Prostate Biopsy after Definitive Treatment by Interstitial ¹²⁵ Iodine Implant or External Beam Radiation Therapy

Abstract

The response to definitive radiation therapy of localized carcinoma of the prostate by 125iodine implantation or external beam radiotherapy was monitored by examining specimens from biopsies performed after treatment. We analyzed 126 biopsy specimens obtained 18 months or more after treatment: 71 were obtained from 109 patients treated by 125iodine and 55 from 197 patients treated by external beam radiotherapy. Thereafter, the disease status of these patients was examined at minimum 3-year intervals. No significant statistical difference was found between the negative specimen rates of the 2 treatment modalities: 46 of 71 (65 per cent) after 125iodine implantation and 39 of 55 (71 per cent) after external beam radiotherapy were negative. To analyze the predictive value of biopsy results 103 patients whose prostatic examination results were normal at biopsy or who showed regression of tumor size and tumor induration after radiation were evaluated. The biopsy results from all patients were combined for analysis. Of 77 patients with negative biopsy specimens 16 (21 per cent) have had recurrent disease, compared to 17 of 26 (65 per cent) with positive biopsy specimens (p equals 0.00005). Of the 77 patients with negative biopsy specimens 7 (9 per cent) had local disease recurrence, compared to 12 of 26 (46 per cent) with a positive biopsy specimen (p equals 0.0001). The value of a positive specimen to predict failure remained significant with patients stratified by pre-treatment clinical stage and grade of the disease. Our results show that patients with positive specimens from the prostate who had been judged clinically by rectal examination to have responded to radiation therapy had a significantly increased incidence of local and distant failure compared to patients who had negative biopsy specimens.

Role of transrectal ultrasound guided salvage cryosurgery for recurrent prostate carcinoma after radiotherapy

“…[5][6][7][8][9] This broad range of recurrence rates is postulated to reflect patient selection criteria, the meticulousness with which the follow-up monitoring and biopsy was performed and variations in radiotherapy techniques applied. Risk factors for failure of radiation therapy have been identified, and include relative radioresistance of the prostatic carcinoma, failure to administer a cytotoxic dose to the entire gland, and limitations in the ability to increase dosing due to the potential of injuring surrounding tissue.…”

“…4 Unfortunately, 25-71% of men will fail radiotherapy, many with isolated local recurrence. [5][6][7][8][9] The treatment options for locally recurrent disease following radical radiotherapy are limited: salvage surgery which has a high risk of significant and frequent morbidity, and hormone therapy which is noncurative. [10][11][12][13] Recently, cryosurgery has been advanced as an option for localized recurrence after radiotherapy based upon its successful application as a primary treatment for localized prostate cancer.…”

Brachytherapy for prostate cancer

“…After two years these figures were 38 percent (n=21) and 67 percent (n=6), respectively. Schellhammer et al 47 reported positive biopsy rates of 30 percent (n=40) for patients with stage B tumors and 43 percent (n=20) for patients with stage C tumors. The authors commented that grade was unpredictable in determining outcome in terms of postoperative biopsy results.…”

Immunology and immunotherapy approaches for prostate cancer

“…130 The recovery probability of early localized PC by radical prostatectomy or radical radiotherapy is quite high; however, between 35 and 61% of patients undergoing such treatment modalities are later found to have non-organ-confined disease or positive prostatic biopsies. [131][132][133] As a result, a significant proportion of patients seem to be left with residual disease, and currently no adjuvant or salvage therapy has been confirmed to be of promising benefit for treating these patients. Whereas androgen deprivation has remained the first line of therapy for advanced PC, other therapies are still required due to progression to an androgenresistant state and eventually loss of control in patients receiving hormonal therapy.…”