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Onal C, Bozca R, Dolek Y, Elmali A, Guler OC. A Comparative Analysis of Implant-sparing Plan Versus Conventional Plans Utilizing Helical Tomotherapy in Breast Cancer Patients Undergoing Breast Reconstruction. In Vivo 2024; 38:1412-1420. [PMID: 38688603 PMCID: PMC11059874 DOI: 10.21873/invivo.13583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 05/02/2024]
Abstract
BACKGROUND/AIM To compare implant sparing irradiation with conventional radiotherapy (RT) using helical (H) and TomoDirect (TD) techniques in breast cancer patients undergoing immediate breast reconstruction (IBR). PATIENTS AND METHODS The dosimetric parameters of 40 patients with retropectoral implants receiving 50.4 Gy delivered in 28 fractions were analyzed. Three plans were created: H plan using conventional planning target volume (PTV) that included the chest wall, skin, and implant; TD plan using conventional PTV; and Hs plan using implant-sparing PTV. The H, TD, and Hs plans were compared for PTV doses, organ-at-risk (OAR) doses, and treatment times. RESULTS Dose distribution in the Hs plan was less homogeneous and uniform than that in the H and TD plans. The TD plan had lower lung, heart, contralateral breast, spinal cord, liver, and esophagus doses than the Hs plan. Compared to the Hs plan, the H plan had lower lung volume receiving 5Gy (V5) (39.1±3.9 vs. 41.2±3.9 Gy; p<0.001), higher V20 (12.3±1.3 vs. 11.5±2.6 Gy; p=0.02), and higher V30 (7.5±1.6 vs. 4.4±1.7 Gy; p<0.001). H plan outperformed Hs plan in heart dosimetric parameters except V20. The Hs plan had significantly lower mean implant doses (43.4±2.1 Gy) than the H plan (51.4±0.5 Gy; p<0.001) and the TD plan (51.9±0.6 Gy; p<0.001). Implementing an implant sparing technique for silicone dose reduction decreases lung doses. CONCLUSION Conventional H and TD plans outperform the implant sparing helical plan dosimetrically. Because capsular contracture during RT is unpredictable, long-term clinical outcomes are required to determine whether silicon should be spared.
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Affiliation(s)
- Cem Onal
- Department of Radiation Oncology, Baskent University Faculty of Medicine Adana Dr Turgut Noyan Research and Treatment Center, Adana, Turkey;
- Department of Radiation Oncology, Baskent University Faculty of Medicine, Ankara, Turkey
| | - Recep Bozca
- Department of Radiation Oncology, Baskent University Faculty of Medicine, Ankara, Turkey
| | - Yemliha Dolek
- Department of Radiation Oncology, Baskent University Faculty of Medicine Adana Dr Turgut Noyan Research and Treatment Center, Adana, Turkey
| | - Aysenur Elmali
- Department of Radiation Oncology, Baskent University Faculty of Medicine, Ankara, Turkey
| | - Ozan Cem Guler
- Department of Radiation Oncology, Baskent University Faculty of Medicine Adana Dr Turgut Noyan Research and Treatment Center, Adana, Turkey
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Onal C, Bozca R, Dolek Y, Guler O, Arslan G. PO-1382: Incidental testicular doses during volumetricmodulated ARC radiotherapy in prostate cancer patients. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01400-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Onal C, Ozyigit G, Guler OC, Hurmuz P, Torun N, Tuncel M, Dolek Y, Yedekci Y, Oymak E, Tilki B, Akyol F. Role of 68-Ga-PSMA-PET/CT in pelvic radiotherapy field definitions for lymph node coverage in prostate cancer patients. Radiother Oncol 2020; 151:222-227. [DOI: 10.1016/j.radonc.2020.08.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/21/2020] [Accepted: 08/25/2020] [Indexed: 02/07/2023]
