Indications for excluding the seminal vesicles when treating clinically localized prostatic adenocarcinoma with radiotherapy alone

Development and Validation of a Genomic Tool to Predict Seminal Vesicle Invasion in Adenocarcinoma of the Prostate

PURPOSE

Pretreatment estimates of seminal vesicle invasion (SVI) are challenging and significantly influence the management of prostate cancer. We sought to improve current models to predict SVI through the development of an SVI prediction genomic signature.

PATIENTS AND METHODS

A total of 15,889 patients who underwent radical prostatectomy (RP) with available baseline clinical, pathology, and transcriptome data were retrieved from the GRID registry (ClinicalTrials.gov identifier: NCT02609269) and other retrospective cohorts. These data were divided into a training (n = 6,766), test (n = 3,363), and two validation (n = 5,062 and 698) cohorts. Multivariable logistic regression was performed to assess the predictive effect of the genomic SVI (gSVI) classifier in the presence of established nomograms (Partin Tables and Memorial Sloan Kettering Cancer Center [MSKCC]).

RESULTS

In the training cohort, univariable filtering identified 2,132 genes that were differentially expressed between RP tumors with and without SVI. Model parameters were tuned to maximize the area under the curve (AUC) in the testing cohort, resulting in a logistic generalized linear model with 581 genes. The gSVI model scores range from 0 to 1. In the first validation set, gSVI showed superior discrimination of patients with and without SVI at RP compared with other prognostic signatures trained to predict distant metastasis or clinical recurrence. Of the 698 patients in the second validation set, gSVI combined with the MSKCC nomogram had a superior AUC (0.86) compared with either nomogram individually (0.81).

CONCLUSION

The gSVI represents a novel and validated expression signature to predict the presence of SVI before treatment with surgery. This genomic tool adds discriminatory power to existing clinical predictive nomograms and may help with pretreatment counseling and decision making.

Single Course IMRT Plan to Deliver 45 Gy to Seminal Vesicles and 81 Gy to Prostate in 45 Fractions

We treat prostate and seminal vesicles (SV) to 45 Gy in 25 fractions (course 1) and boost prostate to 81 Gy in 20 more fractions (course 2) with Intensity Modulated Radiation Therapy (IMRT). This two-course IMRT with 45 fractions delivered a non-uniform dose to SV and required two plans and two QA procedures. We used Linear Quadratic (LQ) model to develop a single course IMRT plan to treat SV to a uniform dose, which has the same biological effective dose (BED) as that of 45 Gy in 25 fractions and prostate to 81 Gy, in 45 fractions. Single course IMRT plans were compared with two-course IMRT plans, retrospectively for 14 patients. With two-course IMRT, prescription to prostate and SV was 45 Gy in 25 fractions and to prostate only was 36 Gy in 20 fractions, at 1.8 Gy/fraction. With 45-fraction single course IMRT plan, prescription to prostate was 81 Gy and to SV was 52 or 56 Gy for a α/β of 1 and 3, respectively. 52 Gy delivered in 45 fractions has the same BED of 72 Gy3 as that of delivering 45 Gy in 25 fractions, and is called Matched Effective Dose (MED). LQ model was used to calculate the BED and MED to SV for α/β values of 1–10. Comparison between two-course and single course IMRT plans was in terms of MUs, dose-max, and dose volume constraints (DVC). DVC were: 95% PTV to be covered by at least 95% of prescription dose; and 70, 50, and 30% of bladder and rectum should not receive more than 40, 60, and 70% of 81 Gy. SV Volumes ranged from 2.9–30 cc. With two-course IMRT plans, mean dose to SV was non-uniform and varied between patients by 48% (54 to 80 Gy). With single-course IMRT plan, mean dose to SV was more uniform and varied between patients by only 9.6% (58.2 to 63.8 Gy), to deliver MED of 56 Gy for α/β − 1. Single course IMRT plan MUs were slightly larger than those for two-course IMRT plans, but within the range seen for two-course plans (549–959 MUs, n=51). Dose max for single-course plans were similar to two-course plans. Doses to PTV, rectum and bladder with single course plans were as per DVC and comparable to two-course plans. Single course IMRT plan reduces IMRT planning and QA time to half.

Optimal contouring of seminal vesicle for definitive radiotherapy of localized prostate cancer: comparison between EORTC prostate cancer radiotherapy guideline, RTOG0815 protocol and actual anatomy

Background

Intermediate- to-high-risk prostate cancer can locally invade seminal vesicle (SV). It is recommended that anatomic proximal 1-cm to 2-cm SV be included in the clinical target volume (CTV) for definitive radiotherapy based on pathology studies. However, it remains unclear whether the pathology indicated SV extent is included into the CTV defined by current guidelines. The purpose of this study is to compare the volume of proximal SV included in CTV defined by EORTC prostate cancer radiotherapy guideline and RTOG0815 protocol with the actual anatomic volume.

Methods

Radiotherapy planning CT images from 114 patients with intermediate- (36.8%) or high-risk (63.2%) prostate cancer were reconstructed with 1-mm-thick sections. The starting and ending points of SV and the cross sections of SV at 1-cm and 2-cm from the starting point were determined using 3D-view. Maximum (D_1H, D_2H) and minimum (D_1L, D_2L) vertical distance from these cross sections to the starting point were measured. Then, CTV of proximal SV defined by actual anatomy, EORTC guideline and RTOG0815 protocol were contoured and compared (paired t test).

Results

Median length of D_1H, D_1L, D_2H and D_2L was 10.8 mm, 2.1 mm, 17.6 mm and 8.8 mm (95th percentile: 13.5mm, 5.0mm, 21.5mm and 13.5mm, respectively). For intermediate-risk patients, the proximal 1-cm SV CTV defined by EORTC guideline and RTOG0815 protocol inadequately included the anatomic proximal 1-cm SV in 62.3% (71/114) and 71.0% (81/114) cases, respectively. While for high-risk patients, the proximal 2-cm SV CTV defined by EORTC guideline inadequately included the anatomic proximal 2-cm SV in 17.5% (20/114) cases.

Conclusions

SV involvement indicated by pathology studies was not completely included in the CTV defined by current guidelines. Delineation of proximal 1.4 cm and 2.2 cm SV in axial plane may be adequate to include the anatomic proximal 1-cm and 2-cm SV. However, part of SV may be over-contoured.

Impact of primary Gleason grade on risk stratification for Gleason score 7 prostate cancers

PURPOSE

To evaluate the primary Gleason grade (GG) in Gleason score (GS) 7 prostate cancers for risk of non-organ-confined disease with the goal of optimizing radiotherapy treatment option counseling.

METHODS

One thousand three hundred thirty-three patients with pathologic GS7 were identified in the Duke Prostate Center research database. Clinical factors including age, race, clinical stage, prostate-specific antigen at diagnosis, and pathologic stage were obtained. Data were stratified by prostate-specific antigen and clinical stage at diagnosis into adapted D'Amico risk groups. Univariate and multivariate analyses were performed evaluating for association of primary GG with pathologic outcome.

RESULTS

Nine hundred seventy-nine patients had primary GG3 and 354 had GG4. On univariate analyses, GG4 was associated with an increased risk of non-organ-confined disease. On multivariate analysis, GG4 was independently associated with seminal vesicle invasion (SVI) but not extracapsular extension. Patients with otherwise low-risk disease and primary GG3 had a very low risk of SVI (4%).

CONCLUSIONS

Primary GG4 in GS7 cancers is associated with increased risk of SVI compared with primary GG3. Otherwise low-risk patients with GS 3+4 have a very low risk of SVI and may be candidates for prostate-only radiotherapy modalities.

