Stage C adenocarcinoma of the prostate. An analysis of 551 patients treated with external beam radiation

[Prophylactic nodal radiotherapy in prostate cancer]

The risk of lymph node invasion, in case of prostate cancer, increases with the clinical stage of the disease, the Gleason score of prostate biopsies and the value of PSA at diagnosis. Historically, beyond 15% risk of lymph node involvement, irradiation of the pelvic areas was performed with prostate radiotherapy (RT) to take into account the risk of occult lymph node metastasis in patients at risk, but the benefit of this therapeutic approach remains to be demonstrated. The data from surgical lymph node dissection seem to question the risk levels, the escalation of the dose on the prostate increases the survival without relapse, the contribution of image-guided radiotherapy, (IGRT) and modulation of intensity (IMRT), decreases the toxicity of pelvic RT. This article reviews the principles of prophylactic ganglion irradiation for prostate cancer and discusses its relevance, current uncertainties, and prospective trials.

Adjuvant Hormone Therapy after Radical Prostatectomy: Indications and Results

Despite recent advances in staging modalities, nearly 30–40% of patients undergoing radical prostatectomy for clinically localized prostate cancer have residual disease. In these cases, one or more of the following conditions may be present: extracapsular disease, positive margins, invasion of the seminal vesicles, lymph node metastases or the postoperative persistence of PSA values above the biological threshold. The optimal management for residual prostate cancer remains controversial and in this setting adjuvant therapy could be appropriate. In the present review we examine the conditions in which hormonal adjuvant therapy can be indicated and the results available from retrospective or non-randomized studies. From the data in the literature and in the absence of randomized prospective studies, prudent conclusions could be drawn on the efficacy of adjuvant hormonal therapy. In cases of small volume, low grade (Gleason score «7) prostate cancer in stage C or D1, radical surgery coupled with adjuvant hormonal therapy leads to survival rates in stage C similar to those in the intraprostatic stage, and in stage D1 with minimal lymph involvement, seems to delay clinical development of metastases. Finally, the quality of life associated with adjuvant therapy and the drug regimens available for this therapy are reviewed.

Prognostic impact of nodal relapse in definitive prostate-only irradiation

BACKGROUND

Whole pelvic irradiation in prostate cancer patients might prevent metastatic spread of cancer cells through lymphatic drainages in patients eligible for definitive radiotherapy, but its use has declined in the last decades in favor of prostate-only irradiation (POI). The aim of our study is to assess the incidence of pelvic lymph nodal relapse and outcome in prostate cancer patients receiving POI.

MATERIALS AND METHODS

Data from 207 consecutive patients were collected. Clinical and treatment variables were collected. Biochemical relapse-free survival (BRFS), pelvic nodal relapse-free survival (PNRFS), distant metastasis-free survival (DMFS), disease-specific survival (DSS) and overall survival (OS) were calculated; analysis of prognostic variables was performed.

RESULTS

Five-year BRFS, PNRFS, DMFS, DSS and OS were, respectively, 90, 98, 96, 97 and 91%. On multivariate analysis, independent negative predictors of BRFS were Gleason score ≥ 7 (HR: 3.25) and PSA nadir ≥ 0.08 (HR: 4.86). Pelvic nodal relapse was not correlated to impaired outcome.

CONCLUSIONS

Lymph nodal pelvic relapse occurs in 2% of patients at 5 years and does not correlate with impaired outcome, suggesting the lack of theoretical benefit of a prophylactic nodal irradiation. Tumor biology and response to treatment are the main determinants of outcome.

Practical evaluation of post-prostatectomy incontinence

For patients undergoing radical prostatectomy, urinary incontinence is not an uncommon postoperative complication. For some, it can resolve over time, while in others the condition persists and requires medical and/or surgical intervention. This summary provides a review of the recommended evaluations to perform in this setting.

Radiosensitization in prostate cancer: mechanisms and targets

Prostate cancer is the second most commonly diagnosed cancer in American men over the age of 45 years and is the third most common cause of cancer related deaths in American men. In 2012 it is estimated that 241,740 men will be diagnosed with prostate cancer and 28,170 men will succumb to prostate cancer. Currently, radiation therapy is one of the most common definitive treatment options for localized prostate cancer. However, significant number of patients undergoing radiation therapy will develop locally persistent/recurrent tumours. The varying response rates to radiation may be due to 1) tumor microenvironment, 2) tumor stage/grade, 3) modality used to deliver radiation, and 4) dose of radiation. Higher doses of radiation has not always proved to be effective and have been associated with increased morbidity. Compounds designed to enhance the killing effects of radiation, radiosensitizers, have been extensively investigated over the past decade. The development of radiosensitizing agents could improve survival, improve quality of life and reduce costs, thus benefiting both patients and healthcare systems. Herin, we shall review the role and mechanisms of various agents that can sensitize tumours, specifically prostate cancer.

Comparison of three-dimensional conformal irradiation techniques for prostate cancer using a low-energy (6 MV) photon beam

Purpose: To evaluate composite coplanar and non-coplanar three-dimensional conformal techniques (3D-CRT) for external-beam prostate radiotherapy using a low-energy (6 MV) photon beam.

Methods and Materials: For treatment-planning purposes, three different planning target volumes (PTV) were defined for ten patients with prostate cancer and as follows: PTV1 (pelvis), PTV2 (prostate + seminal vesicles + 1 cm margin) and PTV3 (prostate + 1 cm margin). Conformal techniques of 2, 3, 4, 5 (coplanar) and 6 (non-coplanar) field techniques have been considered and combined to produce five different plan combinations (i.e. techniques A, B, C, D and E). Treatment plans were generated with a prescription dose of 75 Gy to PTV3, 65 Gy to PTV2 and 45 Gy to PTV1 and were assessed on the basis of 3D dose distributions and dose-volume histograms (DVHs). Normal tissue-dose constraints for the relevant organs at risk (OARs), that is, rectum, bladder and femoral heads, were also considered.

Results: Findings show that all five treatment-plan combinations result in adequate PTV coverage and acceptable OAR irradiated volumes. The greatest rectal spacing in the high-dose region is achieved by technique C; all techniques achieve this, except for technique A, and give approximately the same fraction of volume (of rectum) that receives a dose of 50 Gy (V50) and 60 Gy (V60). When considering the bladder, techniques B, D and E give the best bladder sparing with small absolute differences, whereas technique A results in the lowest dose for femoral heads. Technique E appears to give the best compromise for all three considered OARs, provided the PTV is adequately covered.