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Onal C, Bozca R, Dolek Y, Guler OC, Arslan G. Incidental testicular doses during volumetric-modulated arc radiotherapy in prostate cancer patients. Radiol Med 2020; 125:777-783. [PMID: 32125635 DOI: 10.1007/s11547-020-01158-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/19/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE To compare the incidental testicular doses during volumetric-modulated arc therapy (VMAT) in patients receiving prostate-only and pelvic lymphatic irradiation. MATERIALS AND METHODS Testicular doses in 40 intermediate- and high-risk prostate cancer patients were determined on treatment planning system (TPS) using the VMAT technique at 6 MV. Scattered testicular doses were also measured by MOSFET detectors placed on testis surface. The testicular doses of patients treated with prostate-only and pelvic field irradiation were compared. RESULTS The median testicular doses measured per 200 cGy fraction by TPS and MOSFET detectors were 1.7 cGy (0.7-4.1 cGy) and 4.8 cGy (3.6-8.8 cGy), respectively. The TPS doses and MOSFET readings showed a significant strong correlation (Pearson r = 0.848, p < 0.001). The testicular doses measured by TPS (1.34 ± 0.36 cGy vs. 2.60 ± 0.95 cGy; p < 0.001) and MOSFET (4.52 ± 0.64 cGy vs. 6.56 ± 1.23 cGy; p < 0.001) were significantly lower in patients with prostate-only irradiation than in those with pelvic field irradiation. The mean cumulative scattered dose for prostate-only field delivering 78 Gy was 1.8 Gy and that for pelvic field irradiation was 2.6 Gy, consistent with the reported findings. CONCLUSIONS The patients with prostate-only irradiation received lower testicular doses than those with additional pelvic field irradiation possibly due to the increased scattered doses in large field irradiation using the VMAT technique. The clinical response to increased incidental testicular doses due to pelvic field irradiation remains unknown, and it warrants further investigation.
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Affiliation(s)
- Cem Onal
- Adana Dr. Turgut Noyan Research and Treatment Center, Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120, Adana, Turkey.
| | - Recep Bozca
- Adana Dr. Turgut Noyan Research and Treatment Center, Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120, Adana, Turkey
| | - Yemliha Dolek
- Adana Dr. Turgut Noyan Research and Treatment Center, Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120, Adana, Turkey
| | - Ozan Cem Guler
- Adana Dr. Turgut Noyan Research and Treatment Center, Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120, Adana, Turkey
| | - Gungor Arslan
- Adana Dr. Turgut Noyan Research and Treatment Center, Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120, Adana, Turkey
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Yildirim BA, Dolek Y, Guler OC, Arslan G, Onal C. Dosimetric comparison of vaginal vault brachytherapy vs applicator-guided stereotactic body radiotherapy with volumetric modulated arc therapy and helical tomotherapy for endometrium cancer patients. Med Dosim 2018; 44:332-338. [PMID: 30551844 DOI: 10.1016/j.meddos.2018.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 11/10/2018] [Accepted: 11/27/2018] [Indexed: 10/27/2022]
Abstract
We performed this dosimetric study to compare a nonstandard volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT) techniques with high-dose rate (HDR) brachytherapy (BRT) plan of vaginal vault in patients with postoperative endometrial cancer (EC). Twelve postoperative patients with early stage EC were included in this study. Three plans were performed for each patient; dosimetric and radiobiological comparisons were made using dose-volume histograms and equivalent dose for determining the planning target volume (PTV) coverages in brachytherapy and external beam radiotherapy, and organs-at-risk (OARs) doses between three different delivery techniques. All the plans achieved adequate dose coverage for PTV; however, the VMAT plan yielded better dose conformity, and the HT plan showed better homogeneity for target volume. With respect to the OARs, the bladder D2cc was significantly lower in the BRT plan than in the VMAT and HT plans, with the highest bladder D2cc value being observed in the HT plan. However, no difference was observed in the rectum D2cc of the three plans. Other major advantages of the BRT plan over the VMAT and HT plans were the relatively lower body integral doses and femoral head doses as well as the fact that the integral doses were significantly lower in the BRT plan than in the VMAT and HT plans. This is the first dosimetric comparison of vaginal vault treatment for EC with BRT, VMAT, and HT plans. Our analyses showed the feasibility of stereotactic body radiotherapy technique as an alternative to HDR-BRT for postoperative management of EC patients.
