A Review of Kidney Motion under Free, Deep and Forced-Shallow Breathing Conditions: Implications for Stereotactic Ablative Body Radiotherapy Treatment

Abstract

Motion management strategies are important during stereotactic ablative body radiotherapy for abdominal targets. The kidney is a mobile retroperitoneal organ that moves with respiration. A review of the literature was performed to investigate the reported degree of kidney motion associated with various breathing conditions. A structured search was performed using Medline from January 1970 to May 2013 for all publications describing cranial-caudal kidney motion. Relevance to radiotherapy practice was reviewed based on any breathing instructions and/or immobilization equipment that could affect breathing pattern. Studies were categorized under three types of breathing conditions: Forced-shallow, breath-hold/ deep and free. A total of 25 publications were identified describing cranial-caudal kidney motion with a combined total of 415 participants. Three publications described forced-shallow breathing using prone positioning or abdominal compression plates. Prone positioning, compared to supine positioning, did little to minimise kidney motion, however use of compression plates can result in kidney motion of less than 5 mm. Eight publications described deep breathing/breath hold techniques that showed average kidney motion ranging between 10 mm-40 mm. Fifteen publications investigated kidney motion under free breathing with the majority reporting mean motion of less than 10 mm. Kidney movement of up to 8.1 mm in the anterior posterior direction and 6.2 mm laterally were reported with no indications that breathing technique can influence the extent of this motion. In summary, kidney movement is complex and consideration should be made to ensure that motion management strategies provide the desired radiotherapy benefit. There are limited publications on the effectiveness of abdominal compression on reducing kidney motion which warrant further investigation in this area.

Interfractional renal and diaphragmatic position variation during radiotherapy in children and adults: is there a difference?

“…Since pediatric cancer is a rare disease, and data on organ motion in children is scarce [8], safety margins as currently used in pediatric radiation treatment are mainly based on margins as defined for adults. Abdominal organ position variation and its impact on margin size for different tumor sites have so far only been reported for adult patients [9][10][11][12][13][14] and pediatric patients separately [15][16][17]. In our previous study, we quantified renal and diaphragmatic interfractional motion in children [17].…”

Improvement of SWL Efficacy: Reduction of the Respiration-Induced Kidney Motion by Using an Abdominal Compression Plate

“…2), a 1-minute interval measurement, including 10 to 20 consecutive breath cycles, was regarded sufficient. In a recent review article by Pham et al, 21 numerous studies about the respiratory-induced motion of the kidney were summarized. Among those were four studies that report the mean amplitude of the cranial-caudal kidney motion during free breathing in volunteers.…”

“…Comparison with literature data as reviewed by Pham et al 21 The evaluations were based on different imaging modalities. 4DCT = four-dimensional computed tomography; 4DPET = four-dimensional positron emission tomography; MRI = magnetic resonance imaging; US = ultrasound.…”

Magnitude and influencing factors of respiration-induced liver motion during abdominal compression in patients with intrahepatic tumors

“…In the current study, AC was applied during each patient’s end-expiration until maximum tolerability was reached, as indicated by the patient. We found that abdominal breathing clearly switched to thoracic breathing with satisfactory AC, especially in male patients, and forced shallow breathing also occurred [21]. However, forced shallow breathing was difficult to detect in male patients with severe obesity.…”