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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the recent past there have been major advances in the management of patients with prostate cancer. New imaging procedures as 3-D CRT and IMRT have played a major role in the tretament of patients with localized prostate cancer. 3-D CRT allows higher doses to be delivered more precisely to the target volume with acceptable organs at risk morbidity. Improved tumor control results in lower incidence of distant metastases and better survival with an enhanced quality of life. This outcome yields a lower cost per treatment of patients over their life time.
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PMID:Clinical assessment of outcome of prostate cancer (TCP, NTCP). 1629 3

Based on the successful results achieved in survival and local control with radiotherapy of prostate cancer recent studies tried to establish some models to reliably predict late rectal toxicity. In fact, the rectum, due to its location, represents an organ at risk of acute and late toxicity with the onset of acute or chronic radiation proctitis. The concept of late consequential effect has gained ground. It implies that the late damage might be a direct consequence of the acute damage. Dose-escalation studies, conformal radiotherapy (3D-CRT) and intensity modulated radiotherapy (IMRT) led to the identification of parameters, based on dose-volume histograms (DVH), able to separate patients at low and high risk of toxicity. Precise predictive dosimetric factors play a major role in the definition of the onset of toxicity. The monitoring system of late toxicity used by the authors is presented.
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PMID:Impact of dose and volume on rectal tolerance. 1629 12

Reports on long-term complications resulting from treatment for localized prostate cancer are very inconsistent. In order to estimate the risks of long-term erectile dysfunction, urine symptoms and bowel symptoms following prostatectomy (RP), external conventional or conformal beam radiation (ERT or CRT) and brachytherapy (BRT), 98 papers from the PubMed and Cochrane Clinical Trial databases were selected, reviewed and critically evaluated. The majority of papers were institution-based retrospective and prospective follow-up studies; only two of these studies measured the risk of developing more than one treatment complication. Due to differences in study designs and populations, it is difficult to directly compare studies and not meaningful to calculate summary estimates. In addition to focusing on randomized clinical trials and well-designed population based studies, future research should adopt standardized methodologies and should measure the risk of developing more than one treatment complication.
Prostate Cancer Prostatic Dis 2006
PMID:Estimating the risk of long-term erectile, urinary and bowel symptoms resulting from prostate cancer treatment. 1640 91

The advances in radiotherapy (3D-CRT, IMRT) have enabled high doses of radiation to be delivered with the least possible associated toxicity. However, the persistence of cancer (local recurrence after radiotherapy) despite these increased doses as well as distant failure suggesting the existence of micro-metastases, especially in the case of higher risk disease, have underscored the need for continued improvement in treatment strategies to manage local and micro-metastatic disease as definitively as possible. This has prompted the idea that an increase in the therapeutic index of radiotherapy might be achieved by combining it with in situ gene therapy. The goal of these combinatorial therapies is to maximize the selective pressure against cancer cell growth while minimizing treatment-associated toxicity. Major efforts utilizing different gene therapy strategies have been employed in conjunction with radiotherapy. We reviewed our and other published clinical trials utilizing this combined radio-genetherapy approach including their associated pre-clinical in vitro and in vivo models. The use of in situ gene therapy as an adjuvant to radiation therapy dramatically reduced cell viability in vitro and tumor growth in vivo. No significant worsening of the toxicities normally observed in single-modality approaches were identified in Phase I/II clinical studies. Enhancement of both local and systemic T-cell activation was noted with this combined approach suggesting anti-tumor immunity. Early clinical outcome including biochemical and biopsy data was very promising. These results demonstrate the increased therapeutic efficacy achieved by combining in situ gene therapy with radiotherapy in the management of local prostate cancer. The combined approach maximizes tumor control, both local-regional and systemic through radio-genetherapy induced cytotoxicity and anti-tumor immunity.
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PMID:Expanding the therapeutic index of radiation therapy by combining in situ gene therapy in the treatment of prostate cancer. 1641 99

In men with locally advanced/high-risk prostate cancer, there is an ongoing challenge to achieve improved results. Dose escalation studies using three-dimensional conformal radiotherapy (3D-CRT) or intensity modulated radiation therapy (IMRT) have shown benefit particularly in the intermediate and poor risk groups of patients. Of concern, however, is the increase in documented rectal toxicity. High-dose rate brachytherapy (HDR-BT) as a boost in combination with external beam radiotherapy (EBRT) is an alternative strategy of dose escalation that can potentially achieve an even higher biological equivalent dose (BED) to the tumour. The results so far are very encouraging for men with poor prognosis disease. Moreover the technique is associated with very low rates of acute and late toxicity.
Prostate Cancer Prostatic Dis 2006
PMID:Challenge of dose escalation in locally advanced unfavourable prostate cancer using HDR brachytherapy. 1683 83

