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

For the last 10 years, along with surgery, radiotherapy has become a major issue in the curative treatment of prostate cancer. Several radiotherapy techniques can be used. In good prognosis cancers, when the prostate is small, brachytherapy is one of the therapeutic options. By implanting radioactive seeds within the prostate, this technique permits strictly limited intraprostatic irradiation. Conformal external beam (3D) radiotherapy adapts to individual morphology according to dosimetric CT scan data. This is particularly useful to deliver a high dose in the target volume while limiting the dose in surrounding organs. It is indicated either for localised tumours as an alternative solution to surgery, or for tumours with more aggressive patterns or locally advanced that will in both cases require adjuvant hormotherapy; conventional (2D) radiotherapy can be used in case of isolated clinical or biological relapse after prostatectomy. These last two techniques induce two main types of late toxicity: radio-induced rectitis and sexual impotence. Last but not least, radiotherapy as well as nuclear medicine can be used with palliation intent and may be of great help to relieve pain in case of bone metastases.
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PMID:[External beam radiotherapy and brachytherapy in prostate cancer]. 1501 79

This study updates technical principles and results of 3-dimensional conformal radiation therapy (3D-CRT) in localized carcinoma of the prostate. Between January 1992 and December 1999, 312 patients were treated with 3D-CRT and 135 patients were treated with bilateral arcs standard radiation therapy (SRT) alone for clinical stage T1b-c or T2 histologically confirmed prostate cancer. None of these patients received hormonal therapy. Mean follow-up for patients in the 3D-CRT group was 3.2 years (range, 2-5.9 years) and for SRT patients, 4.7 years (range, 4-7 years). For 3D-CRT, 7 intersecting fields were used (cerrobend blocking or multileaf collimation) to deliver 68-74 Gy to the prostate. Standard radiation therapy consisted of bilateral 120 degree rotational arcs, with portals using 2-cm margins around the prostate to deliver 68-70 Gy to the prostate. The criterion for chemical disease-free survival was a postirradiation prostate-specific antigen (PSA) value following the American Society for Therapeutic Radiology and Oncology guidelines. Symptoms during treatment were quantitated weekly, and late effects were assessed every 4-6 months. Dose-volume histograms showed a two-thirds reduction with 3D-CRT in normal bladder or rectum receiving > or = 70 Gy with 3D-CRT. Higher 5-year chemical disease-free survival was observed with 3D-CRT (75%; for T1b-c and 79%; for T2 tumors) compared with SRT (61% and 65%, P = 0.01 and P = 0.12, respectively). There was no statistically significant difference in chemical disease-free survival in patients with Gleason score of < or = 4 (P = 0.85), but, with Gleason score of 5-7, the 5-year survival rates were 83% with 3D-CRT and 59% with SRT (P < or = 0.01). In 245 patients with pretreatment PSA of < or = 10 ng/mL treated with 3D-CRT, the chemical disease-free rate was 80% versus 72% in 98 patients treated with SRT (P = 0.21). In patients with PSA of 10.1-20 ng/mL, the chemical disease-free survival rate for 50 patients treated with 3D-CRT was 71% compared with 43% for 20 patients treated with SRT (P = 0.02). The corresponding values were 59% and 16%, respectively, for patients with PSA levels > 20 ng/mL (P = 0.09). On multivariate analysis, the most important prognostic factors for chemical failure were pretreatment PSA (P = 0.004), nadir PSA (P = 0.001), and 3D-CRT technique (P = 0.012). Moderate dysuria was reported by 2%-5% of patients treated with 3D-CRT in contrast to 6%-9% of patients treated with SRT. The incidence of moderate loose stools or diarrhea, usually after the fourth week of treatment, was 3%-5% in the 3D-CRT patients and 8%-19% in the SRT group. Late intestinal grade 2 morbidity (proctitis or rectal bleeding) was 1% in the 3D-CRT group in contrast to 7% in SRT patients. The 3D-CRT spares more normal tissues, yields higher chemical disease-free survival, and results in less treatment morbidity than SRT in treatment of stage T1-T2 prostate cancer. Follow-up at > or = 10 years is needed to confirm these observations.
Clin Prostate Cancer 2002 Sep
PMID:Three-dimensional conformal therapy versus standard radiation therapy in localized carcinoma of prostate: an update. 1504

