Elective pelvic irradiation in stage A2, B carcinoma of the prostate: analysis of RTOG 77-06

Phase I trial of pelvic nodal dose escalation with hypofractionated IMRT for high-risk prostate cancer

PURPOSE

Toxicity concerns have limited pelvic nodal prescriptions to doses that may be suboptimal for controlling microscopic disease. In a prospective trial, we tested whether image-guided intensity-modulated radiation therapy (IMRT) can safely deliver escalated nodal doses while treating the prostate with hypofractionated radiotherapy in 5½ weeks.

METHODS AND MATERIALS

Pelvic nodal and prostatic image-guided IMRT was delivered to 53 National Comprehensive Cancer Network (NCCN) high-risk patients to a nodal dose of 56 Gy in 2-Gy fractions with concomitant treatment of the prostate to 70 Gy in 28 fractions of 2.5 Gy, and 50 of 53 patients received androgen deprivation for a median duration of 12 months.

RESULTS

The median follow-up time was 25.4 months (range, 4.2-57.2). No early Grade 3 Radiation Therapy Oncology Group or Common Terminology Criteria for Adverse Events v.3.0 genitourinary (GU) or gastrointestinal (GI) toxicities were seen. The cumulative actuarial incidence of Grade 2 early GU toxicity (primarily alpha blocker initiation) was 38%. The rate was 32% for Grade 2 early GI toxicity. None of the dose-volume descriptors correlated with GU toxicity, and only the volume of bowel receiving ≥30 Gy correlated with early GI toxicity (p = 0.029). Maximum late Grades 1, 2, and 3 GU toxicities were seen in 30%, 25%, and 2% of patients, respectively. Maximum late Grades 1 and 2 GI toxicities were seen in 30% and 8% (rectal bleeding requiring cautery) of patients, respectively. The estimated 3-year biochemical control (nadir + 2) was 81.2 ± 6.6%. No patient manifested pelvic nodal failure, whereas 2 experienced paraaortic nodal failure outside the field. The six other clinical failures were distant only.

CONCLUSIONS

Pelvic IMRT nodal dose escalation to 56 Gy was delivered concurrently with 70 Gy of hypofractionated prostate radiotherapy in a convenient, resource-efficient, and well-tolerated 28-fraction schedule. Pelvic nodal dose escalation may be an option in any future exploration of potential benefits of pelvic radiation therapy in high-risk prostate cancer patients.

Pelvic nodal dose escalation with prostate hypofractionation using conformal avoidance defined (H-CAD) intensity modulated radiation therapy

The management of prostate cancer patients with a significant risk of pelvic lymph node involvement is controversial. Both whole pelvis radiotherapy and dose escalation to the prostate have been linked to improved outcome in such patients, but it is unclear whether conventional whole pelvis doses of only 45-50 Gy are optimal for ultimate nodal control. The purpose of this study is to examine the dosimetric and clinical feasibility of combining prostate dose escalation via hypofractionation with conformal avoidance-based IMRT (H-CAD) dose escalation to the pelvic lymph nodes. One conformal avoidance and one conventional plan were generated for each of eight patients. Conformal avoidance-based IMRT plans were generated that specifically excluded bowel, rectum, and bladder. The prostate and lower seminal vesicles (PTV 70) were planned to receive 70 Gy in 2.5 Gy/fraction while the pelvic lymph nodes (PTV 56) were to concurrently receive 56 Gy in 2 Gy/fraction. The volume of small bowel receiving >or=45 Gy was restricted to 300 ml or less. These conformal avoidance plans were delivered using helical tomotherapy or LINAC-based IMRT with daily imaging localization. All patients received neoadjuvant and concurrent androgen deprivation with a planned total of two years. The conventional, sequential plans created for comparison purposes for all patients consisted of a conventional 4-field pelvic box prescribed to 50.4 Gy (1.8 Gy/fraction) followed by an IMRT boost to the prostate of 25.2 Gy (1.8 Gy/fraction) yielding a final prostate dose of 75.6 Gy. For all plans, the prescription dose was to cover the target structure. Equivalent uniform dose (EUD) analyses were performed on all targets and dose-volume histograms (DVH) were displayed in terms of both physical and normalized total dose (NTD), i.e. dose in 2 Gy fraction equivalents. H-CAD IMRT plans were created for and delivered to all eight patients. Analysis of the H-CAD plans demonstrates prescription dose coverage of >95% of both the PTV 70 (prostate) and PTV 56 (nodes). The EUDs for PTV 70 and PTV 56 were greater than prescription dose for all eight plans. Analysis of bio-effective DVHs demonstrated similar amounts of small bowel receiving >or=45 Gy for H-CAD and sequential plans, in spite of the significantly higher dose to which H-CAD treated the pelvic nodes. The treatment was well tolerated in the eight treated patients in that no grade 2 or higher acute gastrointestinal toxicities were seen. Prostate hypofractionation with concurrent conformal avoidance-based pelvic IMRT for high risk prostate cancer represents an efficient and promising method for achieving dose escalation both of pelvic lymph nodes and the prostate with modest acute toxicity. Unlike a vascular-guided targeting approach, conformal avoidance has the potential advantage of also encompassing at-risk nodes that are not contained within major nodal chains. A phase II trial to more thoroughly examine this treatment approach is currently underway.

Whole pelvic radiotherapy versus prostate only radiotherapy in the management of locally advanced or aggressive prostate adenocarcinoma

PURPOSE

To determine whether whole pelvic radiotherapy (WPRT) or prostate-only radiotherapy (PORT) yields improved biochemical disease-free survival (BDFS) in patients with advanced or aggressive prostate adenocarcinoma.

METHODS AND MATERIALS

Between 2000 and 2007, a consecutive sample of 277 patients with prostate adenocarcinoma and at least a 15% likelihood of lymph node involvement who had undergone WPRT (n = 68) or PORT (n = 209) at two referral centers was analyzed. The median radiation dose in both arms was 75.6 Gy. The outcome measure was BDFS, as determined using the prostate-specific antigen nadir + 2 ng/mL definition of failure. BDFS was calculated using the Kaplan-Meier method and compared with the log-rank test. A multivariate analysis was performed to assess for confounding. Treatment-related toxicity was assessed using the National Cancer Institute's Common Terminology Criteria for Adverse Events guidelines. The median follow-up was 30 months.

