Articles

Articles

eCoil

1. Lee, G. et al. (2022). Prostate MRI: Is Endorectal Coil Necessary?—A Review. Life. 2022; Vol. 12, No.4, pp: 569.
   “The use of an endorectal coil improved image quality with a higher overall signal to noise ratio, posterior and peripheral zone signal to noise ratio, high b-value attenuation diffusion coefficient (ADC) signal to noise ratio, and contrast to noise ratio. Endorectal coil use improved subjective image quality for anatomic detail on T2 weighted images (T2WI) and diffusion weighted images (DWI). Endorectal coil use had less motion artifact on DWI than non-endorectal coil use but produced a higher occurrence of other artifacts on DWI. Endorectal coils had higher sensitivity, specificity, and positive predictive value (PPV) in the detection of overall and index lesions, as well as smaller and less aggressive lesions, missing fewer and smaller lesions than non-endorectal coils. Endorectal coils had higher sensitivity than non-endorectal coils in localizing and staging lesions. Endorectal coils improved quantitative and qualitative image quality and diagnostic performance in the detection of smaller and less aggressive cancers in 3T prostate MRI.”
2. Doan, P. et al. (2022). Final Analysis of the Magnetic Resonance Imaging in ActiveSurveillance Trial. Journal of Urology, Vol. 208,No.5, pp: 1028-1036
   “Final analysis of this single-arm prospective trial indicates that 1-year confirmatory biopsy may be omitted with minimal risk to patients in AS protocols where magnetic resonance targeted saturation template biopsy was performed at baseline. mpMRI and PSA density were strong predictors of progression and can reduce frequency of biopsy in AS patients without significant impact on oncologic outcomes, thus increasing patient acceptance of AS. However, standardized 3-year systematic biopsy should be per-formed regardless of mpMRI and PSA due to occasional MRI-invisible tumors.”
3. PI-RADS Prostate Imaging Reporting & Data System Version 2.1. (2019). American College of Radiology
   “When integrated with external (surface) phased array coils, endorectal coils (ERCs) increase SNR in the prostate at any magnetic field strength. This may be particularly valuable for high spatial resolution imaging used in cancer staging and for inherently lower SNR sequences, such as DWI and high temporal resolution DCE. (…) With some 1.5T MRI systems, especially older ones, use of an ERC is considered indispensable for achieving the type of high resolution diagnostic quality imaging needed for staging prostate cancer.”
4. Costa, D. et al. (2016). Comparison of prostate cancer detection at 3-T MRI with and without an endorectal coil: A prospective, paired-patient study. Urologic Oncology, vol. 34, No. 6, pp: 255.e7-255.e13
   “The use of combined ERC and pelvic phased-array coil for T2-weighted imaging and diffusion-weighted imaging provides superior sensitivity for the detection of PCa compared to an examination performed without the ERC.”
5. Hoffner, M.K. et al. (2016). Impact of an endorectal coil for 1H-magnetic resonance spectroscopy of the prostate at 3.0T in comparison to 1.5T: Do we need an endorectal coil? European Journal of Radiology. Vol. 85, No.8, pp:1432-1438
   “The ERC improves the diagnostic suitability and the SNR in MRSI at 3.0 T. Less voxels at 3.0 T with disabled ERC are suitable for diagnosis compared to 1.5 T with ERC. MRSI at 3.0 T with ERC shows the highest SNR. SNR in dorsal quadrants of the prostate was higher using ERC.”
6. Shah, Z.K. et al. (2015). Performance comparison of 1.5-T endorectal coil MRI with 3.0-T nonendorectal coil MRI in patients with prostate cancer. Academic radiology. Vol. 22, No. 4, pp :467-474.
   “Nonendorectal coil 3.0-T MRI provides prostate images that are natural in shape and that have comparable image quality to those obtained at 1.5 T with an endorectal coil, but not superior diagnostic performance.”
7. Ghafoori, M. et al. (2015). The value of prostate MRI with endorectal coil in detecting seminal vesicle involvement in patients with prostate cancer. Iranian Journal of Radiology, Vol. 12, No. 1, p: e14556.
   “MRI with endorectal coil is a valuable imaging technique with suitable accuracy in detecting seminal vesicle involvement in prostate cancer.”
