1
|
Patel KR, van der Heide UA, Kerkmeijer LGW, Schoots IG, Turkbey B, Citrin DE, Hall WA. Target Volume Optimization for Localized Prostate Cancer. Pract Radiat Oncol 2024:S1879-8500(24)00148-6. [PMID: 39019208 DOI: 10.1016/j.prro.2024.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 06/17/2024] [Accepted: 06/26/2024] [Indexed: 07/19/2024]
Abstract
PURPOSE To provide a comprehensive review of the means by which to optimize target volume definition for the purposes of treatment planning for patients with intact prostate cancer with a specific emphasis on focal boost volume definition. METHODS Here we conduct a narrative review of the available literature summarizing the current state of knowledge on optimizing target volume definition for the treatment of localized prostate cancer. RESULTS Historically, the treatment of prostate cancer included a uniform prescription dose administered to the entire prostate with or without coverage of all or part of the seminal vesicles. The development of prostate magnetic resonance imaging (MRI) and positron emission tomography (PET) using prostate-specific radiotracers has ushered in an era in which radiation oncologists are able to localize and focally dose-escalate high-risk volumes in the prostate gland. Recent phase 3 data has demonstrated that incorporating focal dose escalation to high-risk subvolumes of the prostate improves biochemical control without significantly increasing toxicity. Still, several fundamental questions remain regarding the optimal target volume definition and prescription strategy to implement this technique. Given the remaining uncertainty, a knowledge of the pathological correlates of radiographic findings and the anatomic patterns of tumor spread may help inform clinical judgement for the definition of clinical target volumes. CONCLUSION Advanced imaging has the ability to improve outcomes for patients with prostate cancer in multiple ways, including by enabling focal dose escalation to high-risk subvolumes. However, many questions remain regarding the optimal target volume definition and prescription strategy to implement this practice, and key knowledge gaps remain. A detailed understanding of the pathological correlates of radiographic findings and the patterns of local tumor spread may help inform clinical judgement for target volume definition given the current state of uncertainty.
Collapse
Affiliation(s)
- Krishnan R Patel
- Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
| | - Uulke A van der Heide
- Department of Radiation Oncology, The Netherlands Cancer Institute (NKI-AVL), Amsterdam, The Netherlands
| | - Linda G W Kerkmeijer
- Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ivo G Schoots
- Department of Radiation Oncology, The Netherlands Cancer Institute (NKI-AVL), Amsterdam, The Netherlands
| | - Baris Turkbey
- Molecular Imaging Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Deborah E Citrin
- Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - William A Hall
- Froedtert and the Medical College of Wisconsin, Milwaukee, Wisconsin
| |
Collapse
|
2
|
Spohn SKB, Sachpazidis I, Wiehle R, Thomann B, Sigle A, Bronsert P, Ruf J, Benndorf M, Nicolay NH, Sprave T, Grosu AL, Baltas D, Zamboglou C. Influence of Urethra Sparing on Tumor Control Probability and Normal Tissue Complication Probability in Focal Dose Escalated Hypofractionated Radiotherapy: A Planning Study Based on Histopathology Reference. Front Oncol 2021; 11:652678. [PMID: 34055621 PMCID: PMC8160377 DOI: 10.3389/fonc.2021.652678] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/08/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose Multiparametric magnetic resonance tomography (mpMRI) and prostate specific membrane antigen positron emission tomography (PSMA-PET/CT) are used to guide focal radiotherapy (RT) dose escalation concepts. Besides improvements of treatment effectiveness, maintenance of a good quality of life is essential. Therefore, this planning study investigates whether urethral sparing in moderately hypofractionated RT with focal RT dose escalation influences tumour control probability (TCP) and normal tissue complication probability (NTCP). Patients and Methods 10 patients with primary prostate cancer (PCa), who underwent 68Ga PSMA-PET/CT and mpMRI followed by radical prostatectomy were enrolled. Intraprostatic tumour volumes (gross tumor volume, GTV) based on both imaging techniques (GTV-MRI and -PET) were contoured manually using validated contouring techniques and GTV-Union was created by summing both. For each patient three IMRT plans were generated with 60 Gy to the whole prostate and a simultaneous integrated boost up to 70 Gy to GTV-Union in 20 fractions by (Plan 1) not respecting and (Plan 2) respecting dose constraints for urethra as well as (Plan 3) respecting dose constraints for planning organ at risk volume for urethra (PRV = urethra + 2mm expansion). NTCP for urethra was calculated applying a Lyman-Kutcher-Burman model. TCP-Histo was calculated based on PCa distribution in co-registered histology (GTV-Histo). Complication free tumour control probability (P+) was calculated. Furthermore, the intrafractional movement was considered. Results Median overlap of GTV-Union and PRV-Urethra was 1.6% (IQR 0-7%). Median minimum distance of GTV-Histo to urethra was 3.6 mm (IQR 2 - 7 mm) and of GTV-Union to urethra was 1.8 mm (IQR 0.0 - 5.0 mm). The respective prescription doses and dose constraints were reached in all plans. Urethra-sparing in Plans 2 and 3 reached significantly lower NTCP-Urethra (p = 0.002) without significantly affecting TCP-GTV-Histo (p = p > 0.28), NTCP-Bladder (p > 0.85) or NTCP-Rectum (p = 0.85), resulting in better P+ (p = 0.006). Simulation of intrafractional movement yielded even higher P+ values for Plans 2 and 3 compared to Plan 1. Conclusion Urethral sparing may increase the therapeutic ratio and should be implemented in focal RT dose escalation concepts.