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Affiliation(s)
- Berna Akkus Yildirim
- Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120 Adana, Turkey
| | - Yemliha Dolek
- Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120 Adana, Turkey
| | - Ozan Cem Guler
- Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120 Adana, Turkey
| | - Gungor Arslan
- Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120 Adana, Turkey
| | - Cem Onal
- Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120 Adana, Turkey.
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Onal C, Dolek Y, Ozdemir Y. The impact of androgen deprivation therapy on setup errors during external beam radiation therapy for prostate cancer. Strahlenther Onkol 2017; 193:472-482. [PMID: 28409246 DOI: 10.1007/s00066-017-1131-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 03/22/2017] [Indexed: 02/03/2023]
Abstract
PURPOSE To determine whether setup errors during external beam radiation therapy (RT) for prostate cancer are influenced by the combination of androgen deprivation treatment (ADT) and RT. MATERIALS AND METHODS Data from 175 patients treated for prostate cancer were retrospectively analyzed. Treatment was as follows: concurrent ADT plus RT, 33 patients (19%); neoadjuvant and concurrent ADT plus RT, 91 patients (52%); RT only, 51 patients (29%). Required couch shifts without rotations were recorded for each megavoltage (MV) cone beam computed tomography (CBCT) scan, and corresponding alignment shifts were recorded as left-right (x), superior-inferior (y), and anterior-posterior (z). The nonparametric Mann-Whitney test was used to compare shifts by group. Pearson's correlation coefficient was used to measure the correlation of couch shifts between groups. Mean prostate shifts and standard deviations (SD) were calculated and pooled to obtain mean or group systematic error (M), SD of systematic error (Σ), and SD of random error (σ). RESULTS No significant differences were observed in prostate shifts in any direction between the groups. Shifts on CBCT were all less than setup margins. A significant positive correlation was observed between prostate volume and the z‑direction prostate shift (r = 0.19, p = 0.04), regardless of ADT group, but not between volume and x‑ or y‑direction shifts (r = 0.04, p = 0.7; r = 0.03, p = 0.7). Random and systematic errors for all patient cohorts and ADT groups were similar. CONCLUSION Hormone therapy given concurrently with RT was not found to significantly impact setup errors. Prostate volume was significantly correlated with shifts in the anterior-posterior direction only.
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Affiliation(s)
- Cem Onal
- Faculty of Medicine, Adana Dr. Turgut Noyan Research and Treatment Centre, Department of Radiation Oncology, Baskent University, 01120, Adana, Turkey.
