Escalated-dose versus standard-dose conformal radiotherapy in prostate cancer: first results from the MRC RT01 randomised controlled trial

Improved outcomes with dose escalation in localized prostate cancer treated with precision image-guided radiotherapy

BACKGROUND AND PURPOSE

Dose-escalated radiotherapy (DE) improves outcomes in localized prostate cancer (PCa). The impact of DE in the context of image-guided radiotherapy (IGRT) remains unknown. Herein, we determined outcomes of three sequential cohorts treated with progressive DE-IGRT.

MATERIALS AND METHODS

We analyzed data from 1998 to 2012. Patients treated with radical radiotherapy were included, with three sequential institutional schedules: (A) 75.6Gy, (B) 79.8Gy, (C) 78Gy, with 1.8, 1.9 and 2Gy/fraction, respectively. IGRT consisted of fiducial markers and daily EPID (A, B) or CBCT (C).

RESULTS

961 patients were included, with median follow-up of 6.1y. 30.5%, 32.6% and 36.9% were treated in A, B and C, respectively. Risk category distribution was 179 (18.6%) low-, 653 (67.9%) intermediate- and 129 (13.5%) high-risk. PSA, T-category, androgen deprivation use and risk distribution were similar among groups. BCR (biochemical recurrence) was different (p<0.001) between A, B and C with 5-year rates of 23%, 17% and 9%, respectively (HR 2.68 [95% CI 1.87-3.85] and 1.92 [95% CI 1.33-2.78] for A and B compared to C, respectively). Findings were most significant in the intermediate-risk category. Metastasis, cause-specific-death and toxicities were not different between cohorts.

CONCLUSION

Our findings suggest continuous BCR improvement with progressive DE-IGRT. Prospective validation considering further DE with IGRT seems warranted.

Stereotactic ablative radiotherapy in the treatment of low and intermediate risk prostate cancer: Is there an optimal dose?

PURPOSE

To investigate if stereotactic ablative radiotherapy (SABR) dose is associated with PSA at 3years (PSA_3y) in the treatment of localized prostate cancer and to explore predictors of late genitourinary (GU) toxicity.

MATERIALS AND METHODS

Three prospective trials of SABR were undertaken at our institution: 1) 35Gy/5 fractions/29days; 2) 40Gy/5 fractions/29days; 3) 40Gy/5 fractions/11 or 29days. PSA_3y was analyzed as a continuous variable. Toxicity was defined as the worst new toxicity and assessed using the radiation therapy oncology group (RTOG) late morbidity scheme. Univariate and multivariable regression analyses were conducted to assess the association between dose and PSA_3y, and to explore predictors of late grade 2+ GU toxicity.

RESULTS

Median PSA3y was 0.64 (intraquartile range (IQR): 0.41-1.12) and 0.27 (IQR: 0.12-0.55) ng/mL for patients treated with 35 and 40Gy respectively. A dose of 40Gy was an independent predictor of lower PSA_3y on multivariable analysis (p<0.001). Dose of 40Gy (odds ratio (OR): 16.69, 95%CI: 5.78, 48.20, p<0.001) and higher International Prostate Symptom Score (OR: 1.01, 95%CI: 1.04, 1.16, p=0.001) predicted for late grade 2+ GU toxicity on multivariable logistic regression.

CONCLUSIONS

This analysis suggests that higher SABR dose is associated with lower PSA_3y. Strategies to allow safe SABR dose escalation should be further investigated.

Dosimetric and Radiobiological Evaluation of Multiparametric MRI-Guided Dose Painting in Radiotherapy of Prostate Cancer

Radiotherapy is one of the treatment options for locally advanced prostate cancer; however, with standard radiation doses, it is not always very effective. One of the strategies to improve the efficiency of radiotherapy is increasing the dose. In this study, to increase tumor local control rates, a new radiotherapy method, known as dose painting (DP), was investigated. To compare 3-dimensional conformal radiotherapy (3D-CRT) and intensity modulated radiotherapy (IMRT) plans with DP for prostate cancer. Twenty-four consecutive patients with locally advanced prostate cancer who underwent an multiparametric-magnetic resonance imaging (MP-MRI) (T2w, diffusion weighted image, dynamic contrast enhancement, and MRS) scan before a diagnostic biopsy from September 2015 to April 2016 were invited to take part in this study. The tumor local control probability (TCP) values for 3D-CRT, IMRT, and DP techniques were 45, 56, and 77%, respectively. The DP technique had a 37.5 and 71% higher TCP than IMRT and 3D-CRT, and these differences were statistically significant (P = 0.001). The mean normal tissue complication probability (NTCP) values of the organ at risks for 3D-CRT, IMRT, and DP showed that there were statistically significant differences among them in three plans (P = 0.01). DP by contours using MP-MRI is technically feasible. This study evaluated biological modeling based on both MP-MRI defined subvolumes and pathologically defined subvolumes. The MP-MRI-guided DP results in better TCP/NTCP than 3D-CRT and IMRT.

Randomized Trial of a Hypofractionated Radiation Regimen for the Treatment of Localized Prostate Cancer

Purpose Men with localized prostate cancer often are treated with external radiotherapy (RT) over 8 to 9 weeks. Hypofractionated RT is given over a shorter time with larger doses per treatment than standard RT. We hypothesized that hypofractionation versus conventional fractionation is similar in efficacy without increased toxicity. Patients and Methods We conducted a multicenter randomized noninferiority trial in intermediate-risk prostate cancer (T1 to 2a, Gleason score ≤ 6, and prostate-specific antigen [PSA] 10.1 to 20 ng/mL; T2b to 2c, Gleason ≤ 6, and PSA ≤ 20 ng/mL; or T1 to 2, Gleason = 7, and PSA ≤ 20 ng/mL). Patients were allocated to conventional RT of 78 Gy in 39 fractions over 8 weeks or to hypofractionated RT of 60 Gy in 20 fractions over 4 weeks. Androgen deprivation was not permitted with therapy. The primary outcome was biochemical-clinical failure (BCF) defined by any of the following: PSA failure (nadir + 2), hormonal intervention, clinical local or distant failure, or death as a result of prostate cancer. The noninferiority margin was 7.5% (hazard ratio, < 1.32). Results Median follow-up was 6.0 years. One hundred nine of 608 patients in the hypofractionated arm versus 117 of 598 in the standard arm experienced BCF. Most of the events were PSA failures. The 5-year BCF disease-free survival was 85% in both arms (hazard ratio [short v standard], 0.96; 90% CI, 0.77 to 1.2). Ten deaths as a result of prostate cancer occurred in the short arm and 12 in the standard arm. No significant differences were detected between arms for grade ≥ 3 late genitourinary and GI toxicity. Conclusion The hypofractionated RT regimen used in this trial was not inferior to conventional RT and was not associated with increased late toxicity. Hypofractionated RT is more convenient for patients and should be considered for intermediate-risk prostate cancer.

Acute and late complications after hypofractionated intensity modulated radiotherapy in prostate cancer

PURPOSE

The present study compared the complications associated with hypofractionated intensity-modulated radiation therapy (Hypo-IMRT) of prostate cancer to conventionally fractionated IMRT (Conv-IMRT).

MATERIALS AND METHODS

Hypo-IMRT delivered 70 Gy in 28 fractions, whereas Conv-IMRT delivered 78 Gy in 39 fractions. Toxicity was graded with the Common Terminology Criteria for Adverse Events, version 4.0, weekly during radiotherapy, 1 month after radiotherapy, and annually in both patient groups.