8. Kitajima, K. et al. (2015). Detection of Local Recurrence of Prostate Cancer After Radical Prostatectomy Using Endorectal Coil MRI at 3 T: Addition of DWI and Dynamic Contrast Enhancement to T2-Weighted MRI. American Journal of Roentgenology. Vol. 205, No. 4, pp: 807-816.
   Addition of DCE to T2-weighted imaging in 3-T MRI with an endorectal coil improves the accuracy of detection of local cancer recurrence after radical prostatectomy. The addition of DWI is of limited incremental value for detection, especially of small lesions.
9. Kitajima, K. et al. (2014). Detection of recurrent prostate cancer after radical prostatectomy: comparison of 11C-choline PET/CT with pelvic multiparametric MR imaging with endorectal coil. Journal of Nuclear Medicine. Vol. 55, No. 2, pp. 223-232.
   “Pelvic multiparametric MR imaging performance with endorectal coil is superior in prostatectomy patients in depicting local prostate bed recurrence whereas 11C-choline PET/CT offers an advantage in detecting metastatic disease to LN and bone in high-risk”
10. Rubenstein, J. (2014) How to Code for Magnetic Resonance Imaging–informed Prostate Biopsies. Reviews in Urology, Vol. 16 No. 2, pp: 88-89
11. Turkbey, B. et al (2013). Comparison of endorectal coil and nonendorectal coil T2W and diffusion-weighted MRI at 3 Tesla for localizing prostate cancer: correlation with wholemount histopathology. Journal of Magnetic Resonance Imaging. vol. 39, No. 6, pp: 1443-1448.
    “Dual-coil prostate MRI [at 3.0T] detected more cancer foci than nonendorectal coil MRI. While nonendorectal coil MRI is an attractive alternative, physicians performing prostate MRI should be aware of its limitations.”
12. Somford, D. et al. (2013). The Predictive Value of Endorectal 3 Tesla Multiparametric Magnetic Resonance Imaging for Extraprostatic Extension in Patients with Low, Intermediate and High Risk Prostate Cancer. Journal of Urology, Vol. 190, No.5, pp: 1728-1734
    “Compared to other preoperative parameters MPMRI is the best predictor of EPE [extra prostatic extension] at RP [radical prostatectomy]. With the presence of EPE in 1 of 4 patients in the low risk cohort it is justifiable to evaluate every subject preoperatively with MP-MRI before deciding on nerve sparing approaches […]”
13. Barentsz, J. et al. (2012). ESUR prostate MR guidelines 2012. European radiology. 2012;22(4):746-757.
    “The ERC+PPA coil combination provides excellent SNR and remains state-of-the-art for staging prostate cancer. However, it has recognised drawbacks in terms of cost and patient acceptability.”
14. Tempany, C. (2012). Prostate MRI: Update and current roles. Applied Radiology. Vol. 41, No.3, pp: 17-22.
    “Based upon the published literature, we believe that MRI will become a more requested exam for prostate evaluation and will play a more central role in the diagnosis of prostate cancer. “
15. Morgan, V. et al. (2011). Diffusion-weighted magnetic resonance imaging for monitoring prostate cancer progression in patients managed by active surveillance. British Journal of Radiology, Vol. 84, No. 997, pp: 31-37.
    “This pilot study shows that DW-MRI has potential for monitoring patients with early prostate cancer who opt for active surveillance.”
16. Turkbey, B. et al. (2010). Prostate cancer: value of multiparametric MR imaging at 3 T for detection–histopathologic correlation. Radiology. Vol. 255, No. 1, pp: 89-99.
    “Multiparametric MR imaging (T2-weighted MR imaging, MR spectroscopy, dynamic contrast-enhanced MR imaging) of the prostate at 3 T [including an endorectal coil] enables tumor detection, with reasonable sensitivity and specificity values.”
17. Cascian, E. et al. (2008). Endorectal and dynamic contrast-enhanced MRI for detection of local recurrence after radical prostatectomy. American Journal of Roentgenology, Vol. 190, No. 5, pp: 1187-1192.
    “MRI combined with dynamic contrast-enhanced MRI [using a combination of pelvic phased array coil and endorectal coil] showed a higher sensitivity and specificity compared with MRI alone in detecting local recurrences after radical prostatectomy.”
