Conformal Radiotherapy For Prostate Cancer Research Articles

Results with radical conformal radiotherapy in prostate cancer

Results with radical conformal radiotherapy in prostate cancer

A dosimetric evaluation of intensity modulated radiotherapy and three-dimensional conformal radiotherapy for prostate cancer in Ghana.

External beam radiotherapy incorporates treatment techniques such as three-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT), image-guided radiotherapy and volumetric modulated arc therapy to deliver high-energy radiation to cancer. The use of IMRT for cancer treatment is also associated with significant costs for patients in low-middle-income countries. The purpose of this study was to compare the dosimetric properties of 3DCRT and IMRT treatment plans for the external beam irradiation of patients with prostate cancer (Pca) to ascertain the superiority of IMRT in terms of dose homogeneity, conformity and dose limitation to organs at risk (OAR) in a resource-limited setting. One hundred and sixty treatment plans for 80 patients were created using 3DCRT and IMRT on the Eclipse treatment planning system (version 13.6). Data were collected and assessed from the dose-volume histogram of each plan. The conformity and homogeneity index (HI) for each of the plans were calculated. The doses to the OAR were also recorded and evaluated. The mean HIs for the IMRT and 3DCRT treatment techniques were 0.04 ± 0.02 (range: 0.01-0.011) and 0.09 ± 0.02 (range: 0.04-0.016), respectively. The mean conformity index (CI) for IMRT and 3DCRT techniques were 1.257 ± 0.112 (range: 0.99-1.58) and 1.302 ± 0.196 (range: 1.10-2.26). IMRT had a better significant mean HI and CI compared to 3DCRT. Generally, for this study, IMRT had better organ sparing compared to 3DCRT. The mean doses for the OARs ranged from 4.3-74.6 Gy for IMRT and 3.1-75.9 Gy for the 3DCRT technique. Overall, this study demonstrates that IMRT may offer an enhanced therapeutic profile, potentially reducing toxicity to the patient and ensuring more precise dose delivery to the target volume compared to 3DCRT in PCa external beam irradiation.

P014 - Why volumetric modulated arc therapy is better than three dimensions conformal radiotherapy in prostate cancer? Dosimetric analysis from a tertiary care hospital in Saudi Arabia

P014 - Why volumetric modulated arc therapy is better than three dimensions conformal radiotherapy in prostate cancer? Dosimetric analysis from a tertiary care hospital in Saudi Arabia

Comparison of intensity modulated and 3- dimensional conformal ‎radiotherapy for prostate cancer using ‎6-MV and 15-MV photon ‎energies

Prostate cancer is one of the commonest cancers in men. The purpose of this work was to compare ‎between ‎intensity-modulated radiotherapy (IMRT) versus three-dimensional conformal radiotherapy ‎‎(3D-CRT) planning in patients with prostate cancer using 6-MV and 15-MV photon energies. Twenty ‎patients with localized prostate cancer were planned on Xio treatment planning system. Four treatment ‎plans were generated for each patient. IMRT whether 6 or 15 MV beam was slightly better in terms of ‎target coverage but not significant (p>0.05) in comparison to 3D-CRT in both beam energies. IMRT ‎was better than 3D-CRT in terms of organs at risk (OARs) sparing and conformity index (CI) in both 6 ‎and 15-MV whereas 3D-CRT in both 6 and 15-MV yielded better homogeneity index (HI) compared ‎to IMRT 6 and 15-MV. The number of monitor units (MU) increased in IMRT compared to 3D-CRT. ‎Also,‎‏ ‏MU increased in low energy compared to high energy whether in 3D-CRT or IMRT (p<0.05). ‎When IMRT 6-MV and IMRT 15-MV were compared, no significant difference was found in terms of ‎target coverage and OARs except the rectum was better in IMRT 6-MV compared to IMRT 15-MV. ‎IMRT 6-MV technique should be prioritized when user has options for treatment and then 3D-CRT as ‎a second line when the former is not available. The choice of the energies (6 and 15MV) used with ‎‎3D-CRT depend largely on patient's body geometry while the use of high energy IMRT 15-MV is not ‎recommended.‎