RESULTS

WPRT patients had more advanced and aggressive disease at baseline (p < .001). The 4-year BDFS rate was 69.4% in the PORT cohort and 86.3% in the WPRT cohort (p = .02). Within the entire cohort, after adjustment for confounding variables, the pretreatment prostate-specific antigen (p < .001), Gleason score (p < .001), use of hormonal therapy (p = .002), and use of WPRT (vs. PORT, p = .006) predicted for BDFS. Patients undergoing WPRT had increased acute gastrointestinal toxicity (p = .048), but no significant difference in acute genitourinary toxicity was seen (p = .09). No difference in late toxicity was found.

CONCLUSION

WPRT may yield improved BDFS in patients with advanced or aggressive prostate adenocarcinoma, but results in a greater incidence of acute toxicity.

Does treatment duration affect outcome after radiotherapy for prostate cancer?

PURPOSE

The protraction of external beam radiotherapy (RT) time is detrimental in several disease sites. In prostate cancer, the overall treatment time can be considerable, as can the potential for treatment breaks. We evaluated the effect of elapsed treatment time on outcome after RT for prostate cancer.

METHODS AND MATERIALS

Between April 1989 and November 2004, 1,796 men with prostate cancer were treated with RT alone. The nontreatment day ratio (NTDR) was defined as the number of nontreatment days divided by the total elapsed days of RT. This ratio was used to account for the relationship between treatment duration and total RT dose. Men were stratified into low risk (n = 789), intermediate risk (n = 798), and high risk (n = 209) using a single-factor model.

RESULTS

The 10-year freedom from biochemical failure (FFBF) rate was 68% for a NTDR <33% vs. 58% for NTDR >/=33% (p = 0.02; BF was defined as a prostate-specific antigen nadir + 2 ng/mL). In the low-risk group, the 10-year FFBF rate was 82% for NTDR <33% vs. 57% for NTDR >/=33% (p = 0.0019). The NTDR was independently predictive for FFBF (p = 0.03), in addition to T stage (p = 0.005) and initial prostate-specific antigen level (p < 0.0001) on multivariate analysis, including Gleason score and radiation dose. The NTDR was not a significant predictor of FFBF when examined in the intermediate-risk group, high-risk group, or all risk groups combined.

CONCLUSIONS

A proportionally longer treatment duration was identified as an adverse factor in low-risk patients. Treatment breaks resulting in a NTDR of >/=33% (e.g., four or more breaks during a 40-fraction treatment, 5 d/wk) should be avoided.

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.

Is There a Role for Pelvic Irradiation in Localized Prostate Adenocarcinoma? Preliminary Results of GETUG-01

Purpose

To assess the benefit and toxicity and quality-of-life (QOL) outcomes of pelvic nodes irradiation in nonmetastatic prostate carcinoma patients.

Patients and Methods

Between December 1998 and June 2004, 444 patients with T1b-T3, N0 pNx, M0 prostate carcinoma were randomly assigned to either pelvic and prostate radiotherapy or prostate radiotherapy only. Patients were stratified according to the prognostic factor of lymph node involvement (LNI). Short-term 6-month neoadjuvant and concomitant hormonal therapy was allowed only for patients in the high-risk group. The pelvic dose was 46 Gy. The total dose recommended to the prostate was changed during the course of the study from 66 Gy to 70 Gy. Criteria for progression-free survival (PFS) included biologic prostate-specific antigen recurrences or a local or metastatic evolution. Acute and late toxicities were recorded according to the Radiation Therapy Oncology Group and Late Effects in Normal Tissues Subjective, Objective, Management, and Analytic scales, respectively. The QOL outcome was recorded with the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30, the International Prostatic Symptom Score, and the Sexual Function Index scales.

Results

With a 42.1-month median follow-up time, the 5-year PFS and overall survival were similar in the two treatment arms for the whole series and for each stratified group. On multivariate analysis, low LNI risk and hormonal therapy were statistically associated with increased PFS. However, subgroup analyses based on these factors did not show any benefit for pelvic irradiation. There were no significant differences in acute and late digestive toxicities and in QOL outcomes.

Conclusion

Pelvic node irradiation was well tolerated but did not improve PFS.

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.

Chronic genitourinary and gastrointestinal toxicity of prostate cancer patients undergoing pelvic radiotherapy with intensity-modulated versus 4-field technique

PURPOSE

To compare chronic GU and GI toxicity of pelvic radiotherapy delivered using intensity-modulated radiotherapy (IMRT) versus conventional 4-field technique.

METHODS

The records of consecutive prostate cancer patients receiving RT at a single institution with a minimum follow-up of 120 days were reviewed; 48 of these patients received a prostate boost preceded by pelvic radiotherapy (PRT), 14 with IMRT (IM-PRT), and 34 with 4-field (4F-PRT). Dosimetric endpoints for the bladder, rectum, composite, and target for the PRT plans were compared using the 2-tailed t test. Late RTOG GU and GI toxicity were compared using the chi test. Ordered logit regression analyses were performed using all major patient, disease, and treatment factors as covariates.

RESULTS

IM-PRT demonstrated superior bladder and rectum dosimetric endpoints over 4F-PRT for the PRT portion of the treatment and for the composite treatment at the expense of higher target inhomogeneity in the PRT portion of the treatment plan. Late GU toxicity was significantly lower in the IM-PRT group (P < 0.001), whereas late GI toxicity was similar in both groups (P = 0.44). When considering a similar follow-up interval in both groups, however, the difference in GU toxicity only reached a trend (P = 0.10). The regression analyses showed that no factor, including IMRT, reached significance in predicting GU or GI toxicity.

CONCLUSION

Use of pelvic IMRT for prostate cancer patients was not associated with reduction of late GI toxicity but was associated with a small reduction of late GU toxicity. This reduction of late GU toxicity warrants further exploration in consortium studies.

Relationship between delay in radiotherapy and biochemical control in prostate cancer

PURPOSE

The aim of this study was to investigate whether a delay in radiotherapy is associated with a poorer biochemical control for prostate cancer.

