 2.7+/-0.6 Gy. CONCLUSION: Three-dimension inverse planning provides the ability to balance the target dose coverage against the sparing of organs at risk. For vaginal vault high-dose-rate inverse planning brachytherapy, the use of a CT scan only for the first fraction of treatment is feasible, and the dosimetric impact is minimal.

Significant inter-fraction variations during tangential breast irradiation. An indication for image-guided radiotherapy for simultaneously integrated boost.

OBJECTIVE: To use electronic portal images (EPI) to clinically evaluate inter-fraction variations during tangential breast irradiation, using either a skin marks setup, or a bony anatomy setup, and to determine the required margins for simultaneously integrated boost (SIB) planning target volume (PTV). METHODS: Ten patients undergoing radiotherapy to the entire breast with tangential fields, after breast conservation surgery were considered for this pilot prospective study in the Radiation Therapy Unit of King Abdulaziz University Hospital between February and September 2009. Patient setup was carried out either using skin marks or bony anatomy landmarks. The EPIs of the medial tangential radiation fields were performed daily; displacement of the EPI with respect to the digital reconstructed radiographs (DDRs) was quantified after manual registration with the corresponding DDRs and recorded in both antero-posterior (AP) and cranio-caudal (CC) directions. The inter-fraction variations were used to calculate required margins for SIB PTV. RESULTS: Considerable geometric uncertainties in patient positioning have been observed for both investigated treatment setup protocols. The margins required for a correct assessment of boost PTV were: 15.6 mm for AP and 15.4 mm for CC directions for the skin marks setup protocol, and 12 mm for AP and 12.2 mm for CC directions for the bony anatomy landmarks setup protocol. CONCLUSION: Systematic and random errors induced by inter-fraction patient setup variations are significant in tangential breast radiotherapy, and lead to a large PTV margin for SIB. Such large margins indicate the need for image-guided radiotherapy.

Treatment planning for high dose rate brachytherapy of cervical cancer based on total dose constraints.

OBJECTIVE: To compare the inverse planning optimization based on total dose constraints versus conventional treatment plan (point A planning method) for cervical carcinoma, and evaluate the benefit of CT-based image-guided brachytherapy. METHODS: We prospectively analyzed data of 10 consecutive patients with cervical cancer treated with external beam radiotherapy to the whole pelvis (45 Gy in 25 fractions) followed by high-dose-rate (HDR) brachytherapy (21 Gy in 3 fractions). For treatment planning of HDR brachytherapy, the basic equations of the linear-quadratic model were used to calculate the physical dose for each brachytherapy fraction needed to achieve a given total iso-effective dose for the whole treatment. Specific dosimetric parameters are evaluated for high risk (HR CTV), intermediate risk (IR CTV) clinical target volumes, and organs at risk (OARs). RESULTS: In conventional plans, the HR CTV was well covered in only 15/31, and the IR CTV in 7/31 of the brachytherapy implants, while dose constraints of OARs bladder and rectum were respected in 28/31 and 14/31 implants. After optimization, the HR CTV and IR CTV dose constraints were respected in all the implants, and the bladder and rectum of cases dose constraints were respected in 25/31 and 17/31 of cases. CONCLUSION: Point A is a poor surrogate of target dose. Significant differences between point doses and dose volume histogram parameters indicate the need for inverse planning in image-guided brachytherapy of cervical cancer.

In vivo diode dosimetry vs. computerized tomography and digitally reconstructed radiographs for critical organ dose calculation in high-dose-rate brachytherapy of cervical cancer.

PURPOSE: To investigate the correlation between the dose predicted by the treatment planning system using digitally reconstructed radiographs or three-dimensional (3D)-reconstructed CT images and the dose measured by semiconductor detectors, under clinical conditions of high-dose-rate brachytherapy of the cervix uteri. PATIENTS AND METHODS: Thirty-two intracavitary brachytherapy applications were performed for 12 patients with cancer of the cervix uteri. The prescribed dose to Point A was 7 Gy. Dose was calculated for both International Commissioning on Radiation Units and Measurements (ICRU) bladder and rectal points based on digitally reconstructed radiographs and for 3D CT images-based volumetric calculation of the bladder and rectum. In vivo diode dosimetry was performed for the bladder and rectum. RESULTS: The ICRU reference point and the volumes of 1, 2, and 5cm(3) received 3.6±0.9, 5.6±2.0, 5.1±1.7, 4.3±1.4 and 5.0±1.2, 5.3±1.3, 4.9±1.1, and 4.2±0.9 Gy for the bladder and rectum, respectively. The ratio of the 1cm(3) and the ICRU reference point dose to the diode dose was 1.8±0.7 and 1.2±0.5 for the bladder and 1.9±0.6 and 1.7±0.5 for the rectum, respectively. CONCLUSIONS: 3D image-based dose calculation is the most accurate and reliable method to evaluate the dose given to critical organs. In vivo diode dosimetry is an important method of quality assurance, but clinical decisions should be made based on 3D-reconstructed CT image calculations.

