Carcinoma of the prostate treated by pelvic node dissection, iodine-125 seed implant and external irradiation: a study of rectal complications

The University of Missouri-Columbia protocol for localised cancer of the prostate calls for pelvic node dissection, 10000 cGy at the periphery of the prostate from 125I and 4000 cGy in 20 fractions to the whole pelvis using supervoltage X-ray therapy. Rectal complications were studied in 104 patients; acute and chronic reactions were defined. During external irradiation 54% did not develop diarrhoea, 43% had mild diarrhoea and 3% had severe diarrhoea. In the chronic stage 77% did not have diarrhoea, 12% had delayed, non-distressing rectal bleeding which did not need specific treatment or needed only simple treatment, 7% had prolonged distressing proctitis and 4% had rectal ulceration or recto-urethral fistula necessitating colostomy. Each of the four patients who had colostomy had an additional aetiological factor (arterial disease, pelvic inflammation, additional radiation, pelvic malignancy or second operation). None of the patients entered in the combined brachytherapy and teletherapy programme, and in whom 0.5 cm space was maintained between the closest seed and the rectal mucosa, developed prolonged proctitis.     

Diverting loop colostomy for the treatment of refractory gastrointestinal bleeding secondary to radiation proctitis.

Chronic radiation proctitis is an uncommon and serious complication of radiotherapy for pelvic malignancies. It has been suggested that fecal stream diversion decreases bowel irritation, resulting in decreased rectal bleeding. We report on the outcome of patients after a diverting loop colostomy for the treatment of severe radiation proctitis. All consecutive patients with chronic proctitis treated with diverting loop colostomy for bleeding at one institution between October 1991 and June 1999 were studied. Four patients presented with rectal bleeding and diarrhea, and two patients had only bleeding. The mean dose of radiation received was 6,115.11 +/- 955.11 rad. Symptoms of chronic proctitis appeared at varying intervals of time after radiation, ranging from 14 months to 17 years. There were no operative complications. During follow-up (36 +/- 29 months), only one of nine patient continued to bleed. Four patients died during the study (cancer relapse, two patients; heart failure, one patient; one death was caused by severe radiation proctitis). Diverting sigmoid loop colostomy, when performed in properly selected patients with severe bleeding secondary to radiation proctitis refractory to medical management, is well tolerated and effective.     

Preliminary toxicity and prostate-specific antigen response of a Phase I/II trial of neoadjuvant hormonal therapy, 103Pd brachytherapy, and three-dimensional conformal external beam irradiation in the treatment of locally advanced prostate cancer