RESULTS

The median follow-ups were 39.1 and 38.7 months for patients in the Hypo- and Conv-IMRT groups, respectively. There was no significant difference in rates of acute and late adverse events. The proportions of grade 2 acute genitourinary complications were 48.4 and 51.2% in the Hypo- and Conv-IMRT groups, respectively. The presence of a baseline International Prostate Symptom Score (IPSS) of ten or more was the only significant prognostic factor for grade 2 acute genitourinary toxicity. The incidence of grade 2 late rectal hemorrhage at 3 years was 3.2 and 3.5% in the Hypo- and Conv-IMRT groups, respectively. Small rectal volume was significantly associated with grade 2 late rectal hemorrhage.

CONCLUSION

Regarding acute and late adverse events, hypofractionated IMRT for prostate cancer was well tolerated and comparable with conventionally fractionated IMRT. Clinical trial registration no. UMIN000003218.

Local tumor control and DNA-PK activity of peripheral blood lymphocytes in prostate cancer patients receiving radiotherapy

Repair of DNA damage is critical for genomic stability, and DNA-dependent protein kinase (DNA-PK) has an important role in repairing double-strand breaks. We examined whether the DNA-PK activity of peripheral blood lymphocytes (PBLs) was related to biochemical (prostate-specific antigen: PSA) relapse and radiation toxicity in prostate cancer patients who have received radiotherapy. A total of 69 patients with localized adenocarcinoma of the prostate participated in this study. Peripheral blood was collected 2 years or later after radiotherapy and centrifuged, then DNA-PK activity was measured by a filter binding assay. The high DNA-PK activity group had a significantly higher PSA relapse-free survival rate than the low DNA-PK activity group. The 10-year PSA relapse-free survival was 87.0% in the high DNA-PK activity group, whereas it was 52.7% in the low DNA-PK activity group. Multivariate analysis showed the Gleason score and the level of DNA-PK activity were significant predictors of PSA relapse after radiotherapy. In addition, the low DNA-PK activity group tended to have a higher incidence of Grade 1-2 urinary toxicity than the high DNA-PK activity group. Prostate cancer patients with low DNA-PK activity had a higher rate of PSA relapse and a higher incidence of urinary toxicity. DNA-PK activity in PBLs might be a useful marker for predicting PSA relapse and urinary toxicity, possibly contributing to personalized treatment of prostate cancer.

Silk-elastinlike protein polymers enhance the efficacy of a therapeutic glycosaminoglycan for prophylactic treatment of radiation-induced proctitis

Radiation-induced proctitis (RIP) is the most common clinical adverse effect for patients receiving radiotherapy as part of the standard course of treatment for ovarian, prostate, colon, and bladder cancers. RIP limits radiation dosage, interrupts treatment, and lowers patients' quality of life. A prophylactic treatment that protects the gastrointestinal tract from deleterious effects of radiotherapy will significantly improve patient quality of life and may allow for higher and more regular doses of radiation therapy. Semi-synthetic glycosaminoglycan (GAG), generated from the sulfation of hyaluronic acid, are anti-inflammatory but have difficulty achieving therapeutic levels in many tissues. To enhance the delivery of GAG, we created an in situ gelling rectal delivery system using silk-elastinlike protein polymers (SELPs). Using solutions of SELP 815K (which contains 6 repeats of blocks comprised of 8 silk-like units, 15 elastin-like units, and 1 lysine-substituted elastin-like unit) with GAG GM-0111, we created an injectable delivery platform that transitioned in <5min from a liquid at room temperature to a hydrogel at body temperature. The hydrogels released 50% of their payload within 30min and enhanced the accumulation of GAG in the rectum compared to traditional enema-based delivery. Using a murine model of radiation-induced proctitis, the prophylactic delivery of a single dose of GAG from a SELP matrix administered prior to irradiation significantly reduced radiation-induced pain after 3, 7, and 21days by 53±4%, 47±10%, and 12±6%, respectively. Matrix-mediated delivery of GAG by SELP represents an innovative method for more effective treatment of RIP and promises to improve quality of life of cancer patients by allowing higher radiotherapy doses with improved safety.

Brachytherapy boost for prostate cancer: Trends in care and survival outcomes

PURPOSE

Androgen suppression combined with elective nodal and dose-escalated radiation therapy recently demonstrated an improved biochemical failure-free survival in men who received external beam radiation therapy (EBRT) plus a brachytherapy boost (BB) compared with dose-escalated external beam radiotherapy (DE-EBRT). We sought to analyze the factors predictive for use of EBRT + BB as compared with DE-EBRT and report resulting survival outcomes on a national level using a hospital-based registry.

METHODS AND MATERIALS

We identified 113,719 men from the National Cancer Database from 2004 to 2013 with intermediate- or high-risk prostate cancer who were treated with EBRT + BB or DE-EBRT. We performed univariate and multivariate analyses of all available factors potentially predictive of receipt of treatment selection. Survival was evaluated in a multivariable model with propensity adjustment.

RESULTS

For intermediate-risk patients, utilization of BB decreased from 33.1% (n = 1742) in 2004 to 12.5% (n = 766) in 2013 and for high-risk patients, utilization dropped from 27.6% (n = 879) to 10.8% (n = 479). Numerous factors predictive for use of BB were identified. Cox proportional hazards analysis was performed-adjusting for age, Charlson-Deyo comorbidity score, T stage, prostate-specific antigen, Gleason score, and sociodemographic factors-and demonstrated BB use was associated with a hazard ratio of 0.71 (95% confidence interval, 0.67-0.75; p < 0.0005) and 0.73 (95% confidence interval, 0.68-0.78; p < 0.0005) for intermediate- and high-risk patients, respectively.

CONCLUSIONS

There has been a concerning decline in the utilization of BB for intermediate- and high-risk prostate cancer patients despite an association with improved on overall survival. Numerous factors predictive for use of BB have been identified.

Rectal dose to prostate cancer patients treated with proton therapy with or without rectal spacer

The purpose of this study was to evaluate whether a spacer inserted in the prerectal space could reduce modeled rectal dose and toxicity rates for patients with prostate cancer treated in silico with pencil beam scanning (PBS) proton therapy. A total of 20 patients were included in this study who received photon therapy (12 with rectal spacer (DuraSeal™ gel) and 8 without). Two PBS treatment plans were retrospectively created for each patient using the following beam arrangements: (1) lateral-opposed (LAT) fields and (2) left and right anterior oblique (LAO/RAO) fields. Dose volume histograms (DVH) were generated for the prostate, rectum, bladder, and right and left femoral heads. The normal tissue complication probability (NTCP) for ≥grade 2 rectal toxicity was calculated using the Lyman-Kutcher-Burman model and compared between patients with and without the rectal spacer. A significantly lower mean rectal DVH was achieved in patients with rectal spacer compared to those without. For LAT plans, the mean rectal V70 with and without rectal spacer was 4.19 and 13.5%, respectively. For LAO/RAO plans, the mean rectal V70 with and without rectal spacer was 5.07 and 13.5%, respectively. No significant differences were found in any rectal dosimetric parameters between the LAT and the LAO/RAO plans generated with the rectal spacers. We found that ≥ 9 mm space resulted in a significant decrease in NTCP modeled for ≥grade 2 rectal toxicity. Rectal spacers can significantly decrease modeled rectal dose and predicted ≥grade 2 rectal toxicity in prostate cancer patients treated in silico with PBS. A minimum of 9 mm separation between the prostate and anterior rectal wall yields the largest benefit.