METHODS

The time to treatment (TTT) from diagnosis of prostate cancer to radiotherapy was analyzed with respect to prostate-specific antigen (PSA) control in 1024 hormone-naive patients. The Kaplan-Meier PSA control curves for patients with TTT less than the median were compared with those for patients with TTT greater than the median in 3 predefined risk groups. Statistical significant differences in PSA control were further analyzed using Cox multivariate analysis with pretreatment PSA, Gleason score, T stage, and radiotherapy dose as covariates.

RESULTS

The median TTT and median follow-up are 3.7 months and 49 months respectively. Patients with a longer TTT have a statistically significant better PSA control than patients with a shorter TTT if they have intermediate- or high-risk disease. However in multivariate analysis TTT was not found to be significant in predicting PSA control, with pretreatment PSA and Gleason score emerging as highly significant in predicting PSA failure in both intermediate- and high-risk disease.

CONCLUSION

In this study in prostate cancer patients in British Columbia, there was no evidence that a longer time interval between diagnosis and radiotherapy was associated with poorer PSA control.

Matched-pair analysis of prostate cancer patients with a high risk of positive pelvic lymph nodes treated with and without pelvic RT and high-dose radiation using high dose rate brachytherapy

OBJECTIVE

Adding pelvic radiation to high-dose prostate radiation for prostate cancer patients with a >15% risk of positive lymph nodes (LN) is controversial. We performed a matched-pair analysis of patients treated at 2 institutions to assess the impact of pelvic radiotherapy (P-RT).

METHODS

From January 1993 to March 2003, 2 institutions treated 1432 prostate cancer patients with combined external beam radiotherapy (EBRT) and high-dose rate (HDR) brachytherapy. Those receiving EBRT were treated either to the prostate and seminal vesicles alone or to the entire pelvis (46 Gy). In all cases, prostate dose (EBRT and HDR) resulted in an average BED >100 Gy (alpha/beta = 1.2). There were 755 cases identified as having a pelvic LN risk >15% using the Roach formula. Of these, 255 cases were treated without pelvic RT and randomly matched by Gleason score, T stage, and pretreatment PSA to 500 cases treated with pelvic RT, resulting in 250 pairs (1:1).

RESULTS

Median follow-up was 4.0 years (P = 0.7). The 4-year prostate biochemical failure (22% versus 14%, P = 0.12), distant metastasis (9% versus 4%, P = 0.6), event-free survival (72% versus 78%, P = 0.3), prostate cancer death rate (4% versus 2%, P = 0.9), and overall survival (89% versus 88%, P = 0.7) were not significantly different for patients treated with and without P-RT. Analysis with and without androgen deprivation therapy showed similar results.

CONCLUSION

Improved biochemical, clinical, or survival outcomes were not observed for prostate cancer patients at risk for positive pelvic LN >15% when treated with high-dose EBRT and HDR brachytherapy to the prostate with or without pelvic radiation.

Distribution of lymph nodes in men with prostatic adenocarcinoma and lymphadenopathy at presentation: a retrospective radiological review and implications for prostate and pelvis radiotherapy

AIMS

To describe the distribution of enlarged lymph nodes by nodal group found radiologically in patients presenting with adenocarcinoma of the prostate. This will help to define which nodal groups should be treated during the pelvic radiotherapy of patients with less advanced disease.

MATERIALS AND METHODS

The scans of 55 men presenting with prostate cancer and metastases to lymph nodes only were reviewed. Lymph nodes of 8 mm or more in size were considered to be enlarged.

RESULTS

The medial external iliac (obturator) nodes were most commonly enlarged (75% of patients) followed by nodes in the para-aortic region (26%) and anterior internal iliac region (24%). Para-aortic lymph-node enlargement was uncommon in the absence of pelvic lymphadenopathy. Midline pre-sacral lymph-node enlargement was not observed. Incidence of enlarged lymph nodes in the lateral external iliac group was 18%, an area which may not be routinely included during radiotherapy.

CONCLUSION

There is a case for studying further the role of including lateral external iliac lymph nodes in the pelvic radiotherapy volume, as there may be an appreciable risk of lymph-node spread to this area.

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.

Sexual function after external-beam radiotherapy for prostate cancer: What do we know?

Quality of life in general and sexual functioning in particular have become very important in cancer patients. Due to modern surgical techniques, improved quality of drugs for chemotherapy and very modern radiation techniques, more patients can be successfully treated without largely compromising sexual functioning. One can assume that because of the life-threatening nature of cancer, sexual activity is not important to patients and their partners, but this is not true. Prostate cancer has become the most common non-skin malignant neoplasm in older men in Western countries. In this paper, we discuss the various methods used to evaluate erectile and sexual dysfunction and the definition of potency. Data on the etiology of erectile dysfunction after external-beam radiotherapy for prostate cancer is reviewed, and the literature is been summarized. Patients should be offered sexual counseling and informed about the availability of effective treatments for erectile dysfunction, such as sildenafil, intracavernosal injection, and vacuum devices. Cancer affects quality of life and sexual function. The challenge for oncologists is to address this with compassion.

Intensity-modulated versus conventional pelvic radiotherapy for prostate cancer: Analysis of acute toxicity

OBJECTIVES

To provide a single-institution analysis of the influence of pelvic intensity-modulated radiotherapy (RT) on acute genitourinary (GU) and gastrointestinal (GI) toxicity.

METHODS

The records of 610 consecutive patients with prostate cancer receiving RT were reviewed. Of these 610 patients, 49 had received a prostate boost preceded by pelvic RT (PRT), 15 intensity-modulated PRT (IM-PRT), and 34 four-field PRT (4F-PRT). The dosimetric endpoints for the bladder, rectum, and target for the PRT plans were compared using the paired t test; similar dosimetric analyses were done for the composite plans. Acute GU and GI toxicity were compared using the chi-square test. Ordered logit regression analyses were performed using all major treatment factors as covariates.

RESULTS

The bladder and rectum dosimetric endpoints were improved for IM-PRT compared with 4F-PRT for the PRT portion of the treatment plan (P = 0.06 and P = 0.03, respectively) and for the composite treatment plan (P = 0.04 and P = 0.01, respectively), at the expense of greater target inhomogeneity in the PRT portion of the treatment plan (P < 0.01). GU toxicity was significantly lower in the IM-PRT group (P < 0.001), and GI toxicity was similar in both groups (P = 0.637). The regression analyses showed that intensity-modulated RT for the pelvic portion of treatment was the only factor significantly predicting for GU toxicity (P = 0.05); no major treatment factor reached significance in predicting GI toxicity.