Collapse
Affiliation(s)
- Simon K B Spohn
- Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK). Partner Site Freiburg, Freiburg, Germany.,Berta-Ottenstein-Programme, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ilias Sachpazidis
- Division of Medical Physics, Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Rolf Wiehle
- Division of Medical Physics, Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Benedikt Thomann
- Division of Medical Physics, Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - August Sigle
- Department of Urology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Peter Bronsert
- Institute for Surgical Pathology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Juri Ruf
- Department of Nuclear Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Matthias Benndorf
- Department of Radiology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nils H Nicolay
- Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK). Partner Site Freiburg, Freiburg, Germany
| | - Tanja Sprave
- Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK). Partner Site Freiburg, Freiburg, Germany
| | - Anca L Grosu
- Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK). Partner Site Freiburg, Freiburg, Germany
| | - Dimos Baltas
- German Cancer Consortium (DKTK). Partner Site Freiburg, Freiburg, Germany.,Division of Medical Physics, Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Constantinos Zamboglou
- Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK). Partner Site Freiburg, Freiburg, Germany.,Berta-Ottenstein-Programme, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|
3
|
Becher E, Sali A, Abreu A, Iwata T, Tong A, Deng FM, Iwata A, Gupta C, Gill I, Aron M, Palmer S, Lepor H. MRI predicts prostatic urethral involvement in men undergoing radical prostatectomy: implications for cryo-ablation of localized prostate cancer. World J Urol 2021; 39:3309-3314. [PMID: 33616707 DOI: 10.1007/s00345-020-03566-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 12/12/2020] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To determine whether multi-parametric magnetic resonance imaging (mpMRI) can reliably predict proximity of prostate cancer to the prostatic urethra in a contemporary series of men undergoing radical prostatectomy (RP) at two academic centers. METHODS Clinical characteristics of consecutive men undergoing pre-operative mpMRI prior to RP and whole-mount axial serial step-sectioned pathology examination at two academic centers between Jun 2016 and Oct 2018 were analyzed retrospectively. Every tumor was characterized by its pathologic minimum distance to the prostatic urethral lumen (pMDUL). Only the cancer closest to the urethra represented the prostatic urethral index lesion. The radiologic minimum distance of the index lesion to the prostatic urethral lumen was measured and noted as ≤ 5 mm versus > 5 mm. The sensitivity, specificity, positive and negative predicting values (PPV and NPV) and area under the receivers operating characteristics curve (AUC) were calculated for performance of mpMRI for predicting pMDUL ≤ 5 mm. RESULTS Of the 163 surgical specimens examined, 112 (69%) exhibited a pMDUL ≤ 5 mm. These men had significantly higher grade group (GG) and advanced pathological and clinical stage. The rates of high PI-RADS score and presence of gross extracapsular extension were also significantly greater for the group with pMDUL ≤ 5 mm. The AUC, sensitivity, specificity, PPV, and NPV were 0.641, 51.8, 76.5, 82.9, and 42.4%, respectively, for mpMRI to predict pMDUL < 5 mm. CONCLUSIONS Nearly 70% of men undergoing RP present with tumor within 5 mm of the prostatic urethra. These tumors present higher risk characteristics, and mpMRI exhibited moderate performance and high PPV in their pre-operative detection. Physicians performing partial gland ablation should take these results into consideration during treatment selection and planning.
Collapse
Affiliation(s)
- Ezequiel Becher
- Department of Urology, NYU Langone Health, 222 E41st St, 12th floor, New York, NY, 10017, USA.
| | - Akash Sali
- Department of Urology, Keck School of Medicine, USC Institute of Urology and Catherine and Joseph Aresty, University of Southern California, Los Angeles, CA, USA
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Andre Abreu
- Department of Urology, Keck School of Medicine, USC Institute of Urology and Catherine and Joseph Aresty, University of Southern California, Los Angeles, CA, USA
- Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Tsuyoshi Iwata
- Department of Urology, Keck School of Medicine, USC Institute of Urology and Catherine and Joseph Aresty, University of Southern California, Los Angeles, CA, USA
| | - Angela Tong
- Department of Radiology, NYU Langone Health, New York, NY, USA
| | - Fang-Ming Deng
- Department of Pathology, NYU Langone Health, New York, NY, USA
| | - Atsuko Iwata
- Department of Urology, Keck School of Medicine, USC Institute of Urology and Catherine and Joseph Aresty, University of Southern California, Los Angeles, CA, USA
| | - Chhavi Gupta
- Department of Urology, Keck School of Medicine, USC Institute of Urology and Catherine and Joseph Aresty, University of Southern California, Los Angeles, CA, USA
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Inderbir Gill
- Department of Urology, Keck School of Medicine, USC Institute of Urology and Catherine and Joseph Aresty, University of Southern California, Los Angeles, CA, USA
| | - Manju Aron
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Suzanne Palmer
- Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Herbert Lepor
- Department of Urology, NYU Langone Health, 222 E41st St, 12th floor, New York, NY, 10017, USA
| |
Collapse
|
4
|
