Intratumoral androgen biosynthesis associated with 3β-hydroxysteroid dehydrogenase 1 promotes resistance to radiotherapy in prostate cancer

Half of all men with advanced prostate cancer (PCa) inherit at least 1 copy of an adrenal-permissive HSD3B1 (1245C) allele, which increases levels of 3β-hydroxysteroid dehydrogenase 1 (3βHSD1) and promotes intracellular androgen biosynthesis. Germline inheritance of the adrenally permissive allele confers worse outcomes in men with advanced PCa. We investigated whether HSD3B1 (1245C) drives resistance to combined androgen deprivation and radiotherapy. Adrenally permissive 3βHSD1 enhanced resistance to radiotherapy in PCa cell lines and xenograft models engineered to mimic the human adrenal/gonadal axis during androgen deprivation. The allele-specific effects on radiosensitivity were dependent on availability of DHEA, the substrate for 3βHSD1. In lines expressing the HSD3B1 (1245C) allele, enhanced expression of DNA damage response (DDR) genes and more rapid DNA double-strand break (DSB) resolution were observed. A correlation between androgen receptor (AR) expression and increased DDR gene expression was confirmed in 680 radical prostatectomy specimens. Treatment with the nonsteroidal antiandrogen enzalutamide reversed the resistant phenotype of HSD3B1 (1245C) PCa in vitro and in vivo. In conclusion, 3βHSD1 promotes prostate cancer resistance to combined androgen deprivation and radiotherapy by upregulating DNA DSB repair. This work supports prospective validation of early combined androgen blockade for high-risk men harboring the HSD3B1 (1245C) allele.

Outcomes after PD-103 versus I-125 for low dose rate prostate brachytherapy monotherapy: An international, multi-institutional study

BACKGROUND AND PURPOSE

Pd-103 and I-125 are commonly used in low dose rate (LDR) brachytherapy for prostate cancer. Comparisons of outcomes by isotope type are limited, but Pd-103 has distinct radiobiologic advantages over I-125 despite its lesser availability outside the United States. We evaluated oncologic outcomes after Pd-103 vs I-125 LDR monotherapy for prostate cancer.

MATERIALS AND METHODS

We retrospectively analyzed databases at 8 institutions for men who received definitive LDR monotherapy with Pd-103 (n = 1,597) or I-125 (n = 7,504) for prostate cancer. Freedom from clinical failure (FFCF) and freedom from biochemical failure (FFBF) stratified by isotope were analyzed by Kaplan-Meier univariate and Cox multivariate analyses. Biochemical cure rates (prostate-specific antigen level ≤ 0.2 ng/mL between 3.5 and 4.5 years of follow-up) by isotype were calculated for men with at least 3.5 years of follow-up and compared by univariate and multivariate logistic regression.

RESULTS

Compared with I-125, Pd-103 led to higher 7-year rates of FFBF (96.2% vs 87.6%, P < 0.001) and FFCF (96.5% vs 94.3%, P < 0.001). This difference held after multivariate adjustment for baseline factors (FFBF hazard ratio [HR] = 0.31, FFCF HR = 0.49, both P < 0.001). Pd-103 was also associated with higher cure rates on univariate (odds ratio [OR] = 5.9, P < 0.001) and multivariate (OR = 6.0, P < 0.001) analyses. Results retained significance in sensitivity analyses of data from the 4 institutions that used both isotopes (n = 2,971).

CONCLUSIONS

Pd-103 monotherapy was associated with higher FFBF, FFCF, and biochemical cure rates, and suggests that Pd-103 LDR may lead to improved oncologic outcomes compared with I-125.

A biochemical definition of cure after brachytherapy for prostate cancer

BACKGROUND AND PURPOSE

To identify a PSA threshold value at an intermediate follow-up time after low dose rate (LDR) prostate brachytherapy associated with cure, defined as long-term (10-15 year) freedom from prostate cancer.

MATERIALS AND METHODS

Data from 7 institutions for 14,220 patients with localized prostate cancer treated with LDR brachytherapy, either alone (8552) or with external beam radiotherapy (n = 1175), androgen deprivation (n = 3165), or both (n = 1328), were analyzed. Risk distribution was 42.4% favorable, 49.2% intermediate, and 8.4% high-risk. Patients with clinical failure before 3.5 years were excluded. Kaplan-Meier analysis was used with clinical failure (local, distant, regional or biochemical triggering salvage) as an endpoint for each of four PSA categories: PSA ≤ 0.2, >0.2 to ≤0.5, >0.5 to ≤1.0, and >1.0 ng/mL. PSA levels at 4 years (±6 months) in 8746 patients without clinical failure were correlated with disease status at 10-15 years.

