Intensity-Modulated Radiotherapy in Patients with Cervical Cancer. An intra-individual Comparison of Prone and Supine Positioning

Stromberger, Carmen; Kom, Yves; Kawgan-Kagan, Michael; Mensing, Tristan; Jahn, Ulrich; Schneider, Achim; Budach, Volker; Köhler, Christian; Marnitz, Simone

doi:10.1186/1748-717x-5-63

Cited by 18 publications

(8 citation statements)

References 45 publications

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“…The benefit of prone positioning in reducing low-intermediate doses (<50% of prescription) to SB has not been consistent across studies 5, 16, 17. Some of this variability may be due to differences in patient positioning and belly board construction.…”

Section: Discussionmentioning

confidence: 98%

Impact of prone versus supine positioning on small bowel dose with pelvic intensity modulated radiation therapy

Gonzalez

Hullett

Burt

et al. 2017

Advances in Radiation Oncology

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PurposeTo report the results of a prospective study that compares small bowel doses during prone and supine pelvic intensity modulated radiation therapy.Methods and materialsTen patients receiving pelvic radiation therapy each had 2 intensity modulated radiation therapy plans generated: supine and prone on a belly board (PBB). Computed tomography on rails was performed weekly throughout treatment in both positions (10 scans per patient). After image fusion, doses to small bowel (SB) loops and clinical target volume were calculated for each scan. Changes between the planned and received doses were analyzed and compared between positions. The impact of bladder filling on SB dose was also assessed.ResultsProne treatment was associated with significantly lower volumes of SB receiving ≥20 Gy. On average, prone on a belly board positioning reduced the volume of SB receiving a given dose of radiation by 28% compared with supine positioning. Target coverage throughout the treatment course was similar in both positions with an average minimum clinical target volume dose of 88% of the prescribed prone dose and 89% of the supine (P = .54). For supine treatment, SB dose was inversely correlated with bladder filling (P = .001-.013; P > .15 for prone). For 96% of treatments, the volume of SB that received a given dose deviated >10% from the plan. The deviation between the planned and delivered doses to SB did not differ significantly between the positions.ConclusionsProne positioning on a belly board during pelvic IMRT consistently reduces the volume of SB that receives a broad range of radiation doses. Prone IMRT is associated with interfraction dose variation to SB that is similar to that of supine positioning. These findings suggest that prone positioning with daily image guided radiation therapy is an effective method for maximizing SB sparing during pelvic IMRT.

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Section: Discussionmentioning

confidence: 98%

Impact of prone versus supine positioning on small bowel dose with pelvic intensity modulated radiation therapy

Gonzalez

Hullett

Burt

et al. 2017

Advances in Radiation Oncology

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“…The use of IMRT technique decreases bowel doses by 40-50%, as compared to 3D-CRT [38,39]. In case of gynecological and rectal tumors, a belly board assisted prone position using IMRT results in a further reduction in the irradiated volume of the small intestine, even in low dose areas [40,41]. The advantage of the use of a belly board is also confirmed in postoperatively irradiated patients [42,43], which might be the consequence of the significantly higher mobilization of the small intestine loops.…”

Section: Discussionmentioning

confidence: 99%

Prone Positioning on a Belly Board Decreases Rectal and Bowel Doses in Pelvic Intensity-Modulated Radiation Therapy (IMRT) for Prostate Cancer

Kószó

Varga

Fodor

et al. 2018

Pathol. Oncol. Res.

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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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“…Additionally, the homogeneity index (HI) and conformity index (CI) of target were also calculated by the following: [30] and [31]. For OARs, the mean dose (D mean ) and max dose (D max ) of rectum and bladder were reported, and the volume of these OARs receiving more than 20, 30, 40 and 50 Gy (V 20 , V 30 , V 40 , V 50 ) were analyzed [32, 33]. …”

Section: Methodsmentioning

confidence: 99%

An integrated strategy of biological and physical constraints in biological optimization for cervical carcinoma

et al. 2017

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BackgroundFor cervical carcinoma cases, this study aimed to evaluate the quality of intensity-modulated radiation therapy (IMRT) plans optimized by biological constraints. Furthermore, a new integrated strategy in biological planning module was proposed and verified.MethodsTwenty patients of advanced stage cervical carcinoma were enrolled in this study. For each patient, dose volume optimization (DVO), biological model optimization (BMO) and integrated strategy optimization (ISO) plans were created using same treatment parameters. Different biological models were also used for organ at risk (OAR) in BMO plans, which include the LKB and Poisson models. Next, BMO plans were compared with their corresponding DVO plans, in order to evaluate BMO plan quality. ISO plans were also compared with DVO and BMO plans, in order to verify the performance of the integrated strategy.ResultsBMO plans produced slightly inhomogeneity and less coverage of planning target volume (PTV) (V95=96.79, HI = 0.10: p < 0.01). However, the tumor control probability (TCP) value, both from DVO and BMO plans, were comparable. For the OARs, BMO plans produced lower normal tissue complication probability (NTCP) of rectum (NTCP = 0.11) and bladder (NTCP = 0.14) than in the corresponding DVO plans (NTCP = 0.19 and 0.18 for rectum and bladder; p < 0.01 for rectum and p = 0.03 for bladder). V95, D98, CI and HI values that were produced by ISO plans (V95 = 98.31, D98 = 54.18Gy, CI = 0.76, HI = 0.09) were greatly better than BMO plans (V95 = 96.79, D98 = 53.42Gy, CI = 0.71, HI = 0.10) with significant differences. Furthermore, ISO plans produced lower NTCP values of rectum (NTCP = 0.14) and bladder (NTCP = 0.16) than DVO plans (NTCP = 0.19 and 0.18 for rectum and bladder, respectively) with significant differences.ConclusionsBMO plans produced lower NTCP values of OARs compared to DVO plans for cervical carcinoma cases, and resulted in slightly less target coverage and homogeneity. The integrated strategy, proposed in this study, could improve the coverage, conformity and homogeneity of PTV greater than the BMO plans, as well as reduce the NTCP values of OARs greater than the DVO plans.

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Intensity-Modulated Radiotherapy in Patients with Cervical Cancer. An intra-individual Comparison of Prone and Supine Positioning

Cited by 18 publications

References 45 publications

Impact of prone versus supine positioning on small bowel dose with pelvic intensity modulated radiation therapy

Impact of prone versus supine positioning on small bowel dose with pelvic intensity modulated radiation therapy

Prone Positioning on a Belly Board Decreases Rectal and Bowel Doses in Pelvic Intensity-Modulated Radiation Therapy (IMRT) for Prostate Cancer

An integrated strategy of biological and physical constraints in biological optimization for cervical carcinoma

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