PURPOSE: Standard therapies for locally advanced prostate cancer have resulted in suboptimal disease control rates. A Phase I/II trial was designed for patients with positive seminal vesicle biopsies, prostate-specific antigen (PSA) >15 ng/ml, Gleason score > or =8 or clinical classification T2c-T3 to improve local control and to test the tolerance of the prostate to high-dose radiation by using neoadjuvant hormonal therapy, 103Pd brachytherapy, and conformal three-dimensional external beam radiation therapy (EBRT). This article outlines treatment-related morbidity and PSA response to this regimen and analyzes the effect of escalating doses of brachytherapy. METHODS AND MATERIALS: Forth-three patients with T1c-T3 prostate cancer were enrolled in a Phase I/II trial from March 1994 through September 1997. Follow-up ranged from 12 to 64 months (median, 32 months). Pretreatment PSA ranged from 2.1 to 202 ng/ml (median, 16 ng/ml). Seventy-seven percent (33 of 43) of patients had high-grade tumors (score > or =7). Seventy-four percent (32 of 43) had stage > or =T2c. A total of 21 (49%) patients had positive seminal vesicle biopsies. Treatment consisted of hormonal therapy for 3 months with leuprolide and flutamide followed by a 103Pd implant and, 2 months later, 59.4 Gy of three-dimensional EBRT. Hormonal therapy was continued for 9 months. The planned 103Pd dose was escalated from 57 Gy (13 patients) to 77 Gy (13 patients) to 86 Gy (17 patients). RESULTS: The actuarial freedom from PSA failure (PSA>0.5 ng/ml) at 4 years was 74%. There were no significant differences found when analyzing patients by presenting PSA or seminal vesicle status. There was a trend toward improved outcome with higher doses delivered to the prostate via the implant. Patients receiving doses > or =65 Gy (31 patients) had a freedom from PSA failure rate at 4 years of 89.5%, compared with 52.5% for those receiving doses <65 Gy (10 patients; p=0.08). The last PSA values for those patients free from PSA failure were < or =0.1 ng/ml in 25 (69%), >0.1-0.2 ng/ml in 5 (14%), and >0.2-0.5 ng/ml in 6 (17%). The actuarial freedom from developing Grade 2 proctitis was 75% at 4 years. There was a trend toward increased proctitis with increasing prostate implant doses. Patients with doses < or =70 Gy (n=12) had a 92% freedom from Grade 2 proctitis compared with 67.5% for those with doses delivered to 90% of the gland from a dose-volume histogram of >70 Gy (n=29) (p=0.15). There were no cases of Grade 3 or 4 proctitis. The 3-year actuarial preservation of sexual potency rate was 43%. CONCLUSIONS: The preliminary results from this regimen show an improvement in PSA control for this group of locally advanced prostate cancer patients over more standard therapies. To maximize control while minimizing toxicity, doses of 65-70 Gy of 103Pd should be used when 59.4 Gy of three-dimensional EBRT is delivered. Longer follow-up will be needed to further substantiate these findings.     

Frequency of coexistent disease at CT in patients with prostate carcinoma selected for definitive radiation therapy: is limited treatment-planning CT adequate?

PURPOSE: To document the frequency of clinically important coexistent disease depicted at contrast material-enhanced abdominal and pelvic computed tomography (CT) in patients undergoing definitive radiation therapy for prostate carcinoma, as such lesions might be missed at limited nonenhanced treatment-planning CT. MATERIALS AND METHODS: Of 133 consecutive patients with prostate carcinoma who were referred to the radiation oncology division between January 1, 1994, and December 31, 1996, 77 underwent definitive radiation therapy that required either contrast-enhanced abdominal and pelvic CT (n = 67) or contrast-enhanced pelvic CT (n = 10). Results of these studies were reviewed and retrospectively categorized. RESULTS: Forty-eight (62%) of the 77 patients had either negative studies or minor abnormalities that did not require further follow-up. Only two patients (3%) had major abnormalities that required intervention. Five patients (6%) had new findings of clinically important coexistent disease, but no intervention was required. CONCLUSION: The incidence of clinically important coexistent disease in patients with prostate carcinoma who are referred for definitive radiation therapy is low. Therefore, contrast-enhanced abdominal and pelvic CT in addition to treatment-planning CT is of limited value.     

Image-guided intensity-modulated radiotherapy for prostate cancer: Dose constraints for the anterior rectal wall to minimize rectal toxicity

Rectal adverse events (AEs) are a major concern with definitive radiotherapy (RT) treatment for prostate cancer. The anterior rectal wall is at the greatest risk of injury as it lies closest to the target volume and receives the highest dose of RT. This study evaluated the absolute volume of anterior rectal wall receiving a high dose to identify potential ideal dose constraints that can minimize rectal AEs. A total of 111 consecutive patients with Stage T1c to T3a N0 M0 prostate cancer who underwent image-guided intensity-modulated RT at our institution were included. AEs were graded according to the Common Terminology Criteria for Adverse Events, version 4.0. The volume of anterior rectal wall receiving 5 to 80 Gy in 2.5-Gy increments was determined. Multivariable Cox regression models were used to identify cut points in these volumes that led to an increased risk of early and late rectal AEs. Early AEs occurred in most patients (88%); however, relatively few of them (13%) were grade ≥2. At 5 years, the cumulative incidence of late rectal AEs was 37%, with only 5% being grade ≥2. For almost all RT doses, we identified a threshold of irradiated absolute volume of anterior rectal wall above which there was at least a trend toward a significantly higher rate of AEs. Most strikingly, patients with more than 1.29, 0.73, or 0.45 cm³ of anterior rectal wall exposed to radiation doses of 67.5, 70, or 72.5 Gy, respectively, had a significantly increased risk of late AEs (relative risks [RR]: 2.18 to 2.72; p ≤ 0.041) and of grade ≥ 2 early AEs (RR: 6.36 to 6.48; p = 0.004). Our study provides evidence that definitive image-guided intensity-modulated radiotherapy (IG-IMRT) for prostate cancer is well tolerated and also identifies dose thresholds for the absolute volume of anterior rectal wall above which patients are at greater risk of early and late complications.     