Prognostic value of lymph node ratio in poor prognosis node-positive breast cancer patients in Saudi Arabia.

AIM: Women in Saudi Arabia develop breast cancer at a young age with high prevalence of poor prognostic features. Because of such features, it is necessary to examine prognostic factors in this population. One such factor is the prognostic role of lymph node ratio (LNR). METHODS: We performed retrospective analyses of patients with invasive non-metastatic breast cancer who underwent axillary lymph node dissection and had one or more positive axillary lymph nodes. RESULTS: Two hundred and seventeen patients were considered eligible for the analysis. The median age was 46 years. At a median follow-up of 39.8 months, the median disease-free survival (DFS) was 67.3 months (95% CI, 50.4 to 84.3 months). Neither the classification of patients based on positive lymph node (pN) staging system, nor the absolute number of pN prognosticated DFS. Conversely, age 0.20 to 0.65) LNR categories were the only variables that were independently associated with adverse DFS. Using these variables in a prognostic model allowed the classification of patients into three distinctive risk strata. The overall survival (OS) in this series was 92.5 months (95% CI, 92.1-92.6). Only ER negative tumor adversely influenced OS. CONCLUSION: Analysis of survival outcome of mostly young patients with early breast cancer identified adverse prognostic variables affecting DFS. If the utility of the derived model including LNR is proven in a larger patient population, it may replace the use of absolute number of positive axillary lymph nodes.

Using the computed tomography in comparison to the orthogonal radiography based treatment planning in high dose rate (HDR) brachytherapy in cervical uteri cancer patients; a single institution feasibility study.

INTRODUCTION: Brachytherapy is an integral part in the treatment of cervical uteri cancer patients. Orthogonal treatment planning is the standard mode of calculation based on reference points. Introduction of the innovative 3-D computer based treatment planning allows accurate calculation based on volumetric information as regards the target volume and organs at risk (OAR). Also provide dose volume histogram (DVH) for proper estimation of the dose in relation to the volume. AIM: To correlate and compare the information obtained from the two approaches for high dose rate brachytherapy of cervical uteri cancer; the orthogonal conventional method and the computerized tomography (CT) three dimensions (3D) based calculation method in relation to the target and organ at risk (OAR). METHODS: From 6 patients of cervical uteri cancer, 21 applications with orthogonal planning using the Brachy Vision treatment planning system version 7.3.10 were performed. In 10 applications; comparison between orthogonal and CT based planning was done. In orthogonal planning; the dose to point A, rectum and bladder were defined according to the American Brachytherapy Society (ABS) recommendation. From the CT based planning the target volume and dose volume histogram lpar;DVH) were calculated for the clinical target volume (CTV), rectum and bladder. From these two sets, information was obtained and compared and mean values were derived. RESULTS: For dose prescription at point A, an average of 63.5% of CTV received the prescribed dose. The mean ICRU dose to the bladder point is 2.9 Gy+/-1.2 SD (Standard Deviation) and 17% of the bladder volume derived from CT was encompassed by 2.9 Gy isodose line. The mean ICRU dose at the rectum point is 3.4 Gy+/-1.2 SD and 21% of the rectum volume from CT was encompassed by 3.4 Gy isodose line. The maximum dose to the rectum and the bladder derived from the CT and compared to the maximal dose at ICRU is 1.7 and 2.8 times higher than the orthogonal reference points; with the corresponding p value of (p=0.53 and p=0.005) for the rectum and the bladder respectively. CONCLUSIONS: CT based treatment planning for HDR brachytherapy of cervical uteri cancer is reliable and more accurate in definition and calculation of the dose to the target as well as the critical organs. It allows dose calculation based on the actual volume rather than points or bony landmarks.