18. Futterer, J. et al. (2007). Prostate cancer: comparison of local staging accuracy of pelvic phased-array coil alone versus integrated endorectal-pelvic phased-array coils. Local staging accuracy of prostate cancer using endorectal coil MR imaging. European Radiology, Vol. 17, No.4, pp: 1055-1065.
    “(…) use of endorectal-pelvic phased-array coils resulted in significant improvement of anatomic details, extracapsular extension accuracy and specificity. Overstaging is reduced significantly with equal sensitivity when an endorectal–pelvic phased-array coil array is used. This technique may be a useful tool even in patients who are at low risk of extraprostatic disease.”
19. Heijmink, S. et al. (2007). Prostate cancer: body-array versus endorectal coil MR imaging at 3 T–comparison of image quality, localization, and staging performance. Radiology. Vol. 244, No.1, pp: 184-195.
    “Image quality and localization improved significantly with ERC imaging compared with BAC imaging. For experienced radiologists, the staging performance was significantly better with ERC imaging.”

Pro-Tx Endorectal Balloon

1. Ardekani, M. et al. (2021). Effectiveness of rectal displacement devices in managing prostate motion: a systematic review. Strahlenther Onkol, Vol. 197, pp. 97–115
   “Using an ERB significantly reduces intra-fractional prostate motion. This prostate-stabilizing effect of the ERB can translate into reduced planning target volume (PTV) margins and additional rectal dose sparing. Even with an ERB in place, inter-fractional prostate displacements are seen. As a consequence, ERB application does not obviate daily verification; however, this is not a crucial topic because pretreatment imaging is always done nowadays. As compared with ERB, the hydrogel spacer significantly reduces rectal dose and toxicity without influencing prostate immobilization.”
2. Serrano, N. et al. (2017). Reducing rectal injury in men receiving prostate cancer radiation therapy: current perspectives. Cancer Management and Research, Vol. 9, pp 339-350
   “Endorectal balloons have been studied in patients receiving both 3DCRT and IMRT. However, the recommendation for their use remains controversial, with some studies showing successful reduction of rectal toxicities but with others revealing no difference when compared to patients without balloons.”
3. Xiang, H, et l. (2017). Dosimetric impacts of endorectal balloon in CyberKnife stereotactic body radiation therapy (SBRT) for early-stage prostate cancer. J Appl Clin Med Phys, Vol. 18, no3,pp. 37–43
   “Significant reductions of dose to the rectum using ERB were observed. This may lead to improvement of the rectal toxicity profiles in prostate SBRT.”
4. Smeenk, R. et al. (2012). An Endorectal Balloon Reduces Intrafraction Prostate Motion During Radiotherapy. Int J Radiation Oncol Biol Phys, Vol. 83, No. 2, pp. 661-669
   “In conclusion, an air-filled ERB significantly reduces intrafraction prostate motion, especially after 150s, making it a potentially beneficial instrument to use during longer treatments such as stereotactic hypofractionated RT. Interfraction variation, however, was not influenced by ERB application.”
5. Wootton, L. et al. (2012). Effectiveness of a novel gas-release endorectal balloon in the removal of rectal gas for prostate proton radiation therapy. Journal of Applied clinical Medical Physics, Vol.13, No. 5, pp.190-197
   “We conclude, therefore, that the gas-release ERB effectively removes rectal gas and should be used in patients receiving proton radiation therapy”
6. Smeenk, R. (2010). Is there a role for endorectal balloons in prostate radiotherapy? A systematic review. Radiotherapy and Oncology vol. 95, pp. 277–282
   “ERBs seem well-tolerated and in planning studies reduce anorectal wall doses. This may lead to reduced anorectal toxicity, although clinical studies are warranted to confirm this hypothesis and to further investigate the immobilizing properties of ERBs, preferably in combination with advanced techniques for position verification.”
7. Smeenk, R. et al. (2009). Anal wall sparing effect of an endorectal balloon in 3D conformal and intensity-modulated prostate radiotherapy. Radiotherapy and Oncology, Vol 93, pp. 131-136
   “Application of an ERB showed a significant Awall sparing effect in both 3D-CRT and IMRT. This may lead to reduced late anal toxicity in prostate radiotherapy.”