Survival and biochemical outcome of patients with localized, high-risk prostate cancer treated with definitive three-dimensional conformal radiation therapy (3-D CRT) with or without hormonal therapy are poor. Other therapeutic strategies are needed to improve outcome in these poor-prognostic-group patients. One such strategy involves the use of chemotherapeutic agents to radiosensitize the effects of local 3-D CRT. Very few investigators have tested this novel concept of chemotherapeutic radiosensitization. Two studies evaluated the combination of estramustine phosphate and vinblastine (EV) with radiation therapy (RT). In both studies, the combination of EV and RT resulted in moderate to severe acute and late toxicity. A recently completed, phase I trial evaluated the maximally tolerated dose (MTD) of weekly docetaxel that could be concurrently delivered with 3-D CRT (70.2 Gy) in men with high-risk prostate cancer. The MTD of concurrent weekly docetaxel with 3-D CRT was determined to be 20 mg/m(2), and this combination was shown to be safe and well tolerated. This was the first trial to evaluate taxane radiosensitization in prostate cancer. Other phase I/II studies are needed to further assess chemotherapeutic radiosensitization in localized, high-risk prostate cancer.
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PMID:A new paradigm for the treatment of high-risk prostate cancer: radiosensitization with docetaxel. 1698 54

We retrospectively evaluated acute and late radiation morbidity and short-term PSA relapse-free survival of 53 patients with localized prostate cancer who received three dimensional radiation therapy (3D-CRT) that targeted prostate and seminal vesicles in Hamamatsu Medical Center from 1999.10 to 2005.4. The total dose was increased from 70 to 74 Gy in increments of 2.0 Gy. We divided these patients into two groups who received 70-72 Gy or 74 Gy. Then we analyzed whether there were differences between those two groups in acute radiation morbidity. We also analyzed late radiation morbidity in the 70(-)-72 Gy group. Acute radiation morbidity and late morbidity were described according to the RTOG acute radiation morbidity scoring criteria 1995 and RTOG/EORTC late radiation morbidity scoring scheme 1995, respectively. No acute grade 3 or 4 toxicity and no late grade 4 toxicity was observed. Late grade 3 rectal bleeding was observed in only one patient who received 70 Gy. Acute toxicity was well tolerated and did not correlate with total dose.
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PMID:[Three-dimensional conformal radiation therapy for prostate cancer in Hamamatsu Medical Center]. 1731 Jul 62

The aim of this study is to investigate the feasibility of using conventional jaws to deliver inverse planned intensity-modulated radiotherapy (IMRT) plans for patients with prostate cancer. For ten patients, each had one three-dimensional conformal plan (3D plan) and seven inverse IMRT plans using direct aperture optimization. For IMRT plans using conventional jaws (JO plans), the number of apertures per beam angle was set from two to seven while three apertures per beam angle were set for the multi-leaf collimator (MLC) plans. To evaluate each planning method, we compared average dose volume histograms (DVH), the conformal index (COIN), total number of segments and total number of monitor units. Among the JO plans with the number of apertures per beam angle varying from two to seven, no difference was observed in the average DVHs, and the plan conformal index became saturated after four apertures per beam angle. Subsequently, JO plans with four apertures per beam angle (JO-4A) were compared with 3D and MLC plans. Based on the average DVHs, no difference was found among 3D, JO-4A and MLC plans with regard to the planning target volume and rectum, but the DVHs for the bladder and penile bulb were significantly better with inverse IMRT plans than those with 3D plans. When compared with the plan conformity, the average COIN values for 3D, JO-4A and MLC plans were 0.61 +/- 0.07, 0.73 +/- 0.05 and 0.83 +/- 0.05, respectively. In conclusion, inverse IMRT plans using conventional jaws are clinically feasible, achieving better plan quality than 3D-CRT plans.
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PMID:A feasibility study of using conventional jaws to deliver IMRT plans in the treatment of prostate cancer. 1740 60

Adenocarcinoma of the prostate is one of the most frequently diagnosed cancers of men in the Western hemisphere and is second only to lung cancer for male cancer mortality. Most patients are diagnosed in the early/clinically localized stage, which can be treated curatively with radiation therapy alone. Innovative methods such as brachytherapy, three-dimensional conformal radiotherapy (3D-CRT), and IMRT (intensity modulated radiotherapy) are able to deliver very high tumoricidal doses to the diseased prostate, with minimal side effects to the surrounding tissue. Radiation therapy combined with hormonal treatment can be curative in locally advanced disease. Radiation therapy is also very effective in alleviating symptoms of metastatic prostate cancer (bone metastases, spinal cord compression, and bladder outlet obstruction).
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PMID:Radiation therapy in prostate cancer. 1743 60

External-beam radiation therapy has been one of the treatment options for prostate cancer. The dose response has been observed for a dose range of 64.8-81 Gy. The problem of external-beam RT for prostate cancer is that as the dose increases, adverse effects also increase. Three-dimensional conformal radiation therapy (3D-CRT) has enabled us to treat patients with up to 72-76 Gy to the prostate, with a relatively acceptable risk of late rectal bleeding. Recently, intensity-modulated radiation therapy (IMRT) has been shown to deliver a higher dose to the target with acceptable low rates of rectal and bladder complications. The most important things to keep in mind when using an IMRT technique are that there is a significant trade-off between coverage of the target, avoidance of adjacent critical structures, and the inhomogeneity of the dose within the target. Lastly, even with IMRT, it should be kept in mind that a "perfect" plan that creates completely homogeneous coverage of the target volume and zero or small dose to the adjacent organs at risk is not always obtained. Participating in many treatment planning sessions and arranging the beams and beam weights create the best approach to the best IMRT plan.
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PMID:Current status of intensity-modulated radiation therapy (IMRT). 1807 59


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