Comparison of whole pelvis versus small-field radiation therapy for carcinoma of prostate

Efficacy and Toxicity of Whole Pelvic Radiotherapy Versus Prostate-Only Radiotherapy in Localized Prostate Cancer: A Systematic Review and Meta-Analysis

Background

There is little level 1 evidence regarding the relative efficacy and toxicity of whole pelvic radiotherapy (WPRT) compared with prostate-only radiotherapy (PORT) for localized prostate cancer.

Methods

We used Cochrane, PubMed, Embase, Medline databases, and ClinicalTrials.gov to systematically search for all relevant clinical studies. The data on efficacy and toxicity were extracted for quality assessment and meta-analysis to quantify the effect of WPRT on biochemical failure-free survival (BFFS), progression-free survival (PFS), distant metastasis-free survival (DMFS), overall survival (OS), gastrointestinal (GI) toxicity, and genitourinary (GU) toxicity compared with PORT. The review is registered on PROSPERO, number: CRD42021254752.

Results

The results revealed that compared with PORT, WPRT significantly improved 5-year BFFS and PFS, and it was irrelevant to whether the patients had undergone radical prostatectomy (RP). In addition, for the patients who did not receive RP, the 5-year DMFS of WPRT was better than that of PORT. However, WPRT significantly increased not only the grade 2 or worse (G2+) acute GI toxicity of non-RP studies and RP studies, but also the G2+ late GI toxicity of non-RP studies. Subgroup analysis of non-RP studies found that, when the pelvic radiation dose was >49 Gy (equivalent-doses-in-2-Gy-fractions, EQD-2), WPRT was more beneficial to PFS than PORT, but significantly increased the risk of G2+ acute and late GU toxicity.

Conclusions

Meta-analysis demonstrates that WPRT can significantly improve BFFS and PFS for localized prostate cancer than PORT, but the increased risk of G2+ acute and late GI toxicity must be considered.

Systematic Review Registration

PROSPERO CRD42021254752.

Treatment Options in Hormone-refractory Metastatic Prostate Carcinoma

Prostate cancer represents one of the most important health problems in industrialized countries. It is the second leading cause of cancer-related death in the United States. Therapeutic options are different according to the stage of the disease at the diagnosis. Patients with localized disease may be treated with surgery or radiation, whereas the treatment for patients with a metastatic disease is purely palliative. Hormonal treatment represents the standard therapy for stage IV prostate cancer, but patients ultimately become unresponsive to androgen ablation and are classified as hormone-refractory prostate cancer patients. The molecular mechanisms involved in progression in hormone resistance are characterized by mutations, down and up-regulation in the androgen receptor gene, mutations in p53 and over-expression of Bcl2 and other alterations in genes and in gene expression. The important thing is that we understand these mechanisms to define potential therapeutic agents for the treatment of hormone-refractory prostate cancer patients. Conventional options for patients with hormone-refractory prostate cancer include secondary hormone therapy, radiotherapy and cytotoxic chemotherapy. The commonest antineoplastic agents are mitoxantrone, estramustine and taxanes. Despite an improvement In the palliative benefit, none of these agents has demonstrated a beneficial impact on the overall survival of patients. Therefore, there is no standard therapy for these patients, thus we need new approaches which should be studied in clinical trials. The evaluation and incorporation of new agents into current treatment regimens could have a role in the treatment of hormone-refractory prostate cancer, but their efficacy has not yet been demonstrated.

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.

Newer imaging modalities to assist with target localization in the radiation treatment of prostate cancer and possible lymph node metastases

