Physical examination, serum PSA

This may be particularly important in evaluating the borders of the prostate at the apex and base (Fig. 3). Some authors have advocated the combination of imaging modalities for postimplant dosimetry. The timing of postimplant dosimetry remains controversial. Edema develops in the prostate following seed placement, and it is thought that this affects immediate postimplant dosimetry. Waterman et al reported a 10% underestimate of calculated prostate coverage when CT was performed immediately following the implant procedure. The optimal time for postimplant dosimetry also may differ by isotope. Yue et al performed an image-based dose evaluation for I-125 and Pd-103 prostate brachytherapy implants. Based on the model used, they recommended that postimplant dosimetry be performed at 7 weeks postimplant for I-125 and at 3 weeks postimplant for Pd-103. Because there still remains a lack of consensus with regard to the ideal time for postimplant dosimetry, the ABS recommends that each center perform dosimetric evaluation at a consistent interval. Physical examination, serum PSA, and prostate biopsy The intervals in which patients are seen in the clinic following brachytherapy are dependent on several factors that pertain to the biology of the tumor, treatment algorithm, and side-effect profile experienced by the patient. Patients are seen initially 2 to 3 weeks after brachytherapy for postimplant dosimetry as described above. The next office visit is at 6 to 8 weeks, at which point an evaluation of the patients voiding function is performed. This consists of the application of a voiding questionnaire to quantify a symptom score, combined with evaluation of the postvoid residual, preferably by ultrasonography. The Fig. 1. Multiple CT slices of prostate with postimplant isodose lines overlaid (blue, 100% of dose; aqua, 150% of dose; yellow, 75% of dose). Fig. 2. Comparison between MRI and CT images of the same patient at the same level for radiation planning. Fig. 3. Comparison between postimplant MRI and CT images of the same patient at the same level. E.M. Horwitz et al / Urol Clin N Am 30 (2003) 737–750 741 latter examination is particularly important because a significant minority of patients develop acute urinary retention. Therefore, in patients who are not managed with alpha-receptor antagonists in the pre and postoperative period, initiation of such agents is advisable in the presence of significant postvoid residual. In addition, patients who develop sexual dysfunction [13–15]—due to androgen deprivation or secondary to the brachytherapy procedure are offered management options at this time. Patients with low-risk disease usually are followed every 6 months with a digital rectal examination and PSA. This examination protocol is continued for the first 5 years, after which the frequency is reduced to yearly visits. A similar protocol can be used for patients with high-risk disease, although in many cases such patients have examinations and PSA analysis performed every 3 to 4 months in the first 3 years, followed by a reduction to every 6 months for the next 2 or 3 years, with yearly follow-up thereafter. Recently, nomograms have been developed for patients treated with brachytherapy that can help to guide the intensity of follow-up based on the risk of recurrence. The added benefit of routine prostate biopsies in following brachytherapy in the absence of biochemical failure is unclear. In the setting of EBRT, Crook et al reported prospectively on 226 patients and showed that for those patients with PSA levels near nadir after radiation, there is little value in performing biopsy. Most recently, the American Society for Therapeutic Radiology and Oncology (ASTRO) reported a consensus panel recommendation that routine prostate biopsy should not be performed for evaluation of PSA recurrence after EBRT unless salvage prostatectomy or other salvage procedures were being considered. In addition, if a new nodule is palpated at the follow-up examination, a biopsy should be performed only if the patient is a candidate for potentially curative approaches (discussed below).

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