Implementation of intensity modulated radiotherapy for prostate cancer in a private radiotherapy service in Mexico

Intensity modulated radiation therapy (IMRT) allows physicians to deliver higher conformal doses to the tumour, while avoiding adjacent structures. As a result the probability of tumour control is higher and toxicity may be reduced. However, implementation of IMRT is highly complex and requires a rigorous quality assurance (QA) program both before and during treatment. The present article describes the process of implementing IMRT for localized prostate cancer in a radiation therapy department. In our experience, IMRT implementation requires careful planning due to the need to simultaneously implement specialized software, multifaceted QA programs, and training of the multidisciplinary team. Establishing standardized protocols and ensuring close collaboration between a multidisciplinary team is challenging but essential.     

Image-guided IMRT for localized prostate cancer with daily repositioning: Inferring the difference between planned dose and delivered dose distribution

IntroductionTo investigate the dosimetric impact of daily on-line repositioning during a full course of IMRT for prostate cancer.Materials and methodsTwenty patients were treated with image-guided IMRT. Each pre-treatment plan (Plan A) was compared with a post-treatment plan sum (Plan B) based on couch shifts measured. The delivered dose to the prostate without a daily repositioning was inferred by considering each daily couch shift during the whole course of image-guided IMRT (i.e. plan B). Dose metrics were compared for prostate CTV (P-CTV) and PTV (P-PTV) and for organs at risk. Ten patients were treated with a 5 mm margin and 10 patients with a 10 mm margin.ResultsFor plan A vs plan B: the average D95, D98, D50, D mean and EUD were: 76.4 Gy vs 73.9 Gy (p = 0.0007), 75.4 Gy vs 72.3 Gy (p = 0.001), 78.9 Gy vs 78.4 Gy (p = 0.014), 78.7 Gy vs 77.8 Gy (p = 0.003) and 78.1 Gy vs 75.9 Gy (p = 0.002), respectively for P-CTV, and 73.2 Gy vs 69.3 Gy (p = 0.0006), 70.7 Gy vs 66.0 Gy (p = 0.0008), 78.3 Gy vs 77.5 Gy (p = 0.001), 77.8 Gy vs 76.4 Gy (p = 0.0002) and 74.4 Gy vs 69.2 Gy (p = 0.003), respectively for P-PTV. Margin comparison showed no differences in dose metrics between the two plans except for D98 of the rectum in plan B which was significantly higher with a 10 mm margin.ConclusionsThe absence of daily image-guided IMRT resulted in a significantly less uniform and less homogeneous dose distribution to the prostate. A reduction in PTV margin showed neither a lower target coverage nor a better spare of OAR with and without daily image-guided IMRT.     

Radiobiological evaluation of prostate cancer IMRT and conformal-RT plans using different treatment protocols

The purpose of this study is to evaluate the clinical efficacy of both step-and-shoot IMRT and 3D-Conformal Radiation Therapy modalities (CRT) in treating prostate cancer using radiobiological measures. Another aim was to estimate the risks for developing secondary malignancies in bladder and rectum due to radiotherapy from the corresponding modalities. The treatment plans of ten prostate cancer patients were developed using IMRT and CRT. For the IMRT plans, two beam energies and two treatment protocols were used (the RTOG 0415 and a most restrictive one proposed by Fox Chase Cancer Center (FCCC)). For the evaluation of these plans, the complication-free tumor control probability, the total probability of injury, the total probability of control/benefit, and the biologically effective uniform dose were employed. Furthermore, based on the dosimetric data of IMRT and CRT, the risk for secondary malignancies was calculated for bladder and rectum. The average risk for secondary malignancy was lower for the bladder (0.37%) compared to the rectum (0.81%) based on all the treatment plans of the ten prostate cancer patients. The highest average risk for secondary malignancy for bladder and rectum was for the CRT-6X modality (0.46% and 1.12%, respectively) and the lowest was for the IMRT RTOG-18X modality (0.33% and 0.56%, respectively). The ≥ Grade 2 LENT/SOMA response probability was lower for the bladder than for the rectum in all the plans. For the bladder the highest average value was for the IMRT RTOG-18X (0.9%) and the lowest was for the CRT-18X modality (0.1%). For the rectum, the highest average value was for the IMRT RTOG-6X (11.9%) and the lowest was for the IMRT FCCC-18X modality (2.2%). By using radiobiological measures it is shown that the IMRT FCCC plans had the lowest risks for normal tissue complications, whereas the IMRT RTOG had the highest. Regarding the risk for secondary malignancies, the CRT plans showed the highest values for both bladder and rectum.     