Boissier R, Sanguedolce F, Territo A, Gaya JM, Huguet J, Rodriguez-Faba O, Regis F, Gallioli A, Vedovo F, Martinez C, Palou J, Breda A. Partial salvage cryoablation of the prostate for local recurrent prostate cancer after primary radiotherapy: Step-by-step technique and outcomes. UROLOGY VIDEO JOURNAL 2020. [DOI: 10.1016/j.urolvj.2020.100040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
5
|
WASHINO S, HIRAI M, SAITO K, KOBAYASHI Y, ARAI Y, MIYAGAWA T. Impact of Androgen Deprivation Therapy on Volume Reduction and Lower Urinary Tract Symptoms in Patients with Prostate Cancer. Low Urin Tract Symptoms 2016; 10:57-63. [DOI: 10.1111/luts.12142] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/22/2016] [Accepted: 05/09/2016] [Indexed: 12/15/2022]
Affiliation(s)
- Satoshi WASHINO
- Department of Urology, Saitama Medical Center; Jichi Medical University; Saitama Japan
| | - Masaru HIRAI
- Department of Urology, Saitama Medical Center; Jichi Medical University; Saitama Japan
| | - Kimitoshi SAITO
- Department of Urology, Saitama Medical Center; Jichi Medical University; Saitama Japan
| | - Yutaka KOBAYASHI
- Department of Urology, Saitama Medical Center; Jichi Medical University; Saitama Japan
| | - Yoshiaki ARAI
- Department of Urology; Nishiohmiya Hospital; Saitama Japan
| | - Tomoaki MIYAGAWA
- Department of Urology, Saitama Medical Center; Jichi Medical University; Saitama Japan
| |
Collapse
|
6
|
An investigation of the effects from a urethral warming system on temperature distributions during cryoablation treatment of the prostate: A phantom study. Cryobiology 2014; 69:128-33. [DOI: 10.1016/j.cryobiol.2014.06.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 06/17/2014] [Accepted: 06/18/2014] [Indexed: 11/19/2022]
|
7
|
Prediction of prostate cancer to urethra distance by a pretreatment nomogram: urethral thermoprotection implication in cryoablation. Prostate Cancer Prostatic Dis 2013; 16:372-5. [DOI: 10.1038/pcan.2013.32] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 07/11/2013] [Accepted: 07/31/2013] [Indexed: 11/09/2022]
|
8
|
Chin JL, Al-Zahrani AA, Autran-Gomez AM, Williams AK, Bauman G. Extended Followup Oncologic Outcome of Randomized Trial Between Cryoablation and External Beam Therapy for Locally Advanced Prostate Cancer (T2c-T3b). J Urol 2012; 188:1170-5. [DOI: 10.1016/j.juro.2012.06.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Indexed: 11/25/2022]
Affiliation(s)
- Joseph L. Chin
- Division of Urology, Department of Surgery, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada
- Division of Radiation Oncology, Department of Oncology, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada
| | - Ali A. Al-Zahrani
- Division of Urology, Department of Surgery, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada
- Department of Urology, Dammam University, Dammam, Saudi Arabia
| | - Ana Maria Autran-Gomez
- Division of Urology, Department of Surgery, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada
| | - Andrew K. Williams
- Division of Urology, Department of Surgery, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada
| | - Glenn Bauman
- Division of Radiation Oncology, Department of Oncology, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
9
|
Urethra sparing – potential of combined Nickel–Titanium stent and intensity modulated radiation therapy in prostate cancer. Radiother Oncol 2012; 103:256-60. [DOI: 10.1016/j.radonc.2011.11.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 11/20/2011] [Accepted: 11/22/2011] [Indexed: 11/21/2022]
|
10
|
Gravas S, Tzortzis V, de la Riva SIM, Laguna P, de la Rosette J. Focal therapy for prostate cancer: patient selection and evaluation. Expert Rev Anticancer Ther 2011; 12:77-86. [PMID: 22149434 DOI: 10.1586/era.11.144] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent stage migration toward low-risk prostate cancer, overtreatment of biologically insignificant tumors with radical prostatectomy at the additional expense of a non-negligible morbidity and undertreatment of patients improperly selected for active surveillance are the main reasons that have fueled the concept of focal therapy. Optimal selection of patients is the key for the successful implementation of focal therapy. Selection criteria for focal therapy vary widely and depend on clinical, histological and imaging characteristics of the patients that are highlighted in this article. In addition, the rationales, merits and limitations of the available methods for the assessment of potential candidates, the evaluation of treatment efficacy and follow-up of these patients are discussed.
Collapse
Affiliation(s)
- Stavros Gravas
- Department of Urology, University of Thessaly, Larissa, Greece.
| | | | | | | | | |
Collapse
|
11
|
Andreoiu M, Cheng L. Multifocal prostate cancer: biologic, prognostic, and therapeutic implications. Hum Pathol 2010; 41:781-93. [PMID: 20466122 DOI: 10.1016/j.humpath.2010.02.011] [Citation(s) in RCA: 200] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 02/21/2010] [Accepted: 02/25/2010] [Indexed: 11/18/2022]
Abstract
Prostatic adenocarcinoma is the most common cancer diagnosed in men and is often multifocal. Ongoing controversy exists about the most appropriate system of tumor classification and grading and the optimal curative treatment approaches. This review examines recent progress in the pathogenesis of multifocal prostatic adenocarcinoma and its biologic, pathologic, prognostic, and therapeutic implications. Prostatic cancer multifocality makes accurate clinical staging difficult, and repeated revisions have been undertaken in an effort to optimize prognostic accuracy. Although the 2010 revision represents an improvement over the previous systems, the clinical significance of the T2 substaging is questionable. Also discussed is the potential impact of tumor multifocality and clonal heterogeneity on the oncologic efficacy of novel focal ablative approaches. The clinical significance of smaller secondary tumors and the relationship between extent of chromosomal abnormalities and the metastatic potential of an individual tumor focus were reviewed.