Rectal wall sparing by dosimetric effect of rectal balloon used during intensity-modulated radiation therapy (IMRT) for prostate cancer.

The use of an air-filled rectal balloon has been shown to decrease prostate motion during prostate radiotherapy. However, the perturbation of radiation dose near the air-tissue interfaces has raised clinical concerns of underdosing the prostate gland. The aim of this study was to investigate the dosimetric effects of an air-filled rectal balloon on the rectal wall/mucosa and prostate gland. Clinical rectal toxicity and dose-volume histogram (DVH) were also assessed to evaluate for any correlation. A film phantom was constructed to simulate the 4-cm diameter air cavity created by a rectal balloon. Kodak XV2 films were utilized to measure and compare dose distribution with and without air cavity. To study the effect in a typical clinical situation, the phantom was computed tomography (CT) scanned on a Siemens DR CT scanner for intensity-modulated radiation therapy (IMRT) treatment planning. A target object was drawn on the phantom CT images to simulate the treatment of prostate cancer. Because patients were treated in prone position, the air cavity was situated superiorly to the target. The treatment used a serial tomotherapy technique with the Multivane Intensity Modulating Collimator (MIMiC) in arc treatment mode. Rectal toxicity was assessed in 116 patients treated with IMRT to a mean dose of 76 Gy over 35 fractions (2.17-Gy fraction size). They were treated in the prone position, immobilized using a Vac-Loktrade mark bag and carrier-box system. Rectal balloon inflated with 100 cc of air was used for prostate gland immobilization during daily treatment. Rectal toxicity was assessed using modifications of the Radiation Therapy Oncology Group (RTOG) and late effects Normal Tissue Task Force (LENT) scales systems. DVH of the rectum was also evaluated. From film dosimetry, there was a dose reduction at the distal air-tissue interface as much as 60% compared with the same geometry without the air cavity for 15-MV photon beam and 2x2-cm field size. The dose beyond the interface recovered quickly and the dose reductions due to air cavity were 50%, 28%, 11%, and 1% at 2, 5, 10, and 15 mm, respectively, from the distal air-tissue interface. Evaluating the dose profiles of the more clinically relevant situation revealed the dose at air-tissue interface was approximately 15% lower in comparison to that without an air cavity. The dose built up rapidly so that at 1 and 2 mm, there was only an 8% and 5% differential, respectively. The dosimetric coverage at the depth of the posterior prostate wall was essentially equal with or without the air cavity. The median follow-up was 31.3 months. Rectal toxicity profile was very favorable: 81% (94/116) patients had no rectal complaint while 10.3% (12/116), 6.9% (8/116), and 1.7% (2/116) had grade 1, 2, and 3 toxicity, respectively. There was no grade 4 rectal toxicity. DVH analysis revealed that none of the patients had more than 25% of the rectum receiving 70 Gy or greater. Rectal balloon has rendered anterior rectal wall sparing by its dosimetric effects. In addition, it has reduced rectal volume, especially posterior and lateral rectal wall receiving high-dose radiation by rectal wall distension. Both factors may have contributed to decreased rectal toxicity achieved by IMRT despite dose escalation and higher than conventional fraction size. The findings have clinical significance for future very high-dose escalation trials whereby radiation proctitis is a major limiting factor.     