Precise localization of prostate cancer and the drainage lymph nodes is mandatory to define an accurate clinical target volume for conformal radiotherapy. Better target definition and delineation on a daily basis is surely important in quality assurance for fractionated radiation therapy. This article reviews the evidence for major emerging techniques that show promise in better identifying the clinical target volume. Partial prostate boost by brachytherapy, intensity-modulated radiation therapy, or protons has become possible not only with standard imaging techniques but also with the availability of metabolic images obtained by magnetic resonance spectroscopy. Even though fluorine-18 fluorodeoxyglucose ((18)F-FDG) positron emission tomography has not been found to be useful, novel radiolabeled tracers may eventually prove of value in the diagnosis and treatment planning of prostate cancer. For the metastatic lymph nodes, lymphotropic nanoparticle-enhanced magnetic resonance imaging using ultra-small superparamagnetic iron oxide particles has greater accuracy as compared with conventional techniques and has been instrumental in delineating the lymphatic drainage of the prostate gland. These novel investigational techniques could further help in optimizing conformal radiotherapy for patients with prostate cancer. The concepts of biologic target volume, real target volume, and multidimensional conformal radiotherapy are being explored.

Penile metastasis from a T1b prostate carcinoma

BACKGROUND

Penile metastasis from incidental prostate carcinoma has not been described to date.

CASE REPORT

The case of a 72-year-old man affected by penile metastasis from incidental prostate carcinoma is described. In March 1998, the patient underwent prostate surgery for lower urinary tract symptoms related to benign prostatic obstruction. Histological examination revealed an incidental adenocarcinoma of the prostate. The pre-operative prostate-specific antigen (PSA) value was 3.6 ng/ml. A prostate biopsy in the peripheral prostate lobes was negative. PSA progressively rose to 8 ng/ml. The prostate biopsy was repeated and was still negative. The patient was subjected to radiotherapy, as a result of which his PSA fell to 0.7 ng/ml. 4 years after prostatectomy, the PSA rose again and the patient underwent hormonal therapy. The PSA fell to < 0.001 ng/ml. In May 2004, the patient reported a painful, erythematous nodule on his penis glans. Surgical biopsy showed a metastasis from prostate adenocarcinoma and he underwent partial penectomy. Due to disease progression, the patient underwent medical therapy. PSA and testosterone were always at minimum levels. 20 months later the patient died.

CONCLUSION

We underline the uncertainty of the biological behaviour and optimal management of incidentally identified prostate carcinoma. In addition, we highlight that biological and clinical progression could be the consequence of inadequate treatment recommendations.

Optimized coverage of high-risk adjuvant lymph node areas in prostate cancer using a sentinel node–based, intensity-modulated radiation therapy technique

PURPOSE

Irradiation of adjuvant lymph nodes in high-risk prostate cancer was shown to be associated with improved rates of biochemical nonevidence of disease in the Radiation Therapy Oncology Group trial (RTOG 94-13). To account for the highly individual lymphatic drainage pattern we tested an intensity-modulated radiation therapy (IMRT) approach based on the determination of pelvic sentinel lymph nodes (SN).

METHODS AND MATERIALS

Patients with a risk of more than 15% lymph node involvement were included. For treatment planning, SN localizations were included into the pelvic clinical target volume. Dose prescriptions were 50.4 Gy to the adjuvant area and 70.0 Gy to the prostate. All treatment plans were generated using equivalent uniform dose (EUD)-based optimization algorithms and Monte Carlo dose calculations and compared with 3D conventional plans.

RESULTS

A total of 25 patients were treated and 142 SN were detectable (mean: n = 5.7; range, 0-13). Most SN were found in the external iliac (35%), the internal iliac (18.3%), and the iliac commune (11.3%) regions. Using a standard CT-based planning target volume, relevant SN would have been missed in 19 of 25 patients, mostly in the presacral/perirectal area (22 SN in 12 patients). The comparison of conventional 3D plans with the respective IMRT plans revealed a clear superiority of the IMRT plans. No gastrointestinal or genitourinary acute toxicity Grade 3 or 4 (RTOG criteria) occurred.

CONCLUSIONS

Distributions of SN are highly variable. Data for SN derived from single photon emission computed tomography are easily integrated into an IMRT-based treatment strategy. By using SN data the probability of a geographic miss is reduced. The use of IMRT allows sparing of normal tissue irradiation.

Mapping of nodal disease in locally advanced prostate cancer: Rethinking the clinical target volume for pelvic nodal irradiation based on vascular rather than bony anatomy

PURPOSE

Toxicity from pelvic irradiation could be reduced if fields were limited to likely areas of nodal involvement rather than using the standard "four-field box." We employed a novel magnetic resonance lymphangiographic technique to highlight the likely sites of occult nodal metastasis from prostate cancer.