Collapse
Affiliation(s)
- Matei Andreoiu
- Department of Urology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | |
Collapse
|
12
|
|
13
|
Performance of transperineal template-guided mapping biopsy in detecting prostate cancer in the initial and repeat biopsy setting. Prostate Cancer Prostatic Dis 2009; 13:71-7. [PMID: 19786982 PMCID: PMC2834351 DOI: 10.1038/pcan.2009.42] [Citation(s) in RCA: 205] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Transrectal ultrasound (TRUS) biopsy can miss 20-30% of clinically significant cancers. We evaluate an alternative approach-transperineal template-guided mapping biopsy (TTMB) in the initial and repeat biopsy setting. From January 2005 through September 2008, 373 consecutive men underwent TTMB (294 men with > or =1 prior negative biopsy and 79 men as the initial biopsy). The location of each positive biopsy core, number of positive cores, and percent involvement of each core was recorded. Cancer detection rate for the initial biopsy was 75.9%. For men with 1, 2, and > or =3 prior negative biopsies detection rates were 55.5%, 41.7%, and 34.4%, respectively. In all, 55.5% of the cancers identified were Gleason > or =7. The majority of the cancers were multifocal. There was no significant change in the number of positive cores or Gleason score as the number of prior biopsies increased. The anterior and apical aspects of the prostate were among the most common cancer locations. TTMB provides a high rate of cancer detection as initial and repeat biopsy. TTMB was particularly effective at diagnosing anterior and apical cancer. TTMB may have particular application for men considering active surveillance, with prior negative TRUS biopsies, and those considering subtotal gland or other minimally invasive treatments.
Collapse
|
14
|
Abstract
PURPOSE OF REVIEW Prostate-specific antigen screening has led to a dramatically increased detection of low-grade, small-volume, organ-confined tumors. On the basis of concerns regarding overtreatment of biologically indolent cancers, focal ablative therapy has been introduced as an alternative to radical therapy or active surveillance. Because a critical requirement of focal therapy is appropriate patient selection, we review the pathologic characteristics of localized prostate cancer and methods to identify patients likely to have low-risk disease. RECENT FINDINGS Up to 33% of patients undergoing radical prostatectomy have unilateral, low-grade, organ-confined tumors on final pathology. Standard diagnostic methods such as ultrasound-guided biopsies may not be adequate to reliably identify these patients. Early data on three-dimensional transperineal and transrectal mapping biopsies have suggested an increased ability to precisely localize and characterize low-grade tumors. The addition of multisequence MRI and spectroscopy to standard diagnostic techniques is under study and may eventually further augment disease characterization. SUMMARY Appropriate selection criteria for focal therapy are evolving, and diagnostic techniques widely vary. Further study of extensive mapping biopsies, imaging techniques, and biomarkers are mandatory to improve the recognition and characterization of patients with biologically indolent lesions and better inform their treatment decision making.
Collapse
|
15
|
Pisters LL, Leibovici D, Blute M, Zincke H, Sebo TJ, Slezak JM, Izawa J, Ward JF, Scott SM, Madsen L, Spiess PE, Leibovich BC. Locally recurrent prostate cancer after initial radiation therapy: a comparison of salvage radical prostatectomy versus cryotherapy. J Urol 2009; 182:517-25; discussion 525-7. [PMID: 19524984 DOI: 10.1016/j.juro.2009.04.006] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Indexed: 11/25/2022]
Abstract
PURPOSE We compared the treatment outcomes of salvage radical prostatectomy and salvage cryotherapy for patients with locally recurrent prostate cancer after initial radiation therapy. MATERIALS AND METHODS We retrospectively reviewed the medical records of patients who underwent salvage radical prostatectomy at the Mayo Clinic between 1990 and 1999, and those who underwent salvage cryotherapy at M. D. Anderson Cancer Center between 1992 and 1995. Eligibility criteria were prostate specific antigen less than 10 ng/ml, post-radiation therapy biopsy showing Gleason score 8 or less and prior radiation therapy alone without pre-salvage or post-salvage hormonal therapy. We assessed the rates of biochemical disease-free survival, disease specific survival and overall survival in each group. Biochemical failure was assessed using the 2 definitions of 1) prostate specific antigen greater than 0.4 ng/ml and 2) 2 increases above the nadir prostate specific antigen. RESULTS Mean followup was 7.8 years for the salvage radical prostatectomy group and 5.5 years for the salvage cryotherapy group. Compared to salvage cryotherapy, salvage radical prostatectomy resulted in superior biochemical disease-free survival by both definitions of biochemical failure (prostate specific antigen greater than 0.4 ng/ml, salvage cryotherapy 21% vs salvage radical prostatectomy 61% at 5 years, p <0.001; 2 increases above nadir with salvage cryotherapy 42% vs salvage radical prostatectomy 66% at 5 years, p = 0.002) and in superior overall survival (at 5 years salvage cryotherapy 85% vs salvage radical prostatectomy 95%, p = 0.001). There was no significant difference in disease specific survival (at 5 years salvage cryotherapy 96% vs salvage radical prostatectomy 98%, p = 0.283). After adjusting for post-radiation therapy biopsy Gleason sum and pre-salvage treatment serum prostate specific antigen on multivariate analysis salvage radical prostatectomy remained superior to salvage cryotherapy for the end points of any increase in prostate specific antigen greater than 0.4 ng/ml (HR 0.24, p <0.0001), 2 increases in prostate specific antigen (HR 0.47, p = 0.02) and overall survival (HR 0.21, p = 0.01). CONCLUSIONS Young, healthy patients with recurrent prostate cancer after radiation therapy should consider salvage radical prostatectomy as it offers superior biochemical disease-free survival and may potentially offer the best chance of cure.