The triple clinicopathologic features to seminal vesicle-sparing radical prostatectomy

BACKGROUND AND PURPOSE

With the widespread early detection programs for prostate cancer, there has been a downward stage migration and a marked decrease in the percentage of men with seminal vesicle invasion (SVI) compared with previous data. We evaluated clinicopathologic findings that are associated with SVI to select patients for potential seminal vesicle-sparing surgery.

PATIENTS AND METHODS

We reviewed our radical prostatectomy database from 1997 to 2006 to evaluate the incidence and clinical correlates of SVI. Variables analyzed included serum prostate-specific antigen (PSA) level, clinical stage, percentage of positive cores with cancer, Gleason score on biopsy, age, prostate weight, and urethral and vesical surgical margins. Statistical analysis included univariate and multivariate logistic regressions.

RESULTS

Of 267 patients, 32 (12%) had SVI. Preoperative PSA level, biopsy Gleason score, and percentage of positive cores were highly predictive of SVI on multivariate analysis. SVI was present in only 1/98 patients (1.02 %) with biopsy Gleason score ≤6, 0/23 patients (0%) with serum PSA level <4 ng/mL, and only 1 patient with ≤12.8% of positive cores on biopsy. In all cases of distal SVI, there was proximal involvement.

CONCLUSION

Serum PSA level, Gleason score, and percentage of positive cores on biopsy are statistically significant predictors of SVI on multivariate analysis. Seminal vesiculectomy does not benefit almost 99% of patients with biopsy Gleason score ≤6, PSA level <4 ng/mL, and with <12% cores with cancer. In cases of seminal vesicle-sparing surgery, frozen section of the proximal portion may be of adjunct usefulness for the triple.

Quantitative evaluation of cone-beam computed tomography in target volume definition for offline image-guided radiation therapy of prostate cancer

PURPOSE

To quantitatively evaluate cone-beam CT (CBCT) in target volume definition in an offline image guidance environment.

METHODS AND MATERIALS

Fifteen patients each with five helical CTs (HCT) and eight CBCTs were included. A single physician manually delineated prostate and seminal vesicles (SVs) on each CT. The clinical target volume (CTV) was prostate for low risk group (G1), plus SVs for intermediate risk group (G2). The internal target volumes (ITVs) on CBCT (ITV(CBCT)) were constructed and compared with ITV(HCT). The following comparisons were performed: CTV and ITV in HCT and CBCT; similarity of ITVs using overlap index (OI); surface differences between ITVs; quality assurance of ITV(CBCT) using CTV from weekly CBCT; and dosimetric evaluations of ITV(HCT) coverage on plans from ITV(CBCT).

RESULTS

There was no statistical significant difference of CTV or ITV. The ITV OIs were 91%/88% for G1/G2 patients. They improved significantly with 1-2mm margins. Therefore, the ITVs were mostly within 2mm. The CTVs from weekly CBCT had >95% overlap with ITV(CBCT). The ITV dose differences (D(95), and D(mean)) were <0.3%.

CONCLUSIONS

It is feasible to use CBCT for target definition in offline image guidance, thereby eliminating the separate helical CT scan process.

Is seminal vesiculectomy necessary in all patients with biopsy Gleason score 6?

BACKGROUND AND PURPOSE

Radiotherapists are excluding the seminal vesicles (SVs) from their target volume in cases of low-risk prostate cancer. However, these glands are routinely removed in every radical prostatectomy. Dissection of the SVs can damage the pelvic plexus, compromise trigonal, bladder neck, and cavernosal innervation, and contribute to delayed gain of continence and erectile function. In this study we evaluated the oncological benefit of routine removal of the SVs in currently operated patients.

MATERIALS AND METHODS

A total of 1003 patients (mean age, 59.7 years) with prostate cancer underwent robot-assisted radical prostatectomy between February 2003 and July 2007.

RESULTS

Seminal vesicle invasion (SVI) was found in 46 of the operated patients (4.6%). Biopsy Gleason score (BGS), preoperative serum PSA, clinical tumor stage, percent of positive cores, and maximal percentage of cancer in a core had all a significant impact on the risk of SVI. Only 4/634 patients (0.6%) with BGS < or =6 suffered from SVI, as opposed to 42/369 (11.4%) with higher Gleason scores.

CONCLUSIONS

Seminal vesiculectomy does not benefit more than 99% of the patients with BGS < or =6. Considering the potential neural and vascular damage associated with seminal vesiculectomy, we suggest that routine removal of these glands during radical prostatectomy in these cases is not necessary.

The fate of the seminal vesicle remnant after proximal transection or ligation: an animal model

PURPOSE

Dissection of the seminal vesicles during radical prostatectomy has the potential to damage the pelvic plexus, thus compromising trigonal, bladder neck and cavernous innervation, and contributing to delayed gain of continence and erectile function. The rate of prostate cancer invasion into the seminal vesicles in currently operated patients is low and in most it may be predicted preoperatively. This situation calls for seminal vesicle sparing radical prostatectomy in select patients, leaving a distal remnant of the seminal vesicles in place. We investigated the fate of the seminal vesicle remnant after proximal transection or ligation in an animal model.

MATERIALS AND METHODS

The right seminal vesicle in 36 anesthetized male rats was divided by suture ligation or by transection. The left seminal vesicle served as a control. Six rats per group were sacrificed 1, 2 and 4 weeks after division, respectively. Seminal vesicle morphology was evaluated macroscopically and microscopically.

RESULTS

All rats tolerated surgery well and gained weight postoperatively. Transected seminal vesicles were similar in weight and morphology to control contralateral glands. One week after seminal vesicle ligation the remnants became significantly heavier and showed balloon dilatation of the hollow spaces, while the lining epithelium became significantly flattened. Two and 4 weeks after ligation half of the animals showed gland shrinkage and half demonstrated persistent dilatation.

CONCLUSIONS

Seminal vesicle transection preserves the gland remnant in a relatively normal morphology, while ligation leads to severe and inconsistent morphological changes. When considering seminal vesicle sparing radical prostatectomy, seminal vesicle transection may be preferred to ligation.

Hypofractionated Intensity-Modulated Radiotherapy (70 Gy at 2.5 Gy Per Fraction) for Localized Prostate Cancer: Cleveland Clinic Experience

PURPOSE

To study the outcomes in patients treated for localized prostate cancer with 70 Gy delivered at 2.5-Gy/fraction within 5 weeks.

METHODS AND MATERIALS

The study sample included all 770 consecutive patients with localized prostate cancer treated with hypofractionated intensity-modulated radiotherapy at the Cleveland Clinic between 1998 and 2005. The median follow-up was 45 months (maximum, 86). Both the American Society for Therapeutic Radiology and Oncology (ASTRO) biochemical failure definition and the alternate nadir + 2 ng/mL definition were used.

RESULTS

The overall 5-year ASTRO biochemical relapse-free survival rate was 82% (95% confidence interval, 79-85%), and the 5-year nadir + 2 ng/mL rate was 83% (95% confidence interval, 79-86%). For patients with low-risk, intermediate-risk, and high-risk disease, the 5-year ASTRO rate was 95%, 85%, and 68%, respectively. The 5-year nadir + 2 ng/mL rate for patients with low-, intermediate-, and high-risk disease was 94%, 83%, and 72%, respectively. The Radiation Therapy Oncology Group acute rectal toxicity scores were 0 in 51%, 1 in 40%, and 2 in 9% of patients. The acute urinary toxicity scores were 0 in 33%, 1 in 48%, 2 in 18%, and 3 in 1% of patients. The late rectal toxicity scores were 0 in 89.6%, 1 in 5.9%, 2 in 3.1%, 3 in 1.3%, and 4 in 0.1% (1 patient). The late urinary toxicity scores were 0 in 90.5%, 1 in 4.3%, 2 in 5.1%, and 3 in 0.1% (1 patient).