Is it essential to use fiducial markers during cone-beam CT-based radiotherapy for prostate cancer patients?

PURPOSE

To compare soft-tissue cone-beam computed tomography (CBCT-P) and fiducial marker (CBCT-FM)-based image guided radiotherapy in prostate cancer patients.

MATERIALS AND METHODS

Sixteen prostate cancer patients were treated with volumetric modulated arc therapy. Manual alignment using CBCT-P and CBCT-FM was performed for each patient. Couch shifts were calculated and compared between methods in the left-right (x), superior-inferior (y), and anterior-posterior (z) directions.

RESULTS

CBCT-P and CBCT-FM alignments were compared using 252 scans from the 16 patients. Mean displacement from zero was 2.4 ± 1.3, 1.7 ± 1.2, and 1.8 ± 1.1 mm for CBCT-P and 2.3 ± 1.3, 1.7 ± 1.1 and 1.8 ± 1.1 mm for CBCT-FM in the x, y and z directions, respectively. There was no difference in median displacement between CBCT-P and CBCT-FM; however, there was a significant positive correlation between CBCT-P- and CBCT-FM-based displacements in the x (r = 0.881; p < 0.001), y (r = 0.789; p < 0.001) and z (r = 0.856; p < 0.001) directions by linear regression analysis. Systematic deviations within each group were <1 mm; however, random and systematic errors were similar in the x and y directions but larger in the z direction.

CONCLUSION

Our study demonstrated that CBCT-FM was not superior to CBCT-P for image-guided radiotherapy in prostate cancer patients.

Pelvic symptoms after radiotherapy in prostate cancer: a cross-sectional study

Abstract Introduction: Despite the technical and scientific progress that improved therapeutic resources available in Oncology, adverse effects of treatment can be prominent, impacting the quality of life (QoL). Objective: This research aims to determine the prevalence of post-radiotherapy pelvic symptoms in prostate cancer (PC) and its impact on QoL. Methods: We assessed three groups of patients at different stages during radiotherapy (RT): Pre-RT, evaluated before of RT; Post-RT#1, evaluated between six months and one year post-RT; Post-RT#2, evaluated between two and a half and four years post-RT. The presence of urinary incontinence (UI), its characteristics and impact on daily living activities (DLA) were evaluated by ICIQ-SF questionnaire. WHOQOL-BREF questionnaire was used to assess QoL. Student t test was used, considering significant p < 0.05. Results: Thirty-three men were assessed (pre-RT, n = 12; Post-RT#1, n = 10; Post-RT#2, n = 11). The prevalence of lower urinary tract symptoms (LUTS) was highest in Post-RT#1 group. Post-RT#2 group had the highest prevalence of post-RT UI. In QoL, Pre-RT and Post-RT#2 groups experiencing the greatest impact on physical, environmental and overall QoL. Conclusion: Acute effect of RT is characterized by a high prevalence of LUTS. Post-RT#2 group experienced the most adverse effects on DLA due to a higher prevalence of post-RT UI.

Prostate Cancer Radiation Therapy: What Do Clinicians Have to Know?

Radiotherapy (RT) for prostate cancer (PC) has steadily evolved over the last decades, with improving biochemical disease-free survival. Recently population based research also revealed an association between overall survival and doses ≥ 75.6 Gray (Gy) in men with intermediate- and high-risk PC. Examples of improved RT techniques are image-guided RT, intensity-modulated RT, volumetric modulated arc therapy, and stereotactic ablative body RT, which could facilitate further dose escalation. Brachytherapy is an internal form of RT that also developed substantially. New devices such as rectum spacers and balloons have been developed to spare rectal structures. Newer techniques like protons and carbon ions have the intrinsic characteristics maximising the dose on the tumour while minimising the effect on the surrounding healthy tissue, but clinical data are needed for confirmation in randomised phase III trials. Furthermore, it provides an overview of an important discussion issue in PC treatment between urologists and radiation oncologists: the comparison between radical prostatectomy and RT. Current literature reveals that all possible treatment modalities have the same cure rate, but a different toxicity pattern. We recommend proposing the possible different treatment modalities with their own advantages and side-effects to the individual patient. Clinicians and patients should make treatment decisions together (shared decision-making) while using patient decision aids.

Long-Term Patient-Reported Outcomes From a Phase 3 Randomized Prospective Trial of Conventional Versus Hypofractionated Radiation Therapy for Localized Prostate Cancer

PURPOSE

To assess the long-term quality of life (QoL) outcomes from a phase 3 trial comparing 2 modes of intensity modulated radiation therapy (IMRT): conventional IMRT (CIMRT) versus hypofractionated IMRT (HIMRT) in patients with localized prostate cancer.

METHODS AND MATERIALS

Between 2002 and 2006, 303 men with low-risk to high-risk prostate cancer were randomized to 76 Gy in 38 fractions (CIMRT) versus 70.2 Gy in 26 fractions (HIMRT). QoL was compared by use of the Expanded Prostate Cancer Index Composite (EPIC), the International Prostate Symptom Score (IPSS), and EuroQoL (EQ5D) questionnaires. The primary outcome of the QoL analysis was a minimum clinically important difference defined as a 0.5 standard deviation change from baseline for each respective QoL parameter. Treatment effects were evaluated with the use of logistic mixed effects regression models.

RESULTS

A total of 286, 299, and 218 patients had baseline EPIC, IPSS, or EQ5D data available and were included in the analysis. Overall, there was no statistically significant difference between the 2 treatment arms in terms of EPIC, IPSS, or EQ5D scores over time, although there was a trend toward lower EPIC urinary incontinence scores in the HIMRT arm. More patients in the HIMRT arm had a lower EPIC urinary incontinence score relative to baseline versus patients in the CIMRT arm with long-term follow-up. On multivariable analysis, there was no association between radiation fractionation scheme and any QoL parameter. When other clinical factors were examined, lymph node radiation was associated with worse EPIC hormonal scores versus patients receiving no lymph node radiation. In general, QoL outcomes were generally stable over time, with the exception of EPIC hormonal and EQ5D scores.

CONCLUSIONS

In this randomized prospective study, there were stable QoL changes in patients receiving HIMRT or CIMRT. Our results add to the growing body of literature suggesting that HIMRT may be an acceptable treatment modality in clinically localized prostate cancer.

Rectal Toxicity After Extremely Hypofractionated Radiotherapy Using a Non-Isocentric Robotic Radiosurgery System for Early Stage Prostate Cancer

Background

The aim of the study was to evaluate toxicity after extremely hypofractionated radiotherapy (EHF-RT) using a non-isocentric robotic radiosurgery system for early stage prostate cancer.

Methods

Eligibility criteria of this feasibility study were 50 - 84 years old, and low-risk to intermediate-risk disease. The prescribed dose to the iso-dose line of 95% of planning target volume was 35 Gy in five fractions over 2 weeks. The primary endpoint was the incidence of ≥ grade 2 acute toxicity which indicated symptoms requiring medications.

