Rectal and bladder motion during conformal radiotherapy after radical prostatectomy

Fiorino, Claudio; Foppiano, F.; Franzone, P.; Broggi, S.; Castellone, Pietro; Marcenaro, Michela; Calandrino, R.; Sanguineti, Giuseppe

doi:10.1016/j.radonc.2004.10.002

Cited by 92 publications

(62 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As reported in a recent study, urinary toxicity increases as patients are treated with smaller bladder volumes [18]. Our patients were treated with a mean initial bladder volume of 259 cm 3 , in contrast to 91 cm 3 for the patients in the mentioned study [4]. With possibly less urinary symptoms, the bladder volumes of our patients did not decrease significantly.…”

Section: Volumessupporting

confidence: 42%

“…The increasing CTV size during the course of RT was caused by decreasing bladder and rectal volumes due to urinary and bowel urgency. Fiorino et al [4] described a trend for a rectum volume reduction and significantly smaller bladder volumes during RT in a postoperative study. As reported in a recent study, urinary toxicity increases as patients are treated with smaller bladder volumes [18].…”

Section: Volumesmentioning

confidence: 95%

“…Fiorino et al [4] found a systematic anterior rectal motion during postoperative RT, with consequential higher rectum doses compared to the primary plan, particularly for patients treated < 100 days after surgery. The RT in our study did not start before a postoperative interval of 6 months (to achieve optimal recovery of urinary continence), so that this trend has not been observed.…”

Section: Treatment Planningmentioning

confidence: 99%

“…Only one recent study dealt with organ motion during post-radical prostatectomy RT [4]. A few reports on post-radical prostatectomy intensity-modulated radiotherapy (IMRT) exist [1,23].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Postoperative Radiotherapy for Prostate Cancer

Pinkawa

Siluschek²,

Gagel³

et al. 2007

Strahlenther Onkol

View full text Add to dashboard Cite

show abstract

Section: Volumessupporting

confidence: 42%

Section: Volumesmentioning

confidence: 95%

Section: Treatment Planningmentioning

confidence: 99%

“…Only one recent study dealt with organ motion during post-radical prostatectomy RT [4]. A few reports on post-radical prostatectomy intensity-modulated radiotherapy (IMRT) exist [1,23].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Postoperative Radiotherapy for Prostate Cancer

Pinkawa

Siluschek²,

Gagel³

et al. 2007

Strahlenther Onkol

View full text Add to dashboard Cite

show abstract

“…Hartford et al observed that DVH curves (n = 41) could be statistically successfully grouped into low, medium, and high risk categories, and that a parallelfunction model could be fit which tracked increasing risk (although the model parameters were not given) [97]. As shown by Fiorino et al [98], fraction-to-fraction relative motion of rectal tissue with respect to the high dose-volume causes significant uncertainty in the actual delivered rectal DVH. It seems clear that there is a strong need for imageguided techniques (in addition to effective immobilization, if possible) to better define true rectal DVHs.…”

Section: Late Rectal Toxicity Due To External Beam Prostate Cancer Trmentioning

confidence: 99%

Image-Based Modeling of Normal Tissue Complication Probability for Radiation Therapy

