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Mondal K, Mourya A, Choudhary S, Mandal A, Singh A, Aggarwal LM. Plan quality score to evaluate the dwell time deviation restricted inverse planning by simulated annealing and graphically optimized treatment plans for template based interstitial brachytherapy. Cancer Radiother 2023; 27:196-205. [PMID: 37088572 DOI: 10.1016/j.canrad.2022.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 09/15/2022] [Accepted: 10/18/2022] [Indexed: 04/25/2023]
Abstract
PURPOSE To evaluate the impact of dwell time deviation constraint (DTDC) on the quality of IPSA-optimized treatment plans in comparison with graphical plans using plan quality scores (PQS). MATERIAL AND METHODS Seventy optimized plans (graphical & IPSA with different DTDC values) of ten cervical cancer patients were generated. Various DVH parameters like D90, V100, V150, V200, V300 were compared to evaluate the impact of DTDC on target coverage and high dose regions inside target for different plans. Similarly, for the OAR dose, values of D2cc were compared. Various planning parameters like CI, COIN, DHI, DNR, ODI, EI and gain factor (GF) for different OARs were calculated. Based on these indices a plan quality score (PQS) was formulated and calculated. PQS values were used to see the impact of DTDC on plan quality of IPSA in comparison with dosimetric quality of graphical plan. RESULTS We have found that target coverage is similar for IPSA and graphically optimized treatment plans. However, dose homogeneity was improved in IPSA compared to graphical optimization whereas conformality was better in graphically optimized plans. OAR dose was less in IPSA plans. High-dose regions inside the target were also reduced in IPSA comparatively. However, IPSA plans optimized with various values of DTDC did not necessarily reduce high-dose regions beyond 0.6. Plan quality scores (PQS) were 6.31, 6.31, 6.34, and 6.17 for the graphically optimized plan, IPSA with DTDC values of 0.0, 0.4, and 1.0 respectively. CONCLUSION We found that IPSA is dosimetrically advantageous over graphical optimization. IPSA with a DTDC value of 0.4 improved overall plan quality. However, DTDC value beyond 0.6 produces dosimetrically sub-optimal plans hence the use of DTDC should be very selective and limited.
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Affiliation(s)
- K Mondal
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, Banaras Hindu University, 221005 Varanasi, Uttar Pradesh, India
| | - A Mourya
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, Banaras Hindu University, 221005 Varanasi, Uttar Pradesh, India
| | - S Choudhary
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, Banaras Hindu University, 221005 Varanasi, Uttar Pradesh, India
| | - A Mandal
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, Banaras Hindu University, 221005 Varanasi, Uttar Pradesh, India
| | - A Singh
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, Banaras Hindu University, 221005 Varanasi, Uttar Pradesh, India
| | - L M Aggarwal
- Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, Banaras Hindu University, 221005 Varanasi, Uttar Pradesh, India.
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Azahari AN, Ghani AT, Abdullah R, Jayamani J, Appalanaido GK, Jalil J, Abdul Aziz MZ. Variation of optimization techniques for high dose rate brachytherapy in cervical cancer treatment. NUCLEAR ENGINEERING AND TECHNOLOGY 2022. [DOI: 10.1016/j.net.2021.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Yaegashi Y, Sasaki K. High-dose-rate brachytherapy using inverse planning optimization with tandem and ovoid applicators for locally advanced cervical cancer: a simulation study. Radiol Phys Technol 2021; 14:262-270. [PMID: 34080129 DOI: 10.1007/s12194-021-00624-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 11/30/2022]
Abstract
The purpose of this study was to evaluate the dosimetric advantage of inverse planning optimization (IPO) in locally advanced cervical cancer using high-dose-rate (HDR) brachytherapy (BT). IPO was compared with point A plan and geometric optimization (GO). The three planning methods were evaluated using doses to the virtual organ-at-risk (OAR) and D90 (the minimum dose covering of 90% of the volume) to the virtual high-risk clinical target volume (HR-CTV) based on quantitative analysis. HR-CTV structures measuring 38.5 cm3 and 59.5 cm3 were created based on the outcomes of a European Group cohort study. The HR-CTVs were located either at the center of the cervix (cervical center model) or shifted toward the left (extensive disease model). The distances from the HR-CTVs to the rectum were set at 0 mm, 3 mm, 5 mm, 8 mm, 10 mm, and 15 mm. We analyzed 336 conditions in this study. All doses were evaluated by conversion to doses in 2-Gy fractions of conventional radiotherapy. The D90 of the HR-CTV using GO and IPO could achieve the desired dose in all conditions, providing better results than that of point A plan. IPO makes it possible to deliver a sufficient dose for the D90 of the HR-CTV while reducing OAR doses with smaller HR-CTV values (< 38.5 cm3) in HDR BT. However, taking into consideration the whole treatment planning time, IPO should be used only when the HR-CTV-to-rectum distance is ≤ 5 mm, and the use of GO cannot spare OARs.