CONCLUSIONS

Compared with 4F-PRT, the use of IM-PRT improved dosimetric outcomes, was not associated with a reduction in acute GI toxicity, and was associated with a reduction in acute GU toxicity in the treatment of prostate cancer.

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.

Lack of benefit of pelvic radiation in prostate cancer patients with a high risk of positive pelvic lymph nodes treated with high-dose radiation

PURPOSE

The use of pelvic radiation for patients with a high risk of lymph node (LN) metastasis (>15%) remains controversial. We reviewed the data at three institutions treating patients with a combination of external-beam radiation therapy and high-dose-rate brachytherapy to address the prognostic implications of the use of the Roach formula and the benefit of pelvic treatment.

METHODS AND MATERIALS

From 1986 to 2003, 1,491 patients were treated with external-beam radiation therapy and high-dose-rate brachytherapy. The Roach formula [2/3 prostate-specific antigen + (Gleason score -6) x 10] could be calculated for 1,357 patients. Group I consisted of patients having a risk of positive LN < or = 15% (n = 761), Group II had a risk >15% and < or = 30% (n = 422), and Group III had a risk of LN disease >30% (n = 174). A >15% risk of having positive LN was found in 596 patients and was used to determine the benefit of pelvic radiation. The pelvis was treated at two of the cancer centers (n = 312), whereas at the third center (n = 284) radiation therapy was delivered to the prostate and seminal vesicles alone. Average biologic effective dose was > or = 100 Gy (alphabeta = 1.2). Biochemical failure was as per the American Society for Therapeutic Radiology and Oncology definition. Statistics included the log-rank test as well as Cox univariate and multivariate analysis.

RESULTS

For all 596 patients with a positive LN risk >15%, median follow-up was 4.3 years, with a mean of 4.8 years. For all cases, median follow-up was 4 years and mean follow-up was 4.4 years. Five-year results for the three groups based on their risk of positive LN were significantly different in terms of biochemical failure (p < 0.001), clinical control (p < 0.001), disease-free survival excluding biochemical failure (p < 0.001), cause-specific survival (p < 0.001), and overall survival (p < 0.001). For all patients with a risk of positive LN >15% (n = 596), Group II (>15-30% risk), or Group III (>30% risk), no benefit was seen in the 5-year rates of clinical failure, cause-specific survival, or overall survival with pelvic radiation. In the Cox multivariate analysis for cause-specific survival, Gleason score (p = 0.009, hazard ratio [HR] 3.1), T stage (p = 0.03, HR 1.8), and year of treatment (p = 0.05, HR 1.1) were significant. A log-rank test for cause-specific survival for all patients (n = 577) by the use of pelvic radiation was not significant (p = 0.99) accounting for high-dose-rate brachytherapy dose, neoadjuvant hormones, Gleason score, prostate-specific antigen, T stage, and year of treatment as covariates.

CONCLUSIONS

The use of the Roach formula to stratify patients for clinical and biochemical outcomes is excellent. Pelvic radiation added to high prostate radiation doses did not show a clinical benefit for patients at a high risk of pelvic LN disease (>15%) selected using the Roach formula.

Comparison of external radiation therapy vs radical prostatectomy in lymph node positive prostate cancer patients

INTRODUCTION

Treatment options for lymph node positive prostate cancer are limited. We retrospectively compared patients who underwent external radiotherapy (ERT) to patients treated by radical prostatectomy (RPX).

MATERIALS AND METHODS

A total of 102 lymph node positive patients from the RPX series at Ulm University were evaluated. In all, 76 patients received adjuvant androgen withdrawal as part of their primary treatment. In the ERT group, 44 patients were treated at the University of Michigan using a fractionated regimen. Of these, 21 patients received early adjuvant hormonal therapy. Patients with neoadjuvant therapy before RPX or ERT were excluded.

RESULTS

In the RPX group, PSA nadir (nadir < or = 0.2 vs > 0.2 ng/ml) showed a strong association with outcome. In the ERT group, pretreatment PSA was an independent predictor of outcome (P = 0.04) and patients with adjuvant hormonal therapy had a significant longer recurrence-free interval compared to patients without adjuvant therapy (P = 0.004). Comparing only patients with adjuvant hormonal treatment after cancer-specific therapy, the ERT-treated patients had a borderline longer PSA recurrence-free survival time compared to the RPX-treated patients (P = 0.05).

CONCLUSIONS

In case of positive lymph nodes, RPX and ERT might be considered and need to be explained to the patient. For future treatment decisions, the presented findings and a potential survival benefit need to be evaluated in a larger prospective setting.

Phase III trial comparing whole-pelvic versus prostate-only radiotherapy and neoadjuvant versus adjuvant combined androgen suppression: Radiation Therapy Oncology Group 9413

PURPOSE

This trial tested the hypothesis that combined androgen suppression (CAS) and whole-pelvic (WP) radiotherapy (RT) followed by a boost to the prostate improves progression-free survival (PFS) by 10% compared with CAS and prostate-only (PO) RT. This trial also tested the hypothesis that neoadjuvant and concurrent hormonal therapy (NCHT) improves PFS compared with adjuvant hormonal therapy (AHT) by 10%.

MATERIALS AND METHODS

Eligibility included localized prostate cancer with an elevated prostate-specific antigen (PSA) < or = 100 ng/mL and an estimated risk of lymph node (LN) involvement of 15%. Between April 1, 1995, and June 1, 1999, 1,323 patients were accrued. Patients were randomly assigned to WP + NCHT, PO + NCHT, WP + AHT, or PO + AHT. Failure for PFS was defined as the first occurrence of local, regional, or distant disease; PSA failure; or death for any cause.

RESULTS

With a median follow-up of 59.5 months, WP RT was associated with a 4-year PFS of 54% compared with 47% in patients treated with PO RT (P =.022). Patients treated with NCHT experienced a 4-year PFS of 52% versus 49% for AHT (P =.56). When comparing all four arms, there was a progression-free difference among WP RT + NCHT, PO RT + NCHT, WP RT + AHT, and PO RT + AHT (60% v 44% v 49% v 50%, respectively; P =.008). No survival advantage has yet been seen.