Efficacy of Synbiotics to Reduce Symptoms and Rectal Inflammatory Response in Acute Radiation Proctitis: A Randomized, Double-Blind, Placebo-Controlled Pilot Trial

Purpose: Evaluate whether the daily intake of synbiotics improves symptoms and rectal/systemic inflammatory response in patients with radiation-induced acute proctitis.Methods and Materials: Twenty patients who underwent three-dimensional conformal radiotherapy for prostate cancer were randomized to intake either a synbiotic powder containing Lactobacillus reuteri (108 CFU) and soluble fiber (4.3 g) or placebo. EORTC QLQ-PRT23 questionnaire was applied before the beginning of radiotherapy and after the fifth, sixth, and seventh weeks of treatment, and the sum of both the complete (proctitis symptoms plus quality of life) and partial (proctitis symptoms) scores were compared. Fecal calprotectin was measured at Day 0 and in the fourth week of treatment, and serum C-reactive protein/albumin ratio were measured in the fourth week of treatment.Results: Both the complete and partial questionnaire score (median and range) were higher in the fifth and sixth weeks in the placebo group; there was a higher increase in fecal calprotectin in the placebo group and no difference comparing CRP/albumin ratio.Conclusions: Synbiotics reduce proctitis symptoms and improve quality of life by preventing rectal inflammation during radiotherapy for prostate cancer.

Pudendal nerve injury impairs anorectal function and health related quality of life measures ≥2 years after 3D conformal radiotherapy for prostate cancer

Purpose: To compare GI symptoms, measures of generic and disease specific health related quality of life (HRQoL), anorectal and pudendal nerve function and anal sphincter morphology between (i) patients ≥2 years after 3D conformal radiotherapy (3D-CRT)±high dose rate (HDR) brachytherapy for carcinoma of the prostate and aged matched patients before radiotherapy and (ii) symptomatic and asymptomatic patients ≥2 years after 3D-CRT ± HDR brachytherapy.Material and methods: Methodology included: (i) modified LENT-SOMA scales for GI symptoms, (ii) EORTC QLQ-C30 and EORTC QLQ-PR25 questionnaires for generic and disease specific HRQoL, (iii) anorectal manometry and terminal motor latency for anorectal and pudendal nerve function and (iv) endorectal ultrasound for anal sphincter morphology. GI symptoms, parameters of HRQoL, anorectal and pudendal nerve function and anal sphincter morphology were compared using Mann–Whitney’s U, unpaired t and χ2 tests.Results: Impairment of HRQoL bowel symptoms in the patients ≥2 years after 3D-CRT ± HDR brachytherapy was associated with worse anorectal motor and sensory function, internal and external anal sphincter morphology and 5× greater prevalence of pudendal nerve dysfunction compared with age matched patients before radiotherapy. Symptomatic patients had worse (i) HRQoL measures including global quality of life and bowel and urinary symptom scores, (ii) rectal bleeding, fecal urgency and incontinence scores and (iii) a 2× higher prevalence of pudendal nerve dysfunction compared with asymptomatic patients.Rectal and anal (i) V 40 Gy >65%, (ii) Dmax >60 Gy, (iii) pudendal nerve Dmax >60 Gy and (iv) Anal V 60 Gy >40% were associated with a greater prevalence of pudendal nerve dysfunction.Conclusions: 3D-CRT ± HDR brachytherapy for prostate carcinoma, impairs late functional measures including HRQoL, anorectal and pudendal nerve function. Rectal, anal and pudendal nerve radiation dose constraints are proposed for reducing the prevalence of pudendal nerve dysfunction.

