Does a Three-Field Electron/Minitangent Photon Technique Offer Dosimetric Advantages to a Multifield, Photon-Only Technique for Accelerated Partial Breast Irradiation?

Mydin, Aminudin R.; Gaffney, H.; Bergman, Alanah; McDonald, Rachel; Beckham, Wayne; Truong, Pauline T.; Olivotto, Ivo A.

doi:10.1097/coc.0b013e3181b0c370

Cited by 5 publications

(8 citation statements)

References 15 publications

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“…[3][4][5][6][7] Each modality has been reported ad-vantages and disadvantages, depending on the patient's anatomy and preference, as well as the resources available at a particular radiation oncology facility. 5,8,9) External beam radiation therapy (EBRT), which can be delivered noninvasively, is most common type to deliver PBI using the standard linear accelerator (linac) found in all radiation oncology facilities.…”

Section: Introductionmentioning

confidence: 99%

Effect of Low Magnetic Field on Dose Distribution in the Partial-Breast Irradiation

et al. 2015

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The aim of this study is to investigate the effect of low magnetic field on dose distribution in the partial-breast irradiation (PBI). Eleven patients with an invasive early-stage breast carcinoma were treated prospectively with PBI using 38.5 Gy delivered in 10 fractions using the ViewRay Ⓡ system. For each of the treatment plans, dose distribution was calculated with magnetic field and without magnetic field, and the difference between dose and volume for each organ were evaluated. For planning target volume (PTV), the analysis included the point minimum (Dmin), maximum, mean dose (Dmean) and volume receiving at least 90% (V90%), 95% (V95%) and 107% (V107%) of the prescribed dose, respectively. For organs at risk (OARs), the ipsilateral lung was analyzed with Dmean and the volume receiving 20 Gy (V20 Gy), and the contralateral lung was analyzed with only Dmean. The heart was analyzed with Dmean, Dmax, and V20 Gy, and both inner and outer shells were analyzed with the point Dmin, Dmax and Dmean, respectively. For PTV, the effect of low magnetic field on dose distribution showed a difference of up to 2% for volume change and 4 Gy for dose. In OARs analysis, the significant effect of the magnetic field was not observed. Despite small deviation values, the average difference of mean dose values showed significant difference (p＜0.001), but there was no difference of point minimum dose values in both sehll structures. The largest deviation for the average difference of Dmax in the outer shell structure was 5.0±10.5 Gy (p=0.148). The effect of low magnetic field of 0.35 T on dose deposition by a Co-60 beam was not significantly observed within the body for PBI IMRT plans. The dose deposition was only appreciable outside the body, where a dose build-up due to contaminated electrons generated in the treatment head and scattered electrons formed near the body surface.

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Section: Introductionmentioning

confidence: 99%

Effect of Low Magnetic Field on Dose Distribution in the Partial-Breast Irradiation

et al. 2015

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“…The addition of an electron beam to photons improved conformality but deteriorated homogeneity. According to five reports [ 11 – 14 , 33 ] about the application of the mixed beam technique, the addition of electrons to photon fields decreased the ipsilateral breast dose while the heart and lung doses were different according to the study and obviously the PTV location [ 14 ]. Evidently, the use of an additional electron beam is feasible only in the case of superficial tumour beds [ 10 ].…”

Section: Discussionmentioning

confidence: 99%

“…Due to the rising number of patients needing APBI, and to eliminate the special infrastructural and expertise needs of brachytherapy, the implementation of conformal teletherapy methods, such as 3D-conformal radiation therapy (3D-CRT) with multiple static photon and/or electron fields, intensity-modulated RT (IMRT), volumetric-modulated arc therapy (VMAT), tomotherapy, robotic radiosurgery systems and proton beam therapy has begun emerging [8][9][10][11]. The utilization of a mixed technique combining photon with an 'en face' electron field may result in improved planning target volume (PTV) coverage and organ at risk (OAR) exposure [10][11][12][13][14]. IMRT optimizes dose distribution using structure-based planning and alterable intensity beam fluencies, providing improved dose homogeneity within the PTV, and reduced high dose exposure of normal tissues.…”

Section: Introductionmentioning

confidence: 99%

Individually selected teletherapy technique for accelerated partial breast irradiation

Kószó

Kahán

Darázs

et al. 2021

Rep Pract Oncol Radiother.