Dosimetric and physical comparison of IMRT and CyberKnife plans in the treatment of localized prostate cancer

Aim

The aim of our study was the dosimetric and physical evaluation of the CK and IMRT treatment plans for 16 patients with localized prostate cancer.

Background

Intensity modulated radiation therapy (IMRT) is one of the recent technical advances in radiotherapy. The prostate is a well suited site to be treated with IMRT. The challenge of accurately delivering the IMRT needs to be supported by new advances such as image-guidance and four-dimensional computed conformal radiation therapy (4DCRT) tomography. CyberKnife (CK) provides real time orthogonal X-ray imaging of the patient during treatment course to follow gold fiducials installed into the prostate and to achieve motion correlation between online acquired X-ray imaging and digital reconstructed radiographs (DRRs) which are obtained from planning computed tomography images by translating and rotating the treatment table in five directions.

Methods and materials

Sixteen IMRT and CK plans were performed to be compared in terms of conformity (CI), heterogeneity indices (HI), percentage doses of 100% (V100), 66% (V66), 50% (V50), 33% (V33) and 10% (V10) volumes of the bladder and rectum. Dose-volume histograms for target and critical organs, (CI) and indices (HI) and isodose lines were analyzed to evaluate the treatment plans.

Results

Statistically significant differences in the percentage rectal doses delivered to V10, V33, and V50 of the rectum were detected in favor of the CK plans (p values; <0.001, <0.001 and 0.019, respectively). The percentage doses for V66 and V100 of the rectum were larger in CK plans (13%, 2% in IMRT and 21%, 3% in CK plans, respectively). Percentage bladder doses for V10 and V33 were significantly lower in CK plans [96% in IMRT vs 48% in CK (p < 0.001) and 34% in IMRT vs 24% in CK (p = 0.047)]. Lower percentage doses were observed for V50, V66 of the bladder for the IMRT. They were 5.4% and 3.45% for IMRT and 13.4% and 8.05% for CK, respectively. Median CI of planning target volume (PTV) for IMRT and CK plans were 0.94 and 1.23, respectively (p < 0.001).

Conclusion

Both systems have a very good ability to create highly conformal volumetric dose distributions. Median HI of PTV for IMRT and CK plans were 1.08 and 1.33, respectively (p < 0.001).     

Evaluating the predictive value of quantec rectum tolerance dose suggestions on acute rectal toxicity in prostate carcinoma patients treated with IMRT