EP-1713: Dose-volume analysis of genitourinary toxicity in 3-D conformal radiotherapy for prostate cancer

EP-1713: Dose-volume analysis of genitourinary toxicity in 3-D conformal radiotherapy for prostate cancer

Strategies to evaluate the impact of rectal volume on prostate motion during three-dimensional conformal radiotherapy for prostate cancer.

ObjectiveTo evaluate the rectal volume influence on prostate motion during three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer.Materials and MethodsFifty-one patients with prostate cancer underwent a series of three computed tomography scans including an initial planning scan and two subsequent scans during 3D-CRT. The organs of interest were outlined. The prostate contour was compared with the initial CT images considering the anterior, posterior, superior, inferior and lateral edges of the organ. Variations in the anterior limits and volume of the rectum were assessed and correlated with prostate motion in the anteroposterior direction.ResultsThe maximum range of prostate motion was observed in the superoinferior direction, followed by the anteroposterior direction. A significant correlation was observed between prostate motion and rectal volume variation (p = 0.037). A baseline rectal volume superior to 70 cm3 had a significant influence on the prostate motion in the anteroposterior direction (p = 0.045).ConclusionThe present study showed a significant interfraction motion of the prostate during 3D-CRT with greatest variations in the superoinferior and anteroposterior directions, and that a large rectal volume influences the prostate motion with a cutoff value of 70 cm3. Therefore, the treatment of patients with a rectal volume > 70 cm3 should be re-planned with appropriate rectal preparation.

A.100 - In vivo dosimetry in 3D conformal radiotherapy for prostate cancer with Gafchromic® EBT3 films: A feasibility study

A.100 - In vivo dosimetry in 3D conformal radiotherapy for prostate cancer with Gafchromic® EBT3 films: A feasibility study

Escalated-dose versus control-dose conformal radiotherapy for prostate cancer: long-term results from the MRC RT01 randomised controlled trial

The aim of this trial was to compare dose-escalated conformal radiotherapy with control-dose conformal radiotherapy in patients with localised prostate cancer. Preliminary findings reported after 5 years of follow-up showed that escalated-dose conformal radiotherapy improved biochemical progression-free survival. Based on the sample size calculation, we planned to analyse overall survival when 190 deaths occurred; this target has now been reached, after a median 10 years of follow-up. RT01 was a phase 3, open-label, international, randomised controlled trial enrolling men with histologically confirmed T1b-T3a, N0, M0 prostate cancer with prostate specific antigen of less than 50 ng/mL. Patients were randomly assigned centrally in a 1:1 ratio, using a computer-based minimisation algorithm stratifying by risk of seminal vesicle invasion and centre to either the control group (64 Gy in 32 fractions, the standard dose at the time the trial was designed) or the escalated-dose group (74 Gy in 37 fractions). Neither patients nor investigators were masked to assignment. All patients received neoadjuvant androgen deprivation therapy for 3-6 months before the start of conformal radiotherapy, which continued until the end of conformal radiotherapy. The coprimary outcome measures were biochemical progression-free survival and overall survival. All analyses were done on an intention-to-treat basis. Treatment-related side-effects have been reported previously. This trial is registered, number ISRCTN47772397. Between Jan 7, 1998, and Dec 20, 2001, 862 men were registered and 843 subsequently randomly assigned: 422 to the escalated-dose group and 421 to the control group. As of Aug 2, 2011, 236 deaths had occurred: 118 in each group. Median follow-up was 10·0 years (IQR 9·1-10·8). Overall survival at 10 years was 71% (95% CI 66-75) in each group (hazard ratio [HR] 0·99, 95% CI 0·77-1·28; p=0·96). Biochemical progression or progressive disease occurred in 391 patients (221 [57%] in the control group and 170 [43%] in the escalated-dose group). At 10 years, biochemical progression-free survival was 43% (95% CI 38-48) in the control group and 55% (50-61) in the escalated-dose group (HR 0·69, 95% CI 0·56-0·84; p=0·0003). At a median follow-up of 10 years, escalated-dose conformal radiotherapy with neoadjuvant androgen deprivation therapy showed an advantage in biochemical progression-free survival, but this advantage did not translate into an improvement in overall survival. These efficacy data for escalated-dose treatment must be weighed against the increase in acute and late toxicities associated with the escalated dose and emphasise the importance of use of appropriate modern radiotherapy methods to reduce side-effects. UK Medical Research Council.