Conclusions: Even though the optimum photon-beam energy for conformal prostate radiotherapy is greater than 10 MV, our study shows that a good sparing of OAR can be achieved even with a lower-energy beam (6 MV) and the appropriate plan combination and that the dose to prostate can be as high as 75 Gy.

Stereotactic body radiotherapy as boost for organ-confined prostate cancer

Stereotactic body radiotherapy (SBRT) boost following external beam radiation therapy (EBRT) for advanced localized prostate cancer may reduce toxicity while escalating the dose. We present preliminary biochemical control and urinary, rectal and sexual toxicities for 73 patients treated with SBRT as a boost to EBRT. Forty-one intermediate- and 32 high-risk localized prostate cancer patients received 45 Gy EBRT with SBRT boost. Twenty-eight patients (38.3%) received a total SBRT boost dose of 18 Gy (3 fractions of 6 Gy), 28 patients (38.3%) received 19.5 Gy (3 fractions of 6.5 Gy), and 17 patients (23.2%) received 21 Gy (3 fractions of 7 Gy). Toxicity was assessed using the Radiation Therapy Oncology Group urinary and rectal toxicity scale. Biochemical failure was assessed using the Phoenix definition. The median follow-up was 33 months (range, 22 - 43 months). Less than 7% Grade II and no higher grade acute toxicities occurred. To date, one Grade III and no Grade IV late toxicities occurred. For the 97% of patients with 24 months minimum follow-up, 71.8% achieved a PSA nadir threshold of 0.5 ng/mL. Three intermediate-risk and seven high-risk biochemical failures occurred; one high-risk patient died of his cancer. Three-year actuarial biochemical control rates were 89.5% and 77.7% for intermediate- and high-risk patients, respectively. SBRT boost for prostate cancer treatment is safe and feasible with minimal acute toxicity. At 33 months late toxicity and biochemical control are promising. Long-term durability of these findings remains to be established.

High-dose-rate brachytherapy boost for prostate cancer: comparison of two different fractionation schemes

PURPOSE

This is a retrospective study comparing our experience with high-dose-rate (HDR) brachytherapy boost for prostate cancer, using two different fractionation schemes, 600 cGy × 3 fractions (patient group 1) and 950 cGy × 2 fractions (patient group 2).

METHODS AND MATERIALS

A total of 165 patients were treated for prostate cancer using external beam radiation therapy up to a dose of 45 Gy, followed by an HDR brachytherapy prostate radiation boost. Between July 1997 and Nov 1999, 64 patients were treated with an HDR boost of 600 cGy × 3 fractions; and between June 2000 and Nov 2005, 101 patients were treated with an HDR boost of 950 cGy × 2 fractions. All but 9 patients had at least one of the following risk features: pretreatment prostate-specific antigen (PSA) level >10, a Gleason score ≥7, and/or clinical stage T3 disease.

RESULTS

Median follow-up was 105 months for group 1 and 43 months for group 2. Patients in group 2 had a greater number of high-risk features than group 1 (p = 0.02). Adjusted for comparable follow-up, there was no difference in biochemical no-evidence-of-disease (bNED) rate between the two fractionation scheme approaches, with 5-year Kaplan-Meier estimates of 93.5% in group 1 and 87.3% in group 2 (p = 0.19). The 5-year estimates of progression-free survival were 86% for group 1 and 83% for group 2 (p = 0.53). Among high-risk patients, there were no differences in bNED or PFS rate due to fractionation.

CONCLUSIONS

Results were excellent for both groups. Adjusted for comparable follow-up, no differences were found between groups.

Molecular fingerprinting of radiation resistant tumors: can we apprehend and rehabilitate the suspects?

Radiation therapy continues to be one of the more popular treatment options for localized prostate cancer. One major obstacle to radiation therapy is that there is a limit to the amount of radiation that can be safely delivered to the target organ. Emerging evidence suggests that therapeutic agents targeting specific molecules might be combined with radiation therapy for more effective treatment of tumors. Recent studies suggest that modulation of these molecules by a variety of mechanisms (e.g., gene therapy, antisense oligonucleotides, small interfering RNA) may enhance the efficacy of radiation therapy by modifying the activity of key cell proliferation and survival pathways such as those controlled by Bcl-2, p53, Akt/PTEN and cyclooxygenase-2. In this article, we summarize the findings of recent investigations of radiosensitizing agents in the treatment of prostate cancer.

[Acute and late toxicity in radical radiotherapy of prostate cancer]

INTRODUCTION

Although radical radiotherapy has proved to be a successful method in prostate cancer treatment, the conventional (box) technique can result in significant adverse events.

OBJECTIVE

The objective of our study was to estimate the frequency, type and severity of acute and late toxicity in radical radiotherapy of prostate cancer.

METHODS

In a clinical retrospective study, we included 283 patients with histologically confirmed prostate cancer. All our patients received radical, conventional radiotherapy using the four-field technique. The study was performed at the Radiotherapy Department of the institute for Oncology and Radiology of Serbia between January 1991 and December 2005. During regular follow-up, we analysed the frequency, type and severity of acute and late toxicity.

RESULTS

Two thirds (71%) of our patients had acute toxicity of at least one organ within the radiation field. Most frequent complication was radiation dermatitis (10.5%), and enteritis (9%), cystitis (6%) and proctitis (2.5%). Acute adverse events were mostly low grade (I and II, 28-61%). Late complications were registered in 20.5% of patients. Skin fibrosis was most frequent (12%). Chronic proctitis was detected in 4% and urethral stricture in 4.5% of our patients. All late complications were low grade.

CONCLUSION

Treatment tolerance of radical radiotherapy is relatively good. Although most patients develop acute toxicity, it is commonly low grade and requires the interruption of radiotherapy treatment in 20% of patients only. Late toxicity is rarer than acute and, in most cases, it does not affect the quality of life.

Pelvic lymph node irradiation for prostate cancer: who, why, and when?