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Affiliation(s)
- Yuji Yaegashi
- Department of Radiological Technology, Faculty of Health Sciences, Hokkaido University of Science, 7-15-4-1 Maeda, Teine, Sapporo, Hokkaido, 006-8585, Japan.
| | - Kohei Sasaki
- Department of Radiological Technology, Faculty of Health Sciences, Hokkaido University of Science, 7-15-4-1 Maeda, Teine, Sapporo, Hokkaido, 006-8585, Japan
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Palled SR, Radhakrishna NK, Manikantan S, Khanum H, Venugopal BK, Vishwanath L. Dosimetric comparison of manual forward planning with uniform dwell times versus volume-based inverse planning in interstitial brachytherapy of cervical malignancies. Rep Pract Oncol Radiother 2020; 25:851-855. [PMID: 32982589 DOI: 10.1016/j.rpor.2020.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/31/2020] [Accepted: 08/12/2020] [Indexed: 11/26/2022] Open
Abstract
Aim Dosimetic comparison of manual forward planning(MFP) with inverse planning(IP) for interstitial brachytherapy(ISBT) in cervical carcinoma. Background Brachytherapy planning by MFP is more reliable but time-consuming method, whereas IP has been explored more often for its ease and rapidness. The superiority of either is yet to be established. Methodology Two plans were created on data sets of 24 patients of cervical carcinoma who had undergone ISBT, one by MFP with uniform dwell times and another IP on BrachyVision 13.7 planning system with a dose prescription of 600 cGy. Isodose shaper was used for improving conformity & homogeneity. Dosimetric parameters for target and organs at risk (OARs) were recorded. Conformity index (COIN), dose homogeneity index (DHI), overdose index (OI), Coverage index (CI) and dose nonuniformity ratio (DNR) were calculated. Results Mean high risk clinical target volume: 73.05(±20.7)cc, D90: 5.51 Gy vs. 5.6 Gy (p = 0.017), V100: 81.77 % vs. 83.74 % (p = 0.002), V150: 21.7 % vs. 24.93 % (p = 0.002), V200: 6.3 % vs. 6.4 % (p=0.75) for IP and MFP, respectively. CI: 0.81(IP) and 0.83(MFP) (p = 0.003); however, COIN was 0.79 for both plans. D2cc of OARs was statistically better with IP (bladder 54.7 % vs. 56.1 %, p = 0.03; rectum 63 % vs. 64.7 %, (p = 0.0008). Conclusion Both MFP and IP are equally acceptable dosimetrically. With higher dose achieved to the target, for a similar OAR dose, MFP provides greater user flexibility of dwell positions within the target as well as better optimization. Isodose shaper may be carefully used for fine tuning. Larger sample sizes and clinical correlation will better answer the superiority of one over the other.
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Affiliation(s)
- Siddanna R Palled
- Radiation Oncology, Kidwai Memorial Institute of Oncology, Bengaluru, India
| | | | - Senthil Manikantan
- Medical Physicist, Kidwai Memorial Institute of Oncology, Bengaluru, India
| | - Hashmath Khanum
- Radiation Oncology, Kidwai Memorial Institute of Oncology, Bengaluru, India
| | - Bindu K Venugopal
- Radiation Oncology, Kidwai Memorial Institute of Oncology, Bengaluru, India
| | - Lokesh Vishwanath
- Radiation Oncology, Kidwai Memorial Institute of Oncology, Bengaluru, India
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Kumar M, Thangaraj R, Alva RC, Koushik K, Ponni A, Janaki MG. Interstitial high-dose-rate brachytherapy using cobalt-60 source for cervical cancer: dosimetric and clinical outcomes from a single institute. J Contemp Brachytherapy 2020; 12:351-355. [PMID: 33293974 PMCID: PMC7690231 DOI: 10.5114/jcb.2020.98114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 05/18/2020] [Indexed: 02/01/2023] Open
Abstract