METHODS AND MATERIALS

Eighteen prostate cancer patients with pathologically confirmed node-positive disease had a total of 69 pathologic nodes identifiable by lymphotropic nanoparticle-enhanced MRI and semiquantitative nodal analysis. Fourteen of these nodes were in the para-aortic region, and 55 were in the pelvis. The position of each of these malignant nodes was mapped to a common template based on its relation to skeletal or vascular anatomy.

RESULTS

Relative to skeletal anatomy, nodes covered a diffuse volume from the mid lumbar spine to the superior pubic ramus and along the sacrum and pelvic side walls. In contrast, the nodal metastases mapped much more tightly relative to the large pelvic vessels. A proposed pelvic clinical target volume to encompass the region at greatest risk of containing occult nodal metastases would include a 2.0-cm radial expansion volume around the distal common iliac and proximal external and internal iliac vessels that would encompass 94.5% of the pelvic nodes at risk as defined by our node-positive prostate cancer patient cohort.

CONCLUSIONS

Nodal metastases from prostate cancer are largely localized along the major pelvic vasculature. Defining nodal radiation treatment portals based on vascular rather than bony anatomy may allow for a significant decrease in normal pelvic tissue irradiation and its associated toxicities.

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.

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.

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.

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.

Radiotherapy of prostate cancer: established results and new developments

Radical radiotherapy has been established as an effective modality for eradicating localised prostate cancer. No satisfactory comparisons have been made with patients treated by total prostatectomy, but in surgically staged patients with negative lymph nodes survival after radiotherapy exceeds that of an aged matched population, cancer deaths occurring in only 6-15% of patients and 85% remaining free of local recurrence after 10 years. Results are predictably less satisfactory in surgically unstaged cases and for more advanced localised presentations. Nevertheless, radical radiotherapy achieves local control of disease in the majority of patients. Improved local control may be obtained by increasing radiation dose but at the expense of increased radiation-induced side-effects. Conformal radiotherapy and combined modality treatment with the neoadjuvant or adjuvant androgen deprivation show considerable promise as novel methods to improve the therapeutic ratio, and prospective randomised studies are underway to test these approaches.

Acute toxicity during external-beam radiotherapy for localized prostate cancer: comparison of different techniques

PURPOSE

The chronic and acute toxicities associated with conventional radiotherapy of localized prostate cancer are well documented. However, the degree and incidence of toxicities with conformal techniques are not known. Studying side effects associated with modern radiotherapeutic techniques is more important now since there has been a general trend to use computerized tomography-based techniques in recent years; beam's eye view-based conformal techniques are also becoming more commonplace. It is possible that the local disease control can be improved with the delivery of higher doses than currently used. Conformation of the treatment volume to the target volume may facilitate such dose-escalation. However, prior to such dose-escalation, it is important to know the toxicities associated with such techniques with conventional doses.

METHODS AND MATERIALS

We have compared week-by-week acute toxicities associated with conventional (Group A, 16 patients), computerized tomography-based, manual (Group B, 57 patients) and beam's eye view-based (Group C, 43 patients) techniques during 7 weeks of radiotherapy. Group B and C patients were treated contemporaneously (1988-1990).