CONCLUSION

The outcomes after high-dose hypofractionation were acceptable in the entire cohort of patients treated with the schedule of 70 at 2.5 Gy/fraction.

New implant technique for separation of the seminal vesicle and rectal mucosa for high-dose-rate prostate brachytherapy

PURPOSE

For safer treatment of seminal vesicles (SVs), we initiated a new technique using an anchor applicator for high-dose-rate interstitial brachytherapy (HDR-ISBT) of prostate cancer.

METHODS AND MATERIALS

Between January 2004 and March 2005, 23 intermediate- to high-risk patients were treated with HDR-ISBT as monotherapy. Transrectal ultrasonography guided implantation of the treatment applicator in and around the prostate gland and proximal SV. We used an "anchor" applicator to prevent posterior displacement of the SV. After insertion of the anchor applicator, the actual treatment applicator was implanted at the best position for optimal SV coverage. SV coverage was analyzed using a dose-volume histogram.

RESULTS

Implantation of the applicator on the posterior side of the SV was successful for 43 of 46 SVs (93%). The median percentage of the SVs receiving the prescribed dose was 41% (range 11-86%). Only one case of acute Grade 2 toxicity (3%) was seen.

CONCLUSIONS

Our anchor applicator technique for HDR-ISBT can separate the SV from the rectum. This is the first report of dose-volume histogram analysis of the SV for HDR-ISBT.

When should the seminal vesicles be included in the target volume in prostate radiotherapy?

External beam radiotherapy to the prostate and seminal vesicles as a radical treatment for prostate cancer can result in a significant dose being delivered to the rectum. This can be reduced if the target volume includes the prostate only. Using a Medline search, published studies are reviewed to show that the risk of seminal vesicle involvement can be accurately predicted using readily available pre-treatment parameters. We recommend when to exclude the seminal vesicles from a target volume, and the proportion of seminal vesicles that should be included in a target volume in higher risk patients.

Radiothérapie conformationnelle du cancer de la prostate : technique et résultats

A number of retrospective and prospective studies have demonstrated that radiotherapy of prostate cancer must be actually conformal. Three-dimensional (3D) treatment planning consists in an as accurate as possible definition of target-volume, usually by CT-scan, and design of radiation fields shaped to this target-volume. Several steps are required, each step being important for the overall quality of the treatment. Conformal radiotherapy is better tolerated than conventional irradiation, with significantly less rectal toxicity. It allows dose-escalation up to 80 Gy. It is now possible to go beyond this dose with intensity-modulated radiotherapy. The benefit of these high doses was demonstrated by some large retrospective studies and some prospective dose-escalation trials. Several randomized trials are in progress, preliminary results of two of them have been published, both showing an improvement in disease control with the higher doses. The advantage of higher doses is clearly evident for patients in the intermediate prognostic group, but is still discussed for patients with a low risk tumour or treated in combination with hormone therapy. Late proctitis is the main toxicity of these high doses. Some volume constraints have been defined during the last years and will allow a decrease of the rate of rectal toxicity. Because of these technological improvements, results of radiation therapy are now similar to those of surgery: no direct comparison with a randomized trial is available, but large comparative studies show that long-term disease control are identical with both techniques. Radiation therapy must be proposed to all patients with a prostate carcinoma as an alternative to surgery.

A comparison of three-field and four-field techniques in different clinical target volumes in prostate cancer irradiation using dose volume histograms: a prospective three-dimensional analysis

The purpose of the current study was to quantitatively assess differences between irradiation techniques on normal tissue exposure in different clinical target volumes (CTVs) in irradiation of prostate cancer. 14 patients with prostate cancer undergoing external beam radiotherapy were investigated. The prostate and prostate + proximal/entire seminal vesicles were delineated as CTVs. A three-field and two different four-field plans were generated and compared concerning rectum, bladder and femoral head dose-volume histograms (DVHs). The exposure of the rectum exposed to 40-60 Gy was significantly lower for all CTVs with the three-field technique compared with both four-field techniques. The exposure of the rectum to 70 Gy was significantly lower for all CTVs with the weighted four-field technique compared with the unweighted four-field and three-field techniques. The weighted four-field technique was worst in bladder dose sparing for the three CTVs. Comparing the three-field and the unweighted four-field technique for irradiation of the prostate and prostate + entire seminal vesicles, no technique provided a clear advantage or disadvantage in bladder dose sparing. For irradiation of the prostate + proximal seminal vesicles the unweighted four-field technique provided the best bladder dose sparing. Concerning the exposure of the femoral heads, the three-field technique was significantly worse for the three CTVs compared with both four-field techniques. No difference was found between the unweighted and the weighted four-field techniques. In conclusion, none of the studied techniques consistently proved superior in different CTVs in prostate cancer irradiation with respect to sparing all organs at risk. The absolute differences between the three techniques were small and the clinical relevance of these findings is uncertain.

Hypofractionated intensity-modulated radiotherapy (70 gy at 2.5 Gy per fraction) for localized prostate cancer: long-term outcomes

PURPOSE

To analyze the long-term relapse-free survival and toxicity rates in patients treated with hypofractionated intensity-modulated radiotherapy.

METHODS AND MATERIALS

The study sample includes the first 100 consecutive localized prostate cancer patients treated to 70.0 Gy at 2.5 Gy per fraction. The median follow-up was 66 months (range, 3 to 75 months). Biochemical failure was the study endpoint, using both the ASTRO definition (A-bRFS) and the alternate "nadir + 2 ng/mL" definition (N-bRFS). RTOG scores were used to assess toxicity.

RESULTS

The 5-year A-bRFS and N-bRFS rates were 85% (95%CI, 78-93%) and 88% (95%CI, 82-95%) for all cases, respectively. For low, intermediate and high-risk disease, the 5-year A-bRFS rates were 97%, 88%, and 70%. The corresponding 5-year N-bRFS rates were 97%, 93%, and 75%, respectively. The acute rectal toxicity scores were 0 in 20, 1 in 61, and 2 in 19 patients. The acute urinary toxicity scores were 0 in 9, 1 in 76, and 2 in 15 patients. The late rectal toxicity scores were 0 in 71, 1 in 19, 2 in 7, and 3 in 3 patients. The actuarial late Grade 3 rectal toxicity rate at 5 years was 3%. A number of the toxicities observed either resolved spontaneously or were corrected. At last follow-up, the rate of combined Grades 2 and 3 late rectal toxicity at 5 years was only 5%. The late urinary toxicity scores were 0 in 75, 1 in 13, 2 in 11, and 3 in 1 patients. The actuarial late Grade 3 urinary toxicity rate at 5 years was 1%.

CONCLUSION

With a median follow-up of 66 months, the long-term results after high-dose hypofractionation are excellent. Late toxicity, urinary and rectal, has been limited. High-dose hypofractionation is an alternative dose escalation method in the treatment of localized prostate cancer.