Collapse
Affiliation(s)
- Louis L Pisters
- Department of Urology, The University of Texas, M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
|
17
|
Meiers I, Waters DJ, Bostwick DG. Preoperative prediction of multifocal prostate cancer and application of focal therapy: review 2007. Urology 2008; 70:3-8. [PMID: 18194709 DOI: 10.1016/j.urology.2007.06.1129] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 03/12/2007] [Accepted: 06/06/2007] [Indexed: 11/17/2022]
Abstract
Prostate cancer is a leading malignancy among men. Early prostate cancer is most commonly treated with radical surgery and radiotherapy. In the era of prostate-specific antigen and newly emerging highly specific screening tests, a greater number of men are given a diagnosis earlier in life, and disease is more often confined. Less-invasive treatments, such as focal therapy, are becoming increasingly popular, yielding shorter hospital stays, faster recovery, and fewer complications. Potential drawbacks to focal therapy include the risk of incomplete treatment, which may result from missed cancer foci and inadequate ablation to target tissues. Furthermore, this approach is not universally applicable to all patients--for example, those who have periurethral and extraprostatic extension of the tumor may not benefit from focal treatment. This article reviews the importance of multifocal prostate cancer and the application of focal treatment.
Collapse
|
18
|
Pontones Moreno JL, Morera Martínez JF, Vera Donoso CD, Jiménez Cruz JF. [Cryosurgery in the management of prostate cancer]. Actas Urol Esp 2007; 31:211-32. [PMID: 17658150 DOI: 10.1016/s0210-4806(07)73627-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This article reviews the current status of the prostatic cryosurgery in the management of patients with prostate cancer. Recent advances in cryoablative technology have allowed to treat these patients successfully with decreased morbidity. Using transrectal high-resolution ultrasound imaging, prostate cryotherapy is delivered with multiple ultrathin (17-gauge) cryo-needles, via percutaneous transperineal approach. The extent of freezing can be precisely controlled and monitored with thermic devices, tissue destruction is monitored with real-time visualization of the prostate and surrounding structures, and urethral warming is used to avoid urethral sloughing. However, the results with the second and third-generation cryosurgical equipment will have to be confirmed by means of prospective and randomized trials, because up to now we only have data based on retrospective analyses, which are very heterogeneous. The ability of prostate-specific antigen (PSA) to predict long-term outcome after cryotherapy for localized prostate cancer is not well known because experience with this treatment modality is still limited; however, it seems that a PSA value of 0.5 ng/ml or less after 6 months or longer after cryotherapy would be associated with a high probability (greater than 95%) of negative post-treatment biopsy. Cryosurgery could also be an option of treatment for men with recurrent local disease who have undergone radiotherapy or radical prostatectomy. We have to keep in mind possible complications (incontinence, impotency, urethrorectal fistula or bladder outlet obstruction. The favorable side effect profile and preliminary oncologic and funtional results could suggest that cryosurgery will have a role in the minimally invasive management of selected patients with prostate cancer.
Collapse
|
19
|
Keiler L, Dobbins D, Kulasekere R, Einstein D. Tomotherapy for prostate adenocarcinoma: A report on acute toxicity. Radiother Oncol 2007; 84:171-6. [PMID: 17692975 DOI: 10.1016/j.radonc.2007.07.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 05/11/2007] [Accepted: 07/13/2007] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE To analyze the impact of Tomotherapy (TOMO) intensity modulated radiotherapy (IMRT) on acute gastrointestinal (GI) and genitourinary (GU) toxicity in prostate cancer. MATERIALS AND METHODS The records of 55 consecutively treated TOMO patients were reviewed. Additionally a well-matched group of 43 patients treated with LINAC-based step and shoot IMRT (LINAC) was identified. Acute toxicity was scored according to Radiation Therapy Oncology Group acute toxicity criterion. RESULTS The grade 2-3 acute GU toxicity rates for the TOMO vs. LINAC groups were 51% vs. 28% (p=0.001). Acute grade 2 GI toxicity was 25% vs. 40% (p=0.024), with no grade 3 GI toxicity in either group. In univariate analysis, androgen deprivation, prostate volume, pre-treatment urinary toxicity, and prostate dose homogeneity correlated with acute GI and GU toxicity. With multivariate analysis use of Tomotherapy, median bladder dose and bladder dose homogeneity remained significantly correlated with GU toxicity. CONCLUSIONS Acute GI toxicity for prostate cancer is improved with Tomotherapy at a cost of increased acute GU toxicity possibly due to differences in bladder and prostate dose distribution.