The imaging appearances of prostate cancer are well described in the radiology literature, but little has been written about the detection and appearance of the complications of therapy for this disease. The most frequently used treatments for prostate cancer are surgical therapy (eg, radical retropubic prostatectomy, radical perineal prostatectomy), radiation therapy (eg, brachytherapy, external-beam radiation therapy, three-dimensional conformal radiation therapy, intensity-modulated radiation therapy), and cryoablative therapy, each of which may lead to complications with characteristic imaging appearances. Possible complications include lymphocele formation; injuries to the ureter, rectum, and urethra; prostatic necrosis; vesicourethral anastomotic leak and stricture; urethral stricture, necrosis, and fistula; radiation proctitis; transient bladder outlet obstruction; radiation-induced urethritis; urinary incontinence; and erectile dysfunction. With improvements in surgical techniques and advances in technology, complications of therapy for prostate cancer are decreasing but still occur with sufficient frequency to warrant familiarity on the part of radiologists. Knowledge of the diverse spectrum of these complications and their characteristic radiologic features facilitates prompt diagnosis and treatment.
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PMID:Complications of prostate cancer treatment: spectrum of imaging findings. 1548 40

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.
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PMID:Rectal wall sparing by dosimetric effect of rectal balloon used during intensity-modulated radiation therapy (IMRT) for prostate cancer. 1574 8

There is good evidence that radiation dose escalation in localised prostate cancer is associated with increased cell kill. The traditional two-dimensional (2D) technique of treatment planning and delivery is limited by normal tissue toxicity, such that the dose that can be safely delivered to the prostate by external beam radiotherapy is 65-70 Gy. Several technological advances over the last 20 years have enhanced the precision of external beam radiotherapy (EBRT), and have resulted in improved outcomes. The three-dimensional conformal radiotherapy (3D-CRT) approach reduces the dose-limiting late side-effect of proctitis and has allowed for dose escalation to the whole prostate to 78 Gy. More recently, intensity modulated radiotherapy (IMRT), an advanced form of conformal therapy, has resulted in reduced rectal toxicity when using doses greater than 80 Gy. In addition, IMRT can potentially escalate the dose to specific parts of the prostate where there are resistant subpopulations of tumour clonogens, or can be used to extend the high-dose region to pelvic lymph nodes. The addition of androgen deprivation to conventional radiotherapy has an impact on survival and local control. Initial hormone therapy causes cytoreduction of the prostate cancer allowing for a reduction in radiotherapy volume as well as an additive effect on cell kill. Long-term adjuvant androgen deprivation has been shown to improve overall survival in more advanced tumours. Prostate brachytherapy is now a recognised treatment for those with low-risk disease. It achieves similar long-term outcome to other treatment modalities. Brachytherapy can be used as monotherapy for localised disease, or as boost treatment following conventional EBRT for locally advanced disease. New techniques are available to improve the precision of both target definition and treatment verification. This so-called image-guided radiotherapy will help to enhance the accuracy of dose delivery by correcting both for inter-fraction positional variation and for intra-fraction movement of the prostate in real-time and will allow for tighter tumour margins and avoidance of normal tissues, thereby enhancing the safety of treatment.
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PMID:Technological advances in radiotherapy for the treatment of localised prostate cancer. 1580 57

Although formalin instillation has been proven to be an effective treatment of hemorrhagic radiation proctitis, different techniques with varying success rates have been reported. The aim of this study was to assess our experience with formalin instillation for the treatment of radiation proctitis. After Institutional Review Board approval, all patients who presented with radiation proctitis and were treated with 4% formalin instillation were identified from a prospective database. Techniques of instillation were as follows: a formalin-soaked sponge stick was applied via a proctoscope (SS) and placed at each quadrant with a mean contact of 2.5 minutes (range, 0.5-3 minutes), or the formalin solution was introduced through a proctoscope in aliquots for a total of 350 to 400 mL irrigation (IR), with a mean contact time of 30 seconds in each aliquot. The patients were divided into two groups according to the method of formalin instillation and their outcomes were compared. Between March 1995 and September 2003, 21 patients who underwent formalin treatment were identified: 17 patients were in the SS and 4 patients were in the IR group. The mean age was 74.8+/-6.4 years and 70.5+/-6.8 years and the male/female ratio was 16:1 and 3:1 in the SS and IR groups, respectively. Indications for radiation therapy were prostate cancer in 19 patients: 16 (95.1%) SS patients and 3 (75%) IR patients. Four (23.5%) patients in the SS group were receiving anticoagulants or antiplatelet medications before the procedure. The mean duration of bleeding before formalin instillation was 11.7 months (range, 2-48 months) in the SS and 10.5 months (range, 7-12 months) in the IR group. Sixteen (94.1%) patients in the SS and 4 (100%) in the IR group had previous treatments for radiation proctitis, including hydrocortisone enema, 5-aminosalicylate mesalamine, and endoscopic coagulation. Eight (47.1%) patients in the SS and 2 (50%) in the IR group received a preprocedural blood transfusion, and 1 patient in the SS group required a blood transfusion after the formalin instillation. This patient subsequently underwent restorative proctosigmoidectomy because of persistent bleeding. The mean length of the procedure was 27.1+/-10.8 minutes in the SS group and 22.5+/-6.5 minutes in the IR group. The bleeding was successfully stopped on the first attempt in 14 patients (82.4%) in the SS group and 3 (75%) in the IR group. The instillation was repeated in 1 patient (5.9%) in the SS group and in 1 (25%) in the IR group. Four patients (23.5%) in the SS group experienced rectal pain after the procedure. One patient (5.9%) developed a new onset of fecal incontinence, while another (5.9%) had anococcygeal pain accompanied by worsening of fecal incontinence. One patient (25%) in the IR group developed acute colitis consistent with formalin instillation, which was managed by intravenous antibiotics. The patients were followed for a mean of 10 months (range, 1 to 38 months). Formalin instillation is effective in controlling refractory hemorrhage secondary to radiation proctitis.
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PMID:Formalin instillation for hemorrhagic radiation proctitis. 1603