| | - Yemliha Dolek
- Faculty of Medicine, Adana Dr. Turgut Noyan Research and Treatment Centre, Department of Radiation Oncology, Baskent University, 01120, Adana, Turkey
| | - Yurday Ozdemir
- Faculty of Medicine, Adana Dr. Turgut Noyan Research and Treatment Centre, Department of Radiation Oncology, Baskent University, 01120, Adana, Turkey
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Onal C, Cengiz M, Guler OC, Dolek Y, Ozkok S. The role of delineation education programs for improving interobserver variability in target volume delineation in gastric cancer. Br J Radiol 2017; 90:20160826. [PMID: 28339289 DOI: 10.1259/bjr.20160826] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE To assess whether delineation courses for radiation oncologists improve interobserver variability in target volume delineation for post-operative gastric cancer radiotherapy planning. METHODS 29 radiation oncologists delineated target volumes in a gastric cancer patient. An experienced radiation oncologist lectured about delineation based on contouring atlas and delineation recommendations. After the course, the radiation oncologists, blinded to the previous delineation, provided delineation for the same patient. RESULTS The difference between delineated volumes and reference volumes for pre- and post-course clinical target volume (CTV) were 19.8% (-42.4 to 70.6%) and 12.3% (-12.0 to 27.3%) (p = 0.26), respectively. The planning target volume (PTV) differences pre- and post-course according to the reference volume were 20.5% (-40.7 to 93.7%) and 13.1% (-10.6 to 29.5%) (p = 0.30), respectively. The concordance volumes between the pre- and post-course CTVs and PTVs were 467.1 ± 89.2 vs 597.7 ± 54.6 cm3 (p < 0.001) and 738.6 ± 135.1 vs 893.2 ± 144.6 cm3 (p < 0.001), respectively. Minimum and maximum observer variations were seen at the cranial part and splenic hilus and at the caudal part of the CTV. The kappa indices compared with the reference contouring at pre- and post-course delineations were 0.68 and 0.82, respectively. CONCLUSION The delineation course improved interobserver variability for gastric cancer. However, impact of target volume changes on toxicity and local control should be evaluated for further studies. Advances in knowledge: This study demonstrated that a delineation course based on current recommendations helped physicians delineate smaller and more homogeneous target volumes. Better target volume delineation allows proper target volume irradiation and preventing unnecessary normal tissue irradiation.
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Affiliation(s)
- Cem Onal
- 1 Department of Radiation Oncology, Faculty of Medicine, Baskent University, Adana, Turkey
| | - Mustafa Cengiz
- 2 Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Ozan C Guler
- 1 Department of Radiation Oncology, Faculty of Medicine, Baskent University, Adana, Turkey
| | - Yemliha Dolek
- 1 Department of Radiation Oncology, Faculty of Medicine, Baskent University, Adana, Turkey
| | - Serdar Ozkok
- 3 Department of Radiation Oncology, Faculty of Medicine, Ege University, Izmir, Turkey
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Onal C, Dolek Y, Akkus Yildirim B. Dosimetric comparison of 3-dimensional conformal radiotherapy, volumetric modulated ARC therapy, and helical tomotherapy for postoperative gastric cancer patients. Eur J Cancer 2017. [DOI: 10.1016/s0959-8049(17)30344-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Onal C, Dolek Y, Ozdemir Y. The impact of hormone therapy on setup errors during external beam radiation therapy for prostate cancer. Eur J Cancer 2017. [DOI: 10.1016/s0959-8049(17)30694-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Yildirim BA, Onal C, Dolek Y. Is it essential to use fiducial markers during cone-beam CT-based radiotherapy for prostate cancer patients? Jpn J Radiol 2016; 35:3-9. [PMID: 27730453 DOI: 10.1007/s11604-016-0590-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 09/29/2016] [Indexed: 12/31/2022]
Abstract
PURPOSE To compare soft-tissue cone-beam computed tomography (CBCT-P) and fiducial marker (CBCT-FM)-based image guided radiotherapy in prostate cancer patients. MATERIALS AND METHODS Sixteen prostate cancer patients were treated with volumetric modulated arc therapy. Manual alignment using CBCT-P and CBCT-FM was performed for each patient. Couch shifts were calculated and compared between methods in the left-right (x), superior-inferior (y), and anterior-posterior (z) directions. RESULTS CBCT-P and CBCT-FM alignments were compared using 252 scans from the 16 patients. Mean displacement from zero was 2.4 ± 1.3, 1.7 ± 1.2, and 1.8 ± 1.1 mm for CBCT-P and 2.3 ± 1.3, 1.7 ± 1.1 and 1.8 ± 1.1 mm for CBCT-FM in the x, y and z directions, respectively. There was no difference in median displacement between CBCT-P and CBCT-FM; however, there was a significant positive correlation between CBCT-P- and CBCT-FM-based displacements in the x (r = 0.881; p < 0.001), y (r = 0.789; p < 0.001) and z (r = 0.856; p < 0.001) directions by linear regression analysis. Systematic deviations within each group were <1 mm; however, random and systematic errors were similar in the x and y directions but larger in the z direction. CONCLUSION Our study demonstrated that CBCT-FM was not superior to CBCT-P for image-guided radiotherapy in prostate cancer patients.