Image guidance in prostate cancer - can offline corrections be an effective substitute for daily online imaging?

This aim of this study was to determine if a less resource-intensive and established offline correction protocol - the No Action Level (NAL) protocol was as effective as daily online corrections of setup deviations in curative high-dose radiotherapy of prostate cancer. A total of 683 daily megavoltage CT (MVCT) or kilovoltage CT (kvCBCT) images of 30 patients with localized prostate cancer treated with intensity modulated radiotherapy were evaluated. Daily image-guidance was performed and setup errors in three translational axes recorded. The NAL protocol was simulated by using the mean shift calculated from the first five fractions and implemented on all subsequent treatments. Using the imaging data from the remaining fractions, the daily residual error (RE) was determined. The proportion of fractions where the RE was greater than 3,5 and 7 mm was calculated, and also the actual PTV margin that would be required if the offline protocol was followed. Using the NAL protocol reduced the systematic but not the random errors. Corrections made using the NAL protocol resulted in small and acceptable RE in the mediolateral (ML) and superoinferior (SI) directions with 46/533 (8.1%) and 48/533 (5%) residual shifts above 5 mm. However; residual errors greater than 5mm in the anteroposterior (AP) direction remained in 181/533 (34%) of fractions. The PTV margins calculated based on residual errors were 5mm, 5mm and 13 mm in the ML, SI and AP directions respectively. Offline correction using the NAL protocol resulted in unacceptably high residual errors in the AP direction, due to random uncertainties of rectal and bladder filling. Daily online imaging and corrections remain the standard image guidance policy for highly conformal radiotherapy of prostate cancer.

高精度放射線治療の現状とAdaptive Therapyの展望：前立腺がんに対する放射線治療を中心に

高精度放射線治療の現状とAdaptive Therapyの展望：前立腺がんに対する放射線治療を中心に

Randomised pilot study of dose escalation using conformal radiotherapy in prostate cancer: long-term follow-up

Background:Radical three-dimensional conformal radiotherapy (CFRT) with initial androgen suppression (AS) is a standard management for localised prostate cancer (PC). This pilot study evaluated the role of dose escalation and appropriate target volume margin. Here, we report long-term follow-up.Methods:Eligible patients had T1b-T3b N0 M0 PC. After neoadjuvant AS, they were randomised to CFRT, giving (a) 64 Gy with either a 1.0- or 1.5-cm margin and (b) ±10 Gy boost to the prostate alone.Results:One hundred and twenty-six men were randomised and treated. Median follow-up was 13.7 years. The median age was 66.6 years at randomisation. Median presenting prostate-specific antigen (PSA) was 14 ng ml−1. Sixty-four out of 126 patients developed PSA failure. Forty-nine out of 126 patients restarted AS, 34 out of 126 developed metastases and 28 out of 126 developed castrate-resistant prostate cancer (CRPC). Fifty-one out of 126 patients died; 19 out of 51 died of PC. Median overall survival (OS) was 14.4 years. Although escalated dose results were favourable, no statistically significant differences were seen between the randomised groups; PSA control (hazard ratio (HR): 0.77 (95% confidence interval (CI): 0.47–1.26)), development of CRPC (HR: 0.81 (95% CI: 0.40–1.65)), PC-specific survival (HR: 0.59 (95% CI:0.23–1.49)) and OS (HR: 0.81 (95% CI: 0.47–1.40)). There was no evidence of a difference in PSA control according to margin size (HR: 1.01 (95% CI: 0.61–1.66)).Interpretation:Long-term follow-up of this small pilot study is compatible with a benefit from dose escalation, but confirmation from larger trials is required. There was no obvious detriment using the smaller radiotherapy margin.