Collapse
Affiliation(s)
- Louis Keiler
- Department of Radiation Oncology, University Hospitals of Cleveland, Cleveland, OH 44106, USA.
| | | | | | | |
Collapse
|
20
|
Huang WC, Kuroiwa K, Serio AM, Bianco FJ, Fine SW, Shayegan B, Scardino PT, Eastham JA. The anatomical and pathological characteristics of irradiated prostate cancers may influence the oncological efficacy of salvage ablative therapies. J Urol 2007; 177:1324-9; quiz 1591. [PMID: 17382724 DOI: 10.1016/j.juro.2006.11.069] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE Recurrent or radioresistant prostate cancer occurs in approximately 30% of men receiving primary radiotherapy. For men who are candidates for local salvage therapy, the oncological efficacy of ablative therapies may be affected by the anatomical and pathological features of cancers within irradiated prostate glands. We characterized and mapped the prostate cancers in our series of whole mount salvage radical prostatectomy specimens. MATERIALS AND METHODS A total of 47 salvage radical prostatectomies were performed at our institution between 2000 and 2004. Detailed pathological data, including the anatomical distribution of cancers, were obtained from 46 whole mount salvage radical prostatectomy specimens. RESULTS A total of 70 cancer foci were identified in 46 specimens. Of the specimens 93% had cancer foci at the apex. The median minimum cancer-to-urethra distance was smallest at the apex (4.1 mm) and greatest at the base (13.8 mm). More than 65% of patients had cancer 5 mm or less from the urethra and 7% of patients had cancer directly involving the urethra. Nearly half of all patients had evidence of extraprostatic disease. CONCLUSIONS The anatomical and pathological features in our study demonstrate that a significant portion of irradiated cancers are pathologically advanced and distributed in regions of the prostate (apical and periurethral) which are at risk for undertreatment using current ablative therapies. Our findings raise serious concerns regarding the oncological efficacy of such treatment modalities. Long-term studies without the use of hormonal therapy are needed to determine the oncological efficacy of salvage ablative therapies in patients with radiorecurrent or resistant prostate cancer.
Collapse
Affiliation(s)
- William C Huang
- Departments of Urology, Biostatistics/Epidemiology and Pathology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Allen ZA, Merrick GS, Butler WM, Wallner KE, Kurko B, Anderson RL, Murray BC, Galbreath RW. Detailed urethral dosimetry in the evaluation of prostate brachytherapy-related urinary morbidity. Int J Radiat Oncol Biol Phys 2005; 62:981-7. [PMID: 15989998 DOI: 10.1016/j.ijrobp.2004.12.068] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Revised: 11/03/2004] [Accepted: 12/17/2004] [Indexed: 10/25/2022]
Abstract
PURPOSE To evaluate the relationship between urinary morbidity after prostate brachytherapy and urethral doses calculated at the base, midprostate, apex, and urogenital diaphragm. METHODS AND MATERIALS From February 1998 through July 2002, 186 consecutive patients without a prior history of a transurethral resection underwent monotherapeutic brachytherapy (no supplemental external beam radiation therapy or androgen deprivation therapy) with urethral-sparing techniques (average urethral dose 100%-140% minimum peripheral dose) for clinical T1c-T2b (2002 AJCC) prostate cancer. The median follow-up was 45.5 months. Urinary morbidity was defined by time to International Prostate Symptom Score (IPSS) resolution, maximum increase in IPSS, catheter dependency, and the need for postimplant surgical intervention. An alpha blocker was initiated approximately 2 weeks before implantation and continued at least until the IPSS returned to baseline. Evaluated parameters included overall urethral dose (average and maximum), doses to the base, midprostate, apex, and urogenital diaphragm, patient age, clinical T stage, preimplant IPSS, ultrasound volume, isotope, and D90 and V100/150/200. RESULTS Of the 186 patients, 176 (94.6%) had the urinary catheter permanently removed on the day of implantation with only 1 patient requiring a urinary catheter >5 days. No patient had a urethral stricture and only 2 patients (1.1%) required a postbrachytherapy transurethral resection of the prostate (TURP). For the entire cohort, IPSS on average peaked 2 weeks after implantation with a mean and median time to IPSS resolution of 14 and 3 weeks, respectively. For the entire cohort, only isotope predicted for IPSS resolution, while neither overall average prostatic urethra nor segmental urethral dose predicted for IPSS resolution. The maximum postimplant IPSS increase was best predicted by preimplant IPSS and the maximum apical urethral dose. CONCLUSIONS With the routine use of prophylactic alpha blockers and strict adherence to urethral-sparing techniques, detailed urethral dosimetry did not substantially improve the ability to predict urinary morbidity. Neither the average dose to the prostatic urethra nor urethral doses stratified into base, midprostate, apex, or urogenital diaphragm segments predicted for IPSS normalization. Radiation doses of 100%-140% minimum peripheral dose are well tolerated by all segments of the prostatic urethra with resultant tumoricidal doses to foci of periurethral cancer.
Collapse
Affiliation(s)
- Zachariah A Allen
- Schiffler Cancer Center, Wheeling Hospital, 1 Medical Park, Wheeling, WV 26003-6300, USA
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Merrick GS, Wallner KE, Butler WM. Prostate cryotherapy: More questions than answers. Urology 2005; 66:9-15. [PMID: 15992870 DOI: 10.1016/j.urology.2004.12.039] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Revised: 11/22/2004] [Accepted: 12/15/2004] [Indexed: 11/28/2022]
Affiliation(s)
- Gregory S Merrick
- Schiffler Cancer Center, Wheeling Hospital, Wheeling, West Virginia 26003-6300, USA.