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Background:The aim of the study was to individualize accelerated partial breast irradiation based on optimal dose distribution, protect risk organ and predict most advantageous technique.Materials and methods: 138 breast cancer patients receiving postoperative APBI were enrolled. APBI plans were generated using 3D-conformal (3D-CRT), sliding window intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT). In the case of superficial tumours, additional plans were developed by adding electron beam. To planning target volume (PTV) 37.5 Gy/10 fractions, 1 fraction/day was prescribed. A novel plan quality index (PQI) served as the basis for comparisons.Results: IMRT was the most advantageous technique regarding homogeneity. VMAT provided best conformity, 3D-CRT -the lowest lung and heart exposure. PQI was the best in 45 (32.61%) VMAT, 13 (9.42%) IMRT, 9 (6.52%) 3D-CRT plans. In 71 cases (51.45%) no difference was detected. In patients with large PTV, 3D-CRT was the most favourable. Additional electron beam improved PQI of 3D-CRT plans but had no meaningful effect on IMRT or VMAT. IMRT was superior to VMAT if the tumour was superficial (p < 0.001), situated in the medial (p = 0.032) or upper quadrant (p = 0.046). Conclusions:In half of all cases, individually selected teletherapy techniques provide superior results over others; relevance of a certain technique may be predicted by volume and PTV localization.

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“…The addition of electrons to photon beams provides more conformal but less homogenous dose distribution as compared to the photon only technique. We have found five studies dealing with the mixed beam technique in APBI [83,[90][91][92][93]. All agreed that this approach may lower the ipsilateral breast dose; lung and heart doses varied according to study, and obviously the situation of the tumour bed [92].…”

Section: Dosimetric Comparison Of 3d-crt Sliding Window Imrt and Vmamentioning

confidence: 96%

“…We have found five studies dealing with the mixed beam technique in APBI [83,[90][91][92][93]. All agreed that this approach may lower the ipsilateral breast dose; lung and heart doses varied according to study, and obviously the situation of the tumour bed [92]. Clearly, the use of electrons should be reserved for tumours non-deeply located [94].…”

Section: Dosimetric Comparison Of 3d-crt Sliding Window Imrt and Vmamentioning

confidence: 99%

Individualised radiotherapy serving reduced toxicity in breast and prostate cancer

Kószó¹

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The presence of normal tissues in the irradiated volume limits dose escalation during pelvic radiotherapy (RT) for prostate cancer. Supine and prone positions on a belly board were compared by analyzing the exposure of organs at risk (OARs) using intensity modulated RT (IMRT). The prospective trial included 55 high risk, localized or locally advanced prostate cancer patients, receiving definitive image-guided RT. Computed tomography scanning for irradiation planning was carried out in both positions. Gross tumor volume, clinical and planning target volumes (PTV) and OARs were delineated, defining subprostatic and periprostatic rectal subsegments. At the height of the largest antero-posterior (AP) diameter of the prostate, rectal diameters and distance from the posterior prostate wall were measured. IMRT plans were generated. Normal tissue exposure and structure volumes were compared between supine and prone plans using paired t-test. In the volumes of the prostate, PTV, colon and small bowel, no significant differences were found. In prone position, all rectal volumes, diameters, and rectum-prostate distance were significantly higher, the irradiated colon and small bowel volume was lower in dose ranges of 20-40 Gy, and the exposure to all rectal segments was more favorable in 40-75 Gy dose ranges. No significant difference was found in the exposure of other OARs. Prone positioning on a belly board is an appropriate positioning method aiming rectum and bowel protection during pelvic IMRT of prostate cancer. The relative reduction in rectal exposure might be a consequence of the slight departure between the prostate and rectal wall.

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Does a Three-Field Electron/Minitangent Photon Technique Offer Dosimetric Advantages to a Multifield, Photon-Only Technique for Accelerated Partial Breast Irradiation?

Abstract: The three-field electron/minitangent photon APBI technique was more conformal and reduced the dose to the ipsilateral breast but had the disadvantage of exposing increased volumes of heart and ipsilateral lung to low-dose radiation compared with the photon-only technique.

Cited by 5 publications

References 15 publications

Effect of Low Magnetic Field on Dose Distribution in the Partial-Breast Irradiation

Effect of Low Magnetic Field on Dose Distribution in the Partial-Breast Irradiation

Individually selected teletherapy technique for accelerated partial breast irradiation

Individualised radiotherapy serving reduced toxicity in breast and prostate cancer

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