Complications of radiotherapy: improving the therapeutic index

For every course of radiotherapy treatment, the potential benefit has to be weighed against the risk of normal tissue damage. Radiation-induced proctitis during and after radical radiotherapy for prostate cancer can be decreased by reducing both the size of the target volume and the margins required around this volume. In the future, target volumes could be reduced by both CT/MRI co-registration and dose painting using MR spectroscopy of choline and citrate in the prostate. Improved immobilisation and image-guided radiotherapy should allow reduced margins without compromising the effectiveness of treatment. Similarly, in breast radiotherapy treatment, lung and cardiac complications can be reduced by better patient positioning and ensuring that doses to the heart and lung are minimised during radiotherapy treatment planning. Cosmesis can be improved by using 3D breast planning techniques rather than the conventional 2D approach. These ongoing improvements and developments in radiotherapy treatment planning are leading to treatments which offer both better tumour volume coverage, and are minimising the risk of treatment-related complications. In time, these changes should allow the escalation in dose delivered to the tumour volume with the potential for increased cure rates.

Clinical results of combined treatment conformal high-dose-rate iridium-192 brachytherapy and external beam radiotherapy using staging lymphadenectomy for localized prostate cancer

PURPOSE

To report the first long-term biochemical control rate of patients treated with two protocols using a combination of external beam radiotherapy (EBRT) and high-dose-rate (HDR) brachytherapy for localized prostate cancer in Japan.

METHODS AND MATERIALS

Between October 1997 and July 2001, 71 patients with localized prostatic adenocarcinoma were treated with a combination of EBRT and HDR brachytherapy. Patient age ranged from 58 to 81 years (mean 70.5). Of the 71 patients, 12, 41, and 18 had Stage T1c, T2, and T3, respectively, according to the International Union Against Cancer classification system (1997). The mean initial prostate-specific antigen (PSA) level was 24.2 ng/mL (median, 11.9 ng/mL); 30% of the patients had an initial PSA level >20 ng/mL. Of the 71 patients, 31 had received neoadjuvant hormonal therapy. Hormonal therapy before treatment was stopped at the beginning of RT in all cases. Patients in this series were treated on two protocols. In the initial protocol, patients were treated with whole pelvis EBRT to 45.0 Gy in 25 fractions and three HDR fractions of 5.5 Gy each (35 patients). In the second protocol, patients were treated with prostatic EBRT to 41.8 Gy in 19 fractions, with an added staging lymphadenectomy to rule out lymph node metastasis for patients with high-risk factors, and four HDR fractions of 5.5 Gy each (36 patients). The American Society for Therapeutic Radiology and Oncology consensus definition for biochemical failure was used. Acute and chronic toxicities were scored using the Radiation Therapy Oncology Group guidelines. Follow-up ranged from 24 to 65 months (median, 44 months).

RESULTS

Of the 71 patients, 69 were alive at the last follow-up. Two patients had died of hepatocellular carcinoma and gastric cancer at 3.5 and 4.0 years after treatment with no biochemical failure. Sixty-six patients (93%), including the two who had died of intercurrent disease, showed a tendency for a PSA decline after treatment and had no biochemical or clinical evidence of disease at the last follow-up visit. Sixty patients (85%) achieved PSA nadir levels of < or =1.0 ng/mL. The biochemical/clinical failure-free control rate at 3 and at 5 years was 93% and 93%, respectively. The bladder and rectal complications were minimal.

CONCLUSION

Despite the high frequency of high-risk patients in the present patient population, the actuarial biochemical control rate was 93% at 5 years. Acute and chronic toxicity with this method was acceptable. Additional long-term follow-up is required to assess this treatment, because the median survival is not likely to be reached for several years.

Introducing a prognostic score for pretherapeutic assessment of seminal vesicle invasion in patients with clinically localized prostate cancer

PURPOSE

To identify prostate cancer patients who will have the most likely benefit from sparing the seminal vesicles during 3D conformal radiation therapy.

METHODS AND MATERIALS

From 1988 to 2001, 532 patients underwent radical prostatectomy for clinically localized prostate cancer. Primary endpoint was the pathological evidence of seminal vesicle invasion. Variables for univariate and multivariate analyses were age, prostate weight, clinical stage, PSA level, Gleason score, number and site of positive prostate sextant biopsies. Multivariate logistic regression with backward stepwise variable selection was used to identify a set of independent predictors of seminal vesicle invasion, and the variable selection procedure was validated by non-parametric bootstrap.

RESULTS

Seminal vesicle invasion was reported in 14% of the cases. In univariate analysis, all variables except age and prostate weight were predictors of seminal vesicle invasion. In multivariate analysis, only the number of positive biopsies (P<0.0001), Gleason score (P<0.007) and PSA (P<0.0001) were predictors for seminal vesicles invasion. Based on the multivariate model, we were able to develop a prognostic score for seminal vesicle invasion, which allowed us to discriminate two patient groups: A group with low risk of seminal vesicles invasion (5.7%), and the second with a higher risk of seminal vesicles invasion (32.7%).

CONCLUSIONS

Using the number of positive biopsies, Gleason score and PSA, it is possible to identify patients with low risk of seminal vesicles invasion. In this population, seminal vesicles might be excluded as a target volume in radiation therapy of prostate cancer.

Treatment of prostate cancer with radiotherapy: should the entire seminal vesicles be included in the clinical target volume?

PURPOSE

When treating high-risk prostate cancer with radiation therapy, inclusion of the seminal vesicles (SVs) within the clinical target volume (CTV) can dramatically increase the volume of radiated normal tissues and hinder dose escalation. Because cancer may involve only the proximal portion of the frequently lengthy SVs, we performed a complete pathology review of prostatectomy specimens to determine the appropriate length of SV to include within the CTV when SV treatment is indicated.

METHODS AND MATERIALS

A detailed pathologic analysis was performed for 344 radical prostatectomy specimens (1987-2000). All slides from each case were reviewed by a single pathologist (N.S.G.). Factors recorded for each case included length of each SV (cm), length of cancer involvement in each SV (cm) measured from the prostate-SV junction, and percentage of SV length involved.

RESULTS

Fifty-one patients (15%) demonstrated SV involvement in 81 SVs (21 unilateral, 30 bilateral SV involvement). The median SV length was 3.5 cm (range: 0.7-8.5 cm). Factors associated with SV involvement included the pretreatment PSA level, biopsy Gleason score, and clinical T classification. The commonly used risk group stratification was very effective at predicting SV positivity. Only 1% of low-risk patients (PSA <10 ng/mL, Gleason <or=6, and clinical stage <or=T2a) demonstrated SV involvement vs. 27% of high-risk patients. Patients with only one high-risk feature still demonstrated a 15% risk of SV involvement, whereas 58% of patients with all three high-risk features had positive SVs. The median length of SV involvement was 1.0 cm (90th percentile: 2.0 cm, range: 0.2-3.8 cm). A median of 25% of each SV was involved with adenocarcinoma (90th percentile: 54%, range: 4%-75%). For the 81 positive SVs, no factor was associated with a greater length or percentage of SV involvement. In the entire population, 7% had SV involvement beyond 1.0 cm. There was an approximate 1% risk of SV involvement beyond 2.0 cm or 60% of the SV. In addition, this risk was less than 4% for all subgroups, including high-risk patients.

CONCLUSIONS

A portion of the SV should be included in the CTV only for higher-risk patients (PSA >or=10 ng/mL, biopsy Gleason >or=7, or clinical T stage >or=T2b). When treating the SV for prostate cancer, only the proximal 2.0-2.5 cm (approximately 60%) of the SV should be included within the CTV.

A dose-volume histogram analysis of the seminal vesicles in men treated with conformal radiotherapy to 'prostate alone'

BACKGROUND AND PURPOSE

There is no consensus on whether the seminal vesicles should be included in the clinical target volume (CTV) for radiotherapy of localized prostate cancer. To inform the debate, we have undertaken a dose-volume histogram (DVH) analysis of the seminal vesicles in patients treated with escalated dose conformal radiation to 'prostate alone'.