Prostate cancers are best characterized by their clinical (TNM) stage, Gleason score, and serum prostate-specific antigen (PSA) level. These 3 factors are known to influence the risk of pelvic nodal involvement. By combining these prognostic factors, nomograms and equations have been developed and are widely used in clinical practice as an accurate way of predicting the probability of a given pathological stage. Patients who have a significant risk of pelvic nodal metastasis will likely have higher biochemical failure rates. Results from the multi-institutional prospective trials have shown that patients at an intermediate to high risk for pelvic nodal involvement experience disease progression-free survival benefits from the use of whole pelvic radiotherapy combined with hormone therapy. Yet, significant biological interactions between radiation treatment volumes and timing of hormone therapy have been shown. Further study of these issues is necessary to define the best treatment for patients at significant risk of pelvic lymph node involvement.

10-Year Survival and Quality of Life in Patients With High-Risk PN0 Prostate Cancer Following Definitive Radiotherapy

PURPOSE

To evaluate long-term overall survival (OS), cancer-specific survival (CSS), clinical progression-free survival (cPFS), and health-related quality of life (HRQoL) following definitive radiotherapy (RT) given to T(1-4p)N(0)M(0) prostate cancer patients provided by a single institution between 1989 and 1996.

METHODS AND MATERIALS

We assessed outcome among 203 patients who had completed three-dimensional conformal RT (66 Gy) without hormone treatment and in whom staging by lymphadenectomy had been performed. OS was compared with an age-matched control group from the general population. A cross-sectional, self-report survey of HRQoL was performed among surviving patients.

RESULTS

Median observation time was 10 years (range, 1-16 years). Eighty-one percent had high-risk tumors defined as T(3-4) or Gleason score (GS) > or =7B (4+3). Among these, 10-year OS, CSS, and cPFS rates were 52%, 66%, and 39%, respectively. The corresponding fractions in low-risk patients (T(1-2) and GS < or =7A [3+4]) were 79%, 95%, and 73%, respectively. Both CSS and cPFS were predicted by GS and T-classification; OS was associated with GS only. High-risk, but not low-risk, patients had reduced OS compared with the general population (p < 0.0005). When pelvis-related side effects were included in multivariate analyzes together with physical function and pain, sexual, urinary, and bowel function were not independently associated with self-reported global quality of life.

CONCLUSIONS

Despite surgically proven (p)N(0), RT with dosage <70 Gy as monotherapy does not give satisfactory CSS rates after 10 years in patients with T(3-4) or GS > or =7B.

Evidence-based radiation oncology: Definitive, adjuvant and salvage radiotherapy for non-metastatic prostate cancer

The standard treatment options based on the risk category (stage, Gleason score, PSA) for localized prostate cancer include surgery, radiotherapy and watchful waiting. The literature does not provide clear-cut evidence for the superiority of surgery over radiotherapy, whereas both approaches differ in their side effects. The definitive external beam irradiation is frequently employed in stage T1b-T1c, T2 and T3 tumors. There is a pretty strong evidence that intermediate- and high-risk patients benefit from dose escalation. The latter requires reduction of the irradiated normal tissue (using 3-dimensional conformal approach, intensity modulated radiotherapy, image-guided radiotherapy, etc.). Recent data suggest that prostate cancer may benefit from hypofractionation due to relatively low alpha/beta ratio; these findings warrant confirmation though. The role of whole pelvis irradiation is still controversial. Numerous randomized trials demonstrated a clinical benefit in terms of biochemical control, local and distant control, and overall survival from the addition of androgen suppression to external beam radiotherapy in intermediate- and high-risk patients. These studies typically included locally advanced (T3-T4) and poor-prognosis (Gleason score >7 and/or PSA >20 ng/mL) tumors and employed neoadjuvant/concomitant/adjuvant androgen suppression rather than only adjuvant setting. The ongoing trials will hopefully further define the role of endocrine treatment in more favorable risk patients and in the setting of the dose escalated radiotherapy. Brachytherapy (BRT) with permanent implants may be offered to low-risk patients (cT1-T2a, Gleason score <7, or 3+4, PSA <or=10 ng/mL), with prostate volume of <or=50 ml, no previous transurethral prostate resection and a good urinary function. Some recent data suggest a benefit from combining external beam irradiation and BRT for intermediate-risk patients. EBRT after radical prostatectomy improves disease-free survival and biochemical and local control rates in patients with positive surgical margins or pT3 tumors. Salvage radiotherapy may be considered at the time of biochemical failure in previously non-irradiated patients.

Knock-down of Bcl-2 by antisense oligodeoxynucleotides induces radiosensitization and inhibition of angiogenesis in human PC-3 prostate tumor xenografts

Expression of the proto-oncogene Bcl-2 is associated with tumor progression. Bcl-2's broad expression in tumors, coupled with its role in resistance to chemotherapy and radiation therapy-induced apoptosis, makes it a rational target for anticancer therapy. Antisense Bcl-2 oligodeoxynucleotide (ODN) reagents have been shown to be effective in reducing Bcl-2 expression in a number of systems. We investigated whether treating human prostate cancer cells with antisense Bcl-2 ODN (G3139, oblimersen sodium, Genasense) before irradiation would render them more susceptible to radiation effects. Two prostate cancer cell lines expressing Bcl-2 at different levels (PC-3-Bcl-2 and PC-3-Neo) were subjected to antisense Bcl-2 ODN, reverse control (CTL), or mock treatment. Antisense Bcl-2 ODN alone produced no cytotoxic effects and was associated with G(1) cell cycle arrest. The combination of antisense Bcl-2 ODN with irradiation sensitized both cell lines to the killing effects of radiation. Both PC-3-Bcl-2 and PC-3-Neo xenografts in mice treated with the combination of antisense Bcl-2 ODN and irradiation were more than three times smaller by volume compared with xenografts in mice treated with reverse CTL alone, antisense Bcl-2 ODN alone, irradiation alone, or reverse CTL plus radiotherapy (P = 0.0001). Specifically, PC-3-Bcl-2 xenograft tumors treated with antisense Bcl-2 ODN and irradiation had increased rates of apoptosis and decreased rates of angiogenesis and proliferation. PC-3-Neo xenograft tumors had decreased proliferation only. This is the first study which shows that therapy directed at Bcl-2 affects tumor vasculature. Together, these findings warrant further study of this novel combination of Bcl-2 reduction and radiation therapy, as well as Bcl-2 reduction and angiogenic therapy.