Deasy

Naqa

2008

Cancer Treatment and Research

View full text Add to dashboard Cite

Radiation therapy dose distributions to eradicate tumor cells are typically constrained in extent or intensity to minimize the risk of injury to nearby critical normal tissues. With the widespread use of 3D image-based treatment planning systems, the question naturally arises how patient-specific anatomy and treatment differences affect outcome. It has long been known, that for many organs, variations in the fractional volume irradiated to high doses greatly alters the dose to achieve a given complication level (the "isoeffective dose") [1]. Smaller irradiated fractional volumes often lead to a much lower risk of complication; this is often referred to as the "volume-effect" in the literature, but would be more correctly referred to as the "dose-volume" effect. Normal tissue complication probability (NTCP) modeling is simply the ongoing effort to understand the risk of normal tissue injury as a function of the 3D dose distribution. Recently, there has been a steady accumulation of NTCP studies [2], and this is expected to continue or even accelerate in the future. NTCP models are particularly needed when the "volume-effect" becomes important (i.e., injury depends on the detailed dose distribution), such as for skin, lung, or liver. In this chapter we will review the basic principles of NTCP modeling, as well as publications related to selected endpoints (xerostomia, radiation pneumonitis, late rectal toxicity), and several issues related to the use of NTCP models, especially relating to their safe use. Other recent reviews which further discuss data on endpoints of interest in treatment planning include Deasy and Fowler [3], Moiseenko et al. [4], and the slightly older but still invaluable Seminars in Radiation Oncology issue, edited by Randy Ten Haken, devoted to dose-volume effects in normal tissues [2]. A useful review of models and model principles are the chapters by Jackson and Yorke [5], and Yorke [6]. Many technical issues in modeling dose-volume outcomes were also discussed by Deasy et al. [7].This chapter describes standard NTCP models as well as our own approach, which is more data-driven and image-based [8]. This contrasts with the more common approach of assuming the validity of a specific model and then attempting to fit the model parameters to a given data set. The term "image-based" indicates

show abstract

Inter‐ and intra‐fractional stability of rectal gas in pelvic cancer patients during MRIgRT

et al. 2020

View full text Add to dashboard Cite

Purpose Due to the electron return effect (ERE) during magnetic resonance imaging guided radiotherapy (MRIgRT), rectal gas during pelvic treatments can result in hot spots of over‐dosage in the rectal wall. Determining the clinical impact of this effect on rectal toxicity requires estimation of the amount and mobility (and stability) of rectal gas during treatment. We therefore investigated the amount of rectal gas and local inter‐ and intra‐fractional changes of rectal gas in pelvic cancer patients. Methods To estimate the volume of gas present at treatment planning, the rectal gas contents in the planning computed tomography (CT) scans of 124 bladder, 70 cervical and 2180 prostate cancer patients were calculated. To estimate inter‐ and intra‐fractional variations in rectal gas, 174 and 131 T2‐w MRIs for six cervical and eleven bladder cancer patients were used. These scans were acquired during four scan‐sessions (~20–25 min each) at various time‐points. Additionally, 258 T2‐w MRIs of the first five prostate cancer patients treated using MRIgRT at our center, acquired during each fraction, were analyzed. Rectums were delineated on all scans. The area of gas within the rectum delineations was identified on each MRI slice using thresholding techniques. The area of gas on each slice of the rectum was used to calculate the inter‐ and intra‐fractional group mean, systematic and random variations along the length of the rectum. The cumulative dose perturbation as a result of the gas was estimated. Two approaches were explored: accounting or not accounting for the gas at the start of the scan‐session. Results Intra‐fractional variations in rectal gas are small compared to the absolute volume of rectal gas detected for all patient groups. That is, rectal gas is likely to remain stable for periods of 20–25 min. Larger volumes of gas and larger variations in gas volume were observed in bladder cancer patients compared with cervical and prostate cancer patients. For all patients, local cumulative dose perturbations per beam over an entire treatment in the order of 60 % were estimated when gas had not been accounted for in the daily adaption. The calculated dose perturbation over the whole treatment was dramatically reduced in all patients when accounting for the gas in the daily set‐up image. Conclusion Rectal gas in pelvic cancer patients is likely to remain stable over the course of an MRIgRT fraction, and also likely to reappear in the same location in multiple fractions, and can therefore result in clinically relevant over‐dosage in the rectal wall. The over‐dosage is reduced when accounting for gas in the daily adaption.

show abstract

Rectal and bladder motion during conformal radiotherapy after radical prostatectomy

Cited by 92 publications

References 45 publications

Postoperative Radiotherapy for Prostate Cancer

Postoperative Radiotherapy for Prostate Cancer

Image-Based Modeling of Normal Tissue Complication Probability for Radiation Therapy

Inter‐ and intra‐fractional stability of rectal gas in pelvic cancer patients during MRIgRT

Contact Info

Product

Resources

About