PURPOSE To record and report dosimetric and clinical outcomes of interstitial brachytherapy using cobalt-60 (60Co) source in cervical cancer. MATERIAL AND METHODS Seventy patients who underwent external beam radiotherapy with dose of 45 Gy in 25 fractions, followed by interstitial brachytherapy (ISBT) 6.5 Gy × 4 fractions were included into this study. The ISBT applicators were inserted under combined spinal and epidural anesthesia. Computed tomography (CT) simulation was performed and axial CT images were transferred to treatment planning system. High-risk clinical target volume (CTVHR) and organs at risks (OARs) were contoured. Four fractions of 6.5 Gy were prescribed to CTVHR using inverse planning technique. Patients were followed-up for 3 years. Dosimetric parameters and clinical outcomes were recorded and compared with available literature. RESULTS Seventy patients with FIGO stage IIB-IVA were included in the study. The median EQD2 of 2 cm3 of bladder, rectum, sigmoid and D90 CTVHR were 70 Gy (53-75 Gy), 64 Gy (51-71 Gy), 48 Gy (44-72 Gy), and 77 Gy (70-86 Gy), and dose homogeneity index (DHI), dose non-uniformity ratio (DNR), coverage index (CI), overdose volume index (OI), and conformal index (COIN) were 0.58 (0.39-0.78), 0.42 (0.22-0.61), 0.87 (0.59-0.97), 0.19 (0.09-0.30) and 0.74 (0.52-0.85), respectively. Local control rate at 2 years was 87.14%. Eight patients had local recurrence and one patient had lung metastasis. Also, two patients with local recurrence had recto-vaginal fistula. Two patients had grade 2 proctitis (2.8%) and one patient developed grade 3 proctitis (1.4%). There was no grade 2 or higher bladder toxicity. CONCLUSIONS The dosimetric parameters, local control and toxicities of high-dose-rate interstitial brachytherapy in cervical cancer patients treated by 60Co radioactive source are similar, compared to available literature using iridium-192 (192Ir) source.
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Affiliation(s)
| | | | | | | | - Arul Ponni
- Ramaiah Medical College, Bengaluru, India
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Poddar J, Sharma AD, Suryanarayan U, Shah SP, Parikh A, Mehta V, Kumar T. Calculation of dose volume parameters and indices in plan evaluation of HDR interstitial brachytherapy by MUPIT in carcinoma cervix. Indian J Cancer 2019; 55:238-241. [PMID: 30693886 DOI: 10.4103/ijc.ijc_643_17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Evaluation of a HDR- interstitial brachytherapy plan is a challenging job. Owing to the complexities and diversity of the normalization and optimization techniques involved, a simple objective assessment of these plans is required. This can improve the radiation dose coverage of the tumour with decreased organ toxicity. AIM To study and document the various dose volume indices and parameters required to evaluate a HDR interstitial brachytherapy plan by Volume normalization and graphical optimization using MUPIT (Martinez Universal Perineal Interstitial Template) in patients of carcinoma cervix. SETTINGS AND DESIGN Single arm, retrospective study. METHODS AND MATERIALS 35 patients of carcinoma cervix who received EBRT and HDR brachytherapy using MUPIT, were selected. The dose prescribed was 4 Gray/Fraction in four fractions (16Gy/4) treated twice daily, at least 6 hours apart. CTV and OARs were delineated on the axial CT image set. Volume normalization and graphical optimization was done for planning. Coverage Index (CI), Dose homogeneity index (DHI), Overdose index (OI), Dose non-uniformity ratio (DNR), Conformity Index (COIN) and dose volume parameters i.e. D2cc, D1cc, D0.1cc of rectum and bladder were evaluated. STATISTICAL ANALYSIS SPSS version 16 was used. RESULTS AND CONCLUSION CI was 0.95 ± 1.84 which means 95% of the target received 100% of the prescribed dose. The mean COIN was 0.841 ± 0.06 and DHI was 0.502 ± 0.11. D2cc rectum and bladder was 3.40 ± 0.56 and 2.95 ± 0.62 respectively which was within the tolerance limit of this organs. There should be an optimum balance between these indices for improving the quality of the implant and to yield maximum clinical benefit out of it, keeping the dose to the OARs in limit. Dose optimization should be carefully monitered and an institutional protocol should be devised for the acceptability criteria of these plans.