AimTo investigate the predictive value of convenience of rectum dosimetry with Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) dose limits, maximum rectum dose (Dmax), total rectal volume (TVrectum), rectal volume included in PTV (VrectumPTV) on Grade 2–3 acute rectal toxicity for utilization in clinical practice.BackgroundNumerous previous data have reported frequent acute proctitis after external-beam RT of prostate cancer. Predicting toxicity limited with dose information is inadequate in clinical practice due to comorbidities and medications used.Materials and MethodSixty-four non-metastatic prostate cancer patients treated with IMRT were enrolled. Patients were treated to a total dose of 70–76 Gy. Rectal dose volume histograms (DVH) of all patients were evaluated retrospectively, and a QUANTEC Score between 0 and 5 was calculated for each patient. The correlation between the rectal DVH data, QUANTEC score, TVrectum, VrectumPTV, rectum Dmax and Grade 2–3 rectal toxicity was investigated.ResultsIn the whole group grade 1, 2 and 3 acute rectal toxicities were 25%, 18.8% and 3.1%, respectively. In the DVH data, rectum doses of all patients were under RTOG dose limits. Statistically significant correlation was found between grade 2–3 rectal toxicity and TVrectum (p = 0,043); however. It was not correlated with QUANTEC score, VrectumPTV and Dmax.ConclusionOur results were not able to show any significant correlation between increasing convenience with QUANTEC limits and lower rectal toxicity. Conclusively, new dosimetric definitions are warranted to predict acute rectal toxicity more accurately in prostate cancer patients during IMRT treatment.     

Volumetric modulated arc therapy for prostate cancer patients with hip prosthesis

Aim

To study the use of RapidArc techniques in the treatment of prostate cancer patients with hip prosthesis.

Background

An important aspect of treatment planning is to achieve dose homogeneity inside the planning target volume (PTV). Especially for those patients presenting with hip prosthesis, it becomes a challenging task to achieve dose uniformity inside the PTV.

Materials and methods

Five prostate patients presenting with hip prosthesis who had undergone radical radiotherapy were selected for this study. Depending on the composition of prosthesis, a predefined set of Hounsfield values were assigned to each study set. RapidArc plans were generated on an Eclipse treatment planning system. Two arcs that include clockwise and counter-clockwise arcs were used in all these cases. To avoid beams passing through the prosthesis, a simple structure was defined around it with 1 cm margin and a strict dose constraint applied to the block during VMAT optimization.

Results

The mean D2/D98 ratio of PTV for all the patients was 1.06 ± 0.01. The mean percentage rectum volume receiving 50 Gy, 60 Gy, 70 Gy and 75 Gy for all the patients were 33.1 ± 5.9, 21.7 ± 5.5, 13.8 ± 4.4 and 9.5 ± 3.0, respectively.

Conclusions

This study shows that using a double arc RapidArc technique is a simple and effective treatment method of treating prostate cancer in patients presenting with a hip prosthesis. The definition of a beam avoidance structure encompassing the prosthesis and applying strict dose constraints to it reduces the beam contribution to the prosthesis     

Empirical estimation of beam-on time for prostate cancer patients treated on Tomotherapy

Background and aim

This study proposed a method to estimate the beam-on time for prostate cancer patients treated on Tomotherapy when FW (field width), PF (pitch factor), modulation factor (MF) and treatment length (TL) were given.

Material and methods

The study was divided into two parts: building and verifying the model. To build a model, 160 treatment plans were created for 10 patients. The plans differed in combination of FW, PF and MF. For all plans a graph of beam-on time as a function of TL was created and a linear trend function was fitted. Equation for each trend line was determined and used in a correlation model. Finally, 62 plans verified the treatment time computation model – the real execution time was compared with our estimation and irradiation time calculated based on the equation provided by the manufacturer.

Results

A linear trend function was drawn and the coefficient of determination R² and the Pearson correlation coefficient r were calculated for each of the 8 trend lines corresponding to the adequate treatment plan. An equation to correct the model was determined to estimate more accurately the beam-on time for different MFs. From 62 verification treatment plans, only 5 disagreed by more than 60 s with the real time from the HT software. Whereas, for the equation provided by the manufacturer the discrepancy was observed in 16 cases.

Conclusions

Our study showed that the model can well predict the treatment time for a given TL, MF, FW and it can be used in clinical practice.     