CONCLUSION

WP RT + NCHT improves PFS compared with PO RT and NCHT or PO RT and AHT, and compared with WP RT + AHT in patients with a risk of LN involvement of 15%.

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.

Influence of 3D-CRT pelvic irradiation on outcome in prostate cancer treated with external beam radiotherapy

PURPOSE

The role of pelvic irradiation (PRT) in the treatment of prostate cancer remains unclear. We reviewed our institution's experience with three-dimensional conformal external beam radiotherapy (3D-CRT) during the prostate-specific antigen era to determine the influence of PRT on the risk of biochemical recurrence in patients who have a predicted risk of lymph node involvement.

METHODS AND MATERIALS

Between March 1985 and January 2001, 1832 patients with clinically localized prostate cancer were treated with definitive 3D-CRT. All treatments involved CT planning to ensure coverage of the intended targets. Treatment consisted of prostate-only treatment, prostate and seminal vesicle treatment, or PRT of lymph nodes at risk followed by a boost. To create relatively homogenous analysis groups, each patient's percentage of risk of lymph node (%rLN) involvement was assigned by matching the patient's T stage, Gleason score, and initial prostate-specific antigen level to the appropriate value as described in the updated Partin tables. Three categories of %rLN involvement were defined: low, 0-5%; intermediate, >5-15%; and high, >15%. Biochemical recurrence was defined as the first occurrence of either the American Society for Therapeutic Radiology and Oncology consensus definition of prostate-specific antigen failure or the initiation of salvage hormonal therapy for any reason.

RESULTS

The risk status (%rLN) could be determined for 709 low-risk, 263 intermediate-risk, and 309 high-risk patients. The actuarial freedom from biochemical recurrence (bNED) and the log-rank test for the similarity of the control and treatment survival functions are reported for each risk group. Multivariate analysis demonstrated a statistically significant benefit for the entire population treated with PRT, with a relative risk reduction of 0.72 (95% confidence interval 0.54-0.97). Although the multivariate analysis could not determine the patient population that would most benefit from PRT, the beneficial effect appeared to be most pronounced within the intermediate-risk group. Univariate analysis revealed that the intermediate-risk patients treated with PRT had an improved 2-year bNED rate, 90.1% vs. 80.6% (p = 0.02), and both low-risk and high-risk patients treated with PRT had statistically similar 2-year bNED rates compared with those who did not receive it.

CONCLUSION

Pelvic 3D-CRT appears to improve bNED in prostate cancer patients. Additional studies are needed to elucidate the %rLN population for which this treatment should be recommended.

Practice patterns for prostate cancer in nine central and northern Italy radiation oncology centers: a survey including 1759 patients treated during two decades (1980-1998)

PURPOSE

Prostate cancer patients in Italy are offered the choice of the full spectrum of possible treatment options for their disease, but the diffusion of the more recent technological refinements among the Radiation Oncology centers is not homogeneous and there is a need to establish a reference "historical" data source. This retrospective study describes the changing patterns in prostate cancer patient practice and the therapeutic results obtained in nine Radiation Oncology centers of Northern and Central Italy (five in Northern Italy and four in Central Italy).

METHODS AND MATERIALS

A total of 1759 prostate cancer patients, radically treated in the nine radiotherapy (RT) centers between 1980 and 1998, made up the study population. Data collected for each patient included clinical, pathologic, therapeutic features, and toxicity. The overall survival, disease-specific survival (DSS), and clinical relapse-free survival (RFS) were calculated for the whole series and for the subsets of patients defined by different clinical, pathologic, and therapeutic features, according to three accrual periods (A, 1980-1990; B, 1991-1994; and C, 1995-1998). Univariate and multivariate analyses were performed to identify prognostic factors related to survival and late adverse effects (cystitis and proctitis) probability.

RESULTS

Patient accrual increased markedly during the 2 decades considered, and the percentage of cases with Stage C or D disease dropped from 49% (period A) to 43% (period B) to 37% (period C) (p < 0.0001, chi-square). The baseline prostate-specific antigen value was available for 10%, 76%, and 95% of the cases treated in the three different periods. The major changes in the therapeutic options were an increase in dose to the prostate (>66 Gy in 44%, 84%, and 93% of the patients treated in period A, B, and C, respectively); a reduction in treated volumes, including pelvic lymphatic drainage (56-39% before 1995, 22% thereafter); and an increase in cases treated in association with hormonal therapy (50% before 1991, 80% thereafter). Lower energy (<10 MV) photon beams were progressively abandoned (12% before 1990 vs. 6-7% thereafter), along with an increase in the use of blocks (60% in the last 4 years of the study vs. about 30-40% before 1995) and "conformal" RT (applied in 41% of cases treated after 1994). The actuarial RFS, DSS, and overall survival rate at 5 years was, respectively, 60% +/- 2%, 75% +/- 2%, 66% +/- 2% for period A; 74% +/- 2%, 90% +/- 1%, 83% +/- 2%, for period B; and 67% +/- 5%, 90% +/- 2%, 79% +/- 5% for period C. The actuarial overall survival, DSS, and RFS rate for the whole series of 1759 patients was 77% +/- 1%, 86% +/- 1%, and 68% +/- 1% at 5 years, respectively. Multivariate analysis showed that only American Urologic Association stage, grade, dose to the prostate, accrual period, association with hormonal treatment after (or both after and before) RT (only in terms of DSS and RFS), and baseline prostate-specific antigen value (only for RFS) retained prognostic significance in the final Cox model.

CONCLUSION

The increase in the accrual of prostate cancer patients radically treated with RT has been accompanied by considerable changes in the clinical features at presentation, as well as in the staging and treatment procedures. Patients treated more recently had better survival results. An earlier stage and more favorable grade were linked with better overall, DSS, and RFS at multivariate analysis. Lower prostate-specific antigen baseline values were also related to better RFS. Better results were obtained with higher radiation doses, and the dose to tumor seemed the most important treatment-related prognostic factor. The toxicity (cystitis and proctitis, every Radiation Therapy Oncology Group grade) was substantially the same in the different accrual periods, but larger treated volumes and higher doses appeared to increase the incidence of late effects.