RESULTS

For the 77.1% of patients with 4-year PSA ≤ 0.2, the freedom-from-recurrence (FFR) rates were 98.7% (95% CI 98.3-99.0) at 10 years and 96.1% (95% CI 94.8-97.2) at 15 years. Three independent validation cohorts confirmed 97-99% 10-year FFR rates with 4-year PSA ≤ 0.2. Successive PSA categories were associated with diminished disease-free rates at 10 and 15 years. PSA category was strongly associated with treatment success (p < 0.0005).

CONCLUSIONS

Since 98.7% of patients with PSA ≤ 0.2 ng/mL at 4 years after LDR prostate brachytherapy were disease-free beyond 10 years, we suggest adopting this biochemical definition of cure for patients with ≥4 years' follow-up after LDR brachytherapy.

Principles and practice of high-dose rate penile brachytherapy: Planning and delivery techniques

PURPOSE

To allow for organ preservation, high-dose rate (HDR) brachytherapy may be used in the treatment of localized penile cancer. Penile cancer is a rare malignancy that accounts for <1% of cancers in men in the United States. The standard treatment for localized disease is partial amputation of the penis. However, patients with T1b or T2 disease <4 cm in maximum dimension and confined to the glans penis may be treated with brachytherapy as an organ-sparing approach. Previous works have described the technique involved for low-dose rate brachytherapy; however, we detail the techniques involved with HDR brachytherapy.

METHODS AND MATERIALS

Circumcision should precede brachytherapy. Interstitial brachytherapy needles are placed in the operating room under general anesthesia with the goal to allow for appropriate target coverage. Target definition is done via computed tomography-based simulation and planning. Radiation is delivered using a prescription dose of 3840 cGy in 12 fractions twice daily over a course of 6 days.

RESULTS

Acute toxicities peak upon completion of the radiation therapy and may include dermatitis, sterile urethritis, and adhesions in the urethra. These toxicities are reversible and generally take 2 to 3 months to heal. The two most common and significant late complications of radiation therapy for penile cancer are soft tissue necrosis and meatal stenosis. An increased risk of necrosis has been reported with T3 tumors and higher-volume implants (>30 cm³). Erectile function is generally maintained because the erectile tissues including the penile shaft and corpora have not been irradiated.

CONCLUSIONS

Organ preservation is feasible using HDR brachytherapy with favorable acute and late toxicities.

Secondary Urethral Malignancies Following Prostate Brachytherapy

OBJECTIVE

To understand urethral secondary malignancies among patients treated with brachytherapy (BRT) for primary prostate cancer.

PATIENTS AND METHODS

Institutional retrospective review identified 13 patients evaluated from 2003 to 2014 with urethral cancer and history of BRT monotherapy for prostate cancer. All patients were biochemically free of their primary disease and radiation-associated secondary malignancies (RASMs) were confirmed pathologically to be histologically distinct from primary tumor. BRT characteristics, patient age, presentation, staging workup, and clinical course were evaluated.

RESULTS

The mean time from BRT to presenting symptoms of hematuria, urinary retention, and/or renal failure was 71 months. Symptom onset to RASM diagnosis interval was 24 months. Mean time from BRT to RASM diagnosis was 95 months. Eighty-five percent of patients had an undetectable prostate-specific antigen level (<0.2 ng/mL) at last follow-up. Types of RASM included sarcomatoid carcinoma (6), small cell carcinoma (2), urothelial carcinoma with squamous differentiation (2), squamous cell carcinoma (1), rhabdomyosarcoma (1), and urothelial carcinoma (1). A majority of patients were diagnosed with advanced disease with either distant metastases (54%) or local progression (23%). Ten patients died during this study period with median time to death after RASM diagnosis of 6 months.

CONCLUSION

RASMs localized to the posterior urethra displayed advanced disease and high mortality rates. Refractory lower urinary tract symptoms, hematuria, and history of prostate BRT should raise suspicion for urethral RASMs. Further studies are warranted to determine patient and disease characteristics that correlate with disease-specific mortality of secondary urethral malignancies.