弥散型He-Ne激光治疗放射性直肠炎的临床研究

目的探讨弥散型He-Ne激光直肠内照射对放射性直肠炎的临床治疗作用。方法将功率为30 mW、能量密度为3.62 J/cm2弥散型He-Ne激光导入直肠,使He-Ne激光直接照射直肠病变黏膜,观察患者直肠出血、直肠疼痛、腹泻等,比较治疗前后患者直肠黏膜病理组织学的改变。结果 He-Ne激光可以显著减少放射性直肠炎患者的直肠出血,对直肠疼痛、腹泻等症状的影响不大,能明显减轻黏膜组织的炎症反应,并能促进黏膜的修复。结论弥散性He-Ne激光直肠腔内照射对放射性直肠炎所致的直肠出血有较好的治疗作用。     

Management of epidural cauda equina disease of prostate cancer by radiotherapy

OBJECTIVE: Secondary prostate cancer affection of the cauda equina (SPCCE) can be an ultimate cause of morbidity and mortality. Since the results of management of this particular disease condition remain largely unknown, a retrospective case review was undertaken to determine the effects of treatment by radiation in SPCCE patients. METHODS: The records of 12 patients with SPCCE treated at the Division of Therapeutic Radiology during the period 1984 to 1998 were reviewed. The administered total radiation dosage ranged from 6 Gy to 32 Gy (average, 26.6 +/- 2.0 Gy). Two individuals underwent decompressive laminectomy and bilateral orchiectomy at the time of SPCCE and prostate cancer diagnoses. Ten patients had prior hormonal manipulative treatment (orchiectomy, estrogen, or Flutamide therapy). RESULTS: Pain was relieved in three of four symptomatic patients (75%). Five of nine patients unable to walk before therapy could walk after treatment. One of two individuals with anal or bladder sphincter dysfunction improved following irradiation. The overall mean duration of survival was five months. With treatment, survival was approximately three times as long for ambulatory versus non-ambulatory patients. CONCLUSION: We conclude that radiation treatment is efficacious in promoting palliation of SPCCE, although it may not prolong life.     

Late rectal and urinary toxicity from conformal, dose-escalated radiation therapy for prostate cancer: a prospective study of 402 patients

This study investigates the rate of late rectal and urinary toxicity from three-dimensional conformal radiation therapy (3DCRT) for localized prostate cancer. The influence of neoadjuvant androgen deprivation (AD) on toxicity rates was also examined. A total of 402 men at Liverpool and Westmead hospitals received radical 3DCRT for localized prostate cancer between 1999 and 2003. Patients received either 70 Gy or 74 Gy, according to their prognostic risk grouping and or date of commencing radiation therapy (RT). Late rectal and urinary toxicity data were collected prospectively using Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer criteria. The median follow up of this cohort was 43.5 months. At 36 months, the cumulative incidence of >or=grade 2 rectal and urinary toxicities was 6.7 and 17.5%, respectively. Peak prevalence of late urinary toxicity occurred at 36 months (9.5%), although late rectal toxicity was highest at 12 months (2.9%) from completion of 3DCRT. The use of AD did not cause additional late toxicities. Patients receiving 74 Gy did not experience significantly worse toxicities than the group receiving 70 Gy.     

Radiation-associated changes in the length of telomeres in peripheral leukocytes from inpatients with cancer

Abstract

Purpose: The telomere length of somatic cells shortens with age and with other endogenous and exogenous pathogenic factors. However, the effects of radiation therapy on telomere DNA of non-cancer tissue have not been thoroughly investigated. This study analyzed the telomere length of inpatients with cancer treated with radiation therapy to see whether the telomere lengths change in response to therapeutic radiation.

Materials and methods: Twenty-five patients were enrolled in the study. The patients had lung cancer, prostate cancer, thyroid cancer, hepatoma, or rectal cancer. They received radiation therapy with a dose range of 15–74 Gy. The telomere lengths and telomere length distribution in peripheral leukocytes were analyzed by using a Southern blot-based method.