Sexual (dys)function after radiotherapy for prostate cancer: a review

PURPOSE

Prostate cancer has become the most common nonskin malignant neoplasm in older men in Western countries. As treatment efficacy has improved, issues related to posttherapy quality of life and sexual functioning have become more important.

METHODS AND MATERIALS

We discuss the various methods used to evaluate erectile and sexual dysfunction and the definition of potency. The etiologies of erectile dysfunction after external beam radiotherapy and brachytherapy for prostate cancer are also reviewed. The literature is summarized, and comparative studies of radiation and surgery are surveyed briefly.

RESULTS

Rates of erectile dysfunction vary from 6 to 84% after external beam radiotherapy and from 0 to 51% after brachytherapy. In most of the studies, the analysis is retrospective, the definition of erectile dysfunction is not clear, only one question about sexual functioning is asked, and nonvalidated instruments are used. The etiology of erectile dysfunction after radiation for prostate cancer is not completely understood.

CONCLUSIONS

Because erectile function is only one component of sexual function, it is necessary to assess sexual desire, satisfaction, frequency of intercourse, and other such factors when evaluating the effects of therapy. Patients should be offered sexual counseling and informed about the availability of effective treatments for erectile dysfunction, such as sildenafil, intracavernosal injection, and vacuum devices.

Reduction of small and large bowel irradiation using an optimized intensity-modulated pelvic radiotherapy technique in patients with prostate cancer

PURPOSE

To investigate the role of intensity-modulated radiation therapy (IMRT) to irradiate the prostate gland and pelvic lymph nodes while sparing critical pelvic organs, and to optimize the number of beams required.

METHODS AND MATERIALS

Target, small bowel, colon, rectum, and bladder were outlined on CT planning scans of 10 men with prostate cancer. Optimized conventional (RT) and 3-dimensional conformal radiotherapy (3D-CRT) plans were created and compared to inverse-planned IMRT dose distributions using dose-volume histograms. Optimization of beam number was undertaken for the IMRT plans.

RESULTS

With RT the mean percentage volume of small bowel and colon receiving >45 Gy was 21.4 +/- 5.4%. For 3D-CRT it was 18.3 +/- 7.7% (p = 0.0043) and for 9-field IMRT it was 5.3 +/- 1.8% (p < 0.001 compared to 3D-CRT). For 7, 5, and 3 IMRT fields, it was 6.4 +/- 2.9%, 7.2 +/- 2.8%, and 8.4 +/- 3.8% (all p < 0.001 compared to 3D-CRT). The rectal volume irradiated >45 Gy was reduced from 50.5 +/- 16.3% (3D-CRT) to 5.8 +/- 2.1% by 9-field IMRT (p < 0. 001) and bladder from 52.2 +/- 12.8% to 7 +/- 2.8% (p < 0.001). Similar benefits were maintained for 7, 5, and 3 IMRT fields.

CONCLUSIONS

The reduction in critical pelvic organ irradiation seen with IMRT may reduce side effects in patients, and allow modest dose escalation within acceptable complication rates. These reductions were maintained with 3-5 IMRT field plans which potentially allow less complex delivery techniques and shorter delivery times.

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.

Survival advantage from higher-dose radiation therapy for clinically localized prostate cancer treated on the Radiation Therapy Oncology Group trials

PURPOSE

We evaluated the effect of external-beam radiation therapy on disease-specific survival (death from causes related to prostate cancer) and overall survival in men with clinically localized prostate cancer.

METHODS

From 1975 to 1992, 1,465 men with clinically localized prostate cancer received radiation therapy on four Radiation Therapy Oncology Group phase III randomized trials and were pooled for this analysis. No one received androgen-deprivation therapy with his initial treatment. All original histology had central pathologic review for grading using the Gleason classification system. Total delivered radiation dose ranged from 60 to 78 Gy (median, 68.4 Gy). The median follow-up time was 8 years.

RESULTS

A Cox regression model revealed that Gleason score was an independent predictor of disease-specific survival and overall survival. The 10-year disease-specific survival rates by Gleason score were as follows: score of 2 through 5, 85%; score of 6, 79%; score of 7, 62%; and score of 8 through 10, 43%. Stratifying outcome by this important prognostic factor revealed that higher radiation dose was a significant predictor for improved disease-specific survival and overall survival only for those patients whose cancers had Gleason scores of 8 through 10 (P <.05). After adjusting for clinical T stage, nodal status, and age, treating with a higher radiation dose was associated with a 29% lower relative risk of death from prostate cancer and 27% reduced mortality rate (P <.05).

CONCLUSION

These data demonstrate that higher-dose radiation therapy can significantly reduce the risk of dying from prostate cancer in men with clinically localized disease. This survival benefit is restricted to men with poorly differentiated cancers.

Predicting long-term survival, and the need for hormonal therapy: a meta-analysis of RTOG prostate cancer trials

PURPOSE

To assess the impact of short-term and long-term androgen suppression on the disease-specific and overall survival of 2200 men treated with radiotherapy on one of 5 prospective randomized trials when stratified by prognostic risk groups.

METHODS AND MATERIALS

Between 1975 and 1992, 2742 men were treated for clinically localized prostate cancer on one of 5 consecutive prospective Phase III randomized trials. Patients were selected for this analysis if they were deemed evaluable and eligible for the trial, and if follow-up information was available. For this analysis patients were stratified into four previously described prognostic risk groups: Group 1 patients had a Gleason score (GS) = 2-6, and T1-2Nx; Group 2: GS = 2-6, T3Nx; or GS = 2-6, N+, or GS = 7, T1-2Nx; Group 3: T3Nx, GS = 7; or N+, GS = 7, or T1-2Nx, GS = 8-10; and Group 4 patients were T3Nx, GS = 8-10, or N+, GS = 8-10. The median pretreatment prostate-specific antigen (PSA) was 25 ng/ml for the 434 evaluable patients for whom this information was available. The median follow-up times for patients treated on early studies exceeded 11 years, and for more recent studies 6 years.

RESULTS

Risk group 2 patients with "bulky" or T3 disease appeared to have a disease-specific survival benefit at 8 years with the addition of 4 months of goserelin and flutamide. Group 3 and 4 patients were noted to have an approximately 20% higher survival at 8 years with the addition of long-term hormonal therapy (p < or =0.0004).