Outcome and Toxicity for Patients Treated with Intensity Modulated Radiation Therapy for Localized Prostate Cancer

We evaluate long-term disease control and chronic toxicities observed in patients treated with intensity modulated radiation therapy for clinically localized prostate cancer. A total of 302 patients with localized prostate cancer treated with image guided intensity modulated radiation therapy between July 2000 and May 2005 were retrospectively analyzed. Risk groups (low, intermediate and high) were designated based on National Comprehensive Cancer Network guidelines. Biochemical control was based on the American Society for Therapeutic Radiology and Oncology (Phoenix) consensus definition. Chronic toxicity was measured at peak symptoms and at last visit. Toxicity was scored based on Common Terminology Criteria for Adverse Events v4. The median radiation dose delivered was 75.6 Gy (range 70.2 to 77.4) and 35.4% of patients received androgen deprivation therapy. Patients were followed until death or from 6 to 138 months (median 91) for those alive at last evaluation. Local and distant recurrence rates were 5% and 8.6%, respectively. At 9 years biochemical control rates were 77.4% for low risk, 69.6% for intermediate risk and 53.3% for high risk cases (log rank p = 0.05). On multivariate analysis T stage and prostate specific antigen group were prognostic for biochemical control. At last followup only 0% and 0.7% of patients had persistent grade 3 or greater gastrointestinal and genitourinary toxicity, respectively. High risk group was associated with higher distant metastasis rate (p = 0.02) and death from prostate cancer (p = 0.0012). This study represents one of the longest experiences with intensity modulated radiation therapy for prostate cancer. With a median followup of 91 months, intensity modulated radiation therapy resulted in durable biochemical control rates with low chronic toxicity.

A 2-Stage Genome-Wide Association Study to Identify Single Nucleotide Polymorphisms Associated with Development of Urinary Symptoms After Radiotherapy for Prostate Cancer

We identified single nucleotide polymorphisms associated with change in the AUA Symptom Score after radiotherapy for prostate cancer. A total of 723 patients treated with brachytherapy with or without external beam radiation therapy were assessed at baseline and annually after radiotherapy using the AUA Symptom Score. A 2-stage genome-wide association study was performed with the primary end point of change in AUA Symptom Score from baseline at each of 4 followup periods. Single nucleotide polymorphism associations were assessed using multivariable linear regression adjusting for pre-radiotherapy AUA Symptom Score severity category and clinical variables. Fisher's trend method was used to calculate combined p values from the discovery and replication cohorts. A region on chromosome 9p21.2 containing 8 single nucleotide polymorphisms showed the strongest association with change in AUA Symptom Score (combined p values 8.8×10(-6) to 6.5×10(-7) at 2 to 3 years after radiotherapy). These single nucleotide polymorphisms form a haplotype block that encompasses the inflammation signaling gene IFNK. These single nucleotide polymorphisms were independently associated with change in AUA Symptom Score after adjusting for clinical predictors including smoking history, hypertension, α-blocker use and pre-radiotherapy AUA Symptom Score. An additional 24 single nucleotide polymorphisms showed moderate significance for association with change in AUA Symptom Score. Several of these single nucleotide polymorphisms were more strongly associated with change in specific AUA Symptom Score items, including rs13035033 in the MYO3B gene, which was associated with straining (beta coefficient 0.9, 95% CI 0.6-1.2, p = 5.0×10(-9)). If validated, these single nucleotide polymorphisms could provide insight into the biology underlying urinary symptoms following radiotherapy and could lead to development of an assay to identify patients at risk for experiencing these effects.