Combination of PTEN Gene Therapy and Radiation Inhibits the Growth of Human Prostate Cancer Xenografts

The resistance of prostate cancers to radiation therapy has been linked to abnormalities in overexpression of Bcl-2, an oncogene associated with inhibition of apoptosis. In this study, we evaluated whether the combination of the overexpression of phosphatase and tensin homolog (PTEN), a protein known to inhibit Bcl-2 expression, and radiation therapy would inhibit proliferation of Bcl-2-expressing human prostate cancer cells inoculated into the subcutis of athymic mice. Compared with either treatment alone, the combination of adenoviral vector-expressed PTEN (AdPTEN) and radiation (5 Gy) significantly inhibited xenograft tumor growth. Median tumor size on day 48 was 1030 mm3 in untreated controls, 656 mm3 in mice treated with radiation (5 Gy) alone, 640 mm3 in mice treated with AdPTEN alone, and 253 mm3 in mice treated with the combination (p<0.001). Treatment was well tolerated in all cases. Combination treatment also enhanced apoptosis (p=0.048), inhibited cellular proliferation (p=0.005), and inhibited tumor-induced neovascularity (p=0.030). Interestingly, this treatment increased apoptosis not only in tumor cells but also in tumor-associated endothelial cells. Together, these findings indicate that AdPTEN strongly inhibits the growth of human prostate tumors, especially when combined with radiation therapy, and that this effect is mediated by the induction of apoptosis and by the inhibition of angiogenesis and cellular proliferation.

The role of whole pelvic radiotherapy in locally advanced prostate cancer

Routine PSA testing has led to diagnosis and treatment of prostate cancer at earlier stages than previously. Earlier and technically-improved treatment, together with escalation of dose has enhanced cure rates. Although, the incidence of nodal metastases is now lower than in pre-PSA days, more extended pelvic lymphadenectomies have shown the actual rate of lymph node involvement to be higher than had been determined from standard radical prostate surgery. As in cancers in other sites, especially in their earlier stages, lymph node metastases may exist in the absence of haematogenous dissemination. This, together with the improved rates of control of the primary prostate tumour, suggests that elective irradiation of early-stage lymph nodes from prostate cancer should enhance survival in a manner analogous to improvements seen with this approach in other cancers. Although, the absolute incidence of positive nodes in locally advanced prostate cancer warrants elective radiotherapy, it is relatively low and the modest improvements to be expected may be undetected in the results of a small trial.

Comparison of treatment volumes and techniques in prostate cancer radiation therapy

OBJECTIVE

To compare dose-volume histograms (DVHs) for 3 target volumes (group 1, prostate + seminal vesicles + pelvic lymph nodes; group 2, prostate + seminal vesicles; group 3, prostate only) to determine the difference in dose to normal structures (rectum, bladder, and femoral heads) while controlling for target dose using 3-dimensional conformal radiation therapy (3DCRT) versus intensity modulated radiation therapy (IMRT).

METHODS

Ten patients with localized prostate cancer were randomly selected. 3DCRT and IMRT planning were done to deliver 75.6 Gy to the prostate, 50.4 Gy to the pelvic nodes, and 55.8 Gy to the seminal vesicles at a standard fractionation of 1.8 Gy. An additional plan delivering 75.6 Gy to the seminal vesicles using IMRT was run. DVHs were compared for 3DCRT and IMRT.

RESULTS

In all 3 groups, the percent rectum receiving > or =70 Gy, > or =60 Gy, and > or =40 Gy was significantly less for IMRT than for 3DCRT. Increasing target volumes, as necessary for pelvic nodal irradiation, overall did not result in higher rectal doses for IMRT. With 3DCRT, however, larger target volumes did increase the amount of rectum irradiated. Similar results were obtained for the femoral heads whereas results for the bladder were mixed.

CONCLUSION

When compared with 3DCRT, IMRT delivered equivalent or higher doses to the target volume with greater sparing of critical organs. Because dose-volume parameters have been shown to relate to toxicity, IMRT would appear to be the favored technique for prostate cancer radiation, particularly with regard to nodal treatment.

High-dose-rate brachytherapy combined with long-term hormonal therapy for high-risk prostate cancer: Results of a retrospective analysis

PURPOSE

High-dose-rate (HDR) brachytherapy combined with hormonal therapy (HTx), without the addition of external beam radiation therapy (EBRT) for high-risk prostate cancer was evaluated retrospectively.

MATERIALS AND METHODS

Between May 1995 and April 2002, 35 patients with prostate cancer [Stage > or = T2b (UICC 1997) or tumor grading=3 or prostate-specific antigen (PSA) level > or = 20 ng/mL] were treated with HDR brachytherapy combined with HTx. Most patients (74%) had two or more of these factors. All patients received Iridium-192 HDR brachytherapy with a total dose of 54 Gy/9 fractions/5 days (48 Gy/8 fractions/5 days for the first 6 cases) in one implant session. The median neoadjuvant HTx [luteinizing hormone-releasing hormone (LH-RH) agonist and antiandrogen] period was 7 months. The median adjuvant HTx (ATH) (LH-RH agonist) period was 40 months, and median follow-up was 57 months (range, 23-117 months).

RESULTS

The 5-year actuarial biochemical control, local control, and disease-free rates were 62%, 96%, and 76% respectively. No patients experienced local and/or regional relapse without distant progression. The 5-year actuarial cause-specific survival and overall survival rates were 89% and 87%, respectively. The acute and late toxicity were moderate and well tolerated.

CONCLUSION

HDR brachytherapy plus long-term HTx is at least as effective as conventional EBRT plus long-term HTx.

