Reduction in Patient-reported Acute Morbidity in Prostate Cancer Patients Treated With 81-Gy Intensity-modulated Radiotherapy Using Reduced Planning Target Volume Margins and Electromagnetic Tracking: Assessing the Impact of Margin Reduction Study

Abstract

OBJECTIVE To investigate whether patient-reported quality of life after high-dose external beam intensity-modulated radiotherapy for prostate cancer can be improved by decreasing planning target volume margins while using real-time tumor tracking. METHODS Study patients underwent radiotherapy with nominal 3-mm margins and electromagnetic real-time tracking. Morbidity was assessed before and at the end of radiotherapy using Expanded Prostate Cancer Index Composite (EPIC) questionnaires. Changes in scores were compared between the Assessing Impact of Margin Reduction (AIM) study cohort and the comparator Prostate Cancer Outcomes and Satisfaction with Treatment Quality Assessment (PROST-QA) cohort, treated with conventional margins. RESULTS The 64 patients in the prospective AIM study had generally less favorable clinical characteristics than the 153 comparator patients. Study patients had similar or slightly poorer pretreatment EPIC scores than comparator patients in bowel, urinary, and sexual domains. AIM patients receiving radiotherapy had less bowel morbidity than the comparator group as measured by changes in mean bowel and/or rectal domain EPIC scores from pretreatment to 2 months after start of treatment (−1.5 vs −16.0, P = .001). Using a change in EPIC score >0.5 baseline standard deviation as the measure of clinical relevance, AIM study patients experienced meaningful decline in only 1 health-related quality of life domain (urinary) whereas decline in 3 health-related quality of life domains (urinary, sexual, and bowel/rectal) was observed in the PROST-QA comparator cohort. CONCLUSIONS Prostate cancer patients treated with reduced margins and tumor tracking had less radiotherapy-related morbidity than their counterparts treated with conventional margins. Highly contoured intensity-modulated radiotherapy shows promise as a successful strategy for reducing morbidity in prostate cancer treatment.

Patient-reported quality of life after stereotactic body radiotherapy (SBRT), intensity modulated radiotherapy (IMRT), and brachytherapy

“…The date of treatment was also slightly different, such that IMRT and brachytherapy technique and outcomes had improved by the time the SBRT cohort was collected [25][26][27]. However, we note that IMRT was associated with an MCD only for bowel QOL in our multivariable model, and margin reduction through IGRT has been shown to minimize bowel QOL impact in other studies using the EPIC survey [26,27]. Therefore, modern IMRT is likely to cause few QOL MCDs at 2 years, as we found for SBRT.…”

“…Efficacy and QOL after radiotherapy for localized prostate cancer have improved steadily with radiotherapy technology and technique development, such as reduction of IMRT target margins through image guidance [26,27,29] or changes in LDR brachytherapy technique [25], highlighting the continual need to gather toxicity data. SBRT represents a newly-developed technique that is convenient for patients, less expensive, and appears to be efficacious in institutional trials [30].…”

“…In contrast, single-institutional studies evaluating QOL after prostate SBRT revealed transient declines in urinary QOL that resolved within 6 months after treatment while GI QOL was minimally affected, and sexual QOL appeared to decline similar to other radiotherapy modalities [12][13][14][15][16]. Here, we present a pooled analysis of QOL across multiple cohorts of patients treated with IMRT, brachytherapy, or SBRT with 2-years of follow-up using the validated Expanded Prostate Cancer Index Composite Short Form (EPIC- 26) survey.…”

Electromagnetic Tracking in Medicine—A Review of Technology, Validation, and Applications

“…Although the results were promising because of better quality of life outcome and a reduced mortality [157], more prospective validation is needed [90].…”

“…[76] ENT surgery [InstaTrak] 4 studies, when compared to optical tracking [108]: no differences. Others without control group [41,78,184] Advantages: Accurate structure localization [78,184], fast setup time [41] Drawbacks: High costs, low availability [184] Radiotherapy [Calypso] 3 studies [37,157,193] Advantages: Better patient outcome compared to conventional radiotherapy [157] Drawbacks: High costs, lower accuracy than US localization [37], tracks position (no orientation) only of up to three sensors [104], more prospective validation is needed [90] in the field of the abdomen. Motion compensation may be beneficial in this area [198].…”