Assessing the consistency of bladder filling using an ultrasonic Bladderscan® device

Free AccessCorrespondenceAssessing the consistency of bladder filling using an ultrasonic Bladderscan® deviceN J DudleyN J DudleySearch for more papers by this authorPublished Online:28 Jan 2014https://doi.org/10.1259/bjr/24030690SectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail AboutThe Editor,Hynds et al [1] assessed the daily consistency of bladder filling using a BVI 6400 Bladderscan® (Verathon Medical UK, Sandford, UK). This device is marketed to help in the diagnosis of urinary retention as an aid in prevention of unnecessary catheterisation and is widely and successfully used for this purpose. However, the device may not be suitable for the accurate measurement of bladder volume for other purposes. The manufacturers quote an accuracy of ±15%, ±15 ml when used to measure a phantom; they do not guarantee an accuracy in humans owing to variations in anatomy and pathology, so we may expect less accurate measurements in clinical practice.A fundamental element of this paper is the validation of bladder volume measurements by comparison with the CT planning scan. The authors state that validity of the volume measurement was confirmed and provide a Bland–Altman plot together with a Pearson's correlation coefficient of 0.91. Bland and Altman [2] stated that the correlation coefficient measures the degree of association between two quantities, not how closely they agree. The Bland–Altman plot shows large differences within pairs of CT and ultrasound measurements; it appears that about half of the measurements differ by >15%. This is reflected in the limits of agreement shown on the plot of almost ±100 ml (this is the 95% confidence limit on any measurement).The authors also stated that larger volumes demonstrate a greater difference; in fact there is no relation between bladder volume and the magnitude of the difference, although the differences are both positive and negative at lower volumes and mainly positive at higher volumes (giving an apparent weak correlation).Given the size of these differences, the value of any further analysis is questionable. The conclusion that a hand-held bladder ultrasound scanner is effective in this application is not supported by any good evidence.References1 Hynds S , McGarry CK , Mitchell DM , Early S , Shum L , Stewart DP , et al.. Assessing the daily consistency of bladder filling using an ultrasonic Bladderscan device in men receiving radical conformal radiotherapy for prostate cancer. Br J Radiol 2011;84:813–18. Link ISI, Google Scholar2 Bland JM , Altman DG . Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986;1:307–10. Crossref Medline ISI, Google Scholar Previous article Next article FiguresReferencesRelatedDetails Volume 85, Issue 1018October 2012Pages: 1333-e960 © 2012 The British Institute of Radiology History ReceivedOctober 25,2011AcceptedNovember 07,2011Published onlineJanuary 28,2014 Metrics Download PDF

Target registration errors with surface imaging system in conformal radiotherapy for prostate cancer: study on 19 patients

Accurate patient setup is a prerequisite for conformal radiotherapy (3D-CRT) and is based on various methods, including surface imaging systems. To evaluate the validity of a surface imaging system (AlignRT), we analysed setup reproducibility of a cohort of patients. Nineteen patients affected by prostate adenocarcinoma were enrolled in this study. We acquired 653 surface images and 99 digital portal images (DPI). Setup errors were found by matching surface images with computed tomography (CT) and DPI images. The setup errors from the threshold of 5 mm detected by AlignRT along the Y, Z and X axes occurred in 47.4%, 42.1% and 5.3% of patients, respectively. For the threshold of 3 mm, shifts along the Y, Z and X axes were observed in 68%, 69% and 10%, respectively. Comparing AlignRT and DPI, we found a statistically significant difference in the detection of shifts along the Y and Z axes. For a threshold ≥ 5 mm, the two systems provided corresponding setup errors along the Y and Z axes, whereas along the X axis, the threshold was not necessary. AlignRT is an accurate technique for setup in 3D-CRT prostate cancer patients, especially along the lateral direction.