RESULTS

Acute side effects gradually increased from week 1 through weeks 4-5 and generally declined or plateaued after that. The incidence of acute toxicities was significantly less with the beam's eye view/based technique than with the other two methods. For instance, the percentages of Grade 2 acute genitourinary toxicities for Groups A, B, and C were as follows: Week 1-0, 0, 0; Week 2-6, 0, 0; Week 3-6, 9, 2; Week 4-12, 14, 9; Week 5-35, 14, 9; Week 6-31, 16, 7; Week 7-33, 8, 8, respectively. The p values associated with differences in acute genitourinary toxicities for Weeks 1-7 using chi-square test were 0.072, 0.627, 0.389, 0.538, 0.123, 0.06, and 0.012; the p values for acute gastrointestinal toxicities were 0.512, 0.09, 0.031, 0.031, 0.003, < 0.0001, and 0.004, respectively. Pairwise comparison (Wilcoxon rank-sum test) showed statistically significant lower acute toxicity in Group C than Group B (e.g., p values, Weeks 1-7 for gastrointestinal toxicity: 0.633, 0.056, 0.010, 0.014, < 0.0001, < 0.0001, and < 0.0001, respectively) in the latter part of the treatment course. No correlation was found between the extent of toxicity and the patient age or the overall treatment time. Also, no correlation was found between the degree of toxicity and the radiation dose and fraction size, within the narrow ranges used (65-70 Gy and 180-200 cGy, respectively). A trend suggesting increased severity of toxicity with increase in the volume of treatment was seen.

CONCLUSION

The findings in this retrospective study need to be confirmed by other prospective studies.

Radiation therapy in prostate cancer: whole pelvis with prostate boost or small field to prostate?

The purpose of this retrospective study is to identify prostate cancer patients who would benefit from pelvic nodes irradiation (whole pelvis) as opposed to the small-field irradiation to the prostate only. Between 1975 and 1983, 126 patients were treated by whole pelvis (4,600-5,000 cGY) with prostate boost (2,000 cGY) radiation (WP + P). Median follow-up was six years and six months. Comparison was made with historic control of 116 patients irradiated at the same institutions between 1971 and 1977 by small field to the prostate (P) to a dose of 7,000-7,500 cGY. There was a significant five-year survival improvement in the current WP + P radiation in Stage C (72% vs 40%, p = 0.0004) and Stage B (92% vs 70%, p = 0.025) but not in Stage A2 patients. However, WP + P radiation significantly improved disease-free survival (DFS) in only well and moderately but not in poorly differentiated carcinoma with a combined well and moderately differentiated five-year DFS of 63 percent compared with the 45 percent in P radiation (p = 0.0228). Local tumor control was significantly improved in WP + P radiation in only Stage C cancers with their local recurrence rate 16 percent as compared with the 34 percent in P radiation (p = 0.0172). Although acute radiation reactions were more frequent in WP + P than P radiation (61% vs 41%, p = 0.0022), chronic radiation morbidity in both series were similar. Thus, whole pelvis with prostate boost radiation should be utilized in Stage B and Stage C cancers as this has shown to increase the survival of the patient without increasing chronic radiation morbidity.

Prostate cancer: a model of cancer in the elderly

Prostate cancer is the most common malignancy in men over 70. Chronic course of the disease and multiple therapeutic options allow a customized management of the patient's individual problems. Prognostic factors are stage, size of primary tumors, serum acid phosphatase levels, number of metastases, ureteral obstruction and patient's age. In localized disease, surgery and radiation therapy are equally effective for patients with a life expectancy less than or equal to 10 years. Surgery may be superior to radiation if longer survival is expected. In locally advanced disease radiation therapy is preferred to surgery, due to a lower rate of complications. Management of metastatic disease requires offsetting androgen effects by castration or by antiandrogens. Orchiectomy, the safest way to produce castration, is unacceptable to 50% of patients. LHRH analogs are safer than estrogens, but more expensive; the risk of tumor flare up controindicates these compounds in life-threatening situations. The use of ketoconazole is limited by long-term toxicity, but may be life-saving in life-threatening situations, due to a rapid onset of action. Antiandrogens are as effective as castration, but are not commercially available in the USA. Alternative treatments include Estracyt, intermittent estrogentherapy, progesterone derivative and aminogluthetimide. Radical prostatectomy and radiation therapy to the prostate cause erectile impotence with persistence of orgasmic sensations. These patients are ideal candidates for erection-restoring interventions, such as intrapenile injections or penile implants.