Three-dimensional quality assurance of IMRT prostate plans using gel dosimetry

Intensity modulated radiotherapy (IMRT) is one of the most modern radiation therapy treatment techniques. Although IMRT can deliver high and complex conformational doses to the tumor volume, its implementation requires rigorous quality assurance (QA) procedures that include a dosimetric pre-treatment verification of individual patient planning. This verification usually involves measuring a small volume of absolute dose with an ionization chamber and checking bi-dimensional fluency with an array of detectors. The planning technique has tri-dimensional characteristics, but no tridimensional dosimetry has been established in the clinical routine. One strategy to perform three-dimensional dosimetry is to use polymeric gels associated with magnetic resonance imaging to evaluate dose distribution. Here, we have compared the results of conventional QA procedures involving one- and two-dimensional dosimetry to the results of three-dimensional dosimetry conducted with MAGIC-f gel in 10 cases of prostate cancer IMRT planning. More specifically, we used the gamma index (3%/3 mm) to compare the results of three-dimensional dosimetry to the expected dose distributions obtained with the treatment planning system. Except for one IMRT treatment plan, the gel dosimetry results agreed with the conventional quality control and provided an overview of dose distribution in the target volume.     

Deep learning dose prediction for IMRT of esophageal cancer: The effect of data quality and quantity on model performance

PurposeTo investigate the effect of data quality and quantity on the performance of deep learning (DL) models, for dose prediction of intensity-modulated radiotherapy (IMRT) of esophageal cancer.Material and methodsTwo databases were used: a variable database (VarDB) with 56 clinical cases extracted retrospectively, including user-dependent variability in delineation and planning, different machines and beam configurations; and a homogenized database (HomDB), created to reduce this variability by re-contouring and re-planning all patients with a fixed class-solution protocol.Experiment 1 analysed the user-dependent variability, using 26 patients planned with the same machine and beam setup (E26-VarDB versus E26-HomDB). Experiment 2 increased the training set by groups of 10 patients (E16, E26, E36, E46, and E56) for both databases.Model evaluation metrics were the mean absolute error (MAE) for selected dose-volume metrics and the global MAE for all body voxels.ResultsFor Experiment 1, E26-HomDB reduced the MAE for the considered dose-volume metrics compared to E26-VarDB (e.g. reduction of 0.2 Gy for D95-PTV, 1.2 Gy for Dmean-heart or 3.3% for V5-lungs). For Experiment 2, increasing the database size slightly improved performance for HomDB models (e.g. decrease in global MAE of 0.13 Gy for E56-HomDB versus E26-HomDB), but increased the error for the VarDB models (e.g. increase in global MAE of 0.20 Gy for E56-VarDB versus E26-VarDB).ConclusionA small database may suffice to obtain good DL prediction performance, provided that homogenous training data is used. Data variability reduces the performance of DL models, which is further pronounced when increasing the training set.     

Normal tissue sparing using different techniques for prostate irradiation

AimThe aim of this study was to investigate normal tissue sparing through dosimetric parameters of normal tissue volumes using different irradiation techniques for conventional (CFRT) and simultaneously integrated boost (SIB) schedules.BackgroundSeveral dose-escalation studies for localized prostate cancer (PCa) have shown advanced biochemical relapse-free (bRFS) rates and also better local control for higher total doses using either CFRT or SIB schedules. Besides the most important organs-at-risk, absorbed dose reduction of other surrounding normal tissues are also preferable. In order to analyse the normal tissue sparing, dosimetric parameters of different normal tissue volumes were examined.Materials and methodsTreatment plans for 15 high risk prostate cancer patients were created using RapidArc (RA), Sliding Window (SW) IMRT and 4-field box (3D-CRT) technique. In order to evaluate normal tissue sparing, the volume of pelvic region was divided into six normal tissue cylinders with 1 cm wall thickness, located in each other.ResultsAll plans met the criteria of target coverage (V95%>95%). All techniques provided the same results for OARs except 3D-CRT for rectum and bilateral femoral heads. The values of V5, V10 and V15 increased in cases which included RapidArc technique and decreased for V20 and V30.ConclusionsThe dosimetric parameters for the cylindrical normal tissue volumes show that using RapidArc technique gives equal or slightly better normal tissue sparing and SIB provided the same normal tissue sparing as CFRT planned with RapidArc.     