Evaluation of the current prostate cancer staging system based on cancer-specific mortality in the surveillance, epidemiology, and end results database

BACKGROUND

Prostate cancer is the most common noncutaneous malignancy diagnosed in men. From a large population-based database, this study aimed to report prostate cancer-specific mortality (PCSM) rates of men diagnosed with various presentations of prostate cancer and to examine the adequacy of the current American Joint Committee on Cancer (AJCC) staging system.

PATIENTS AND METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for all patients diagnosed with prostate cancer from 1997 to 2005. PCSM was reported by the classification of extent of disease provided by the SEER database, for clinically staged and pathologically staged cohorts.

RESULTS

Using the cumulative incidence method, PCSM at 10 years for all patients (n = 354,326) was 5% for clinically localized (CL) lesions, 7% for T3aN0M0, 14% for T3bN0M0, 26% for T4N0M0, 27% for TanyN1M0, and 66% for TanyNanyM1. Within the pathologically staged subgroup (n = 108,135), PCSM at 10 years was 1% for CL lesions, 4% for T3aN0M0, 9% for T3bN0M0, 9% for T4N0M0, and 19% for TanyN1M0.

CONCLUSION

Staging of any disease site aims to accurately communicate, prognosticate, and guide management for that particular level of disease. Stage IV prostate cancer is a diverse group, with PCSM in the subgroups ranging from 9% to 68% in this study. Considering the favorable outcomes of those with T4 or N1 nonmetastatic prostate cancer relative to those with M1 disease, the authors propose that T4 or N1 M0 prostate cancer should be reclassified into a new stage IIIB and that patients with such disease should be offered curative-intent therapy whenever possible.

PARP inhibition sensitizes to low dose-rate radiation TMPRSS2-ERG fusion gene-expressing and PTEN-deficient prostate cancer cells

Exposure to genotoxic agents, such as irradiation produces DNA damage, the toxicity of which is augmented when the DNA repair is impaired. Poly (ADP-ribose) polymerase (PARP) inhibitors were found to be “synthetic lethal” in cells deficient in BRCA1 and BRCA2 that impair homologous recombination. However, since many tumors, including prostate cancer (PCa) rarely have on such mutations, there is considerable interest in finding alternative determinants of PARP inhibitor sensitivity. We evaluated the effectiveness of radiation in combination with the PARP inhibitor, rucaparib in PCa cells. The combination index for clonogenic survival following radiation and rucaparib treatments revealed synergistic interactions in a panel of PCa cell lines, being strongest for LNCaP and VCaP cells that express ETS gene fusion proteins. These findings correlated with synergistic interactions for senescence activation, as indicated by β--galactosidase staining. Absence of PTEN and presence of ETS gene fusion thus facilitated activation of senescence, which contributed to decreased clonogenic survival. Increased radiosensitivity in the presence of rucaparib was associated with persistent DNA breaks, as determined by χ-H2AX, p53BP1, and Rad51 foci. VCaP cells, which harbor the TMPRSS2-ERG gene fusion and PC3 cells that stably express a similar construct (fusion III) showed enhanced sensitivity towards rucaparib, which, in turn, increased the radiation response to a similar extent as the DNA-PKcs inhibitor NU7441. Rucaparib radiosensitized PCa cells, with a clear benefit of low dose-rate radiation (LDR) administered over a longer period of time that caused enhanced DNA damage. LDR mimicking brachytherapy, which is used successfully in the clinic, was most effective when combined with rucaparib by inducing persistent DNA damage and senescence, leading to decreased clonogenic survival. This combination was most effective in the presence of the TMPRSS2-ERG and in the absence of PTEN, indicating clinical potential for brachytherapy in patients with intermediate and high risk PCa.

Prediction of erectile function following treatment for prostate cancer

CONTEXT

Sexual function is the health-related quality of life (HRQOL) domain most commonly impaired after prostate cancer treatment; however, validated tools to enable personalized prediction of erectile dysfunction after prostate cancer treatment are lacking.

OBJECTIVE

To predict long-term erectile function following prostate cancer treatment based on individual patient and treatment characteristics.