Results

We enrolled 20 patients from December 2012 to August 2014, and the median follow-up time was 30 months (range: 18 - 36). Sixteen patients had a short overall treatment time (OTT) of EHF-RT (9 - 10 days), and four patients had a long OTT (11 - 12 days) because of national holidays and patient’s preference. The incidences of ≥ grade 2 acute toxicity in all sites, that in the rectum, and that in the genitourinary system, were 30%, 20%, and 10%, respectively. No patient developed severe acute toxicity (≥ grade 3). Among 16 patients with a short OTT of EHF-RT, four patients developed grade 2 acute rectal toxicity. Rectum-V_{28 Gy} (rectal volume receiving ≥ 28 Gy) of 3.8 mL or higher had a tendency to increase grade 2 acute rectal toxicity (P = 0.058). One patient developed grade 3 late rectal toxicity and no patient developed severe late genitourinary toxicity.

Conclusion

The incidences of ≥ grade 2 acute toxicity in all sites and that in the rectum after EHF-RT of 35 Gy in five fractions were 30% and 20%, respectively. High rectum-V_{28 Gy} was associated with grade 2 acute rectal toxicity after EHF-RT for early prostate cancer.

Fiducial marker guided prostate radiotherapy: a review

Image-guided radiotherapy (IGRT) is an essential tool in the accurate delivery of modern radiotherapy techniques. Prostate radiotherapy positioned using skin marks or bony anatomy may be adequate for delivering a relatively homogeneous whole-pelvic radiotherapy dose, but these surrogates are not reliable when using reduced margins, dose escalation or hypofractionated stereotactic radiotherapy. Fiducial markers (FMs) for prostate IGRT have been in use since the 1990s. They require surgical implantation and provide a surrogate for the position of the prostate gland. A variety of FMs are available and they can be used in a number of ways. This review aimed to establish the evidence for using prostate FMs in terms of feasibility, implantation procedures, types of FMs used, FM migration, imaging modalities used and the clinical impact of FMs. A search strategy was defined and a literature search was carried out in Medline. Inclusion and exclusion criteria were applied, which resulted in 50 articles being included in this review. The evidence demonstrates that FMs provide a more accurate surrogate for the position of the prostate than either external skin marks or bony anatomy. A combination of FM alignment and soft-tissue analysis is currently the most effective and widely available approach to ensuring accuracy in prostate IGRT. FM implantation is safe and well tolerated. FM migration is possible but minimal. Standardization of all techniques and procedures in relation to the use of prostate FMs is required. Finally, a clinical trial investigating a non-surgical alternative to prostate FMs is introduced.

78Gy with Fiducial Marker Image-Guided Radiotherapy in Prostate Cancer: Single Center Analysis of 301 Patients

AIM

In prostate cancer, fiducial marker image-guided radiotherapy (FMIGRT) allows correction of setup errors and interfraction physiological motion resulting in improved accuracy of target and sparing of at risk organs. We aim to report outcomes and toxicities observed in patients treated with dose escalation to 78Gy with FMIGRT in our center.

METHODS AND MATERIALS

Retrospective review of consecutive patients with histologically confirmed T1-4N0M0 localized prostate cancer treated with dose escalation to 78Gy with FMIGRT in our center. All patients had 3-D conformal radiotherapy. Duration of androgen deprivation therapy use was tailored to risk group. Toxicity was scored according to CTCAE.v04. Kaplan-Meier analysis was performed for freedom from biochemical failure (FFBF), prostate cancer-specific survival and overall survival.

RESULTS

Median follow-up was 48.6 months. Median duration of androgen deprivation therapy was 6 and 23 months in the intermediate- and high-risk group, respectively. FFBF at 5 years was 88.8%. FFBFs when stratified to risk groups were 100% for low risk, 88.9% for low-intermediate risk, 89.9% for high-intermediate risk and 85.4% for high risk, respectively. Acute severe toxicity (grade≥3) rate for both genitourinary (GU) and gastrointestinal (GI) was 1%. Late moderate-to-severe toxicity (grade≥2) rates for GU and GI were 15% and 17%, respectively, with severe (grade≥3) toxicity rate for GU and GI at 2% and 3%, respectively.

CONCLUSION

Dose escalation to 78Gy with FMIGRT in our series achieved good FFBF at 5 years with low acute and late toxicity rates. These results provide a good comparator cohort to our current use of image-guided intensity modulated radiotherapy.

Acute and Late Adverse Events Associated With Radical Radiation Therapy Prostate Cancer Treatment: A Systematic Review of Clinician and Patient Toxicity Reporting in Randomized Controlled Trials

PURPOSE

This review aimed to determine the clinician and patient reported outcome (PRO) instruments currently usedin randomized controlled trials (RCTs) of radical radiation therapy for nonmetastatic prostate cancer to report acute and late adverse events (AEs), review the quality of methodology and PRO reporting, and report the prevalence of acute and late AEs.

METHODS AND MATERIALS

The MEDLINE, EMBASE, and Cochrane databases were searched between April and August 2014 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. Identified reports were reviewed according to the PRO Consolidated Standards of Reporting Trials (CONSORT) guidelines and the Cochrane Risk of Bias tool. In all, 1149 records were screened, and 21 articles were included in the final review.

RESULTS

We determined the acute and late AEs for 9040 patients enrolled in 15 different RCTs. Only clinician reported instruments were used to report acute AEs <3 months (eg, Radiation Therapy Oncology Group [RTOG] and Common Terminology Criteria for Adverse Events [CTCAE]). For late clinician reporting, the Late Effects on Normal Tissues-Subjective, Objective, Management and Analytic scale and RTOG were used and were often augmented with additional items to provide comprehensive coverage of sexual functioning and anorectal symptoms. Some late AEs were reported (48% articles) using PROs (eg, ULCA-PCI [University of California, Los Angeles Prostate Cancer Index], FACT-G and P [Functional Assessment of Cancer Therapy General & Prostate Module], EORTC QLQC-30 + PR25 [European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire & Prostate Module]); however, a definitive "preferred" instrument was not evident.

DISCUSSION

Our findings are at odds with recent movements toward including patient voices in reporting of AEs and patient engagement in clinical research. We recommend including PRO to evaluate radical radiation therapy before, during, and after the treatment to fully capture patient experiences, and we support the development of predictive models for late effects based on the severity of early toxicity.

CONCLUSION

Patient reporting of acute and late AEs is underrepresented in radiation therapy trials. We recommend working toward a consistent approach to PRO assessment of radiation therapy-related AEs.

Clinical management and research priorities for high-risk prostate cancer in the UK: Meeting report of a multidisciplinary panel in conjunction with the NCRI Prostate Cancer Clinical Studies Localised Subgroup

The management of high-risk prostate cancer has become increasingly sophisticated, with refinements in radical therapy and the inclusion of adjuvant local and systemic therapies. Despite this, high-risk prostate cancer continues to have significant treatment failure rates, with progression to metastasis, castrate resistance and ultimately disease-specific death. In an effort to discuss the challenges in this field, the UK National Clinical Research Institute’s Prostate Cancer Clinical Studies localised subgroup convened a multidisciplinary national meeting in the autumn of 2014. The remit of the meeting was to debate and reach a consensus on the key clinical and research challenges in high-risk prostate cancer and to identify themes that the UK would be best placed to pursue to help improve outcomes. This report presents the outcome of those discussions and the key recommendations for future research in this highly heterogeneous disease entity.

ADD-ASPIRIN: A phase III, double-blind, placebo controlled, randomised trial assessing the effects of aspirin on disease recurrence and survival after primary therapy in common non-metastatic solid tumours

BACKGROUND

There is a considerable body of pre-clinical, epidemiological and randomised data to support the hypothesis that aspirin has the potential to be an effective adjuvant cancer therapy.

