Background: Low-dose rate brachytherapy (LDR-BT) has been used in Sweden for more than a decade for treatment of low-risk prostate cancer. This study presents the outcome for patients treated with LDR-BT at a single institution with focus on the association between dose and biochemical failure-free survival (BFFS).Methods: In total 195 patients were treated with LDR-BT between 2004 and 2008. The patients were followed systematically for side effects for at least one year. PSA levels were followed regularly from three months and for at least five years. Outcome was analyzed in relation to clinical variables at baseline and to radiotherapy data.Results: Kaplan-Meier estimated BFFS at five years was 95.7%. Dose to the prostate in terms of D-90% was significantly associated with BFFS [HR 0.90 (95%CI 0.83-0.96), p=0.002].Conclusion: Out data confirmed that absorbed dose is a predictive factor for BFFS for low-risk patients without androgen deprivation therapy. With our treatment routines and dosimetry, a D-90% in the range of 170-180Gy gives excellent outcomes with acceptable toxicity for patients with low-risk prostate cancer.

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text E. Alerstam, T. Svensson, M. Einarsdóttír, K. Svanberg, and S. Andersson-Engels, "Time-resolved In Vivo Spectroscopy of Human Prostate evaluated using White Monte Carlo," in Biomedical Optics, OSA Technical Digest (CD) (Optica Publishing Group, 2008), paper BSuE67. Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

The recent interest in photodynamic therapy of human prostate cancer is accompanied by a need for techniques for in vivo monitoring of optical and physiological characteristics. We propose time‐of‐flight (TOF) spectroscopy in combination with Monte Carlo evaluation as a reliable optical technique for quantitative assessment of absorption, scattering, hemoglobin content and tissue oxygenation in the human prostate. For the first time, we demonstrate Monte Carlo‐based evaluation of in vivo TOF photon migration data. We show that this approach is crucial in order to avoid the large errors associated with the use of time‐resolved diffusion theory of light propagation in prostate‐like tissues. This progress also allows us to present the first in vivo scattering spectroscopy of human prostate tissue. Furthermore, TOF spectroscopy, in contrast to the more common steady‐state approach, is insensitive to bleedings, and has been found highly reliable (100% success rate). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Photodynamic therapy (PDT) for the treatment of prostate cancer has been demonstrated to be a safe treatment option capable of inducing tissue necrosis and decrease in prostate specific antigen (PSA). Research groups report on large variations in treatment response, possibly due to biological variations in tissue composition and short-term response to the therapeutic irradiation. Within our group, an instrument for interstitial PDT on prostate tissue that incorporates realtime treatment feedback is being developed. The treatment protocol consists of two parts. The first part incorporates the pre-treatment plan with ultrasound investigations, providing the geometry for the prostate gland and surrounding risk organs, an iterative random-search algorithm to determine near-optimal fiber positions within the reconstructed geometry and a Block-Cimmino optimization algorithm for predicting individual fiber irradiation times. During the second part, the therapeutic light delivery is combined with measurements of the light transmission signals between the optical fibers, thus monitoring the tissue effective attenuation coefficient by means of spatially resolved spectroscopy. These data are then used as input for repeated runs of the Block-Cimmino optimization algorithm. Thus, the irradiation times for individual fibers are updated throughout the treatment in order to compensate for the influence of changes in tissue composition on the light distribution at the therapeutic wavelength.

The development of photodynamic therapy into a modality for treatment of prostate cancer calls for reliable optical dosimetry. We employ, for the first time, interstitial time-resolved spectroscopy to determine in vivo optical properties of human prostate tissue. Nine patients are included in the study, and measurements are conducted prior to primary brachytherapy treatment of prostate cancer. Intrasubject variability is examined by measuring across three tissue volumes within each prostate. The time-resolved instrumentation proves its usefulness by producing good signal levels in all measurements. We are able to present consistent values on reduced scattering coefficients (mu(s)'), absorption coefficients (mu(a)), and effective attenuation (mu(eff)) at the wavelengths 660, 786, and 916 nm. At 660 nm, mu(s)' is found to be 9+/-2 cm(-1), and mu(a) is 0.5+/-0.1 cm(-1). Derived values of mu(eff) are in the range of 3 to 4 cm(-1) at 660 nm, a result in good agreement with previously published steady state data. Total hemoglobin concentration (THC) and oxygen saturation are spectroscopically determined using derived absorption coefficients. Derived THC values are fairly variable (215+/-65 microM), while derived values of oxygen saturation are gathered around 75% (76+/-4%). Intrasubject variations in derived parameters correlate (qualitatively) with the heterogeneity exhibited in acquired ultrasound images.

Tissue samples were obtained from normal (n = 92), hyperplastic (n = 22) and malignant (n = 35) endometria. Urokinase and tissue plasminogen activators (u-PA, t-PA) were assayed in acetate detergent buffer extracts and their mRNAs quantitated in autoradiograms of Northern blots. The tissue content of u-PA was significantly higher in adenocarcinomas compared to normal and hyperplastic endometria. Tumors with poor differentiation and extensive myometrial invasion had the highest levels. The content of t-PA was increased in hyperplastic endometria but not in adenocarcinomas. The tissue content of t-PA was inversely related to clinical stage and loss of differentiation in malignant tumors. In contrast to the protein data, u-PA mRNA was not higher and t-PA mRNA was much lower in malignant compared to benign tumors. Thus, high tumor tissue content of u-PA does not result from transcriptional regulation, and reduction of t-PA mRNA may indicate down-regulation of transcription or possibly reduced mRNA stability. Furthermore, the discrepancy between protein and mRNA for both activators probably indicates up-regulation of the translation process since decreased degradation of activator proteins is a less likely explanation.

The aim of the present investigation was to see if alternative histopathological parameters could identify a smaller high risk group than commonly seen using routine histopathological parameters. The material consisted of 150 primary resected patients of FIGO Ia-Ic diagnosed as endometrial carcinoma and 12 cases of atypical hyperplasias which were suspected to contain small areas of carcinoma. The patients were treated from December 1979 to April 1993 at the Department of Obstetrics and Gynecology, University Hospital, Lund, Sweden. Those with deep myometrial invasion (> 50%) were given external radiotherapy (20-30 Gy) postoperatively. The follow-up period ranged from 2.5 to 5 years with 116 patients followed-up for more than 5 years. As no therapy was given before surgery we could investigate histopathologic variables such as degree of differentiation and cytology, number of mitoses per high power field (x 40), nuclear polymorphism, mode of invasion, the extension of myometrial invasion, vessel invasion as well as grade of lymphocyte reaction around the tumour cells. We found the degree of differentiation, vessel invasion, number of mitoses, mode of invasion and cytologic abberation to be significant prognostic parameters. The frequency of deep myometrial invasion (> 50%) was extremly high (51/150 = 33%). However, this usually strong parameter was only significant when comparing stage Ia with Ic. Thus the prognostic capacity of myometrial invasion is diminished in primary hysterectomized patients. In the regression analyses only vascular invasion remained significant. By combining vascular invasion with the degree of differentiation we diminished the high-risk group consisting of candidates for further investigation and treatment. Thus a high risk group consisting of poorly differentiated carcinomas with vascular invasion was constructed comprising 24 of 139 patients with a mortality rate of 60%.