Radiotherapeutic techniques for prostate cancer, dose escalation and brachytherapy

There is evidence to confirm a dose-response relationship in prostate cancer. The relative benefit is dependent on the clinical prognostic risk factors (T stage, Gleason score and presenting prostate-specific antigen [PSA]) being more favourable for intermediate-risk patients. Refinement of prognostic groups and clinical threshold parameters is ongoing. Escalation of dose in prostate radiotherapy using conventional techniques is limited by rectal tolerance. Substantial advances have been made in radiotherapy practice, such as the development of conformal radiotherapy (CFRT) and intensity-modulated radiotherapy (IMRT). Randomised data support the value of CFRT in reducing rectal toxicity. IMRT can permit higher-dose escalation while still respecting known rectal tolerance thresholds. Brachytherapy is a recognised alternative for low-risk prostate cancer subgroups. New radiotherapeutic strategies for prostate cancer include pelvic nodal irradiation, exploiting the presumed low alpha/beta ratio in prostate cancer for hypofractionation and combining external beam with high-dose-rate brachytherapy boosts. New image-guided methodologies will enhance the therapeutic ratio of any radiotherapy technique or dose escalation programme by enabling more reliable and accurate treatment delivery for improved patient outcomes.

Intensity modulated radiotherapy for high risk prostate cancer based on sentinel node SPECT imaging for target volume definition

Background

The RTOG 94-13 trial has provided evidence that patients with high risk prostate cancer benefit from an additional radiotherapy to the pelvic nodes combined with concomitant hormonal ablation. Since lymphatic drainage of the prostate is highly variable, the optimal target volume definition for the pelvic lymph nodes is problematic. To overcome this limitation, we tested the feasibility of an intensity modulated radiation therapy (IMRT) protocol, taking under consideration the individual pelvic sentinel node drainage pattern by SPECT functional imaging.

Methods

Patients with high risk prostate cancer were included. Sentinel nodes (SN) were localised 1.5–3 hours after injection of 250 MBq ^99mTc-Nanocoll using a double-headed gamma camera with an integrated X-Ray device. All sentinel node localisations were included into the pelvic clinical target volume (CTV). Dose prescriptions were 50.4 Gy (5 × 1.8 Gy / week) to the pelvis and 70.0 Gy (5 × 2.0 Gy / week) to the prostate including the base of seminal vesicles or whole seminal vesicles. Patients were treated with IMRT. Furthermore a theoretical comparison between IMRT and a three-dimensional conformal technique was performed.

Results

Since 08/2003 6 patients were treated with this protocol. All patients had detectable sentinel lymph nodes (total 29). 4 of 6 patients showed sentinel node localisations (total 10), that would not have been treated adequately with CT-based planning ('geographical miss') only. The most common localisation for a probable geographical miss was the perirectal area. The comparison between dose-volume-histograms of IMRT- and conventional CT-planning demonstrated clear superiority of IMRT when all sentinel lymph nodes were included. IMRT allowed a significantly better sparing of normal tissue and reduced volumes of small bowel, large bowel and rectum irradiated with critical doses. No gastrointestinal or genitourinary acute toxicity Grade 3 or 4 (RTOG) occurred.

Conclusion

IMRT based on sentinel lymph node identification is feasible and reduces the probability of a geographical miss. Furthermore, IMRT allows a pronounced sparing of normal tissue irradiation. Thus, the chosen approach will help to increase the curative potential of radiotherapy in high risk prostate cancer patients.

Role of prostate dose escalation in patients with greater than 15% risk of pelvic lymph node involvement

PURPOSE

To determine whether the radiation dose is a determinant of clinical outcome in patients with a lymph node risk of >15% treated using whole pelvic (WP), partial pelvic (PP), or prostate only (PO) fields.

METHODS AND MATERIALS

A total of 420 patients with prostate cancer treated with three-dimensional conformal radiotherapy with or without short-term androgen deprivation (STAD) between June 1989 and July 2000 were included in this study. Patients had an initial pretreatment prostate-specific antigen level of <100 ng/mL and a lymph node index of > or =15% or T2c tumors with a Gleason score of 6-10. No patient had radiologic evidence of lymph node involvement. Of the 460 patients, 48 were treated with PO, 74 with PP, and 298 with WP fields. The median prostate dose was 74 Gy for PO, 82 Gy for PP, and 76 Gy for WP. The median radiation dose to the pelvis was 46 Gy for both PP and WP. Of the 460 patients, 72 underwent STAD for a median of 3 months (range, 3-6 months). Cox regression multivariate analysis was used to identify independent predictors of freedom from biochemical failure (FFBF) defined according to the American Society for Therapeutic Radiology Oncology consensus guidelines. Univariate comparisons were done using the Kaplan-Meier method and the log-rank test.

RESULTS

At a median follow-up of 43 months, 121 patients had treatment failure: 22, 7, and 92 in the PO, PP, and WP arms, respectively. Independent predictors of FFBF in multivariate analysis included radiation dose, T stage, Gleason score, and initial prostate-specific antigen level. The 5-year FFBF rate by dose group was 48% for <73 Gy, 64% for 73-76.9 Gy, and 74% for > or =77 Gy (p = 0.002). The use of STAD and radiation field size were not significantly associated with FFBF.

CONCLUSION

The radiation dose was the most significant determinant of FFBF in patients with a lymph node risk >15% in the patient population studied. These data suggest that the primary tumor takes precedence over lymph node coverage or the use of STAD. Doses >70 Gy are of paramount importance in such intermediate- and high-risk patients.

Combined modality treatment with high-dose-rate brachytherapy boost for locally advanced prostate cancer

PURPOSE

This is a retrospective review of our experience using high-dose-rate (HDR) brachytherapy boost for prostate cancer.

METHODS AND MATERIALS

During the study period, we recommended external beam radiotherapy (45 Gy) and HDR boost (18 Gy in three fractions) combined with hormonal therapy (HT) for 2 months before and during radiotherapy to patients with at least one of the following risk features: pretreatment prostate-specific antigen>10, Gleason score (GS)>or=7, and clinical T3 disease. Additional HT for 2 years after radiotherapy was recommended for patients with GS>7. To patients whose risk of positive nodes exceeded 15%, we recommended whole pelvic radiotherapy. We administered HDR via single implant, and all fractions were given within 24h.

RESULTS

This report is based on our initial 64 patients treated with HDR boost. The median follow-up was 50 months (range 25-68 months). The 4-year estimates of overall and disease-free survival were 98% and 92%, respectively. One patient experienced late grade 4 gastrointestinal toxicity.

CONCLUSIONS

HDR brachytherapy is an effective means of delivering conformal prostate radiotherapy, and may be used with whole pelvic radiotherapy and HT.