MATERIAL AND METHODS

Twenty-five consecutive patients receiving conformal radiation to the prostate, to a dose of 75.6 Gy in 42 daily fractions, were studied. The CTV was defined as the prostate only, and the planning target volume (PTV) was defined by a 10 mm margin, except posteriorly where the margin was 7 mm. DVHs were calculated for the entire seminal vesicles, and for 6 mm segments through the seminal vesicles.

RESULTS

Incorporating a correction for organ motion, the D90 (minimum dose received by 90% of the volume of interest) for the most inferior 6 mm volume of the seminal vesicles (SV1) ranged from 25 to 70 Gy, and the percentage volume of SV1 receiving 50 Gy ranged from 47-100%. Using a D90 of 50 Gy as a cut-off, eight of the 25 patients had unacceptably low-dose coverage of SV1.

CONCLUSIONS

Escalated dose conformal radiation to the 'prostate alone' does not ensure adequate dose coverage of even the most inferior 6 mm of the seminal vesicles. We consider such treatment acceptable in patients at low risk of seminal vesicle involvement (T1/2ab, Gleason < or = 7, PSA < 10 ng/ml). In higher risk patients, if it is deemed necessary to treat the possibility of sub-clinical seminal vesicle involvement, this should be reflected in the definition of the CTV.

Adjuvant androgen deprivation impacts late rectal toxicity after conformal radiotherapy of prostate carcinoma

To evaluate whether androgen deprivation impacts late rectal toxicity in patients with localised prostate carcinoma treated with three-dimensional conformal radiotherapy. One hundred and eighty-two consecutive patients treated with 3DCRT between 1995 and 1999 at our Institution and with at least 12 months follow-up were analysed. three-dimensional conformal radiotherapy consisted in 70-76 Gy delivered with a conformal 3-field arrangement to the prostate+/-seminal vesicles. As part of treatment, 117 patients (64%) received neo-adjuvant and concomitant androgen deprivation while 88 (48.4%) patients were continued on androgen deprivation at the end of three-dimensional conformal radiotherapy as well. Late rectal toxicity was graded according to the RTOG morbidity scoring scale. Median follow up is 25.8 (range: 12-70.2 months). The 2-year actuarial likelihood of grade 2-4 rectal toxicity was 21.8+/-3.2%. A multivariate analysis identified the use of adjuvant androgen deprivation (P=0.0196) along with the dose to the posterior wall of the rectum on the central axis (P=0.0055) and the grade of acute rectal toxicity (P=0.0172) as independent predictors of grade 2-4 late rectal toxicity. The 2-year estimates of grade 2-4 late rectal toxicity for patients receiving or not adjuvant hormonal treatment were 30.3+/-5.2% and 14.1+/-3.8%, respectively. Rectal tolerance is reduced in presence of adjuvant androgen deprivation.

Dose/volume relationship of late rectal bleeding after external beam radiotherapy for localized prostate cancer: absolute or relative rectal volume?

PURPOSE

The purpose of this study was to analyze predictors of late rectal bleeding after external-beam radiotherapy for localized prostate cancer, with a focus on the volume of rectum irradiated.

MATERIALS AND METHODS

One hundred twenty-eight patients were treated with external-beam radiotherapy at the Cleveland Clinic Foundation between January 1998 and June 1999. Conformal radiotherapy (CRT) was used to deliver 78 Gy at 2 Gy per fraction in 76 cases, and short-course intensity-modulated radiotherapy (SCIM-RT) was used to deliver 70 Gy at 2.5 Gy per fraction in 52 cases. All contours were determined by one physician. The rectum was outlined from 1 cm above the target structures to 1 cm below the target structures. The entire volume of the rectum, along with the outer rectal wall, was included. All cases had detailed planning parameters that specifically determined the rectal volume receiving the prescription dose (VrPr), that is, 78 Gy for CRT and 70 Gy for SCIM-RT, and the percent of rectal volume receiving the prescription dose (%VrPr). The RTOG scales were used to evaluate late toxicity. The median follow-up was 24 months for all cases (range, 3-34 months), 21 months for SCIM-RT cases (range, 11-26 months), and 28 months for CRT cases (range, 3-34 months).

RESULTS

To date, five patients have had grade 1 late rectal toxicity (one CRT case and four SCIM-RT cases), one patient had grade 2 late rectal toxicity (CRT), and three patients had grade 3 late rectal toxicity (all CRT cases). Because of the low number of events, the analysis was performed with all patients experiencing rectal bleeding grouped together. The actuarial rectal bleeding rates at 18 and 24 months were 6% and 8%, respectively. The actuarial rectal bleeding rates at 24 months were identical (8%) for both SCIM-RT and CRT. A multivariate analysis of the following parameters was performed to determine independent predictors of rectal bleeding: age (continuous variable), race (Caucasian vs African American), coverage of seminal vesicles (yes vs no), adjuvant androgen deprivation (yes vs no), technique (CRT vs SCIM-RT), Radiation Therapy Oncology Group acute rectal toxicity score (continuous variable), VrPr (continuous variable in cubic centimeters), and %VrPr (continuous variable). Only the VrPr (cubic centimeter) was an independent predictor of rectal bleeding; %VrPr was not. With different cut-off levels being used, a VrPr of 15 cm3 was significant on univariate analysis; the actuarial rectal bleeding rates at 24 months for patients with a VrPr < or = 15 cm3 versus a VrPr > 15 cm3 were 5% versus 22%, respectively. CONCLUSION> In our study sample, which included both conformal and intensity-modulated radiotherapy patients, the volume of rectum receiving the prescribed radiation dose (the equivalent of 78 Gy) was an independent predictor of late rectal bleeding. The percent of rectal volume receivingthe full dose was not. Using actual volume rather than percent volume also avoids the dependence on the extent of rectal volume contours. We recommend 15 cm3 as the cut-off of the rectal volume not to exceed the prescription dose. The rectal bleeding rate at 2 years for cases with < 15 cm3 receiving the full dose was only 5%.

Short-course intensity-modulated radiotherapy (70 GY at 2.5 GY per fraction) for localized prostate cancer: preliminary results on late toxicity and quality of life

PURPOSE

To present our preliminary observations on the late toxicity and quality of life (QOL) of patients treated with short-course intensity-modulated radiotherapy (SCIM-RT).

METHODS AND MATERIALS

Fifty-one patients were treated with SCIM-RT at the Cleveland Clinic Foundation between October 1998 and May 1999. The technique consisted of intensity-modulated radiotherapy using 5 static fields (anterior, 2 laterals, and 2 anterior obliques). Inverse plans were generated by the Corvus treatment-planning system. The treatment delivery was performed with a dynamic multileaf collimator. A total of 70.0 Gy was prescribed in all cases at 2.5 Gy per fraction to be delivered in 28 fractions over 5 and a half weeks. The location of the prostate gland was verified and adjusted daily with the BAT transabdominal ultrasound system. The median follow-up was 18 months (range: 11 to 26 months). The Radiation Therapy Oncology Group (RTOG) scales were used to evaluate late toxicity. The Expanded Prostate Cancer Index Composite (EPIC) was used to evaluate QOL. A total of 24 patients completed the EPIC questionnaire at approximately 2 years after therapy (median time from treatment to questionnaire administration: 24 months; range: 21 to 26 months). The results from the EPIC questionnaires were compared to scores from 46 patients treated during the same time period with conformal radiotherapy (CRT) to 78 Gy at 2 Gy per fraction.