DESIGN

Pretreatment patient characteristics, sexual HRQOL, and treatment details measured in a longitudinal academic multicenter cohort (Prostate Cancer Outcomes and Satisfaction With Treatment Quality Assessment; enrolled from 2003 through 2006), were used to develop models predicting erectile function 2 years after treatment. A community-based cohort (community-based Cancer of the Prostate Strategic Urologic Research Endeavor [CaPSURE]; enrolled 1995 through 2007) externally validated model performance. Patients in US academic and community-based practices whose HRQOL was measured pretreatment (N = 1201) underwent follow-up after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer. Sexual outcomes among men completing 2 years' follow-up (n = 1027) were used to develop models predicting erectile function that were externally validated among 1913 patients in a community-based cohort.

MAIN OUTCOME MEASURES

Patient-reported functional erections suitable for intercourse 2 years following prostate cancer treatment.

RESULTS

Two years after prostate cancer treatment, 368 (37% [95% CI, 34%-40%]) of all patients and 335 (48% [95% CI, 45%-52%]) of those with functional erections prior to treatment reported functional erections; 531 (53% [95% CI, 50%-56%]) of patients without penile prostheses reported use of medications or other devices for erectile dysfunction. Pretreatment sexual HRQOL score, age, serum prostate-specific antigen level, race/ethnicity, body mass index, and intended treatment details were associated with functional erections 2 years after treatment. Multivariable logistic regression models predicting erectile function estimated 2-year function probabilities from as low as 10% or less to as high as 70% or greater depending on the individual's pretreatment patient characteristics and treatment details. The models performed well in predicting erections in external validation among CaPSURE cohort patients (areas under the receiver operating characteristic curve, 0.77 [95% CI, 0.74-0.80] for prostatectomy; 0.87 [95% CI, 0.80-0.94] for external radiotherapy; and 0.90 [95% CI, 0.85-0.95] for brachytherapy).

CONCLUSION

Stratification by pretreatment patient characteristics and treatment details enables prediction of erectile function 2 years after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer.

Low-dose-rate brachytherapy as salvage treatment of local prostate cancer recurrence after radical prostatectomy

OBJECTIVES

To present our initial experience with brachytherapy used as a salvage procedure for local recurrence of prostate cancer in the prostatic fossa after radical prostatectomy.

METHODS

The patients included 5 consecutive men who underwent brachytherapy as a salvage procedure after radical prostatectomy from December 2006 to March 2008. We used a technique of implanting the local recurrences similar to the American Brachytherapy Society Guidelines for implanting an intact prostate as definitive therapy. Two modifications were made related to the recurrence location: a rare need to manage urethral doses because the recurrence was typically perirectal, and more aggressive management of the dose to the rectum because of this proximity.

RESULTS

All patients tolerated the brachytherapy procedure well and showed a decline in the prostate-specific antigen level, with a median nadir of 0.72 ng/mL at a median follow-up of 13 months. The postprocedural symptoms were minor and included limited new-onset urgency. At the last follow-up visit, all patients had prostate-specific antigen doubling times, which have been associated with long median survival times.

CONCLUSIONS

Salvage brachytherapy for biopsy-proven local recurrence of prostate cancer is a technically feasible alternative to external beam radiotherapy for local control of recurrences in the prostatic fossa in selected patients after radical prostatectomy.

Prostate-specific antigen bounce after prostate brachytherapy: review of a confusing phenomenon

Prostate brachytherapy is a commonly used modality for the treatment of prostate cancer. After prostate brachytherapy, the prostate-specific antigen (PSA) level may fluctuate and increase temporarily without a clear reason in 30-40% of successfully treated men. This phenomenon is called "PSA bounce" and engenders anxiety on the part of the patient and physician. Having reviewed the literature we found 19 articles and summarized in the current review to delineate the facts of this relatively common and ambiguous phenomenon. Although several patient and treatment related factors were assessed by studies, only age remained as the most consistent predictor.

Outcomes for intermediate risk prostate cancer: are there advantages for surgery, external radiation, or brachytherapy?

The treatment of localized prostate cancer remains controversial because of the lack of conclusive well-controlled or randomized studies comparing outcome of various forms of radiotherapy (RT) to radical prostatectomy (RP). We review recent results from an institutional database and prospective quality of life study comparing cancer-related and quality of live (QOL) outcomes among different treatment modalities for intermediate risk prostate cancer. The results suggest similar short-term survival but domain-specific effects on QOL after treatment with radical prostatectomy, brachytherapy, or external beam radiotherapy.