CONCLUSIONS

Based on this meta-analysis of RTOG trials, subsets of patients can be identified who either do not appear to benefit from the use of hormonal therapy, benefit from short-term hormonal therapy, or who benefit only from long-term hormonal therapy. These observations should be confirmed by prospective randomized trials before they can be considered conclusive. In the meantime, however, these observations provide rational guidelines for deciding who should receive hormonal therapy and for how long.

Curative external beam radiotherapy for prostate carcinoma: results in 231 patients treated in Lyon

BACKGROUND

Radical prostatectomy and external beam radiation therapy (EBRT) are the mainstays of treatment of prostate cancer with curative intent. The possible development of radiation proctitis and rectal bleeding are major concerns when using EBRT. Recently, conformal radiotherapy has been introduced in an attempt to improve the results of EBRT. This paper presents an overview of the Lyon experience using standard EBRT with doses of 68 Gy, and reports the preliminary results of a study of conformal radiotherapy with dose escalation.

METHODS

From 1981 to 1995, EBRT was used to treat 231 patients with localized adenocarcinomas of the prostate. The dose of EBRT was 68 Gy/34 fractions/7 weeks using a four-field box technique with 18-MeV photons. A feasibility study of conformal radiotherapy was commenced in 1996. To date, 145 patients have been treated with doses escalating from 68 to 80 Gy.

RESULTS

In the EBRT group of 231 patients, the 5-year overall survival was 80.3%. Anorectal function was scored as excellent in 90% of patients. Rectal bleeding was seen in 14.3% of patients and required local treatment in only seven. In the group treated with conformal radiotherapy, the preliminary results indicate good early tolerance.

CONCLUSION

The curative treatment of patients with prostate cancer using EBRT gives good long-term survival with low rectal toxicity. Conformal radiotherapy appears to be an interesting approach to improve local control and perhaps survival.

Cost-benefit analysis of 3D conformal radiation therapy--treatment of prostate cancer as a model

Three-dimensional conformal radiation therapy (3D-CRT) is a promising new treatment technique based on the principle that improved precision in both tumor definition and dose delivery will enhance outcomes by maximizing dose to the tumor area while minimizing dose to normal tissue. Using a cost-benefit analysis, in terms of outcomes, we first examined the overall risks and benefits of 3D-CRT. We then used the treatment of prostate cancer as a model to compare actual clinical outcomes reported between 3D-CRT and standard radiation therapy (SRT). Our analysis shows that application of 3D-CRT to the clinical setting remains difficult because of the continual difficulties of target definition, and that dose escalation cannot yet be justified on the basis of the lack of benefit found, and suggested increased late toxicity, in most of the dose escalation series compared with SRT.

Long term tolerance of high dose three-dimensional conformal radiotherapy in patients with localized prostate carcinoma

BACKGROUND

The current study was undertaken to evaluate the incidence and predictors of late toxicity in patients with localized prostate carcinoma treated with high dose three-dimensional conformal radiotherapy (3D-CRT).

METHODS

A total of 743 patients with prostate carcinoma classified as T1c-T3 were treated with 3D-CRT that targeted the prostate and seminal vesicles. A minimum tumor dose of 64.8 gray (Gy) was given to 96 patients (13%), 70.2 Gy to 266 patients (365), 75.6 Gy to 320 patients (43%), and 81.0 Gy to 61 patients (8%). The median follow-up time was 42 months (range, 18-109 months). Late toxicity was graded according to the Radiation Therapy Oncology Group morbidity scoring scale.

RESULTS

Late gastrointestinal (GI) and urinary (GU) toxicities were absent or minimal (Grade 0 or 1) in 90% of patients. The 5-year actuarial likelihood of the development of Grade 2 and 3 late GI toxicities was 11% and 0.75%, respectively. A multivariate analysis identified doses > or =75.6 Gy (P<0.001), history of diabetes mellitus (P = 0.01), and the presence of acute GI symptoms during treatment (P = 0.02) as independent predictors of Grade > or =2 late GI toxicity. The 5-year actuarial likelihood of the development of Grade 2 and 3 late GU toxicities was 10% and 3%, respectively. Doses > or =75.6 Gy (P = 0.008) and acute GU symptoms (P<0.001) were independent predictors of Grade > or =2 late GU toxicity. Among 544 patients who were potent before treatment (73% of all patients), 211 (39%) became impotent after 3D-CRT. The 5-year actuarial risk of potency loss was 60%. Doses > or =75.6 Gy (P<0.001) and the use of neoadjuvant androgen deprivation (P = 0.01) were independent predictors of posttreatment erectile dysfunction.

CONCLUSIONS

The incidence of severe late complications after high dose 3D-CRT was minimal. Radiation doses > or =75.6 Gy and the presence of acute treatment-related symptoms during 3D-CRT correlated with a higher incidence of Grade > or =2 late GI and GU toxicities. In addition to higher doses, the use of androgen deprivation therapy increased the likelihood of permanent impotence in these patients. Intensity-modulated radiotherapy, which makes it possible to enhance the conformality of the dose distribution, has recently been implemented in an attempt to reduce the incidence of moderate grade toxicities in patients receiving high dose 3D-CRT.

Efficacy of oral sildenafil in patients with erectile dysfunction after radiotherapy for carcinoma of the prostate

OBJECTIVES

To determine the efficacy of sildenafil for patients with erectile dysfunction after radiotherapy for localized prostate cancer.

METHODS

Fifty patients with erectile dysfunction after radiotherapy were treated with sildenafil. Their median age was 68 years (range 54 to 78). All were treated with a three-dimensional conformal external beam radiotherapy approach, and the median dose prescribed to the planning target volume was 75.6 Gy. Patients were initially given 50 mg of sildenafil and instructed to use the medication on at least three occasions. They were then contacted to ascertain the efficacy of and tolerance to the medication.

RESULTS

Significant improvement in the firmness of the erection after sildenafil was reported in 37 patients (74%), 2 (4%) had partial improvement, and 11 (22%) had no response. Significant improvement in the durability of the erection was reported in 33 patients (66%), 3 (6%) had partial improvement, and 14 (28%) reported no improvement. Patients with partial or moderate erectile function before using sildenafil were more likely to benefit from the medication compared with those with absent function. Among 29 patients with erections classified as partial after radiotherapy, 26 (90%) had a significant response to the medication. In contrast, only 11 (52%) of 21 with erections classified as flaccid after radiotherapy had a significant response to the medication (P = 0.007).