Choosing between conventional and hypofractionated prostate cancer radiation therapy: Results from a study of shared decision-making

AimTo evaluate patient choice of prostate cancer radiotherapy fractionation, using a decision aid.BackgroundRecent ASTRO guidelines recommend patients with localised prostate cancer be offered moderately hypofractionated radiation therapy after discussing increased acute toxicity and uncertainty of long-term results compared to conventional fractionation.Materials and methodsA decision aid was designed to outline the benefits and potential downsides of conventionally and moderately hypofractionated radiation therapy. The aid incorporated the ASTRO guideline to outline risks and benefits.ResultsIn all, 124 patients with localised prostate cancer were seen from June-December 2018. Median age was 72 (range 50–90), 49.6 % were intermediate risk (50.4 % high risk). All except three patients made a choice using the aid; the three undecided patients were hypofractionated. In all, 33.9 % of patients chose hypofractionation: falling to 25.3 % for patients under 75 years, 24.3 % for patients living within 30 miles of the cancer centre, and 14.3 % for patients with baseline gastrointestinal symptoms. On multivariate analysis, younger age, proximity to the centre, and having baseline gastrointestinal symptoms significantly predicted for choosing conventional fractionation. Insurance status, attending clinician, baseline genitourinary symptoms, work/carer status, ECOG, cancer risk group and driving status did not impact choice. Reasons for choosing conventional fractionation were certainty of long-term results (84 %) and lower acute bowel toxicity (51 %).ConclusionsMost patients declined the convenience of moderate hypofractionation due to potentially increased acute toxicity, and the uncertainty of long-term outcomes. We advocate that no patient should be offered hypofractionation without a thorough discussion of uncertainty and acute toxicity.     

The role of medical physics in prostate cancer radiation therapy

Medical physics, both as a scientific discipline and clinical service, hugely contributed and still contributes to the advances in the radiotherapy of prostate cancer. The traditional translational role in developing and safely implementing new technology and methods for better optimizing, delivering and monitoring the treatment is rapidly expanding to include new fields such as quantitative morphological and functional imaging and the possibility of individually predicting outcome and toxicity. The pivotal position of medical physicists in treatment personalization probably represents the main challenge of current and next years and needs a gradual change of vision and training, without losing the traditional and fundamental role of physicists to guarantee a high quality of the treatment. The current focus issue is intended to cover traditional and new fields of investigation in prostate cancer radiation therapy with the aim to provide up-to-date reference material to medical physicists daily working to cure prostate cancer patients. The papers presented in this focus issue touch upon present and upcoming challenges that need to be met in order to further advance prostate cancer radiation therapy. We suggest that there is a smart future for medical physicists willing to perform research and innovate, while they continue to provide high-quality clinical service. However, physicists are increasingly expected to actively integrate their implicitly translational, flexible and high-level skills within multi-disciplinary teams including many clinical figures (first of all radiation oncologists) as well as scientists from other disciplines.     

Potential interest of developing an integrated boost dose escalation for stereotactic irradiation of primary prostate cancer