| | | | | |
Collapse
|
23
|
Sherar MD, Trachtenberg J, Davidson SRH, Gertner MR. Interstitial microwave thermal therapy and its application to the treatment of recurrent prostate cancer. Int J Hyperthermia 2005; 20:757-68. [PMID: 15675670 DOI: 10.1080/02656730410001734146] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Interstitial microwave thermal therapy may be an effective alternative to surgery for the treatment of some solid tumours. Arrays of helical antennae can produce complex heating patterns which when combined with active cooling of normal tissue structures can provide conformal heating for thermal coagulation of tumours. The development of a clinical protocol involving phantom and animal model studies, treatment planning, tissue property measurement and methods for on-line treatment monitoring is reviewed. The technology developed has been applied to the problem of recurrent prostate cancer following failed radiation treatment where available curative options are associated with high normal tissue morbidity. The purpose was to develop a treatment option for this group of patients with a very low side-effect profile that would not preclude further treatment if the disease progressed. Results of a Phase I/II trial demonstrate safety, promising efficacy and a low complication rate. As the technology for delivering this treatment matures, larger multi-institutional trials should be considered.
Collapse
Affiliation(s)
- M D Sherar
- Medical Physics Division, Ontario Cancer Institute/Princess Margaret Hospital, Toronto, Canada.
| | | | | | | |
Collapse
|
24
|
Abstract
Traditional treatments for men with localized prostate cancer have included both surgical removal and radiation therapy, with their potential adverse effects on patient quality of life. Thus, there has been increasing interest in the development of minimally invasive procedures that use various technologies to deliver lethal doses of heat or cold to the prostate in an attempt to kill cancer cells. At the same time, it is vital that these newer techniques ablate prostate tissue and spare vital periprostatic organs essential for maintaining function and quality of life. In this article, we evaluate the current status of tissue ablation modalities in the treatment of clinically localized prostate cancer, focusing on the different methods, early results, and possible future directions. Although still in the beginning stages, these newer forms of treatment offer exciting potential for first-line and second-line treatment of this common urologic malignancy.
Collapse
Affiliation(s)
- Michael D Gillett
- Department of Urology, Mayo Clinic College of Medicine, Rochester, Minn 55905, USA
| | | | | | | |
Collapse
|
25
|
Diederich CJ, Stafford RJ, Nau WH, Burdette EC, Price RE, Hazle JD. Transurethral ultrasound applicators with directional heating patterns for prostate thermal therapy: in vivo evaluation using magnetic resonance thermometry. Med Phys 2004; 31:405-13. [PMID: 15000627 DOI: 10.1118/1.1639959] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
A catheter-based transurethral ultrasound applicator with angularly directional heating patterns has been designed for prostate thermal therapy and evaluated in canine prostate in vivo using MRI to monitor and assess performance. The ultrasound transducer array (3.5 mm diameter tubular transducers, 180 degrees active sectors, approximately 7.5 MHz) was integrated to a flexible delivery catheter (4 mm OD), and encapsulated within an expandable balloon (35 mm x 10 mm OD, 80 ml min(-1) ambient water) for coupling and cooling of the prostatic urethra. These devices were used to thermally coagulate targeted portions of the canine prostate (n = 2) while using MR thermal imaging (MRTI) to monitor the therapy. MRI was also used for target definition, positioning of the applicator, and evaluation of target viability post-therapy. MRTI was based upon the complex phase-difference mapping technique using an interleaved gradient echo-planar imaging sequence with lipid suppression. MRTI derived temperature distributions, thermal dose exposures, T1-contrast enhanced MR images, and histology of sectioned prostates were used to define destroyed tissue zones and characterize the three-dimensional heating patterns. The ultrasound applicators produced approximately 180 degrees directed zones of thermal coagulation within targeted tissue which extended 15-20 mm radially to the outer boundary of the prostate within 15 min. Transducer activation lengths of 17 mm and 24 mm produced contiguous zones of coagulation extending axially approximately 18 mm and approximately 25 mm from base to apex, respectively. Peak temperatures around 90 degrees C were measured, with approximately 50 degrees C-52 degrees C corresponding to outer boundary t43 = 240 min at approximately 15 min treatment time. These devices are MRI compatible, and when coupled with multiplanar MRTI provide a means for selectively controlling the length and sector angle of therapeutic thermal treatment in the prostate.
Collapse
Affiliation(s)
- C J Diederich
- Thermal Therapy Research Group, Radiation Oncology Department, University of California, San Francisco, California 94143-1708, USA.
| | | | | | | | | | | |
Collapse
|
26
|
Pisansky TM, Davis BJ, Stone NN. Morbidity after brachytherapy for prostate adenocarcinoma. Mayo Clin Proc 2004; 79:946-7; author reply 947-9. [PMID: 15244398 DOI: 10.4065/79.7.946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
27
|
Frank I, Blute ML. Defining the appropriate patient population for primary brachytherapy for localized prostate cancer: work in progress. Mayo Clin Proc 2004; 79:307-8. [PMID: 15008602 DOI: 10.4065/79.3.307] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
28
|
Affiliation(s)
- Gregory S Merrick
- Schiffler Cancer Center, Wheeling Hospital, Wheeling, West Virginia 26003-6300, USA
| | | | | |
Collapse
|
29
|
Mynderse LA, Larson TR. Transurethral hot water balloon thermotherapy for benign prostatic hyperplasia. Curr Urol Rep 2003; 4:287-91. [PMID: 12882720 DOI: 10.1007/s11934-003-0086-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Lance A Mynderse
- Department of Urology, Mayo Foundation, 200 First Street SW, Rochester, MN 55905, USA.