RESULTS

The dose was prescribed to an isodose line ranging from 82.0% to 90.0% (mean: 87.2%). The range of the individual prostate mean doses was 73.5 to 78.5 Gy (average: 75.3 Gy). To date, only 1 patient had Grade 1 late urinary toxicity. To date, only 4 patients had Grade 1 late rectal toxicity. No Grade 2 or 3 late urinary or rectal complications have occurred. The actuarial rectal bleeding rate observed at 18 months was 7%. There were no differences in scores from the urinary, bowel, hormonal, and overall QOL domains between SCIM-RT patients and patients treated with CRT. The overall physical and mental QOL scores were also nearly identical to scores reported for the general U.S. population.

CONCLUSION

Preliminary late toxicity results up to 2 years after SCIM-RT are encouraging, with a median follow-up of 18 months (range 11 to 26 months). Late toxicity assessed by the physicians using RTOG late toxicity scores has been excellent. QOL reported by the patients using the EPIC questionnaire reveals no difference between patients treated with high-dose CRT at standard fractionation and patients treated with SCIM-RT. SCIM-RT is an alternative method of dose escalation in the treatment of localized prostate cancer. The proposed schedule significantly increases convenience to patients due to the decrease in overall treatment time.

[Prostate cancer]

Radiation therapy of prostate carcinoma with a curative intent implies to treat the whole prostate at high dose (at least 66 Gy). According to clinical stage, PSA level, Gleason's score, the clinical target volume may include seminal vesicles and less often pelvic lymph nodes. Microscopic extracapsular extension is found in 15 to 60% of T1-T2 operated on, specially in apex tumors. On contrary, cancers developing from the transitional zone may stay limited to the prostate even with a big volume and with a high PSA level. Zonal anatomy of the prostate identifies internal prostate, including the transitional zone (5% of the prostate in young people). External prostate includes central and peripheral zones. The inferior limit of the prostate is not lower than the inferior border of the pubic symphysis. Clinical and radiological examination: ultrasonography, nuclear magnetic resonance (NMR), CT-scan identify prognostic factors as tumor volume, capsule effraction, seminal vesicles invasion and lymph node extension. The identification of the clinical target volume is now done mainly by CT-Scan which identifies prostate and seminal vesicles. NMR could be helpful to identify more precisely prostate apex. The definition of margins around the clinical target volume has to take in account daily reproducibility and organ motion and of course the maximum tolerable dose for organs at risk.

Three-dimensional computed tomography-guided monotherapeutic pararectal brachytherapy of prostate cancer with seminal vesicle invasion

PURPOSE

To treat patients with prostate cancer and seminal vesicle invasion with monotherapeutic three dimensional computed tomography (3-DCT)-guided posterior pararectal brachytherapy.

METHODS AND MATERIALS

Three hundred and sixty two patients with clinical stage T1 a,b or T2 a,b of prostate cancer were referred for 3-DCT-guided brachytherapy. Each underwent ftirther staging with 3-D CT-guided pararectal biopsy of the seminal vesicles under local anesthesia during the pre-treatment CT-planning. Forty-three patients (12%) were upstaged to T3 cNoMo disease. In the set of 43 patients, Eight had Gleason's score< or =6, 24 Gleason's score=7, and 11 patients > or =8. Initial PSA was <10 ng/ml in 14 patients, 10-20 ng/ml in 11 patients, and >20 in 18 patients. Of the 43 patients, 37 patients were treated monotherapeutically with 3-D CT-guided brachytherapy. No patients received hormone therapy after the implant. The prescribed dosage to the seminal vesicles and prostate is 120 Gy with Pd-103 seeds and 144 Gy with 1-125 seeds.

RESULTS

The prescribed dosage was achieved in all 37 patient's throughout the seminal vesicles whose range of target radiation extended 5-10 mm outside the target in the adjacent fat as calculated with post-implant CT-dosimetry with Varian Brachy Vision or MMS software. Prostate Specific Antigen (PSA) outcome data were available in 34 patients treated with monotherapy and follow up ranged from 12-56 months (median, 24 months). Decreased PSA levels were stratified into six groups based on the presenting Gleason's score and initial PSA. In the first group (with Gleason's score< or =6 and initial PSA <20 ng/ml), PSA levels decreased to less than 0.5 ng/ml in all seven patients (100%) after brachytherapy. In the second group (with Gleason's=7 and initial PSA<20 ng/ml), PSA levels decreased to less than 1 ng/ml in 11 of 13 patients (85%); additionally PSA levels decreased to less than 0.5 ng/ml in ten patients (77% in this group). In the third group (with Gleason's score=7 and initial PSA> 20 ng/ml), PSA decreased to less than 0.5 ng/ml in four out of eight patients (50%). All of the patients in the fourth group (with Gleason's score> or =8 and initial PSA<20 ng/ml) decreased their PSA levels to less than 0.5 ng/ml in three of three patients. PSA decreased less than 0.5 ng/ml in two out of three patients (67% in the last group with Gleason's score> or =8 and initial PSA> 20 ng/ml). There were no patients with Gleason's score of 1-6 and greater than 20 ng/ml initial PSA. Patients, irrespective of the Gleason's score and PSA, had an overall response of decreased PSA (less than 1 ng/ml) of 79%.

CONCLUSION

3-D CT-guided brachytherapy delivers adequate dosage to the seminal vesicles. Clinical and biochemical results are encouraging in patients with low initial PSA levels regardless of their Gleason's scores, but longer-term data in a greater number of patients is necessary.

Localized prostate cancer

Much controversy still surrounds the diagnosis and treatment of localized prostate cancer. Urologists generally believe that early detection and aggressive surgical therapy saves lives despite the absence of confirmatory randomized trials. Furthermore, a recent survey of radiation oncologists and urologists revealed marked polarization toward their own specialties when asked how they would counsel patients on therapy for newly diagnosed localized disease. Some issues are not controversial, however. There is general agreement that pretreatment tumor characteristics, including serum prostate-specific antigen level at diagnosis, tumor grade, and clinical stage as judged by digital rectal examination, are important prognosticators for treatment outcomes independent of the type of treatment. Also, there is sufficient experience with standard therapies (radical prostatectomy and external beam radiotherapy) to counsel patients on the chance for cure and the expected incidence of acute and chronic toxicities. A comparative evaluation of various therapies for prostate cancer should include consideration of cancer control, acute toxicity, treatment-related quality of life issues, salvage of treatment failures, and cost. Within this context, we believe that newly diagnosed patients should be counseled on all available treatment options before embarking on a course of therapy.

Radiotherapy of prostate cancer with or without intensity modulated beams: a planning comparison

PURPOSE

To evaluate whether intensity modulated radiotherapy (IMRT) by static segmented beams allows the dose to the main portion of the prostate target to escalate while keeping the maximal dose at the anterior rectal wall at 72 Gy. The value of such IMRT plans was analyzed by comparison with non-IMRT plans using the same beam incidences.

METHODS AND MATERIALS

We performed a planning study on the CT data of 32 consecutive patients with localized adenocarcinoma of the prostate. Three fields in the transverse plane with gantry angles of 0 degrees, 116 degrees, and 244 degrees were isocentered at the center of gravity of the target volume (prostate and seminal vesicles). The geometry of the beams was determined by beam's eye view autocontouring of the target volume with a margin of 1.5 cm. In study 1, the beam weights were determined by a human planner (3D-man) or by computer optimization using a biological objective function with (3D-optim-lim) or without (3D-optim-unlim) a physical term to limit target dose inhomogeneity. In study 2, the 3 beam incidences mentioned above were used and in-field uniform segments were added to allow IMRT. Plans with (IMRT-lim) or without (IMRT-unlim) constraints on target dose inhomogeneity were compared. In the IMRT-lim plan, target dose inhomogeneity was constrained between 15% and 20%. After optimization, plans in both studies were normalized to a maximal rectal dose of 72 Gy. Biological (tumor control probability [TCP], normal tissue complication probability [NTCP]) and physical indices for tumor control and normal tissue complication probabilities were computed, as well as the probability of the uncomplicated local control (P+).