Intensity Modulated Radiation Therapy Replaces 3-Dimensional Conformal Radiotherapy as Prostate Cancer Treatment

We describe trends in the use of intensity modulated radiotherapy vs 3-dimensional conformal radiotherapy for prostate cancer and identified predictors of intensity modulated radiotherapy use. From the SEER (Surveillance, Epidemiology and End Results)-Medicare database we identified 52,290 men with incident nonmetastatic prostate cancer from 2000 to 2007 who were treated with radiotherapy. We tracked trends in the use of intensity modulated radiotherapy, 3-dimensional conformal radiotherapy, brachytherapy and combinations. Patient demographic and clinical characteristics were described and compared using chi-square and multivariate logistic regression. Trends at the place of service were also examined. Intensity modulated radiotherapy use increased from 1% of all radiotherapy in 2000 to 70% in 2007. Three-dimensional conformal radiotherapy use decreased from 75% to 12%. Most cases were treated with intensity modulated radiotherapy monotherapy. In 2007, 12% of the cohort received intensity modulated radiotherapy plus brachytherapy. In 2005, 81% of all external radiation was given as intensity modulated radiotherapy. Except for geography there were minimal differences in patient demographic and clinical characteristics between those treated with 3-dimensional conformal radiotherapy vs intensity modulated radiotherapy. On multivariate analysis significant predictors of the odds of receiving intensity modulated radiotherapy vs 3-dimensional conformal radiotherapy were low Gleason score, high education, white or Asian race and urban place of residence. The odds of receiving intensity modulated radiotherapy varied greatly by registry. A lesser part of the growth in intensity modulated radiotherapy use occurred at freestanding facilities. Intensity modulated radiotherapy has replaced 3-dimensional conformal radiotherapy as the primary form of external radiation for prostate cancer. The choice of intensity modulated radiotherapy over 3-dimensional conformal radiotherapy is not related to common clinical factors such as age, comorbidities or tumor aggressiveness. Although geographic variations exist, by 2007 intensity modulated radiotherapy dominated in all regions studied.

High Dose Brachytherapy as Monotherapy for Intermediate Risk Prostate Cancer

We evaluated our retrospective, single institution experience with high dose rate brachytherapy as monotherapy for intermediate risk prostate cancer. Our cohort included 284 patients with intermediate risk prostate cancer, defined as clinical stage T2b/T2c, Gleason score 7 and/or prostate specific antigen 10 to 20 ng/ml, and 1-year minimum followup. Treatment was 2 high dose rate brachytherapy sessions at 3 fractions of 6.5 Gy each for a mean of 19 days. Prostate specific antigen failure was defined as nadir +2 ng/ml. Mean followup was 35.1 months (median 31.9). Actuarial 5-year cause specific survival and clinical local control were 100%, distant-metastasis-free survival 98.8% and biochemical disease-free survival 94.4%. Clinical stage predicted biochemical disease-free survival. For stage T2a or less 5-year biochemical disease-free survival was 95.1% vs 100% for stage T2b and 77.4% for T2c (p = 0.012). Percent positive biopsy cores and prostate specific antigen nadir were also predictive. International Prostate Symptom Score results remained stable and potency was maintained in 82.6% of patients at 2 years. Pads were used for the first time after brachytherapy in 22 patients (7.7%), mostly for grade 1 incontinence (occasionally or less per week). Excluding patients with prior transurethral prostatectomy, stroke or tremor 2.5% used pads for the first time after treatment. No patient had urethral stricture. Radiation Therapy Oncology Group grade 1 rectal toxicity developed in 12 patients (4.2%) but not beyond grade 1. High dose rate brachytherapy as monotherapy is safe and effective for patients with intermediate risk prostate cancer. We recommend caution for percent positive biopsy cores exceeding 75% or clinical stage T2c. Excluding such patients the 5-year biochemical disease-free survival rate was 97.5%.

Late Radiation Toxicity after Conformal Radiotherapy for Prostate Cancer among Patients with Diabetes Mellitus

Late Radiation Toxicity after Conformal Radiotherapy for Prostate Cancer among Patients with Diabetes Mellitus