IntroductionThe stereotactic irradiation is a new approach for low-risk prostate cancer. The aim of the present study was to evaluate a schema of stereotactic irradiation of the prostate with an integrated-boost into the tumor.Material and methodsThe prostate and the tumor were delineated by a radiologist on CT/MRI fusion. A 9-coplanar fields IMRT plan was optimized with three different dose levels: 1) 5 × 6.5 Gy to the PTV1 (plan 1), 2) 5 × 8 Gy to the PTV1 (plan 2) and 3) 5 × 6.5 Gy on the PTV1 with 5 × 8 Gy on the PTV2 (plan 3). The maximum dose (MaxD), mean dose (MD) and doses received by 2% (D2), 5% (D5), 10% (D10) and 25% (D25) of the rectum and bladder walls were used to compare the 3 IMRT plans.ResultsA dose escalation to entire prostate from 6.5 Gy to 8 Gy increased the rectum MD, MaxD, D2, D5, D10 and D25 by 3.75 Gy, 8.42 Gy, 7.88 Gy, 7.36 Gy, 6.67 Gy and 5.54 Gy. Similar results were observed for the bladder with 1.72 Gy, 8.28 Gy, 7.01 Gy, 5.69 Gy, 4.36 Gy and 2.42 Gy for the same dosimetric parameters. An integrated SBRT boost only to PTV2 reduced by about 50% the dose difference for rectum and bladder compared to a homogenous prostate dose escalation. Thereby, the MD, D2, D5, D10 and D25 for rectum were increased by 1.51 Gy, 4.24 Gy, 3.08 Gy, 2.84 Gy and 2.37 Gy in plan 3 compared to plan 1.ConclusionsThe present planning study of an integrated SBRT boost limits the doses received by the rectum and bladder if compared to a whole prostate dose escalation for SBRT approach.     

Outcome modeling techniques for prostate cancer radiotherapy: Data,models, and validation

Prostate cancer is a frequently diagnosed malignancy worldwide and radiation therapy is a first-line approach in treating localized as well as locally advanced cases. The limiting factor in modern radiotherapy regimens is dose to normal structures, an excess of which can lead to aberrant radiation-induced toxicities. Conversely, dose reduction to spare adjacent normal structures risks underdosing target volumes and compromising local control. As a result, efforts aimed at predicting the effects of radiotherapy could invaluably optimize patient treatments by mitigating such toxicities and simultaneously maximizing biochemical control. In this work, we review the types of data, frameworks and techniques used for prostate radiotherapy outcome modeling. Consideration is given to clinical and dose-volume metrics, such as those amassed by the QUANTEC initiative, and also to newer methods for the integration of biological and genetic factors to improve prediction performance. We furthermore highlight trends in machine learning that may help to elucidate the complex pathophysiological mechanisms of tumor control and radiation-induced normal tissue side effects.     

Results of combined radiotherapy and hormonal treatment of prostate cancer patients with initial PSA value >40 ng/ml

AimTo evaluate the outcome of prostate cancer patients with initial PSA value >40 ng/ml.BackgroundThe outcome of prostate cancer patients with very high initial PSA value is not known and patients are frequently treated with palliative intent. We analyzed the outcome of radical combined hormonal treatment and radiotherapy in prostate cancer patients with initial PSA value >40 ng/ml.MethodsBetween January 2003 and December 2007 we treated, with curative intent, 56 patients with non-metastatic prostate cancer and initial PSA value >40 ng/ml. The treatment consisted of two months of neoadjuvant hormonal treatment (LHRH analog), radical radiotherapy (68–78 Gy, conformal technique) and an optional two-year adjuvant hormonal treatment.ResultsThe median time of follow up was 61 months. 5-Year overall survival was 90%. 5-Year biochemical disease free survival was 62%. T stage, Gleason score, PSA value, and radiotherapy dose did not significantly influence the outcome. Late genitourinal and gastrointestinal toxicity was acceptable.ConclusionRadical treatment in combination with hormonal treatment and radiotherapy can be recommended for this subgroup of prostate cancer patients with good performance status and life expectancy.     

Predicting toxicity in radiotherapy for prostate cancer

This comprehensive review addresses most organs at risk involved in planning optimization for prostate cancer. It can be considered an update of a previous educational review that was published in 2009 (Fiorino et al., 2009).The literature was reviewed based on PubMed and MEDLINE database searches (from January 2009 up to September 2015), including papers in press; for each section/subsection, key title words were used and possibly combined with other more general key-words (such as radiotherapy, dose-volume effects, NTCP, DVH, and predictive model). Publications generally dealing with toxicity without any association with dose–volume effects or correlations with clinical risk factors were disregarded, being outside the aim of the review.A focus was on external beam radiotherapy, including post-prostatectomy, with conventional fractionation or moderate hypofractionation (<4 Gy/fraction); extreme hypofractionation is the topic of another paper in this special issue. Gastrointestinal and urinary toxicity are the most investigated endpoints, with quantitative data published in the last 5 years suggesting both a dose–response relationship and the existence of a number of clinical/patient related risk factors acting as dose–response modifiers. Some results on erectile dysfunction, bowel toxicity and hematological toxicity are also presented.     