RESULTS

The IMRT-lim plan was superior to all other plans concerning TCP (p < 0.0001). The IMRT-unlim plan had the worst TCP. Within the 3D plans, the 3D-optim-unlim had the best TCP, which was significantly different from the 3D-optim-lim plan (p = 0.0003). For rectal NTCP, both IMRT plans were superior to all other plans (p < 0.0001). The IMRT-unlim plan was significantly better than the IMRT-lim plan (p < 0.0001). Again, 3D-optim-unlim was superior to the other 3D plans (p < 0. 0007). Physical endpoints for target showed the mean minimal target dose to be the lowest in the IMRT-unlim plan, caused by a large target dose inhomogeneity (TDI). Medial target dose, 90th percentile, and maximal target dose were significantly higher in both IMRT plans. Physical endpoints for the rectum showed the IMRT-unlim plan to be superior compared to all other plans. There was a strong correlation between the 65th percentile (Rp65) and rectal NTCP (correlation coefficient > or =89%). For bladder, maximal bladder dose was significantly higher in the IMRT-unlim plan compared to all other plans (p < or = 0.0001).P+ was significantly higher in both IMRT-plans than in all other plans. The 3D-optim-unlim plan was significantly better than the two other 3D plans (p < 0.0001).

CONCLUSION

IMRT significantly increases the ratio of TCP over NTCP of the rectum in the treatment of prostate cancer. However, constraints for TDI are needed, because a high degree of TDI reduced minimal target dose. IMRT improved uncomplicated local control probability. In our department, IMRT by static segmented beams is planned and delivered in a cost-effective way. IMRT-lim has replaced non-modulated conformal radiotherapy as the standard treatment for prostate cancer.

Short-course intensity-modulated radiotherapy for localized prostate cancer with daily transabdominal ultrasound localization of the prostate gland

PURPOSE

To present our initial observations on the clinical feasibility of the technique of short-course intensity-modulated radiotherapy (SCIM-RT) in the treatment of localized prostate cancer coupled with daily transabdominal ultrasound localization of the prostate. The proposed regimen consists of a hypofractionated course delivering 70.0 Gy in 28 fractions.

METHODS AND MATERIALS

The treatment data of the first 51 patients treated with SCIM-RT at the Cleveland Clinic Foundation are presented in this report. The technique consisted of intensity-modulated radiotherapy using 5 static fields (anterior, 2 laterals, and 2 anterior obliques). Inverse plans were generated by the Corvus treatment-planning system. The treatment delivery was performed with a Varian Dynamic Multileaf Collimator. The target was the prostate only in patients with low-risk disease (stage T1-T2, pretreatment PSA < or =10, and biopsy Gleason < or =6). The target was the prostate and seminal vesicles in patients with high-risk disease (stage T3 or pretreatment PSA > 10 or biopsy Gleason > or =7). In the Corvus planning system, the margins for the planning target volume (PTV) were 4 mm posteriorly, 8 mm laterally, and 5 mm in all other directions. A total of 70.0 Gy (mean prostate dose approximately 75 Gy) was prescribed in all cases at 2.5 Gy per fraction to be delivered in 28 fractions over 5 1/2 weeks. Prior to treatment delivery, the patients were minimally immobilized on the treatment table, only using lasers and skin marks. The location of the prostate gland was verified daily with the BAT transabdominal ultrasound system and patient position adjustments were performed accordingly. Fifty-one patients completed therapy between October 1998 and May 1999.

RESULTS

The dose was prescribed to an isodose line ranging from 82.0% to 90.0% (mean: 87.2%). The range of the individual prostate mean doses was 73.5 to 78.5 Gy (average: 75.3 Gy). The range of the maximum doses was 77.4 to 84.5 Gy (average: 80.2 Gy). The range of the minimum doses was 64.3 to 69.2 Gy (average: 67.5 Gy). The average time for the prostate position verification and alignment of the prostate using the BAT system was 5 minutes. The entire localization/alignment process was performed by the radiation therapists. The daily alignment images were automatically saved and reviewed by the radiation oncologist, a process similar to port film checks. The total treatment (beam-on) time was around 6 minutes using the 5 static intensity-modulated fields. The mean and standard deviation (SD) of bladder volumes irradiated to 50, 60, and 70 Gy were as follows: 24 +/- 11 cc, 16 +/- 8 cc, and 8 +/- 6 cc. The mean and SD of rectal volumes irradiated to 50, 60, and 70 Gy were as follows: 22 +/- 11 cc, 15 +/- 8 cc, and 7 +/- 5 cc. The RTOG acute bladder toxicity scores were as follows: 0 in 3 (6%), 1 in 38 (74%), and 2 in 10 (20%). The RTOG acute rectal toxicity scores for SCIM-RT cases were as follows: 0 in 10 (20%), 1 in 33 (65%), and 2 in 8 (16%). No Grade 3 or 4 acute toxicities were observed.

CONCLUSION

The delivery of our proposed hypofractionated-schedule SCIM-RT in combination with daily target localization/alignment with the BAT transabdominal ultrasound system is clinically feasible. It is an alternative method of dose escalation in the treatment of localized prostate cancer. The proposed schedule would significantly increase convenience to patients due to the decrease in overall treatment time. Preliminary acute toxicity results are extremely encouraging. Long-term follow-up is needed to assess late complications and treatment efficacy.

Higher than standard radiation doses (> or =72 Gy) with or without androgen deprivation in the treatment of localized prostate cancer

PURPOSE

To study the effect on biochemical relapse-free survival (bRFS) and clinical disease-free survival of radiation doses delivered to the prostate and periprostatic tissues for localized prostate cancer.

METHODS AND MATERIALS

A total of 1041 consecutive localized prostate cancer cases treated with external beam radiotherapy (RT) at our institution between 7/86 and 2/99 were reviewed. All cases had available pretreatment parameters including pretreatment prostate-specific antigen (iPSA), biopsy Gleason score (bGS), and clinical T stage. The median age was 69 years. Twenty-three percent of cases (n = 238) were African-American. The distribution by clinical T stage was as follows: T1 in 365 cases (35%), T2 in 562 cases (54%), and T3 in 114 cases (11%). The median iPSA level was 10.1 ng/ml (range: 0.4-692.9). The distribution by biopsy Gleason score (bGS) was as follows: < or =6 in 580 cases (56%) and > or =7 in 461 cases (44%). Androgen deprivation (AD) in the adjuvant or neoadjuvant setting was given in 303 cases (29%). The mean RT dose was 71.9 Gy (range: 57.6-78.0 Gy). The median RT dose was 70.2 Gy, with 458 cases (44%) receiving at least 72.0 Gy. The average dose in patients receiving <72 Gy was 68.3 Gy (median 68.4) versus 76.5 Gy (median 78.0) for patients receiving > or =72 Gy. The mean follow-up was 38 months (median 33 months). The number of follow-up prostate-specific antigen (PSA) levels available was 5998.