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Affiliation(s)
- Berna A Yildirim
- Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120, Adana, Turkey
| | - Cem Onal
- Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120, Adana, Turkey.
| | - Yemliha Dolek
- Department of Radiation Oncology, Baskent University Faculty of Medicine, 01120, Adana, Turkey
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Onal C, Arslan G, Dolek Y, Efe E. EP-1692: Dosimetric analysis of testicular doses in prostate radiotherapy at different energy levels. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32943-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Onal C, Arslan G, Dolek Y, Efe E. Dosimetric analysis of testicular doses in prostate intensity-modulated and volumetric-modulated arc radiation therapy at different energy levels. Med Dosim 2016; 41:310-314. [DOI: 10.1016/j.meddos.2016.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 07/11/2016] [Accepted: 07/14/2016] [Indexed: 10/21/2022]
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Onal C, Guler O, Dolek Y, Cengiz M. The Role of Delineation Courses for Improving Observer Variability in Target Delineation for Gastric Cancer. Int J Radiat Oncol Biol Phys 2015. [DOI: 10.1016/j.ijrobp.2015.07.985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
OBJECTIVE To evaluate the incidence, size and predisposing factors for air pockets around the vaginal cylinder and their dosimetric effect on the vaginal mucosa. METHODS We investigated 174 patients with endometrial carcinoma treated with external radiotherapy (RT) and brachytherapy (BRT) (101 patients, 58%) or BRT alone (73 patients, 42%). The quantity, volume and dosimetric impact of the air pockets surrounding the vaginal cylinder were quantified. The proportions of patients with or without air pockets during application were stratified according to menopausal status, treatment modality and interval between surgery and RT. RESULTS Air pockets around the vaginal cylinder were seen in 75 patients (43%), while 99 patients (57%) had no air pockets. Only 11 patients (6.3%) received less than the prescribed dose (average 93.9% of prescribed dose; range, 79.0-99.2%). Air pockets were significantly fewer in pre-menopausal patients or in patients treated with the combination of external RT and BRT than in post-menopausal patients or patients treated with BRT alone. A significant correlation existed between the mucosal displacement of the air gap and the ratio of the measured dose at the surface of the air gap and prescribed dose (Pearson r = -0.775; p < 0.001). CONCLUSION Air pockets were still a frequent problem during vaginal vault BRT, especially in post-menopausal patients or in patients treated with BRT alone, which may potentially cause dose reductions at the vaginal mucosa. ADVANCES IN KNOWLEDGE Air pockets around the vaginal cylinder remain a significant problem, which may potentially cause dose reduction in the target volume.