Quality assurance of the 22961 EORTC trial. A phase III study of the optimal combination of hormonal adjuvant treatment by LHRH analogue and radiation therapy for the management of locally advanced prostate cancer: the dummy run

PURPOSE

The EORTC trial 22961, opened in 1997, was designed to investigate the optimal combination of hormonal adjuvant treatment by LHRH analogue and radiation therapy for the management of locally advanced prostate cancer. A dummy run was established to assess centre compliance to the radiotherapy protocol.

MATERIALS AND METHODS

Medical and anatomical data obtained from 37 CT slices (5mm thickness) of an eligible patient were sent to 19 participating centres, which were asked to complete a questionnaire according to their practice and plan a theoretical radiotherapy treatment. The Planning Target Volume 1 (PTV1) should include prostate, seminal vesicles, internal iliac lymph nodes and inferior part of common iliac lymph nodes (extended pelvic fields). Centres which usually irradiate with small pelvic fields (N0 patients), were allowed to include the prostate, seminal vesicles and internal iliac lymph nodes plus a safety margin of 2 cm. For the Planning Target Volume 2 (PTV2), a safety margin of 1.5 to 2 cm should be around the prostate and seminal vesicles. Checks included patient positioning, treatment simulation, target volume definition, treatment set-up and clinical controls during treatment.

RESULTS

Eleven institutions with actual 81% of patients' accrual in the protocol have responded. All centres used a supine treatment position and positioning lasers for the set-up, while 73 and 45% of the centres performed cystograms and used rectal contrast, respectively. Among the participating centres, 45% and 55% used blocks and MLC, respectively, to treat patients. Extended pelvic fields in terms of PTV1 were used by 63% of the centres. The remaining centres treated a small PTV1 with a 10-20 mm margin around to CTV1. All centres defined PTV2 according to protocol guidelines. Doses to PTV1 and PTV2 were correctly prescribed. It was difficult to assess the treated volumes due to a lack of standardisation in DVH calculations.

CONCLUSION

In general, centres participating in the dummy run adhered to the guidelines. The dummy run enhances the reliability of the conclusions of the trial.

Stage T1c prostate cancer: a heterogeneous category with widely varying prognosis

PURPOSE

Stage T1c prostate cancer is defined as nonpalpable disease diagnosed by needle biopsy. As more patients are being diagnosed early because of prostate-specific antigen (PSA) screening, the distribution of patients by stage has shifted dramatically. Although this group has traditionally been characterized as having early-stage disease and the best prognosis, on review of these patients, we instead found a very heterogeneous group with a wide spectrum of outcomes that depend on both patient (Gleason grade and pretreatment PSA) and treatment (dose) factors.

METHODS AND MATERIALS

A retrospective analysis was performed on 353 patients with stage T1c prostate adenocarcinoma who were referred for radiation therapy from 1989-1999. All patients underwent central review of pathology. Patients were treated with external-beam radiation to doses of 60-78 Gy; 66% of the patients were treated with a dose of 70 Gy or higher. Clinical local recurrence, nodal recurrence, distant metastases, and PSA relapse were recorded. Kaplan-Meier methodology was used to determine survival. For evaluation of prognostic variables, the patients were grouped by Gleason score (2-6, 7, 8-10), pretreatment PSA level (< 10, 10-20, > 20 ng/mL), and dose delivered to the prostate (< or = 70 Gy, > 70 Gy). The log-rank test was used for univariate analysis, and Cox-regression was used for multivariate analysis.

RESULTS

The median age was 69 years, and the median follow-up of surviving patients was 47 months. As a percentage of all patients with prostate cancer, stage T1c continually increased from 6% in 1989 to 47% in 1999. Of the 353 patients with T1c, 66% of the patients were in the Gleason group of 2-6, 27% had a Gleason score of 7, and 7% had a Gleason score of 8-10. Sixty-five percent of the group had a pretreatment PSA level of < 10 ng/ mL, 31% had a PSA level of 10-20 ng/mL, and 5% had a PSA level of > 20 ng/mL. For the entire group, the 8-year overall survival was 86%, and PSA relapse-free survival was 78%. By univariate analysis, Gleason score and pretreatment PSA were significant predictors of overall survival and PSA relapse-free survival. For PSA relapse-free survival, a radiation dose of more than 70 Gy was also a significant factor. By multivariate analysis, Gleason score, pretreatment PSA level, and radiation dose over 70 Gy were significant predictors of PSA relapse-free survival. As expected, patients with Gleason score < or = 6 and pretreatment PSA < 10 had an 8-year RFS of 90%, whereas patients with Gleason score of 8-9 and pretreatment PSA > 20 had a relapse-free survival of zero percent.

DISCUSSION

Contrary to general assumption, stage T1c prostate cancer is composed of a very heterogeneous group of patients with varying outcomes. When treatment modalities and institutional data are evaluated, the spectrum of disease must be accounted for by additional prognostic factors and subset analysis. Improvement in prostate imaging and multiple core biopsies may be helpful in better defining the extent of disease in the individual patient.

Dose escalation using conformal high-dose-rate brachytherapy improves outcome in unfavorable prostate cancer

PURPOSE

To overcome radioresistance for patients with unfavorable prostate cancer, a prospective trial of pelvic external beam irradiation (EBRT) interdigitated with dose-escalating conformal high-dose-rate (HDR) prostate brachytherapy was performed.

METHODS AND MATERIALS

Between November 1991 and August 2000, 207 patients were treated with 46 Gy pelvic EBRT and increasing HDR brachytherapy boost doses (5.50-11.5 Gy/fraction) during 5 weeks. The eligibility criteria were pretreatment prostate-specific antigen level >or=10.0 ng/mL, Gleason score >or=7, or clinical Stage T2b or higher. Patients were divided into 2 dose levels, low-dose biologically effective dose <93 Gy (58 patients) and high-dose biologically effective dose >93 Gy (149 patients). No patient received hormones. We used the American Society for Therapeutic Radiology and Oncology definition for biochemical failure.