RESULTS

The 5- and 8-year bRFS rates were 61% (95% CI 55-65%) and 58% (95% CI 51-65%), respectively. The 5-year bRFS rates for patients receiving radiation doses > or =72 Gy versus <72 Gy were 87% (95% CI 82-92%) and 55% (95% CI 49-60%), respectively. The 8-year bRFS rates for patients receiving radiation doses > or =72 Gy versus <72 Gy were 87% (95% CI 82-92%) and 51% (95% CI 44-58%), respectively (p < 0.001). A multivariate analysis of factors affecting bRFS was performed using the following parameters: age (continuous variable), race, T-stage (T1-T2 vs. T3), iPSA (continuous variable), bGS (< or =6 vs. > or =7), use of AD (yes vs. no), radiation technique (conformal versus standard), and radiation dose (continuous variable). T-stage (p < 0.001), iPSA (p < 0.001), bGS (p < 0.001), and RT dose (p < 0.001) were independent predictors of outcome. Age (p = 0.74), race (p = 0.96), radiation technique (p = 0.15), and use of AD (p = 0.31) were not. We observed 11% clinical failures (local, distant, or both) at 5 years and 15% at 8 years for the entire cohort. There was a statistically significant improvement with higher radiation doses (p = 0.032). The 5-year clinical relapse rates for patients receiving > or =72 Gy versus <72 Gy were 5% and 12%, respectively. The 8-year clinical relapse rates for patients receiving radiation doses > or =72 Gy versus <72 Gy were 5% and 17%, respectively (p = 0.026).

CONCLUSION

Patients receiving radiation doses exceeding 72 Gy had significantly better bRFS and clinical disease-free survival rates. Although results need to be confirmed with longer follow-up, these preliminary results are extremely encouraging. If these results are confirmed by other institutions and by longer follow-up, RT doses exceeding 72 Gy should be considered as standard of care.

Importance of high radiation doses (72 Gy or greater) in the treatment of stage T1-T3 adenocarcinoma of the prostate

OBJECTIVES

To analyze the effect of total radiation dose on the outcome of patients treated with external beam radiotherapy for early-stage prostate cancer.

METHODS

The records of a total of 738 patients with localized prostate cancer treated with external beam radiotherapy (RT) and no androgen deprivation at our institution between July 1986 and February 1999 were reviewed. Two risk groups were defined: favorable (Stage T1-T2, pretreatment prostate-specific antigen [PSA] level 10.0 ng/mL or less, and biopsy Gleason score 6 or less) and unfavorable (Stage T3 lesion or pretreatment PSA level greater than 10.0 ng/mL or biopsy Gleason score 7 or greater). The median RT dose was 70.0 Gy (range 57.6 to 78.0), with 192 patients (26%) receiving at least 72.0 Gy. The mean follow-up was 45 months.

RESULTS

The 5-year biochemical relapse-free survival (bRFS) rate was 58%. The 5-year bRFS rate for patients who received radiation doses of 72 Gy or greater versus less than 72 Gy was 85% and 54%, respectively (P <0.001). On multivariate analysis of factors affecting bRFS rates, the number of follow-up PSA levels (P <0.001), tumor stage (P <0.001), pretreatment PSA (P <0.001), biopsy Gleason score (P <0.00 1), and RT dose (P = 0.001) were the only independent predictors of outcome. For favorable tumors, the 5-year bRFS rate for patients who received radiation doses of 72 Gy or greater versus less than 72 Gy was 98% and 81 %, respectively (P = 0.023). For unfavorable tumors, the 5-year bRFS rate for patients who received radiation doses of 72 Gy or greater versus less than 72 Gy was 75% and 41 %, respectively (P = 0.001).

CONCLUSIONS

Patients receiving radiation doses of 72 Gy or higher had a significantly better outcome. The improvement was seen in all subgroups of patients. If these results are confirmed, radiation doses exceeding 72 Gy should be considered the standard of care. Inc.

Long-term morbidity and quality of life in patients with localized prostate cancer undergoing definitive radiotherapy or radical prostatectomy

PURPOSE

To assess morbidity, side effects, and quality of life (QoL) in patients treated for localized prostate cancer with curative aim.

METHODS AND MATERIALS

This descriptive cross-sectional study comprises 154 patients who had undergone definitive radiotherapy (RAD) and 108 patients with radical prostatectomy (PRECT) at the Norwegian Radium Hospital during 1987-1995. At least 1 year after treatment the patients completed several questionnaires assessing quality of life (European Organization for Research and Treatment of Cancer QLQ-C30 instrument [EORTC QLQ-C30]), lower urinary tract symptoms (LUTS): International Prostate Symptom Score (IPSS), or sexuality (selected questions from the Psychosocial Adjustment to Illness Scale [PAIS]). Urinary incontinence and bowel distress were evaluated by ad hoc constructed questionnaires. A control group (OBS) consisted of 38 patients following the watch-and-wait policy.

RESULTS

Twenty percent of the patients from the RAD Group had moderate (14%) or severe (6%) LUTS as compared to 12% in the PRECT group. However, 35% of men from the latter group reported moderate to severe urinary incontinence. "Overall" sexuality was moderately or severely impaired in 71% of the PRECT and 50% of the RAD patients. In the former group high age was correlated with erectile impotency (p < 0.001). In the RAD comorbidity was associated with erectile impotency (p < 0.001). Between 13-38% of the patients recorded moderate or severe bowel distress (blood per rectum: 13%; bowel cramps: 26%; flatulence: 38%), without significant differences comparing patients who had received conventional small 4-field box radiotherapy and patients who had undergone strictly conformal radiotherapy. Despite malignancy and/or treatment-related morbidity, QoL was comparable in both groups with respectively 9% and 6% RAD and PRECT patients, reporting moderately or severely impaired QoL. In the multivariate analysis physical function, emotional function and fatigue were significantly correlated with QoL, whereas sexuality, lower urinary symptoms, and urinary incontinence correlated with QoL only in the univariate analysis.

CONCLUSION

In spite of considerable malignancy and/or treatment-related morbidity QoL was good or only slightly impaired in the majority of patients with localized prostate cancer who presented with stable disease > 1 year after definitive radiotherapy or radical prostatectomy with no difference as compared to the age-matched normal population. Clinicians should be aware of the fact that general QoL dimensions (physical function, emotional function, fatigue) are as a rule of greater significance for QoL than sexuality and lower urinary tract symptoms.

[Probability of seminal vesicle involvement in localized prostatic carcinoma. Significance in conformal radiotherapy]

PURPOSE

The development of objective criteria for selecting patients for seminal vesicle irradiation on radical radiotherapy for prostate cancer will be important for successful planning of 3D conformal radiotherapy.

MATERIALS AND METHODS

Based on morphometric studies from radical prostatectomy specimens, new imaging modalities with potential in the investigation of patients with gross seminal vesicle involvement and clinical factors with potential in the identification of patients with subclinical disease the development of objective guidelines is possible.

RESULTS

Clinical tumor stage as determined by digital rectal examination, diagnostic tumor biopsy (Gleason Score), and pretherapy serum prostate-specific antigen value were significant factors for the probability of involvement of seminal vesicles. Studies show that seminal vesicle involvement is unlikely if the PSA is < 4 ng/ml or 4 to 10 ng/ml and Gleason Score < 7 and stage < or = T2b. In contrast, involvement of seminal vesicles is highly likely with levels above 20 ng/ml. In patients with PSA levels between 10 and 20 ng/ml and Gleason Score < 7 ultrasonographic findings with regard to tumor volume and localization will be useful to determine the extent of the target volume. For treatment planning a significant reduction in the volumes of irradiation to the rectum and bladder is evident when seminal vesicles were excluded.

CONCLUSION

Prospective use of the objective criteria will be useful in the selection of patients for seminal vesicle involvement and should be an integral part in 3D conformal radiotherapy of prostate cancer.