Quality of life and satisfaction with outcome among prostate-cancer survivors

BACKGROUND

We sought to identify determinants of health-related quality of life after primary treatment of prostate cancer and to measure the effects of such determinants on satisfaction with the outcome of treatment in patients and their spouses or partners.

METHODS

We prospectively measured outcomes reported by 1201 patients and 625 spouses or partners at multiple centers before and after radical prostatectomy, brachytherapy, or external-beam radiotherapy. We evaluated factors that were associated with changes in quality of life within study groups and determined the effects on satisfaction with the treatment outcome.

RESULTS

Adjuvant hormone therapy was associated with worse outcomes across multiple quality-of-life domains among patients receiving brachytherapy or radiotherapy. Patients in the brachytherapy group reported having long-lasting urinary irritation, bowel and sexual symptoms, and transient problems with vitality or hormonal function. Adverse effects of prostatectomy on sexual function were mitigated by nerve-sparing procedures. After prostatectomy, urinary incontinence was observed, but urinary irritation and obstruction improved, particularly in patients with large prostates. No treatment-related deaths occurred; serious adverse events were rare. Treatment-related symptoms were exacerbated by obesity, a large prostate size, a high prostate-specific antigen score, and older age. Black patients reported lower satisfaction with the degree of overall treatment outcomes. Changes in quality of life were significantly associated with the degree of outcome satisfaction among patients and their spouses or partners.

CONCLUSIONS

Each prostate-cancer treatment was associated with a distinct pattern of change in quality-of-life domains related to urinary, sexual, bowel, and hormonal function. These changes influenced satisfaction with treatment outcomes among patients and their spouses or partners.

Effect of increasing radiation doses on local and distant failures in patients with localized prostate cancer

PURPOSE

To study the effect of radiation dose on local failure (LF) and distant metastasis (DM) in prostate cancer patients treated with external beam radiotherapy.

METHODS AND MATERIALS

The study sample consisted of 919 Stage T1-T3N0M0 patients treated with radiotherapy alone. Three separate dose groups were analyzed: <72 Gy (n = 552, median dose, 68.4 Gy), > or =72 but <82 Gy (n = 215, median dose, 78 Gy), and > or =82 Gy (n = 152, median dose, 83 Gy). The median follow-up period for all patients and those receiving <72 Gy, > or =72 but <82 Gy, and > or =82 Gy was 97, 112, 94, and 65 months, respectively.

RESULTS

For all patients, the LF rate at 10 and 15 years was 6% and 13%, respectively. The 7-year LF rate stratified by dose group (<72 Gy, > or =72 but <82 Gy, and > or =82 Gy) was 6%, 2%, and 2%, respectively (p = 0.012). For all patients, the DM rate at 10 and 15 years was 10% and 17%, respectively. The 7-year DM rate stratified by dose group (<72 Gy, > or =72 but <82 Gy, and > or =82 Gy) was 9%, 6%, and 1%, respectively (p = 0.008). Multivariate analysis revealed T stage (p < 0.001), pretreatment prostate-specific antigen level (p = 0.001), Gleason score (p < 0.001), and dose (p = 0.018) to be independent predictors of DM. For all 919 patients, multivariate analysis revealed only Gleason score (p = 0.009) and dose (p = 0.004) to be independent predictors of LF.

CONCLUSION

Although the effect of increasing radiation doses has been documented mostly for biochemical failure rates, the results of our study have shown a clear association between greater radiation doses and lower LF and DM rates.

Long-term potency after iodine-125 radiotherapy for prostate cancer and role of sildenafil citrate

OBJECTIVES

To assess the long-term sexual potency and attrition in sexual function after iodine-125 ((125)I) seed radiotherapy and the effect of sildenafil on radiation-induced erectile dysfunction (ED).

METHODS

This prospective study consisted of 86 sexually active patients (mean age 63.5 +/- 7.7 years) who underwent (125)I seed implantation from 1997 to 1999 to treat low-volume prostate cancer (prostate-specific antigen less than 10 ng/mL, Gleason score 6 or less, stage T1-T2). All patients were followed up every 6 to 8 months for 4 years. Patients prescribed sildenafil citrate for ED completed the abridged five-item version of the International Index of Erectile Function (IIEF) and the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) questionnaires.