RESULTS

The median age was 69 years. The mean follow-up for the group was 4.4 years, and for the low and high-dose levels, it was 7.0 and 3.4 years, respectively. The actuarial 5-year biochemical control rate was 74%, and the overall, cause-specific, and disease-free survival rate was 92%, 98%, and 68%, respectively. The 5-year biochemical control rate for the low-dose group was 52%; the rate for the high-dose group was 87% (p <0.001). Improvement occurred in the cause-specific survival in favor of the brachytherapy high-dose level (p = 0.014). On multivariate analysis, a low-dose level, higher Gleason score, and higher nadir value were associated with increased biochemical failure. The Radiation Therapy Oncology Group Grade 3 gastrointestinal/genitourinary complications ranged from 0.5% to 9%. The actuarial 5-year impotency rate was 51%.

CONCLUSION

Pelvic EBRT interdigitated with transrectal ultrasound-guided real-time conformal HDR prostate brachytherapy boost is both a precise dose delivery system and a very effective treatment for unfavorable prostate cancer. We demonstrated an incremental beneficial effect on biochemical control and cause-specific survival with higher doses. These results, coupled with the low risk of complications, the advantage of not being radioactive after implantation, and the real-time interactive planning, define a new standard for treatment.

[Prostate cancer: has local radiation treatment had an impact on survival?]

Local control is an important goal in the treatment of prostate cancer. Firstly, it avoids the morbidity due to locoregional evolution (urethral obstruction, vascular compression, rectal or vesical involvement). Moreover, local control of the disease may decrease the mortality due to metastases disseminated from local relapse. Local control evaluation remains difficult: neither rectal examination nor imaging or prostate biopsies have an absolute value in diagnostic of local relapse. PSA increase does not permit to differentiate local from distant relapses. Recent developments in radiotherapy techniques allow dose escalation without major toxicity. Retrospective studies and one randomized study have shown that an increase from 70 to 80 Gy or more, improve biological relapse-free survival. In one randomized study comparing 70 to 78 Gy, the biochemical disease-free survival was improved from 69 to 79% at five years. Such an improvement can only be explained by an improvement of local control. The benefit in term of overall survival is not yet demonstrated and needs a longer follow-up and other studies. Another approach to improve local control is the association of a local radiotherapy with hormonal adjuvant therapy. Four randomized studies have been published for locally advanced prostate cancer. These studies have all demonstrated an improvement of local control, and a decrease of metastatic risk. The benefit in term of overall survival, observed in one of this trial, may be explained by the improvement of either local or distant control or both. Such therapeutic progress, associated with the development of prostate cancer screening should lead to a decrease of prostate cancer mortality for the next ten years.

Endoscopic therapy for radiation proctitis-induced hemorrhage in patients with prostatic carcinoma using argon plasma coagulator application

BACKGROUND

Recurrent hemorrhage in patients with severe radiation proctitis is very common. It is often refractory to medical therapy. Endoscopic and surgical treatment may be required when conservative medical therapy fails. The aim of this study was to assess the therapeutic results of the Argon Plasma Coagulator (APC) (ERBE USA, Inc., Marietta, GA, USA) application in patients with radiation proctitis-induced hemorrhage.

METHODS

Forty patients with radiation-induced proctitis causing severe bleeding, who had failed conservative medical management were treated endoscopically. Twenty-one patients in this group required blood transfusions.

RESULTS

APC application was used in 40 patients with only one failure. The failed patient underwent formalin application using 4% formalin solution with resolution of the bleeding.

CONCLUSION

Argon plasma coagulation application is a safe, well-tolerated treatment option and, historically, has been superior to Nd:YAG laser ablation.

Urinary incontinence following treatment of localized prostate cancer

BACKGROUND

Urinary incontinence (UI) following treatment for localized prostate cancer is a significant adverse consequence most commonly seen after radical prostatectomy. UI can significantly impair the quality of life of patients who can otherwise expect a long survival.

METHODS

The authors review past and present literature on UI following treatment for localized prostate cancer. Special focus is placed on the rate of UI following different modes of therapy, the effect of posttreatment UI on patients' quality of life, and the success of different methods used to treat the incontinence.

RESULTS

Postprostatectomy UI has been reported in 25%-70% of cases, but few patients report being significantly bothered by the symptom. Postradiation adverse effects are mainly acute inflammatory, while late complications are rare but usually more serious. Comparative studies estimate UI following prostatectomy to be two times more common than following radiation, and surgical patients are three times more likely to continue to use pads. Watchful waiting carries a risk of incontinence related to prostate tumor progression. Several interventions can improve UI.

CONCLUSIONS

UI is the most common adverse consequence from treatment for localized prostate cancer. All of the possible treatment modalities carry some risk of UI. Providing accurate information to patients allows them to make informed decisions regarding treatment and can improve the quality of life in the posttreatment period.

Matched-pair analysis of conformal high-dose-rate brachytherapy boost versus external-beam radiation therapy alone for locally advanced prostate cancer

PURPOSE

We performed a matched-pair analysis to compare our institution's experience in treating locally advanced prostate cancer with external-beam radiation therapy (EBRT) alone to EBRT in combination with conformal interstitial high-dose-rate (HDR) brachytherapy boosts (EBRT + HDR).

MATERIALS AND METHODS

From 1991 to 1998, 161 patients with locally advanced prostate cancer were prospectively treated with EBRT + HDR at William Beaumont Hospital, Royal Oak, Michigan. Patients with any of the following characteristics were eligible for study entry: pretreatment prostate-specific antigen (PSA) level of >/= 10.0 ng/mL, Gleason score >/= 7, or clinical stage T2b to T3c. Pelvic EBRT (46.0 Gy) was supplemented with three (1991 through 1995) or two (1995 through 1998) ultrasound-guided transperineal interstitial iridium-192 HDR implants. The brachytherapy dose was escalated from 5.50 to 10.50 Gy per implant. Each of the 161 EBRT + HDR patients was randomly matched with a unique EBRT-alone patient. Patients were matched according to PSA level, Gleason score, T stage, and follow-up duration. The median PSA follow-up was 2.5 years for both EBRT + HDR and EBRT alone.

RESULTS

EBRT + HDR patients demonstrated significantly lower PSA nadir levels (median, 0.4 ng/mL) compared with those receiving EBRT alone (median, 1.1 ng/mL). The 5-year biochemical control rates for EBRT + HDR versus EBRT-alone patients were 67% versus 44%, respectively (P <.001). On multivariate analyses, pretreatment PSA, Gleason score, T stage, and the use of EBRT alone were significantly associated with biochemical failure. Those patients in both treatment groups who experienced biochemical failure had a lower 5-year cause-specific survival rate than patients who were biochemically controlled (84% v 100%; P <.001).