Results: The telomere length and the telomere length distribution of the peripheral leukocytes did not change after radiation therapy. However, there was a significant proportional decrease in the short telomere fraction (< 4.4 kb) per day and per Gy.

Conclusions: This observation suggested that the telomere length distribution of peripheral leukocytes could be affected by radiation therapy, and that the effect of radiation tends to appear in cells with short telomeres. Radiation therapy-associated somatic telomere length change within a short range of time, about three months or shorter, can be detected by analyzing the mean telomere length and telomere length distribution.     

The prostate: diagnostic evaluation of metastatic disease

One of the single most important considerations in clinical management of the patient with prostate cancer is whether or not metastatic disease is present. The identification of metastatic disease in a patient with newly diagnosed prostate cancer represents an absolute contraindication to definitive local therapies such as radial prostatectomy or radiation therapy. Similarly, the identification of metastatic disease in a patient with disease recurrence after definitive local therapy represents an absolute contraindication to salvage radiotherapy or cryosurgery. Patients with metastatic disease do not benefit from definitive therapy, and the cost and morbidity associated with such treatment should therefore be avoided in these patients. Because of the significance of metastatic disease to clinical management, it is important for the diagnostic radiologist to be aware of important considerations in the metastatic work-up of patients with newly diagnosed prostate cancer and patients with suspected cancer recurrence after definitive local therapy.     

Localized prostate cancer: use of serial prostate-specific antigen measurements during radiation therapy.

The serum half-life of prostate-specific antigen (PSA) after radical prostatectomy is about 3 days; to the authors' knowledge, the PSA half-life during radiation therapy (RT) has not been investigated with weekly serial measurements. To determine the rate of decline and the half-life of PSA, serial measurements were obtained during 6-8 weeks of external-beam RT for localized prostate cancer. PSA values were determined immediately before and approximately 24 hours after the first dose of RT; thereafter, weekly measurements were made. There was a downward trend in PSA levels in 19 patients, with a median half-life of 58.5 days; the mean decline was 1.6% per day. However, in four patients, PSA levels either rose and fell to pre-RT values or increased steadily. The effect of digital rectal examination (DRE) on PSA levels was also analyzed. When the dates of DRE and subsequent PSA levels were inspected, no increase in PSA levels subsequent to DRE was found, although three of the four patients in whom PSA levels did not decrease underwent multiple DREs. The authors found a statistically significant (P = .023) transient elevation in the mean PSA values after the first fraction of RT (2 Gy) was administered; the mechanism and importance of which are not known.     

Influence of Organ at Risk Definition on Rectal Dose-Volume Histograms in Patients with Prostate Cancer Undergoing External-Beam Radiotherapy

PURPOSE: To evaluate rectal dose-volume relations during three-dimensional conformal radiotherapy of patients with prostate cancer by means of different rectal volume contours. PATIENTS AND METHODS: 55 patients with prostate cancer underwent three-dimensional conformal external-beam radiotherapy. Rectal dose-volume histograms were calculated for four separately contoured rectal volumes in all patients resulting in four groups. In group 1 the outer rectal wall was contoured two CT slices above and below the planning target volume. The rectal contour of group 2 was drawn from the anal verge up to the sigmoid. Furthermore, the posterior half of the rectum was contoured for both volumes mentioned above (groups 1a and 2a). Statistical analysis was then performed using nonparametric Wilcoxon tests. RESULTS: The mean target dose was 72.9 Gy (standard deviation [SD] +/- 2.1 Gy). The minimum target dose was 70.2 Gy. Mean rectum dose (+/- SD) over all patients was 50.7 Gy (+/- 4.6 Gy), 45.2 Gy (+/- 5.4 Gy), 43.2 Gy (+/- 4.2 Gy), and 38.7 Gy (+/- 5.5 Gy) for group 1, 2, 1a, and 2a, respectively. The corresponding volumes receiving > or = 70 Gy for groups 1 and 2 were 14.0% (+/- 5.3%) and 11.9% (+/- 4.5%). These differences were statistically significant. Comparison of minimum and mean rectal dose also revealed a statistically significant difference toward higher doses in groups 1 and 1a (p < 0.001). Maximum rectal doses for groups 1 and 2 as well as for groups 1a and 2a revealed no statistically significant difference (p = 1.0). CONCLUSION: Data from the literature on normal-tissue complication probability (rectal bleeding) refer to different rectal contours. When applying dose restrictions to the rectum, contouring becomes a significant factor that determines the risk of rectal toxicity. The results of this study show that different ways of rectal contouring significantly influence doses to the rectum. The influence of organ at risk contouring should be considered thoroughly in conformal radiotherapy of prostate cancer patients, especially in dose escalation studies. It is recommended to calculate the doses for absolute rectal volumes and correlate these data with toxicity in order to be able to achieve comparable results among different institutions.     