RESULTS

The median follow-up was 49.7 months (range 36 to 66). Of 86 patients, 43 (50%) did not initiate drug therapy; and only 36 (83.7%) of the 43 were interviewed at 4 years. Twenty-three (63.8%) of the 36 patients had erections sufficient for vaginal penetration, with a total mean +/- SD IIEF-5 score of 15.76 +/- 1.13. The other 50% (43 of 86) initiated sildenafil citrate for treatment of ED after seed implantation, with a minimal follow-up of 6 months. At 4 years, 32 (74%) of the 43 were responding positively to sildenafil citrate, with a total IIEF-5 score of 18.3 +/- 1.2. The mean EDITS +/- SD score was 76.5 +/- 3.2, and the spousal satisfaction rate was 72% (31 of 43). The dropout rate was 37% (16 of 43); 10 (63%) of the 16 discontinued because of a lack of efficacy, 3 (19%) because of a return of natural erections sufficient for vaginal penetration, and 3 (19%) discontinued because of side effects (headaches).

CONCLUSIONS

ED is a major long-term issue after (125)I seed radiotherapy, with a long-term potency rate of 29%. Sildenafil citrate improves erections in most patients after (125)I seed implantation.

Carotid brachytherapy for in-stent restenosis

Carotid stenting has emerged as an alternative revascularization modality to endarterectomy for the treatment of carotid artery disease. Restenosis of a carotid stent may be occasionally seen. Our experience in intravascular radiation therapy for coronary restenosis has provided us the opportunity to explore this treatment strategy for carotid restenosis. We report our initial experience with brachytherapy for the treatment of restenosis after carotid stenting.

Does paclitaxel improve the chemoradiotherapy of locoregionally advanced esophageal cancer? A nonrandomized comparison with fluorouracil-based therapy

PURPOSE

A phase II trial of accelerated fractionation radiation with concurrent cisplatin and paclitaxel chemotherapy was performed to investigate the role of the paclitaxel, when substituted for fluorouracil (5-FU), in the chemoradiotherapy of esophageal cancer.

PATIENTS AND METHODS

Patients with an esophageal ultrasound stage of T(3) or N(1) or M(1) (nodal) esophageal cancer were treated with two courses of a cisplatin infusion (20 mg/m(2)/d for 4 days) and paclitaxel (175 mg/m(2) over 24 hours) concurrent with a split course of accelerated fractionation radiation (1.5 Gy bid to a total dose of 45 Gy). Surgical resection was performed 4 to 6 weeks later followed by a single identical postoperative course of chemoradiotherapy (24 Gy) in patients with significant residual tumor at surgery. Toxicity and results of this treatment were retrospectively compared with our previous 5-FU and cisplatin chemoradiotherapy experience.

RESULTS

Between September 1995 and July 1997, 40 patients were entered onto this study. Although dysphagia proved worse in our 5-FU-treated patients, profound leukopenia and a need for unplanned hospitalization were significantly more common in the paclitaxel group. Thirty-seven patients (93%) proved resectable for cure. The 3-year projected overall survival is 30%, locoregional control is 81%, and distant metastatic disease control is 44%. When compared with a similarly staged cohort of 5-FU-treated patients, there was no advantage for any survival function studied.

CONCLUSION

This paclitaxel-based treatment regimen for locoregionally advanced esophageal cancer produced increased toxicity with no improvement in results when compared with our previous 5-FU experience. Paclitaxel-based treatments must be carefully and prospectively studied before their incorporation into the standard management of esophageal cancer.

The palliative role of radiotherapy in the management of the cancer patient

Radiotherapy (RT) plays a major role in the palliation of cancer symptoms. Cancer-related bone pain, bronchial obstruction, superior vena cava syndrome, spinal cord compression, and central neurologic dysfunction due to brain metastases are all treated effectively and safely by RT. Although numerous techniques and radiation dose fractionation schemes are used in practice, substantial palliation often may be accomplished by just two to 10 appropriately targeted treatments. Thus, palliative RT regimens need not be highly protracted to be effective. Several new techniques, including strontium 89 radiopharmaceutical therapy, high-dose-rate endobronchial brachytherapy, and stereotactic radiosurgery, are now being evaluated in clinical trials to determine their efficacy in the relief of various oncologic symptoms. Palliative RT continues to be a mainstay of treatment in the management of cancer patients with advanced disease.