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Affiliation(s)
- Jyoti Poddar
- Department of Radiotherapy, Gujarat Cancer and Research Institute, Ahmedabad, Gujarat, India
| | - Ashutosh Das Sharma
- Department of Radiotherapy, Gujarat Cancer and Research Institute, Ahmedabad, Gujarat, India
| | - U Suryanarayan
- Department of Radiotherapy, Gujarat Cancer and Research Institute, Ahmedabad, Gujarat, India
| | - Sonal Patel Shah
- Department of Radiotherapy, Gujarat Cancer and Research Institute, Ahmedabad, Gujarat, India
| | - Ankita Parikh
- Department of Radiotherapy, Gujarat Cancer and Research Institute, Ahmedabad, Gujarat, India
| | - Vimesh Mehta
- Department of Radiotherapy, Gujarat Cancer and Research Institute, Ahmedabad, Gujarat, India
| | - Tarun Kumar
- Department of Radiotherapy, Gujarat Cancer and Research Institute, Ahmedabad, Gujarat, India
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A feasibility study for using ABS plastic and a low-cost 3D printer for patient-specific brachytherapy mould design. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2015; 38:399-412. [DOI: 10.1007/s13246-015-0356-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 06/11/2015] [Indexed: 10/23/2022]
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Pelagade S, Maddirala HR, Misra R, Suryanarayan U, Neema JP. Dosimetric comparison of volume-based and inverse planning simulated annealing-based dose optimizations for high-dose rate brachytherapy. Med Dosim 2015; 40:235-9. [PMID: 25795565 DOI: 10.1016/j.meddos.2015.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 01/12/2015] [Accepted: 01/12/2015] [Indexed: 11/28/2022]
Abstract
The aim of this study was to compare the clinical benefits of inverse planning simulated annealing (IPSA)-based optimization over volume-based optimization for high-dose rate (HDR) cervix interstitial implants. Overall, 10 patients of cervical carcinoma were considered for treatment with HDR interstitial brachytherapy. Oncentra Master Plan brachytherapy planning system was used for generating 3-dimensional HDR treatment planning for all patients. All patient treatments were planned using volume-based optimization and inverse planning optimization (IPSA). The parameters V100, V150, and V200 for the target; D(2 cm³) of bladder, rectum, and sigmoid colon; and V80 and V100 for bladder, rectum, and sigmoid colon were compared using dose-volume histograms (DVHs). The conformity index (CI), relative dose homogeneity index, overdose volume index (ODI), and dose nonuniformity index (DNR) were computed from cumulative DVHs. Good target coverage for prescription dose was achieved with volume-based optimization as compared with IPSA-based dose optimization. Homogeneity was good with the IPSA-based technique as compared with the volume-based dose optimization technique. Volume-based optimization resulted in a higher CI (with a mean value of 0.87) compared with the IPSA-based optimization (with a mean value of 0.76). ODI and DNR are better for the IPSA-based plan as compared with the volume-based plan. Mean doses to the bladder, rectum, and sigmoid colon were least with IPSA. IPSA also spared the critical organs but with considerable target conformity as compared with the volume-based plan. IPSA significantly reduces overall treatment planning time with improved reduced doses to the organs at risk compared with the volume-based optimization treatment planning method.
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Affiliation(s)
| | | | - Rahul Misra
- Department of Radiotherapy, Gujarat Cancer & Research Institute, Ahmedabad, India
| | - U Suryanarayan
- Department of Radiotherapy, Gujarat Cancer & Research Institute, Ahmedabad, India
| | - J P Neema
- Department of Radiotherapy, Gujarat Cancer & Research Institute, Ahmedabad, India
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Bahadur YA, Constantinescu C, Hassouna AH, Eltaher MM, Ghassal NM, Awad NA. Single versus multichannel applicator in high-dose-rate vaginal brachytherapy optimized by inverse treatment planning. J Contemp Brachytherapy 2015; 6:362-70. [PMID: 25834580 PMCID: PMC4300361 DOI: 10.5114/jcb.2014.47816] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 08/29/2014] [Accepted: 11/11/2014] [Indexed: 11/22/2022] Open
Abstract
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.