High-dose-rate brachytherapy for localized prostate adenocarcinoma post abdominoperineal resection of the rectum and pelvic irradiation: Technique and experience

PurposeTreatment options are limited for patients with localized prostate cancer and a prior history of abdominoperineal resection (APR) and pelvic irradiation. We have previously reported on the successful utility of high-dose-rate (HDR) brachytherapy salvage for prostate cancer failing definitive external beam radiation therapy (EBRT). In this report, we describe our technique and early experience with definitive HDR brachytherapy in patients post APR and pelvic EBRT.Patients and MethodsSix men with newly diagnosed localized prostate cancer had a prior history of APR and pelvic EBRT. Sixteen to 18 HDR catheters were placed transperineally under transperineal ultrasound–guidance. The critical first two catheters were placed freehand posterior to the inferior rami on both sides of the bulbar urethra under cystoscopic visualization. A template was used for subsequent catheter placement. Using CT-based planning, 5 men received 36 Gy in six fractions as monotherapy. One patient initially treated with EBRT to 30 Gy, received 24 Gy in four fractions.ResultsMedian age was 67.5 (56–74) years. At a median followup of 26 (14–60) months, all patients are alive and with no evidence of disease per the Phoenix definition of biochemical failure, with a median prostate-specific antigen nadir of 0.19 ng/mL. Three men have reported grade 2 late genitourinary toxicity. There has been no report of grade 3–5 toxicity.ConclusionTransperineal ultrasound–guided HDR brachytherapy using the above technique should be considered as definitive therapy for patients with localized prostate cancer and a prior history of APR and pelvic EBRT.     

Prostate-specific antigen: effect of pelvic irradiation

PURPOSE: To study the effect of pelvic irradiation on the level of serum prostate-specific antigen (PSA). MATERIALS AND METHODS: Of 33 patients treated with pelvic irradiation to the prostate and seminal vesicles for anal and rectal cancer, 26 received 50.4 Gy or more (1. 8 Gy per fraction), and seven received 25.0 Gy (5.0 Gy per fraction). PSA levels were measured before (n = 33), during (n = 26), and after radiation therapy (n = 33). In 24 patients, follow-up (mean, 15.7 months) PSA data were obtained. Actual and pretreatment PSA levels were compared (Wilcoxon rank test). RESULTS: During the first 3 weeks in all patients, PSA levels rose steeply, culminating in a 3. 7-fold increase (P =.02). At the end of radiation therapy (7 weeks), the PSA level was no longer significantly different from the pretreatment value. In the long term, the PSA level decreased to 77% of the pretreatment value (P =.04). CONCLUSION: Irradiation of the prostate initially elevates serum PSA levels. Apparently PSA release is determined by the duration of radiation therapy, while the accumulated dose has a minor effect. In the long term, PSA production is impaired after radical radiation therapy. PSA reference concentrations should be adjusted to these reduced levels.     