METHODS

Add-Aspirin is a phase III, multi-centre, double-blind, placebo-controlled randomised trial with four parallel cohorts. Patients who have undergone potentially curative treatment for breast (n=3100), colorectal (n=2600), gastro-oesophageal (n=2100) or prostate cancer (n=2120) are registered into four tumour specific cohorts. All cohorts recruit in the United Kingdom, with the breast and gastro-oesophageal cohort also recruiting in India. Eligible participants first undertake an active run-in period where 100mg aspirin is taken daily for approximately eight weeks. Participants who are able to adhere and tolerate aspirin then undergo a double-blind randomisation and are allocated in a 1:1:1 ratio to either 100mg aspirin, 300mg aspirin or a matched placebo to be taken daily for at least five years. Those participants ≥75years old are only randomised to 100mg aspirin or placebo due to increased toxicity risk.

RESULTS

The primary outcome measures are invasive disease-free survival for the breast cohort, disease-free survival for the colorectal cohort, overall survival for the gastro-oesophageal cohort, and biochemical recurrence-free survival for the prostate cohort, with a co-primary outcome of overall survival across all cohorts. Secondary outcomes include adherence, toxicity including serious haemorrhage, cardiovascular events and some cohort specific measures.

CONCLUSIONS

The Add-Aspirin trial investigates whether regular aspirin use after standard therapy prevents recurrence and prolongs survival in participants with four non-metastatic common solid tumours.

Dosimetric analysis of testicular doses in prostate intensity-modulated and volumetric-modulated arc radiation therapy at different energy levels

The aim of this study is to evaluate the incidental testicular doses during prostate radiation therapy with intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) at different energies. Dosimetric data of 15 patients with intermediate-risk prostate cancer who were treated with radiotherapy were analyzed. The prescribed dose was 78Gy in 39 fractions. Dosimetric analysis compared testicular doses generated by 7-field intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy with a single arc at 6, 10, and 15MV energy levels. Testicular doses calculated from the treatment planning system and doses measured from the detectors were analyzed. Mean testicular doses from the intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy per fraction calculated in the treatment planning system were 16.3 ± 10.3cGy vs 21.5 ± 11.2cGy (p = 0.03) at 6MV, 13.4 ± 10.4cGy vs 17.8 ± 10.7cGy (p = 0.04) at 10MV, and 10.6 ± 8.5cGy vs 14.5 ± 8.6cGy (p = 0.03) at 15MV, respectively. Mean scattered testicular doses in the phantom measurements were 99.5 ± 17.2cGy, 118.7 ± 16.4cGy, and 193.9 ± 14.5cGy at 6, 10, and 15MV, respectively, in the intensity-modulated radiotherapy plans. In the volumetric-modulated arc radiotherapy plans, corresponding testicular doses per course were 90.4 ± 16.3cGy, 103.6 ± 16.4cGy, and 139.3 ± 14.6cGy at 6, 10, and 15MV, respectively. In conclusions, this study was the first to measure the incidental testicular doses by intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy plans at different energy levels during prostate-only irradiation. Higher photon energy and volumetric-modulated arc radiotherapy plans resulted in higher incidental testicular doses compared with lower photon energy and intensity-modulated radiotherapy plans.

Proton therapy for early stage prostate cancer: is there a case?

Proton-beam therapy (PBT) for prostate cancer has been in used for several decades, with its technique evolving significantly over this period. A growing number of centers now routinely utilize pencil-beam scanning as an advanced technique of PBT. Interest and controversy concerning its use have recently come under scrutiny. While the past decade has produced an assemblage of evidence suggesting that PBT is safe and effective for early stage prostate cancer, it is still unknown whether the theoretical dosimetric advantages of PBT translate into meaningful clinical improvements over routine intensity-modulated radiation therapy, which is commonly used for these patients. Outcomes from early trials using whole courses of PBT have shown mixed results when compared with routine intensity-modulated radiation therapy. Therefore, randomized trials comparing these two techniques should be undertaken, as this would help in defining the role of PBT for this patient group. This article aims to describe the basics of PBT, review the reasons for the growing interest in PBT, review the evidence for PBT, review the controversy surrounding PBT, and inquire about PBT's future in the treatment of prostate cancer, with attention to its physical properties, comparative clinical and cost-effectiveness, and advances in its delivery.

Dosimetric correlation of acute and late toxicities in high-risk prostate cancer patients treated with three-dimensional conformal radiotherapy followed by intensity modulated radiotherapy boost

Introduction:

In prostate cancer, higher radiation doses are often related to higher local control rates. However, the clinical effect of these higher doses on normal tissue toxicities is generally overlooked. We dosimetrically analyze sequential intensity modulated radiotherapy (IMRT) plans in high-risk prostate cancer patients and correlate them with acute and late normal tissue toxicities.

Materials and Methods:

Twenty-five high-risk prostate cancer patients were planned with three-dimensional conformal radiotherapy to a dose of 50 Gy delivered in 25 fractions in 5 weeks, followed by seven-field IMRT boost, to a dose of 24 Gy delivered in 12 fractions in 2.5 weeks, along with hormonal therapy. Acute and late toxicities were analyzed using Radiation Therapy Oncology Group toxicity criteria. Student's t-test was used for correlating doses received by normal tissues with toxicity grade. Five-year disease-free survival (DFS) and biochemical relapse-free survival (RFS) were evaluated using Kaplan–Meier analysis.

Results:

Median follow-up of patients was 65 months. Of 25 patients, two developed acute Grade 2 rectal toxicity. Only 1 patient developed acute Grade 2 bladder toxicity. Late Grade 2 and 3 rectal toxicity was seen in 2 and 1 patient, respectively. Late Grade 2 and 3 bladder toxicity was seen in 1 patient each. Grade 2 or more acute rectal toxicity correlated significantly with rectal volume receiving >70 Gy (P = 0.04). The 5-year DFS and biochemical RFS was 70.2% and 79.2%, respectively. One patient failed locally and seven failed at distant sites.

Conclusion:

Sequential IMRT with a dose of 74 Gy and maximum androgen blockade is well tolerated in high-risk patients in Indian setup with adequate control rates.

A comparison of robotic arm versus gantry linear accelerator stereotactic body radiation therapy for prostate cancer

Prostate cancer is the most prevalent cancer diagnosed in men in the United States besides skin cancer. Stereotactic body radiation therapy (SBRT; 6–15 Gy per fraction, up to 45 minutes per fraction, delivered in five fractions or less, over the course of approximately 2 weeks) is emerging as a popular treatment option for prostate cancer. The American Society for Radiation Oncology now recognizes SBRT for select low- and intermediate-risk prostate cancer patients. SBRT grew from the notion that high doses of radiation typical of brachytherapy could be delivered noninvasively using modern external-beam radiation therapy planning and delivery methods. SBRT is most commonly delivered using either a traditional gantry-mounted linear accelerator or a robotic arm-mounted linear accelerator. In this systematic review article, we compare and contrast the current clinical evidence supporting a gantry vs robotic arm SBRT for prostate cancer. The data for SBRT show encouraging and comparable results in terms of freedom from biochemical failure (>90% for low and intermediate risk at 5–7 years) and acute and late toxicity (<6% grade 3–4 late toxicities). Other outcomes (eg, overall and cancer-specific mortality) cannot be compared, given the indolent course of low-risk prostate cancer. At this time, neither SBRT device is recommended over the other for all patients; however, gantry-based SBRT machines have the abilities of treating larger volumes with conventional fractionation, shorter treatment time per fraction (~15 minutes for gantry vs ~45 minutes for robotic arm), and the ability to achieve better plans among obese patients (since they are able to use energies >6 MV). Finally, SBRT (particularly on a gantry) may also be more cost-effective than conventionally fractionated external-beam radiation therapy. Randomized controlled trials of SBRT using both technologies are underway.