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

From 1978 to 1983 the Radiation Therapy Oncology Group conducted a study to evaluate the role of elective pelvic lymph node irradiation in carcinoma of the prostate. Eligible patients were those with clinical Stage A2 (occult disease with more than 3 positive chips and poorly differentiated tumor) and Stage B without clinical (lymphangiogram) or biopsy evidence of lymph node involvement. The patients were randomized to receive 6.5 weeks of either prostatic bed irradiation only 6500 cGy at 180-200 cGy per treatment or pelvic node irradiation to 4500 cGy with a boost of 2000 cGy to the prostatic bed bringing the total dose to 6500 cGy. As of February, 1988, the median follow up has been 7 years and there were 445 analyzable cases who were evaluated for local control, incidence of distant metastases, ned (no evidence of disease) survival and survival. The results of the study revealed no statistically significant benefit of elective pelvic irradiation.

Prostatic carcinoma: limited field irradiation

This is a retrospective study of 251 patients with histologically proven adenocarcinoma treated primarily with limited field radiotherapy techniques, under the principle direction of authors JMV and JPG, between 1968 and 1981 in San Francisco, California. All patients are followed for a minimum of 3 years; mean follow-up is 7.3 years. Routine clinical staging procedures included: H&P, digital prostate exam, cystoscopy, biopsy, blood studies including serum acid phosphatase, and imaging studies including chest X ray, IVP, bone survey or radionucleotide bone scan, and in recent years, pelvic CT scans. Twelve patients are Stage A1, 37-Stage A2, 50-Stage B, 140-Stage C1 and 12-Stage C2. Ninety percent of all cases and 85% of Stage C patients were treated with limited fields to the prostate and periprostatic volume only. Total doses were prescribed at midplane or isocenter and were generally 6500-7000 cGy, daily doses of 180-200 cGy, 5 days per week. Actuarial 5- and 10-year survival rates are: entire population-69% and 47%; Stage A1-74% and 50%; Stage A2-81% and 67%; Stage B-84% and 53%; Stage C1-63% and 42%; Stage C2-32% and 11%. The 5- and 10-year disease-free actuarial survivals are: entire population-71% and 50%; Stage A1-89% and 74%; Stage A2-82% and 69%; Stage B-71% and 52%; Stage C1-67% and 44%; Stage C2-0%. Sites of recurrence, alone or as a component of the failure pattern are: 37 (15%) local, 11 (4%) symptomatic regional recurrence (lower extremity edema, pelvic pain/sciatica, hydroureteronephrosis), and 87 (35%) distant metastasis. Seven (3%) had unknown sites of failure. Local-regional failure occurred in 42% of Stage C2 patients. Concomitant hormonal therapy has no survival impact on Stage C1 patients and poorly differentiated histology is associated with decreased determinate and disease-free survival rate of 5 years. Complications correlate with treatment technique, being more frequent with single field per day treatment plans. In patients treated with multiple fields per day or rotational plans, complications occur in less than 8% of patients and major complications have not occurred.

Definitive radiotherapy of prostatic cancer: the Norwegian Radium Hospital's experience (1976-1982)

During the years 1976 to 1982 definitive curatively aimed radiotherapy to the primary tumor was given to 53 patients with prostatic cancer confined to the true pelvis (T0, 2; T1-2, 19; T3, 24; T4, 8; N0, 18; N+, 2; Nx, 33); all patients were of the Mo-category. The pelvic lymph nodes received a total dose of 2 Gy X 25 by means of an anterior and posterior radiation field. The prostatic gland was irradiated by an additional booster dose of 2 Gy X 10 given to a perineal field. Twenty-four patients have relapsed after their prostatic radiotherapy, only three of them within the irradiated area. For the patients with T0-T2 tumors, the 5-year crude survival was 69%, whereas it was only 37% for patients with T3 tumors. Thirty-five patients developed intestinal (26 patients) and/or urogenital (23 patients) radiation side effects. In three patients a colostomy had to be performed owing to rectal stricture or fistula. The poor survival after radiotherapy in the present series is probably due to a high incidence of unrecognized pelvic lymph node metastases. In the future only prostatic cancer patients without pelvic lymph node spread will be considered candidates for definitive radiotherapy. An optimal radiation technique is mandatory in order to avoid major radiotherapy-induced toxicity.