| | | |
Collapse
|
30
|
Merrick GS, Wallner KE, Butler WM. Permanent interstitial brachytherapy for the management of carcinoma of the prostate gland. J Urol 2003; 169:1643-52. [PMID: 12686802 DOI: 10.1097/01.ju.0000035544.25483.61] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE We summarize the permanent prostate brachytherapy literature, including biochemical outcomes, quality of life parameters and areas of controversy. MATERIALS AND METHODS The permanent prostate brachytherapy literature was reviewed using MEDLINE searches to ensure completeness. RESULTS Using various planning and intraoperative techniques the majority of the brachytherapy literature demonstrates durable biochemical outcomes for patients with low, intermediate and high risk features. For low risk patients there is no advantage to combining supplemental external beam radiation therapy with brachytherapy. In addition, supplemental external beam radiation therapy may not improve biochemical outcomes for patients at intermediate and high risk if the target volume consists of the prostate with a generous periprostatic margin. There is no defined role for adjuvant hormonal manipulation. Although a reliable set of pretreatment criteria to predict implant related morbidity is not available, severe urinary and rectal morbidity is rare. The incidence of brachytherapy induced erectile dysfunction is significantly greater than initially reported but the majority of patients respond favorably to sildenafil. CONCLUSIONS Continued refinements in brachytherapy planning and implementation techniques, postimplantation evaluation and continued elucidation of the etiology of urinary, bowel and sexual dysfunction should result in further improvements in biochemical and quality of life outcomes.
Collapse
Affiliation(s)
- Gregory S Merrick
- Schiffler Cancer Center, Wheeling Hospital, Wheeling, West Virginia, USA
| | | | | |
Collapse
|
31
|
Davidson SRH, Sherar MD. Theoretical modelling, experimental studies and clinical simulations of urethral cooling catheters for use during prostate thermal therapy. Phys Med Biol 2003; 48:729-44. [PMID: 12699191 DOI: 10.1088/0031-9155/48/6/303] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Urethral cooling catheters are used to prevent thermal damage to the urethra during thermal therapy of the prostate. Quantification of a catheter's heat transfer characteristics is necessary for prediction of the catheter's influence on the temperature and thermal dose distribution in periurethral tissue. Two cooling catheters with different designs were examined: the Dornier Urowave catheter and a prototype device from BSD Medical Corp. A convection coefficient, h. was used to characterize the cooling ability of each catheter. The value of the convection coefficient (h = 330 W m(-2) C(-1) for the Dornier catheter. h = 160 W m(-2) C(-1) for the BSD device) was obtained by comparing temperatures measured in a tissue-equivalent phantom material to temperatures predicted by a finite element method simulation of the phantom experiments. The coefficient was found to be insensitive to the rate of coolant flow inside the catheter between 40 and 120 ml min(-1). The convection coefficient method for modelling urethral catheters was incorporated into simulations of microwave heating of the prostate. Results from these simulations indicate that the Dornier device is significantly more effective than the BSD catheter at cooling the tissue surrounding the urethra.
Collapse
Affiliation(s)
- Sean R H Davidson
- Division of Medical Physics, Ontario Cancer Institute/Princess Margaret Hospital, University Health Network, Toronto, Canada
| | | |
Collapse
|
32
|
Rukstalis DB, Goldknopf JL, Crowley EM, Garcia FU. Prostate cryoablation: a scientific rationale for future modifications. Urology 2002; 60:19-25. [PMID: 12206844 DOI: 10.1016/s0090-4295(02)01680-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This investigation was designed to identify potential directions for future modification of the percutaneous prostate cryoablation procedure. An analysis of prostate cancer location and volume in radical prostatectomy specimens was performed to evaluate the potential clinical consequences of these proposed modifications. A list of recommendations for improvements in the prostate cryoablation procedure was compiled from informal discussions held with participants in 9 training courses and conferences on prostate cryoablation over 18 months. Subsequently, a population of 112 consecutive, sagittally sectioned whole-mount radical prostatectomy samples was evaluated for prostate cancer volume, number of individual foci, and location to examine the disease-specific outcomes of these proposed modifications. The most common areas for potential alterations in the current cryoablation technique include modifications that would further simplify the procedure, continue to reduce real and perceived toxicity, and augment efficacy. Importantly, modifications designed to reduce treatment side effects could conflict with efforts designed to improve eradication of prostate cancer. Pathologic analysis revealed multifocal cancer in 79.5% of the samples, with 66% of cases exhibiting cancer within 5 mm of the urethra. The median volume of the index cancer was 1.6 cm3, whereas the median volume of the smaller ancillary lesions was 0.3 cm3. Prostate parenchymal-sparing alterations, proposed to reduce incontinence and erectile dysfunction by targeting the index cancer, would likely eradicate clinically significant cancer in 79% of men. The recent enthusiasm for prostate cryoablation as a reasonable minimally invasive treatment option for men with clinically localized cancer is likely to result in modifications of the established surgical technique. Knowledge of the anatomic location and cancer volume within the prostate gland is an important adjunct to planning such alterations. It is possible that parenchymal-sparing modifications to total gland prostate cryoablation can eradicate clinically significant cancer in most men, with a reduction in toxicity and cost.
Collapse
Affiliation(s)
- Daniel B Rukstalis
- Department of Surgery, Division of Urology, MCP Hahnemann University School of Medicine, Philadelphia, Pennsylvania 19129, USA.
| | | | | | | |
Collapse
|
33
|
EDITORIAL COMMENT. J Urol 2001. [DOI: 10.1016/s0022-5347(01)69514-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|