Patterns of Postprostatectomy Adjuvant Radiotherapy Techniques for Nonmetastatic Prostate Cancer in a Large National Cohort

PURPOSE

To analyze the contemporary patterns of care regarding adjuvant radiotherapy (RT) techniques for patients with pT3/4 disease or positive margins after prostatectomy.

PATIENTS AND METHODS

Men who were diagnosed with nonmetastatic prostate cancer and underwent prostatectomy between 2004 and 2012 were abstracted from the National Cancer Data Base. Only those with pT3-4Nx-0M0 or pT2cNx-0M0 with positive margins were included. We identified patients receiving RT to the pelvis to a dose between 5940 and 7560 cGy. Delivery of hormone therapy was also identified. Descriptive statistics were used to determine adjuvant RT use as well as patterns of care regarding RT dose and hormone use; data were compared by Pearson's chi-square test.

RESULTS

A total of 133,874 men were included in this study, of whom 12,073 (9.0%) received adjuvant RT. Of those receiving adjuvant RT, 4011 (33.2%) also received hormone therapy. There was a trend toward more frequent use of higher RT doses over time. RT doses of ≥ 7000 cGy were provided 21.4% of the time in 2004-2006 and increased over time to 38.9% by 2010-2012 (P < .001). There was also a rapid increase in the use of intensity-modulated radiotherapy from 20.7% of patients in 2004 to 69.2% in 2012.

CONCLUSION

Most men (91.0%) with pT3/T4 or pT2 disease with positive margins do not receive adjuvant RT. Use of intensity-modulated radiotherapy and RT dose escalation increased over time and are now used routinely. Hormone therapy is used in about one third of patients who are receiving RT, and its use has remained relatively stable over time.

Assessing the Optimum Use of Androgen-Deprivation Therapy in High-Risk Prostate Cancer Patients Undergoing External Beam Radiation Therapy

The optimum use of androgen deprivation therapy (ADT) in high-risk prostate cancer patients has not been defined in the setting of dose-escalated external beam radiation therapy. A retrospective analysis of 1,290 patients with high-risk prostate cancer from June 1987 through March 2010 treated with external beam radiation therapy was performed. Median follow-up was 7.2 years, and 797 patients received ADT, with 384 patients experiencing a biochemical failure and 145 with distant metastasis. ADT was associated with lower risk of biochemical failure and distant metastasis than no ADT after adjusting for age, prostate-specific antigen (PSA), Gleason score, year of diagnosis, tumor stage, and radiation dose. ADT was associated with a greater reduction in biochemical failure in the low-dose radiation group than in the high-dose group. Patients with >24 months of ADT had a lower risk of PSA failures than those with <24 months. ADT was associated with decreased risk of biochemical failure and distant metastasis in all patients. The effect of ADT on reducing risk of biochemical failure was greater among men with low-dose radiation. There was a benefit in PSA and distant metastasis-free survival with >24 months of ADT in all patients who received ADT.

What is the best way to radiate the prostate in 2016?

Prostate cancer treatment with definitive radiation therapy (RT) has evolved dramatically in the past 2 decades. From the initial 2-dimensional planning using X-rays, advances in technology led to 3-dimensional conformal RT, which used computerized tomography-based planning. This has allowed delivery of higher doses of radiation to the prostate while reducing dose to the surrounding organs, resulting in improved cancer control. Today, intensity-modulated RT (IMRT) is considered standard, where radiation beams of different shapes and intensities can be delivered from a wide range of angles, thus further decreasing doses to normal organs and likely reducing treatment-related toxicity. In addition, image guidance ascertains the location of the prostate before daily treatment delivery. Brachytherapy is the placement of radioactive seeds directly in the prostate, and has a long track record as a monotherapy for low-risk prostate cancer patients with excellent long-term cancer control and quality of life outcomes. Recent studies including several randomized trials support the use of brachytherapy in combination with external beam RT for higher-risk patients. RT for prostate cancer continues to evolve. Proton therapy has a theoretical advantage over photons as it deposits most of the dose at a prescribed depth with a rapid dose fall-off thereafter; therefore it reduces some doses delivered to the bladder and rectum. Prospective studies have shown the safety and efficacy of proton therapy for prostate cancer, but whether it leads to improved patient outcomes compared to IMRT is unknown. Hypofractionated RT delivers a larger dose of daily radiation compared to conventional IMRT, and thus reduces the overall treatment time and possibly cost. An extreme form of hypofractionation is stereotactic body radiation therapy where highly precise radiation is used and treatment is completed in a total of 4 to 5 sessions. These techniques take advantage of the biological characteristic of prostate cancer, which is more sensitive to larger radiation doses per fraction, and therefore could be more effective than conventional IMRT. Multiple randomized trials have demonstrated noninferiority of moderately hypofractionated RT compared to conventional fractionation. There is also a growing body of data demonstrating the safety and efficacy of stereotactic body radiation therapy for low- and intermediate-risk prostate cancer.

Comparison of outcomes and toxicities among radiation therapy treatment options for prostate cancer

We review radiation therapy (RT) options available for prostate cancer, including external beam (EBRT; with conventional fractionation, hypofractionation, stereotactic body RT [SBRT]) and brachytherapy (BT), with an emphasis on the outcomes, toxicities, and contraindications for therapies. PICOS/PRISMA methods were used to identify published English-language comparative studies on PubMed (from 1980 to 2015) that included men treated on prospective studies with a primary endpoint of patient outcomes, with ⩾70 patients, and ⩾5year median follow up. Twenty-six studies met inclusion criteria; of these, 16 used EBRT, and 10 used BT. Long-term freedom from biochemical failure (FFBF) rates were roughly equivalent between conventional and hypofractionated RT with intensity modulation (evidence level 1B), with 10-year FFBF rates of 45-90%, 40-60%, and 20-50% (for low-, intermediate-, and high-risk groups, respectively). SBRT had promising rates of BF, with shorter follow-up (5-year FFBF of >90% for low-risk patients). Similarly, BT (5-year FFBF for low-, intermediate-, and high-risk patients have generally been >85%, 69-97%, 63-80%, respectively) and BT+EBRT were appropriate in select patients (evidence level 1B). Differences in overall survival, distant metastasis, and cancer specific mortality (5-year rates: 82-97%, 1-14%, 0-8%, respectively) have not been detected in randomized trials of dose escalation or in studies comparing RT modalities. Studies did not use patient-reported outcomes, through Grade 3-4 toxicities were rare (<5%) among all modalities. There was limited evidence available to compare proton therapy to other modalities. The treatment decision for a man is usually based on his risk group, ability to tolerate the procedure, convenience for the patient, and the anticipated impact on quality of life. To further personalize therapy, future trials should report (1) race; (2) medical comorbidities; (3) psychiatric comorbidities; (4) insurance status; (5) education status; (6) marital status; (7) income; (8) sexual orientation; and (9) facility-related characteristics.