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Affiliation(s)
- C Onal
- Department of Radiation Oncology, Baskent University Faculty of Medicine, Adana, Turkey
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Onal C, Sonmez A, Arslan G, Oymak E, Kotek A, Efe E, Sonmez S, Dolek Y. Dosimetric comparison of the field-in-field technique and tangential wedged beams for breast irradiation. Jpn J Radiol 2011; 30:218-26. [PMID: 22183829 DOI: 10.1007/s11604-011-0034-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Accepted: 11/15/2011] [Indexed: 10/14/2022]
Abstract
PURPOSE To analyze tangential wedged beam and field-in-field (FIF) technique doses using dose-volume histograms and conformality indices for target volume and healthy tissues within the irradiated volume. MATERIALS AND METHODS Thirty patients treated with breast-conserving surgery and postoperative whole breast radiotherapy were enrolled. Three plans were generated: a standard tangential plan with either one outer field wedge or bilateral wedges, and an FIF plan. Three indices were used: the dose homogeneity index (DHI), PTV dose improvement index (PDI(index)) and geometric conformity index (g). Also ipsilateral lung, heart and contralateral breast doses were compared for each plan. RESULTS Dose homogeneity index was significantly lower for the FIF (0.117 ± 0.021) than for the single wedge (0.131 ± 0.025, p = 0.02) and double wedged plan (0.128 ± 0.025, p = 0.04), respectively. The g was significantly less in the FIF (0.70 ± 0.14) compared to the wedge plans (0.80 ± 0.17, p = 0.02 and 0.83 ± 0.16, p = 0.003). Contralateral breast doses were significantly lower in the FIF plan. The FIF plan significantly lowered MU compared to both the single wedge and bilateral wedge plans. CONCLUSION The dose distribution within the target was more homogenous, and the doses for healthy tissue were less in the FIF plan compared to the tangential wedge plans.
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Affiliation(s)
- Cem Onal
- Department of Radiation Oncology, Adana Research and Treatment Centre, Baskent University Faculty of Medicine, 01120 Adana, Turkey.
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Pehlivan B, Topkan E, Onal C, Nursal GN, Yuksel O, Dolek Y, Yavuz MN, Yavuz AA. Comparison of CT and integrated PET-CT based radiation therapy planning in patients with malignant pleural mesothelioma. Radiat Oncol 2009; 4:35. [PMID: 19758456 PMCID: PMC2754492 DOI: 10.1186/1748-717x-4-35] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Accepted: 09/16/2009] [Indexed: 11/19/2022] Open
Abstract
Background When combined with adequate tumoricidal doses, accurate target volume delineation remains to be the one of the most important predictive factors for radiotherapy (RT) success in locally advanced or medically inoperable malignant pleural mesothelioma (MPM) patients. Recently, 18-fluorodeoxyglucose positron emission tomography (PET) has demonstrated significant improvements in diagnosis and accurate staging of MPM. However, role of additional PET data has not been studied in RT planning (RTP) of patients with inoperable MPM or in those who refuse surgery. Therefore, we planned to compare CT with co-registered PET-CT as the basis for delineating target volumes in these patients group. Methods Retrospectively, the CT and co-registered PET-CT data of 13 patients with histologically proven MPM were utilized to delineate target volumes separately. For each patient, target volumes (gross tumor volume [GTV], clinical target volume [CTV], and planning target volume [PTV]) were defined using the CT and PET-CT fusion data sets. The PTV was measured in two ways: PTV1 was CTV plus a 1-cm margin, and PTV2 was GTV plus a 1-cm margin. We analyzed differences in target volumes. Results In 12 of 13 patients, compared to CT-based delineation, PET-CT-based delineation resulted in a statistically significant decrease in the mean GTV, CTV, PTV1, and PTV2. In these 12 patients, mean GTV decreased by 47.1% ± 28.4%, mean CTV decreased by 38.7% ± 24.7%, mean PTV1 decreased by 31.1% ± 23.1%, and mean PTV2 decreased by 40.0% ± 24.0%. In 4 of 13 patients, hilar lymph nodes were identified by PET-CT that was not identified by CT alone, changing the nodal status of tumor staging in those patients. Conclusion This study demonstrated the usefulness of PET-CT-based target volume delineation in patients with MPM. Co-registration of PET and CT information reduces the likelihood of geographic misses, and additionally, significant reductions observed in target volumes may potentially allow escalation of RT dose beyond conventional limits potential clinical benefits in tumor control rates, which needs to be tested in future studies.
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Affiliation(s)
- Berrin Pehlivan
- Department of Radiation Oncology, Baskent University Medical Faculty, Adana Medical and Research Center, Kisla Campus, Adana, Turkey.
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