CONCLUSIONS

Sildenafil improved erectile function in greater than two thirds of patients with postradiotherapy impotence. Patients with less severe dysfunction are most likely to benefit from this intervention.

Long-term survival after radiotherapy alone: radiation therapy oncology group prostate cancer trials

PURPOSE

We assess the relative importance of the several pretreatment characteristics in predicting death from prostate cancer in patients treated with curative intent with external beam radiotherapy alone.

MATERIALS AND METHODS

Patients entered on 4 prospective phase III randomized trials conducted by the Radiation Therapy Oncology Group between 1975 and 1992 were selected for this analysis if they were deemed evaluable and eligible for the trial, they had received no hormonal therapy with initial treatment and followup information was available. A disease specific survival event was declared if death was certified as due to prostate cancer, complications of treatment or unknown causes with clinically active malignancy. Median followup for patients treated on early and late studies exceeded 11 and 6 years, respectively.

RESULTS

Most of the patients (1,557) had tumors clinically staged as T3 (59%), and 87 (36%) with clinically staged T1-2 tumors had pathologically positive lymph nodes. On multivariate analysis Gleason score, clinical stage and nodal status were associated with a less favorable overall and disease specific survival, whereas others factors, such as age and race, were not. A Gleason score of 8 to 10 was associated with a high risk of dying of prostate cancer in the first 5 years (risk ratio 20.0, p = 0.0001). The 10-year disease specific survival for patients with a Gleason score of 2 to 5, 6 to 7 and 8 to 10 was 87, 75 and 44%, respectively, following radiotherapy. Based on published reports these rates were higher than expected with observation alone.

CONCLUSIONS

In the first 10 years Gleason score was the single most important predictor of death. Gleason score should be incorporated into the current clinical staging system.

Pion conformal radiation of prostate cancer: results of a randomized study

PURPOSE

To compare the efficacy of pion radiation therapy with conventional external beam photon therapy, for the treatment of locally advanced stage T3/4, N0, M0 adenocarcinoma of the prostate.

METHODS AND MATERIALS

Two hundred seventeen eligible patients were randomly allocated to either photon or pion therapy. No adjuvant hormone therapy was used.

RESULTS

Median follow-up was 42 months (range 2-90). Acute bladder toxicity was worse in the pion arm, p = 0.2, but other acute toxicity did not differ. Late grade 2 toxicity was significantly less in the pion arm (29% at 5 years versus 48%, p = 0.002), but late grade 3 or 4 toxicity did not differ. Clinical local control was not significantly different between treatment arms (64% after 5 years with photons, 56% with pions, p = 0.6). Cause-specific and overall survival also did not differ (p = 0.7). There was a significant delay in time to first failure in the photon arm, largely as a result of decreased biochemical relapse, p = 0.01. A multivariate analysis is presented.

CONCLUSION

Pion therapy was well tolerated, with increased acute toxicity and significantly decreased late tissue injury. This contrasts with the late toxicity observed with higher LET particle therapy such as neutron therapy. No improvement in local control with pion therapy was observed.

Improved freedom from PSA failure with whole pelvic irradiation for high-risk prostate cancer

PURPOSE

To determine the impact of whole pelvic irradiation on the risk of PSA failure in prostate cancer patients, at high predicted risk for lymph node involvement, receiving definitive radiotherapy.

MATERIALS AND METHODS

Between October 1987 and December 1995, 506 patients with clinically localized prostate cancer were treated with definitive radiotherapy at UCSF and affiliated institutions. Treatment consisted of 4-field whole pelvic irradiation followed by a prostate-only boost, or prostate-only treatment (median follow-up was 35 months and 30 months, respectively). PSA failure was defined as: 1. a PSA value > or = 1 ng/ml; or 2. a PSA value that rose > or = 0.5 ng/ml in < or = 1 year posttreatment on two consecutive measurements, with the first rise defined as the time of failure. The calculated risk of lymph node positivity (%rLN+) was defined as 2/3(iPSA) + 10(GS-6), and high risk was defined as %rLN+ > or = 15%. Univariate and multivariate analyses were performed.

RESULTS

A total of 201 high-risk patients were identified. High-risk patients who received whole pelvic irradiation had significantly improved freedom from PSA failure compared to those who received prostate-only treatment (median PFS = 34.3 months vs. 21.0 months; p = 0.0001). Potential confounding variables, including initial PSA, Gleason score, T stage, radiation dose, year of treatment, use of three-dimensional (3D) conformal techniques, and use of hormone therapy, did not account for the observed difference in time to PSA failure. Multivariate analysis revealed type of radiation treatment to be the most significant independent predictor of outcome.

CONCLUSION

Whole pelvic radiotherapy significantly improves the PSA failure-free survival in patients with a high calculated risk of lymph node positivity.

The Role of Radiotherapy in the Treatment of Carcinoma of the Prostate: A Survey of Clinical Practices in Lombardy, Italy, by the Airo-Lombardia Cooperative Group

Aims and background

We report the results of a survey performed in 1994 by the AIRO-Lombardia Cooperative Group, on the clinical patterns of radiation treatment for prostatic carcinoma in Lombardy, Italy, involving all radiotherapy centers serving an overall local population of about 8,800,000 people.

Methods

A questionnaire was sent to all 13 radiotherapy centers throughout Lombardy, asking for demographic and treatment details concerning the local population of patients with a localized (T1-4, N0-1, M0) carcinoma of the prostate treated with radiotherapy; 12 centers responded, making the basis for the present report.

Results

Analysis of collected data showed that in Lombardy: a) approximately 400 patients per year are irradiated for a localized carcinoma of the prostate, accounting for less than 30% of the total expected number of patients with this disease presentation; b) a complete staging (with PSA, transrectal ultrasonography, abdomino-pelvic CT or MRI scan and total-body bone scan) is performed in over 95% of patients before initiating radiotherapy; c) significant differences exist between radiotherapy centers as regards treatment planning and delivery.

Conclusions

An urgent need exists for implementing procedures aimed at standardizing radiotherapy procedures within Lombardy.