An investigation of the dose distribution effect related with collimator angle in volumetric arc therapy of prostate cancer

To investigate the dose-volume variations of planning target volume (PTV) and organ at risks (OARs) in eleven prostate cancer patients planned with single and double arc volumetric modulated arc therapy (VMAT) when varying collimator angle. Single and double arc VMAT treatment plans were created using Monaco5.0^® with collimator angle set to 0°. All plans were normalized 7600 cGy dose to the 95% of clinical target volume (CTV) volume. The single arc VMAT plans were reoptimized with different collimator angles (0°, 15°, 30°, 45°, 60°, 75°, and 90°), and for double arc VMAT plans (0–0°, 15°–345, 30–330°, 45–315°, 60–300°, 75–285°, 90–270°) using the same optimization parameters. For the comparison the parameters of heterogeneity index (HI), dose-volume histogram and minimum dose to the 95% of PTV volume (D95 PTV) calculated and analyzed. The best plans were verified using 2 dimensional ion chamber array IBA Matrixx^® and three-dimensional IBA Compass^® program. The comparison between calculation and measurement were made by the γ-index (3%/3 mm) analysis. A higher D95 (PTV) were found for single arc VMAT with 15° collimator angle. For double arc, VMAT with 60–300° and 75–285° collimator angles. However, lower rectum doses obtained for 75–285° collimator angles. There was no significant dose difference, based on other OARs which are bladder and femur head. When we compared single and double arc VMAT's D95 (PTV), we determined 2.44% high coverage and lower HI with double arc VMAT. All plans passed the γ-index (3%/3 mm) analysis with more than 97% of the points and we had an average γ-index for CTV 0.36, for PTV 0.32 with double arc VMAT. These results were significant by Wilcoxon signed rank test statistically. The results show that dose coverage of target and OAR's doses also depend significantly on the collimator angles due to the geometry of target and OARs. Based on the results we have decided to plan prostate cancer patients in our clinic with double arc VMAT and 75°–285° collimator angles.

Evolving Paradigm of Radiotherapy for High-Risk Prostate Cancer: Current Consensus and Continuing Controversies

High-risk prostate cancer is an aggressive form of the disease with an increased risk of distant metastasis and subsequent mortality. Multiple randomized trials have established that the combination of radiation therapy and long-term androgen deprivation therapy improves overall survival compared to either treatment alone. Standard of care for men with high-risk prostate cancer in the modern setting is dose-escalated radiotherapy along with 2-3 years of androgen deprivation therapy (ADT). There are research efforts directed towards assessing the efficacy of shorter ADT duration. Current research has been focused on assessing hypofractionated and stereotactic body radiation therapy (SBRT) techniques. Ongoing randomized trials will help assess the utility of pelvic lymph node irradiation. Research is also focused on multimodality therapy with addition of a brachytherapy boost to external beam radiation to help improve outcomes in men with high-risk prostate cancer.

The Effectiveness of Intensity Modulated Radiation Therapy versus Three-Dimensional Radiation Therapy in Prostate Cancer: A Meta-Analysis of the Literatures

BACKGROUND AND PURPOSE

Intensity modulated radiation therapy (IMRT) can deliver higher doses with less damage of healthy tissues compared with three-dimensional radiation therapy (3DCRT). However, for the scenarios with better clinical outcomes for IMRT than 3DCRT in prostate cancer, the results remain ambiguous. We performed a meta-analysis to assess whether IMRT can provide better clinical outcomes in comparison with 3DCRT in patients diagnosed with prostate cancer.

MATERIALS AND METHODS

We conducted a meta-analysis of 23 studies (n = 9556) comparing the clinical outcomes, including gastrointestinal (GI) toxicity, genitourinary (GU) toxicity, biochemical controland overall survival (OS).

RESULTS

IMRT was significantly associated with decreased 2-4 grade acute GI toxicity [risk ratio (RR) = 0.59 (95% confidence interval (CI), 0.44, 0.78)], late GI toxicity [RR = 0.54, 95%CI (0.38, 0.78)], late rectal bleeding [RR = 0.48, 95%CI (0.27, 0.85)], and achieved better biochemical control[RR = 1.17, 95%CI (1.08, 1.27)] in comparison with 3DCRT. IMRT and 3DCRT remain the same in regard of grade 2-4 acute rectal toxicity [RR = 1.03, 95%CI (0.45, 2.36)], late GU toxicity [RR = 1.03, 95%CI (0.82, 1.30)] and overall survival [RR = 1.07, 95%CI (0.96, 1.19)], while IMRT slightly increased the morbidity of grade 2-4 acute GU toxicity [RR = 1.08, 95%CI (1.00, 1.17)].

CONCLUSIONS

Although some bias cannot be ignored, IMRT appears to be a better choice for the treatment of prostate cancer when compared with 3DCRT.

Faculty of Radiation Oncology Position Paper on the use of Image-Guided Radiation Therapy

The development of technology such as intensity-modulated radiotherapy (IMRT), volumetric arc therapy (VMAT) and stereotactic ablative body radiotherapy (SABR) has resulted in highly conformal radiotherapy treatments. While such technology has allowed for improved dose delivery, it has also meant that improved accuracy in the treatment room is required. Image-guided radiotherapy (IGRT), the use of imaging prior to or during treatment delivery, has been shown to improve the accuracy of treatment delivery and in some circumstances, clinical outcomes. Allied with the adoption of highly conformal treatments, there is a need for stringent quality assurance processes in a multidisciplinary environment. In 2015, the Royal Australian and New Zealand College of Radiologist (RANZCR) updated its position paper on IGRT. The draft document was distributed through the membership of the Faculty of Radiation Oncology (FRO) for review and the final version was endorsed by the board of FRO. This article describes issues that radiotherapy departments throughout Australia and New Zealand should consider. It outlines the role of IGRT and reviews current clinical evidence supporting the benefit of IGRT in genitourinary, head and neck, and lung cancers. It also highlights important international publications which provide guidance on implementation and quality assurances for IGRT. A set of key recommendations are provided to guide safe and effective IGRT implementation and practice in the Australian and New Zealander context.

Localized prostate cancer treated with external beam radiation therapy: Long-term outcomes at a European comprehensive cancer centre

AIMS AND BACKGROUND

To present survival and toxicity outcomes in patients with clinically localized, non-metastatic prostate cancer (PCa) treated with external beam radiotherapy (EBRT) combined with androgen deprivation therapy (ADT).

MATERIALS AND METHODS

Retrospective study of 849 PCa patients (pts) treated from 1996 to 2005. Until August 2000, all patients (281) were treated with conventional dose EBRT (<76 Gy); subsequent pts received ≥76 Gy (565 pts). Median age was 70 years (range, 39-82). Most pts were intermediate (353; 42.8%) or high-risk (344; 41.7%). Mean PSA was 10.1 ng/ml. Median dose to the prostate was 75 Gy. Complete ADT was administered to 525 pts (61.8%).

RESULTS

Median follow-up was 109.6 months (range, 68.3-193.4). Overall survival (OS) was 92.5% and 81.1% at 5 and 10 years; by risk group (low, intermediate, high), 5- and 10-year OS rates were 94.3% and 85.9%, 92.3% and 79.2%, and 91.9% and 80.2% (p = 0.728). Five- and 10-year BRFS was 94.1% and 80.6% (low risk), 86.4% and 70.9% (intermediate), and 85.2% and 71.4% (high) (p = 0.0666). Toxicity included rectitis: grade 1 (G1) (277 pts; 32.6%), G2 (108; 12.7%), and G3 (20; 2.6%) and urethritis: G1 (294; 34.6%); G2 (223; 26.2%), and G3 (11; 1.3%). By dose rate (<76 Gy vs. ≥76 Gy), 5 and 10-year BRFS rates were 83.1% and 68.3% vs. 88.4% and 74.8% (p = 0.038).