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Affiliation(s)
- Yasir A. Bahadur
- Department of Radiology, King Abdulaziz University Hospital, Jeddah, Saudi Arabia
| | - Camelia Constantinescu
- Department of Bio-Medical Physics, King Faisal Specialist Hospital & Research Center, Jeddah, Saudi Arabia
| | - Ashraf H. Hassouna
- Department of Oncology, King Faisal Specialist Hospital & Research Center, Jeddah, Saudi Arabia
- Department of Radiation Oncology, National Cancer Institute, Cairo University, Egypt
| | - Maha M. Eltaher
- Department of Radiology, King Abdulaziz University Hospital, Jeddah, Saudi Arabia
- Department of Radiation Oncology, National Cancer Institute, Cairo University, Egypt
| | - Noor M. Ghassal
- Department of Bio-Medical Physics, King Faisal Specialist Hospital & Research Center, Jeddah, Saudi Arabia
| | - Nesreen A. Awad
- Department of Radiology, King Abdulaziz University Hospital, Jeddah, Saudi Arabia
- Department of Radiation Oncology, National Cancer Institute, Cairo University, Egypt
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De Boeck L, Beliën J, Egyed W. Dose optimization in high-dose-rate brachytherapy: A literature review of quantitative models from 1990 to 2010. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.orhc.2013.12.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Treatment planning methods in high dose rate interstitial brachytherapy of carcinoma cervix: a dosimetric and radiobiological analysis. ISRN ONCOLOGY 2014; 2014:125020. [PMID: 24587919 PMCID: PMC3920807 DOI: 10.1155/2014/125020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 11/19/2013] [Indexed: 11/24/2022]
Abstract
Treatment planning is a trial and error process that determines optimal dwell times, dose distribution, and loading pattern for high dose rate brachytherapy. Planning systems offer a number of dose calculation methods to either normalize or optimize the radiation dose. Each method has its own characteristics for achieving therapeutic dose to mitigate cancer growth without harming contiguous normal tissues. Our aim is to propose the best suited method for planning interstitial brachytherapy. 40 cervical cancer patients were randomly selected and 5 planning methods were iterated. Graphical optimization was compared with implant geometry and dose point normalization/optimization techniques using dosimetrical and radiobiological plan quality indices retrospectively. Mean tumor control probability was similar in all the methods with no statistical significance. Mean normal tissue complication probability for bladder and rectum is 0.3252 and 0.3126 (P = 0.0001), respectively, in graphical optimized plans compared to other methods. There was no significant correlation found between Conformity Index and tumor control probability when the plans were ranked according to Pearson product moment method (r = −0.120). Graphical optimization can result in maximum sparing of normal tissues.
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Gloi AM. First clinical implementation of the Capri applicator. J Appl Clin Med Phys 2014; 15:4581. [PMID: 24423857 PMCID: PMC5711241 DOI: 10.1120/jacmp.v15i1.4581] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/13/2013] [Accepted: 09/09/2013] [Indexed: 12/12/2022] Open
Abstract
This study was to assess the Capri applicator for patients with endometrial cancer undergoing high‐radiation dose treatments following external‐beam radiation therapy. The Capri applicator is an inflatable vaginal cylinder with multiple channels. It is used to tailor the dose distribution to an asymmetric vaginal disease, and better spare organs at risk. Five patients with high‐risk endometrial cancer were selected for this study. The patients were treated with a high dose of radiation using the Capri applicator: daily fraction of 7 Gy was prescribed for a total dose of 21 Gy. The treatment plans included radiobiological parameters such as equivalent uniform dose (EUD), normal tissue complication probability (NTCP), and tumor control probability (TCP). Based on the dose‐volume histograms (DVH), we also calculated four quality factors: conformity index (CI), dose homogeneity index (DHI), dose nonuniformity index (DNR), and overdose index (OI). The TCP values range from 82.26% to 95.92%. Very low values of NTCP were observed for the bladder and rectum. The EUDs to organs at risk ranged from 4.65 Gy to 18.22 Gy for the bladder, and from 3.41 Gy from to 6.56 Gy for the rectum. The mean CI was 1.05(SD=0.0008). The mean DNR was 0.10(range0.0−0.295,SD=0.100). The mean OI was 0.019(SD=0.028). The DHIs were in the range of 1.0−0.754(mean0.886,SD=0.116). The use of a multichannel vaginal cylinder may not only help cover extensive vaginal disease, but also reduce the dose to the rectum. This dosimetric analysis shows that rectal doses could be reduced using a multichannel cylinder. However, the dose delivered to the bladder based on EUD calculation may be higher than that obtained with other methods. Each patient must be evaluated independently to determine if a multichannel treatment is appropriate. Clinical followup will show whether this rectal dose sparing translates into a real toxicity improvement. PACS number: 3.6.96.0
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Ferré M, Mailleux H, Pierrat N, Dejean C. Calcul de la distribution de dose en curiethérapie. Cancer Radiother 2013; 17:89-92. [DOI: 10.1016/j.canrad.2013.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 01/15/2013] [Indexed: 10/27/2022]
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Chopra S, Shukla P, Paul SN, Engineer R, Phurailatpam R, Swamidas J, Mahantshetty U, Shrivastava SK. Evaluation of quality indices during multifractionated pelvic interstitial brachytherapy for cervical cancer. Brachytherapy 2013. [DOI: 10.1016/j.brachy.2012.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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