CONCLUSION

Locally advanced prostate cancer patients treated with EBRT + HDR demonstrate improved biochemical control compared with those who are treated with conventional doses of EBRT alone.

Treatment of locally advanced prostate cancer: is chemotherapy the next step?

PURPOSE

Management of locally advanced prostate cancer remains controversial. Various single and combination modality approaches have been advocated, but an accepted standard of care remains undefined. The purpose of this review is to define the current knowledge in managing locally advanced prostate cancer and to propose new treatment approaches based on current knowledge.

MATERIALS AND METHODS

A MEDLINE search to detect all relevant articles on the management of locally advanced prostate cancer was performed. A review of the staging, natural history, and prognosis of this disease was also performed.

RESULTS

The lack of a clearly defined treatment approach to patients with locally advanced prostate cancer stems from multiple factors, including ambiguities in clinical staging, inadequate knowledge of the natural history of the cancer, and a dearth of comparative randomized trials evaluating efficacy of different therapies. Single modality treatment, including radical prostatectomy (RP) or external-beam radiotherapy alone, is associated with high rates of failure. The use of adjuvant hormonal ablation therapy in combination with external-beam radiotherapy has shown improvement in progression-free and overall survival, although similar improvements have not been clearly demonstrated for surgical patients treated with hormonal therapy. New advances in chemotherapy for hormone-refractory prostate cancer suggest that response rates may be as high as 50% or more, and current trials are evaluating the addition of chemotherapy to hormonal ablation in either surgery or radiation therapy in locally advanced prostate cancer.

CONCLUSION

Optimal management of locally advanced prostate cancer remains undefined. Standard treatment options include RP, external-beam radiotherapy, or hormonal ablation therapy, alone or in combination. New approaches being tested include improved methods for delivering radiation or combining hormonal ablation with surgery or radiation. It is possible that other forms of systemic therapy, including chemotherapy, may become important components of multimodality treatment. Clinical trials designed to test this hypothesis are ongoing.

Conventional external-beam radiation therapy alone or with androgen ablation for clinical stage III (T3, NX/N0, M0) adenocarcinoma of the prostate

PURPOSE

To evaluate the outcome of clinical Stage III (T3, N0/NX, M0) prostate cancer treated by conventional radiation alone or with adjuvant androgen ablation.

METHODS AND MATERIALS

Three hundred forty-four men with T3, N0/NX, M0 adenocarcinoma of the prostate who received conventional radiation alone (260) or with androgen ablation (84) were analyzed for relapse or rising prostate-specific antigen (PSA), using univariate and multivariate techniques.

RESULTS

With a median follow-up of 68 months, the 260 men treated with radiation alone had a 10-year actuarial rate of relapse or rising PSA of 76%. Pretreatment PSA level (< or = 10 ng/ml vs. > 10 < or = 20 ng/ml vs. > 20 ng/ml) and radiation dose (< 68 Gy vs. > or = 68 Gy) were the only independently significant determinants of biochemical failure; Gleason score (2-7 vs. 8-10) was an additional determinant of metastatic relapse. Patients treated to doses < 68 Gy experienced 6-year failure rates exceeding 50% regardless of PSA level. Patients with PSA < or = 10 ng/ml and receiving 68-70 Gy had a 6-year failure of 24%, but those with PSA > 10 ng/ml had relapse rates exceeding 50% even at doses of 70 Gy. At a median follow-up of 44 months, the 84 patients treated with radiation and androgen ablation had a 6-year biochemical failure rate of 22%. The only significant determinant of outcome in this group was pretreatment PSA; patients with PSA < or = 80 ng/ml had a 6-year failure rate of only 12% compared to a failure rate of 53% for those with PSA > 80 ng/ml. The outcome for those treated with combined modalities was significantly better than for those treated with radiation alone in all PSA strata.

CONCLUSION

Conventional radiation alone has little curative potential for Stage III disease. Doses < 68 Gy are particularly ineffective. Patients with PSA < or = 10 ng/ml may be candidates for conventional radiation to a dose of 70 Gy. Other patients are probably best served by combined radiation-androgen ablation or high-dose conformal radiation.

Is there more than one late radiation proctitis syndrome?

PURPOSE

To investigate the significance of the various late rectal symptoms that appear after radical prostatic irradiation.

PATIENTS AND METHODS

Patients with localised prostate cancer treated between 1987 and 1994 at the Mater Hospital, Newcastle with radical megavoltage irradiation were recalled for examination and to complete a detailed questionnaire concerning late radiation-induced symptoms and their effects on normal daily life. The influence of patient age treatment related variables and acute proctitis symptoms occurring during therapy or the late symptoms recorded were assessed and the relationship between late symptoms and late EORTC/RTOG score and impact on normal daily life were studied.

RESULTS

The presence of symptoms of acute proctitis was the only factor to predict any of three late symptoms (urgency, frequency and diarrhoea) and late EORTC/RTOG score in this series (odds ratios: 1.7-2.57, P-values: 0.009-0.0007). Cluster and discriminant function analyses revealed the presence of five subgroups of patients with varying permutations of different late rectal symptoms, including one group with minimal symptoms (P < 0.0001). While bleeding and rectal discharge were the major contributors to late EORTC/RTOG score (P < 0.0001 and 0.04), faecal urgency and bleeding were the most important factors to impact on normal daily life (P < 0.0001 and P < 0.0003). A relatively low concordance was found between late EORTC/RTOG score and the patients' self assessment on the effect of their symptoms on their normal daily lives. Some late symptoms, including bleeding and rectal discharge become less prevalent after 3 years of follow-up with a resulting improvement in EORTC/RTOG score.

CONCLUSIONS

There may be more than one late (chronic) proctitis syndrome which may be linked in greater or lesser degrees to acute proctitis symptoms occurring during therapy. Urgency is a common late symptom which often has an important impact on normal daily life and deserves recognition in late normal tissue scoring systems. Assessment of the incidence of bleeding as a measure of late rectal morbidity following prostate irradiation may underestimate the impact of these chronic effects. Confirmatory studies are necessary.