CONCLUSIONS

Our results are comparable to other published series in terms of disease control and toxicity. These findings confirm the need for dose escalation to achieve better biochemical control and the benefits of ADT in high-risk PCa patients.

Dose escalation to dominant intraprostatic lesions with MRI-transrectal ultrasound fusion High-Dose-Rate prostate brachytherapy. Prospective phase II trial

BACKGROUND AND PURPOSE

To demonstrate the feasibility, safety and effectiveness of dose escalation to intraprostatic lesions with MRI-transrectal ultrasound fusion High-Dose-Rate (HDR) brachytherapy.

MATERIALS AND METHODS

15 patients with intermediate-high risk prostate cancer and visible dominant intra-prostatic nodule on mpMRI have been treated. The treatment consisted of combined MRI-TRUS fusion HDR-brachytherapy (1 fraction of 1500cGy) and hypofractionated external beam (3750cGy in 15 fractions). A dose of 1875Gy was delivered to at least 98% of the DIL volume.

RESULTS

Median prostate volume was 23.8cc; median number of needles was 16 (13-18). Dose escalation to DIL was feasible in 14/15 patients (93%) without violating dosimetric constraints and 1 patient presented a minimal deviation of dosimetric restrictions. With a median follow-up of 18months (17-24), none of the patients developed acute urinary retention or grade ⩾3 toxicity. In addition to standard PSA follow-up, response has been assessed by mpMRI at 12months. All patients presented adequate morphological responses on anatomical and functional sequences.

CONCLUSIONS

HDR brachytherapy using MRI-transrectal ultrasound fusion for image guidance is a suitable technique for partial prostate dose escalation. Tolerance and toxicity profiles are excellent and results are encouraging in terms of biochemical, morphological and functional response.

Dose escalation with external beam radiation therapy and high-dose-rate brachytherapy combined with long-term androgen deprivation therapy in high and very high risk prostate cancer: Comparison of two consecutive high-dose-rate schemes

PURPOSE

To compare rectal toxicity, urinary toxicity, and nadir+2 PSA relapse-free survival (bRFS) in two consecutive Phase II protocols of high-dose-rate (HDR) brachytherapy used at the authors institution from 2001 to 2012.

METHODS AND MATERIALS

Patients with National Comprehensive Cancer Network high risk and very high risk prostate cancer enrolled in studies HDR4 (2001-2007, n = 183) and HDR2 (2007-2012, n = 56) were analyzed. Patients received minipelvis external beam radiation therapy/intensity-modulated external radiotherapy to 54 Gy and 2 years of androgen blockade along with HDR brachytherapy. HDR4 protocol consisted of four 4.75 Gy fractions delivered in 48 hours; the HDR2 protocol delivered two 9.5 Gy fractions in 24 hours. Average 2-Gy equivalent dose (α/β = 1.2) prostate D90 doses for the HDR4 and HDR2 groups were 89.8 Gy and 110.5 Gy, respectively (p = 0.0001). Both groups were well balanced regarding risk factors. Prior transurethral resection of the prostate was more frequent in the HDR2 group (p = 0.001).

RESULTS

After a median followup of 7.4 years (range, 2-11.2), there was no difference in adverse grade ≥ 2 rectal events (HDR4 = 10.4% vs. HDR2 = 12.5%; p = ns) or grade ≥3 (HDR4 = 2.2% vs. HDR2 = 3.6%; p = ns). No differences in urinary grade ≥2 adverse events (HDR4 = 23% vs. HDR2 = 26.8%; p = ns) or grade ≥3 (HDR4 = 7.7% vs. HDR2 = 8.9%; p = ns) were detected. The 7-year bRFS for HDR4 and HDR2 protocols was 88.7% and 87.8%, respectively (p = ns).

CONCLUSIONS

HDR4 and HDR2 protocols produce similar results in terms of toxicity and bRFS at the intermediate time point of 7 years.

Outcomes of hypofractionated stereotactic body radiotherapy boost for intermediate and high-risk prostate cancer

BACKGROUND AND PURPOSE

Treatment of intermediate and high-risk prostate cancer with a high BED has been shown to increase recurrence free survival (RFS). While high dose rate (HDR) brachytherapy, given as a boost is effective in delivering a high BED, many patients are not candidates for the procedure or wish to avoid an invasive procedure. We evaluated the use of stereotactic body radiotherapy (SBRT) as a boost, with dosimetry modeled after HDR-boost.

MATERIAL AND METHODS

Fifty patients were treated with two fractions of SBRT (9.5-10.5 Gy/fraction) after 45 Gy external-beam radiotherapy, with 48 eligible for analysis at a median follow-up of 42.7 months.

RESULTS

The Kaplan-Meier estimates of biochemical control post-radiation therapy (95 % Confidence Interval) at 3, 4 and 5 years were 95 % (81-99 %), 90 % (72-97 %) and 90 % (72-97 %), respectively (not counting 2 patients with a PSA bounce as failures). RFS (defined as disease recurrence or death) estimates at 3, 4 and 5 years were 92 % (77-97 %), 88 % (69-95 %) and 83 % (62-93 %) if patients with PSA bounces are not counted as failures, and were 90 % (75-96 %), 85 % (67-94 %) and 75 % (53-88 %) if they were. The median time to PSA nadir was 26.2 months (range 5.8-82.9 months), with a median PSA nadir of 0.05 ng/mL (range <0.01-1.99 ng/mL). 2 patients had a "benign PSA bounce", and 4 patients recurred with radiographic evidence of recurrence beyond the RT fields. Treatment was well tolerated with no acute G3 or higher GI or GU toxicity and only a single G3 late GU toxicity of urinary obstruction.

CONCLUSIONS

SBRT boost is well-tolerated for intermediate and high-risk prostate cancer patients with good biochemical outcomes and low toxicity.

Cost-effectiveness analysis of intensity-modulated radiation therapy with normal and hypofractionated schemes for the treatment of localised prostate cancer

The aim of our analysis was to compare the cost-effectiveness of high-dose intensity-modulated radiation therapy (IMRT) and hypofractionated intensity-modulated radiation therapy (HF-IMRT) versus conventional dose three-dimensional radiation therapy (3DCRT) for the treatment of localised prostate cancer. A Markov model was constructed to calculate the incremental quality-adjusted life years and costs. Transition probabilities, adverse events and utilities were derived from relevant systematic reviews. Microcosting in a large university hospital was applied to calculate cost vectors. The expected mean lifetime cost of patients undergoing 3DCRT, IMRT and HF-IMRT were 7,160 euros, 6,831 euros and 6,019 euros respectively. The expected quality-adjusted life years (QALYs) were 5.753 for 3DCRT, 5.956 for IMRT and 5.957 for HF-IMRT. Compared to 3DCRT, both IMRT and HF-IMRT resulted in more health gains at a lower cost. It can be concluded that high-dose IMRT is not only cost-effective compared to the conventional dose 3DCRT but, when used with a hypofractionation scheme, it has great cost-saving potential for the public payer and may improve access to radiation therapy for patients.