Displacements of fiducial markers in patients with prostate cancer treated with image guided radiotherapy: A single-institution descriptive study

Aim

To describe daily displacements when using fiducial markers as surrogates for the target volume in patients with prostate cancer treated with IGRT.

Background

The higher grade of conformity achieved with the use of modern radiation technologies in prostate cancer can increase the risk of geographical miss; therefore, an associated protocol of IGRT is recommended.

Materials and methods

A single-institution, retrospective, consecutive study was designed. 128 prostate cancer patients treated with daily on-line IGRT based on 2D kV orthogonal images were included. Daily displacement of the fiducial markers was considered as the difference between the position of the patient when using skin tattoos and the position after being relocated using fiducial markers. Measures of central tendency and dispersion were used to describe fiducial displacements.

Results

The implant itself took a mean time of 15 min. We did not detect any complications derived from the implant. 4296 sets of orthogonal images were identified, 128 sets of images corresponding to treatment initiation were excluded; 91 (2.1%) sets of images were excluded from the analysis after having identified that these images contained extreme outlier values. If IGRT had not been performed 25%, 10% or 5% of the treatments would have had displacements superior to 4, 7 or 9 mm respectively in any axis.

Conclusions

Image guidance is required when using highly conformal techniques; otherwise, at least 10% of daily treatments could have significant displacements. IGRT based on fiducial markers, with 2D kV orthogonal images is a convenient and fast method for performing image guidance.     

Metformin and statins: a possible role in high-risk prostate cancer

Aim and backgroundThere is increasing evidence that statins and oral anti-diabetic drugs, such as metformin, can have a favorable role in advanced prostate cancer treatment.Metformin has been shown to inhibit proliferation of tumor cells in vitro and statins inhibit carcinogenesis by suppressing angiogenesis/invasion mechanisms. However, clinical evidence on the protective effect of these drugs is still weak.The purpose of this study is to analyze if these drugs have an impact on Biochemical-Failure-Free-Survival (BFFS) and on Distant-Failure-Free-Survival (DFFS) in localized high-risk prostate cancer.Material and MethodsFrom 2002–2016, 447 patients with histologically confirmed high-risk prostate cancer were retrospectively evaluated. All patients received radiotherapy and androgen deprivation therapy. Biochemical recurrence was determined by the Phoenix criteria and metastatic patients were defined by the presence of radiological metastasis. Survival analysis was performed using the Kaplan-Meier method.Results175 patients were treated with statins (65.3 % with a dose ≤ 20 mg/day) and 70 with metformin (75.7 % with a dose ≤ 1700 mg/day). Median follow-up was 88 months (1–194) with no differences in BFFS and DFFS between metformin and non-metformin patients (77.4 % versus 80 %, p = 0.91 and 89.4 % versus 88.7 %, p = 0.56, respectively). We did not find a statistical difference in BFFS and DFFS in patients taking higher doses of those drugs.ConclusionMetformin and statins were not associated with BFFS or DFFS improvement in our analysis. However, the small number of patients treated with these drugs limits the reliability of the results and prospective studies are needed.     

Acute toxicity and quality of life in high risk prostate cancer patients: Updated results of randomized hypofractionation trial

Purpose

The aim of our study was to perform the final analysis of acute toxicity and quality of life data obtained from 221 consecutive patients who suffered from intermediate-to-high risk prostate cancer.