Prostate cancer radiation therapy

This royal-blue-colored drug is an anthracenedione that inhibits DNA topoisomerase II. The pharmacokinetics of mitoxantrone may best be described by a three-compartment model, with an a half-life of 3 to 10 minutes, a 3 half life of 0.3 to 3 hours, and a median terminal half-life of 12 days. Biliary elimination appears to be the primary route of elimination, with less than 10% of the drug eliminated by the kidney.23 Mitoxantrone has shown clinical activity in the treatment of acute leukemias, breast and prostate cancer, and non-Hodgkin s lymphomas. Myelosuppression, mucositis, nausea and vomiting, and cardiac toxicity are side effects of this drug. The total cumulative dose limit is 160 mg/m2 for patients who have not received prior anthracycline or mediastinal radiation. Patients who have received prior doxorubicin or daunorubicin therapy should not receive a cumulative dose greater than 120 mg/m2 of mitoxantrone. Patients should be counseled that their urine will turn a blue-green color. 

Androgen ablation with a luteinizing hormone-releasing hormone (LHRH) agonist plus an antiandrogen should be used prior to radiation therapy for patients with locally advanced prostate cancer to improve outcomes over radiation therapy alone. 

Individuals with T2b and T2c disease or a Gleason score of 7 or a PSA ranging from 10 to 20 ng/mL (10 to 20 mcg/L) are considered at intermediate risk for prostate cancer recurrence.26 Individuals with less than a 10-year expected survival may be offered expectant managment, radiation therapy, or radical prostatectomy, and those with a greater than or equal to 10-year life expectancy may be offered either radical prostatectomy or radiation therapy (Table 89-5). 

The two commonly used methods for radiation therapy are external-beam radiotherapy and brachytherapy.26 In external-beam radiotherapy, doses of 70 to 75 Gy are delivered in 35 to 41 fractions in patient with low-grade prostate cancer and 75 to 80 Gy for those with intermediate- or high-grade prostate cancer. Brachytherapy involves the permanent implantation of radioactive beads of 145 Gy of 125I or 124 Gy of 103Pd and generally is reserved for individuals with low-risk cancers. 

Secondary or salvage therapies for patients who progress after their initial therapy depend on what was used for initial management.26 For patients diagnosed initially with localized prostate cancer, radiotherapy can be used in the case of failed radical prostatectomy. Alternatively, androgen ablation can be used in patients who progress after either radiation therapy or radical prostatectomy. 

Prostate cancer treatment depends on the stage, age, Gleason score, and PSA concentration. Treatment options include expectant management, radiation therapy, radical prostatectomy, hormonal therapy, and chemotherapy. 

Patients must be monitored to assess their response to treatment and to detect recurrent diseases. PSA as a specific marker for prostate cancer is most useful in monitoring patients who have been treated with radical prostatectomy, radiation therapy, or endocrine therapy. The concentration of PSA falls to undetectable levels following a radical prostatectomy because all prostate tissue has been removed. Generally, PSA is measured at periodic intervals. In studies, the extent of disease at the time of surgery correlated well with the postoperative PSA concentration. A significant measurable PSA concentration after prostatectomy indicates that residual tumor may be present. PSA concentrations decline gradually after radiation therapy (36). 

Prostate cancer is a malignant neoplasm that arises from the prostate gland. Prostate cancer has an indolent course localized prostate cancer is curable by surgery or radiation therapy but advanced prostate cancer is not yet curable. 

Radical prostatectomy and radiation therapy are generally considered equivalent for localized prostate cancer, and neither has been shown to be superior to observation alone. 

Androgen deprivation therapy (ADT) is being used increasingly as neo-adjuvant and adjuvant therapy. Neo-adjuvant ADT for 4-6 months before external beam radiation can enhance survival and reduce the prostate volume to be irradiated. Similar benefits have not been seen prior to radical prostatectomy. The benefits of neo-adjuvant therapy are most evident for high risk localized prostate cancer. Adjuvant ADT for up to 2 years following external beam radiation increases disease-free survival and overall survival for locally advanced (T3) tumors. 

The Radiation Therapy Oncology Group (RTOG), 1997, compared mixed beam (a combination of photons and neutrons) to conventional photons for locally advanced prostatic cancer. Loco-regional control as well as survival were significantly superior after mixed-beam irradiation (Fig. 11) [34]. 

Self-administration of untested medical therapy for treatment of prostate cancer can lead to clinically significant adverse events. Int J Radiation Oncol Biol Phys 2002 54 1311-13. 

Satoh, T., Teh, B. S., Timme, T. L., et al. Enhanced systemic T-cell activation after in situ gene therapy with radiotherapy in prostate cancer patients. Int. J. Radiat. Oncol. Biol. Phys. 59(2) 562-571, 2004. 

Treatment of prostate cancer for the various stages is summarized as follows radiation or radical prostatectomy for stages A and B and radiation with or without hormonal therapy for stage C prostate cancer (G4). Through the years, the method of choice in treatment of advanced stage D prostate cancer has been... 

Xu L, et al. (-)-Gossypol enhances response to radiation therapy and results in tumor regression of human prostate cancer. Mol. Cancer Ther. 2005 4 197-205. 

International Agency for Research on Cancer has determined that radioactive strontium is a human carcinogen. Sr has been explored as an anticancer treatment, for example, for prostate cancer, and has been used as palliative treatment for patients with bone pain from osseous metastases. Excellent clinical responses for bone pain treatment have been observed (acceptable hematologic toxicity and clinical results rival those of external beam radiation therapy). 

The greatest clinical use of PSA is in the monitoring of definitive treatment of prostate cancer. This treatment includes radical prostatectomy, radiation therapy, and antiandrogen therapy. PSA has also been suggested to play a role in tumor progression. ... 

Treatment of localized prostate cancer is controversial. While early-stage disease is curable by surgery or radiation therapy, both modalities have significant morbidity and mortality and... 

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