For every course of radiotherapy treatment, the potential benefit has to be weighed against the risk of normal tissue damage. Radiation-induced proctitis during and after radical radiotherapy for prostate cancer can be decreased by reducing both the size of the target volume and the margins required around this volume. In the future, target volumes could be reduced by both CT/MRI co-registration and dose painting using MR spectroscopy of choline and citrate in the prostate. Improved immobilisation and image-guided radiotherapy should allow reduced margins without compromising the effectiveness of treatment. Similarly, in breast radiotherapy treatment, lung and cardiac complications can be reduced by better patient positioning and ensuring that doses to the heart and lung are minimised during radiotherapy treatment planning. Cosmesis can be improved by using 3D breast planning techniques rather than the conventional 2D approach. These ongoing improvements and developments in radiotherapy treatment planning are leading to treatments which offer both better tumour volume coverage, and are minimising the risk of treatment-related complications. In time, these changes should allow the escalation in dose delivered to the tumour volume with the potential for increased cure rates.
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PMID:Complications of radiotherapy: improving the therapeutic index. 1615 24

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

Prostate cancer is a complex disease, with many controversial aspects of management in almost all stages of disease. The natural history of this tumor is variable and is influenced by multiple prognostic factors. Radical prostatectomy and radiotherapy are standard treatment options for disease limited to the prostate. The data in literature does not provide clear- cut evidence for the superiority of any treatment. Neo- adjuvant or adjuvant hormonal therapy improves local control and survival in locally advanced disease. The patients treated with radiotherapy would have a relatively long life expectancy, not great risk factors for radiation toxicity and a preference for radiotherapy. The advantages of radiotherapy are that it has a significant potential for cure, it is well tolerated in the majority of men especially when the modern techniques of conformal radiotherapy and intensity modulated therapy are used and it is non-invasive therapeutic options with no anesthesia risk. Expected complications like radiation cystitis, impotence and proctitis are registered in about 1% of patients.
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PMID:Radiotherapy in prostate cancer treatment. 1667 4

A number of retrospective and prospective studies have demonstrated that radiotherapy of prostate cancer must be actually conformal. Three-dimensional (3D) treatment planning consists in an as accurate as possible definition of target-volume, usually by CT-scan, and design of radiation fields shaped to this target-volume. Several steps are required, each step being important for the overall quality of the treatment. Conformal radiotherapy is better tolerated than conventional irradiation, with significantly less rectal toxicity. It allows dose-escalation up to 80 Gy. It is now possible to go beyond this dose with intensity-modulated radiotherapy. The benefit of these high doses was demonstrated by some large retrospective studies and some prospective dose-escalation trials. Several randomized trials are in progress, preliminary results of two of them have been published, both showing an improvement in disease control with the higher doses. The advantage of higher doses is clearly evident for patients in the intermediate prognostic group, but is still discussed for patients with a low risk tumour or treated in combination with hormone therapy. Late proctitis is the main toxicity of these high doses. Some volume constraints have been defined during the last years and will allow a decrease of the rate of rectal toxicity. Because of these technological improvements, results of radiation therapy are now similar to those of surgery: no direct comparison with a randomized trial is available, but large comparative studies show that long-term disease control are identical with both techniques. Radiation therapy must be proposed to all patients with a prostate carcinoma as an alternative to surgery.
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PMID:[Conformal radiotherapy of prostate cancer]. 1697 66


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