8. Vargas, C. et al. (2007). Rectal dose–volume differences using proton radiotherapy and a rectal balloon or water alone for the treatment of prostate cancer. Int. J. Radiation Oncology Biol. Phys., Vol. 69, No. 4, pp. 1110–1116
   “Rectum and rectal wall doses with proton radiation were low whether using water or an RB. Selected patients will have a small but significant advantage with an RB; however, water alone was well tolerated and will be an alternative for most patients.”
9. Ronson, B. et al. (2006). Patient tolerance of rectal balloons in conformal radiation therapy treatment of prostate cancer. Int. J. Radiation Oncology Biol. Phys., Vol. 64, No. 5, pp. 1367–1370
   “Intrarectal balloons are well tolerated over a course of conformal prostate irradiation.”
10. Hille, A., et al. (2005). The Impact of Varying Volumes in Rectal Balloons on Rectal Dose Sparing in Conformal Radiation Therapy of Prostate Cancer. Strahlentherapie und Onkologie. Vol.181, No. 11, pp.709-716
    “The use of a rectal balloon filled with 60 ml air led to a significantly decreased proportion of the irradiated rectal wall for all CTVs. This volume filled in rectal balloons is therefore recommended for use. In case of irradiation of the prostate without the seminal vesicles, the use of a rectal balloon should be considered carefully concerning the patients’ imaginable discomfort using a rectal balloon and a questionable advantage concerning the estimated risk for chronic toxicity.”
11. van Lin, E. et al. (2005). Rectal wall sparing effect of three different endorectal balloons in 3D conformal and IMRT prostate radiotherapy. Int. J. Radiation Oncology Biol. Phys., Vol. 63, No. 2, pp. 565–576
    “In 3D-CRT, any ERB showed a significant rectal wall sparing effect. (…). For both 3D-CRT and IMRT, a reduction of the relative inner Rwall surface exposed to intermediate and high doses was found, which may lead to reduced late rectal toxicity.”
12. Patel, R. et al. (2003). Rectal dose sparing with a balloon catheter and ultrasound localization in conformal radiation therapy for prostate cancer. Radiotherapy and Oncology Vol. 67, pp. 285–294
    “These results indicate that use of a rectal balloon with a 3D-CRT plan incorporating typical treatment margins will produce significant high dose rectal sparing that is comparable to that achieved by a highly conformal IMRT with ultrasound localization. Further sparing is achieved with the inclusion of a balloon catheter in an IMRT plan. Thus, in addition to a previously reported advantage of prostate immobilization, the use of a rectal displacement balloon during daily treatment results in high dose rectal wall sparing during both modestly and highly conformal radiotherapy. Such sparing could assist in controlling and limiting rectal toxicity during increasingly aggressive dose escalation.”
13. Teh, B. et al. (2002). The Use of Rectal Balloon During the Delivery of Intensity Modulated Radiotherapy (IMRT) for Prostate Cancer: More Than Just a Prostate Gland Immobilization Device? The Cancer Journal, Vol. 8, No. 6
    “A rectal balloon used during the delivery of IMRT significantly reduces prostate motion, even with breathing. Prostate immobilization thus allows a safer and smaller planning target volume margin. (…) The reduction of rectal volume receiving high-dose radiation can also be achieved with rectal wall distension by the balloon. All these factors may have further contributed to the favorable rectal toxicity profile rendered by IMRT, despite dose escalation and higher-than-conventional fraction size used.”
14. McGary, J. (2002). Prostate immobilization using a rectal balloon. Journal of Applied Clinical Medical Physics. Vol. 3, No. 1
    “Using a rectal balloon immobilizer for prostate IMRT reduces prostate motion, both in terms of interfraction organ displacement and movement due to breathing. (With respect to interfractionprostate displacement, the anterior-posterior ~AP! organ displacement is ,1 mm and the cranialcaudal displacement range is less than 5 mm. In addition, ventilatory movement of the prostate is essentially eliminated with respect to skeletal motion. To date, patients have tolerated the balloon without much discomfort and the use of the rectal balloon has been shown to be clinically viable.”