High-dose-rate brachytherapy for prostate cancer in a previously radiated patient with polyethylene glycol hydrogel spacing to reduce rectal dose: Case report and review of the literature

PurposeTo describe the use of a temporary spacer to reduce rectal dose prior to prostate radiation in a man with prior pelvic radiotherapy and review the relevant literature.Methods and MaterialsA healthy 57-year-old man presented with high-risk prostate cancer (Gleason score of 8, prostate-specific antigen level [PSA] 12.6 ng/mL, T3a by magnetic resonance imaging [MRI]), only 2.5 years after a low anterior resection followed by pelvic chemo-radiotherapy to 50.4 Gy for a locally advanced rectal cancer. Due to the prior radiation, he was not felt to be a candidate for surgery or external beam radiation, so he chose long-term androgen deprivation therapy (ADT) plus high-dose-rate brachytherapy to 36 Gy in 6 fractions. To reduce the radiation dose to the anterior rectal wall, 10 mL of a polyethylene glycol hydrogel spacer was injected between the prostate and rectum and created between 1.4 and 1.5 cm of separation along the length of the prostate.ResultsTwo randomized trials demonstrating that local therapy plus ADT improves overall survival compared to ADT alone provided the rationale for additional prostate radiotherapy in this otherwise healthy patient. Salvage brachytherapy is associated with a 3.4% rate of rectal fistula among the 251 cases reported in the literature from 2000–2007, with rates as high as 12% in one series. The spacer allowed the rectal dose constraint goals to be easily met.ConclusionsInjecting an absorbable polyethylene glycol hydrogel to separate the prostate and rectum appears to be associated with decreased maximum and mean rectal doses, and may have particular utility in previously irradiated patients.     

The clinical utility of prostate-specific antigen and bone scintigraphy in prostate cancer follow-up.

To assess the value of serum prostate-specific antigen (PSA) in prostate cancer follow-up, we prospectively studied 107 consecutive patients with: (1) pathologically confirmed prostate cancer; (2) definitive prostatectomy and/or radiation therapy greater than or equal to 3 mo prior to bone scanning; and (3) one bone scan and serum PSA sampling within 3 mo of each other. The mean and range of patient follow-up since definitive therapy was 1.6 and 0.5-8 yr, respectively. Abnormal bone scans were correlated with pertinent radiographs. Of 107 bone scans, 16 demonstrated metastatic bone disease. A PSA value of less than or equal to 8 ng/ml excluded bone metastases with a predictive value of a negative test of 98.5%. Without radiographic correlation, abnormal bone scans rarely represented metastases if the PSA value was less than or equal to 8 ng/ml. In summary, serum PSA concentration determines the need for follow-up bone scanning and assists in scan interpretation in patients status post definitive therapy for prostate cancer.     

The impact of a rectal hydrogel spacer on dosimetric and toxicity outcomes among patients undergoing combination therapy with external beam radiotherapy and low-dose-rate brachytherapy

PurposeRectal hydrogel spacers have been shown to decrease rectal radiation dose and toxicity. In this study, we compared prostate and rectal dosimetry and acute toxicity outcomes in patients who had and had not received a rectal hydrogel spacer prior to combination therapy with external beam radiotherapy and low-dose-rate brachytherapy.Materials and MethodsAll patients with intermediate-risk and high-risk prostate cancer who received combination therapy at our institution were identified between 2014 and 2019. Dosimetric outcomes of brachytherapy implants and quality of life (QOL) outcomes were compared between patients who had and had not received a hydrogel spacer.ResultsA Total of 168 patients meeting our inclusion criteria were identified. Twenty-two patients had received a rectal hydrogel spacer, among whom the mean separation between the rectum and prostate was 7.5 mm, and the V100_rectum was reduced by 47% (0.09 cc vs. 0.17 cc, p = 0.04). There was no difference in the percentage of patients achieving a D90 of ≥100 Gy between those who had and had not received a spacer. The mean rate of change in I-PSS and SHIM scores did not differ between the two groups at 2 months after PID.ConclusionLDR brachytherapy appears feasible after the placement of a rectal hydrogel spacer. While there was a significantly reduced V100_rectum among patients who had received a hydrogel spacer, there was no statistically significant difference in patients achieving a D90_prostate of ≥100 Gy. Although there was no difference appreciated in QOL scores, the length of follow-up was limited in the rectal-spacer group.