Routine radiographic staging, such as with bone scan, computed tomography (CT), or magnetic resonance imaging (MRI), or surgical staging with pelvic lymph node dissection is not necessary in all cases of newly diagnosed prostate cancer (Figure 1).3, 4 Clinical criteria can identify patients for whom such staging studies are appropriate.
Although this guideline is commonly used by the experts in the field, supporting data are lacking. CT scan is not a useful staging procedure for the vast majority of patients with newly diagnosed prostate cancer for whom the estimated incidence of positive lymph nodes is approximately 5%.11-13 CT is rarely positive when the PSA is 14
68. Dotan, Z.A., Bianco, F.J., Jr., Rabbani, F., et al: Pattern of prostate-specific antigen (PSA) failure dictates the probability of a positive bone scan in patients with an increasing PSA after radical prostatectomy. J Clin Oncol, 23: 1962, 2005
63. Robinson, D., Sandblom, G. Johansson, R., Garmo, H. Aus, G., Hedlund, P.O., Varenhorst, E: the Scandinavian Prostate Cancer Group. PSA kinetics provide improved prediction of survival in metastatic hormone-refractory prostate cancer. Urol, 2008
12. Flanigan, R.C., McKay, T.C., Olson, M., et al: Limited efficacy of preoperative computed tomographic scanning for the evaluation of lymph node metastasis in patients before radical prostatectomy. Urology, 48: 428, 1996
Additionally, several studies have found a correlation between Gleason score and lymphadenopathy detected on imaging; 1.2% of patients with Gleason score =7 have detectable lymph node enlargement on CT scan, compared to 12.5% in men with Gleason score =8 .9 However, it should be noted that many men with Gleason scores of 8-10 on biopsy, may be downgraded based on examination of radical prostatectomy specimens.15 CT scan identification of pelvic adenopathy depends upon lymph node enlargement, and the correlation between nodal size and metastatic involvement is poor.16 Although the histologic incidence of positive pelvic lymph nodes is substantial when PSA levels exceed 25.0 ng/mL, the sensitivity of CT scanning for detecting positive nodes is only about 30% to 35%, even at these levels.12
For similar reasons, MRI scanning using a body coil is also not a useful staging procedure in the vast majority of patients with newly diagnosed prostate cancer, because sensitivity is again determined by lymph node size.17 Its sensitivity for detecting nodal metastases, as determined from the analysis of seven studies using MRI, was only 36%.13 Endorectal coil MRI together with magnetic resonance spectroscopy (MRS) for characterization of cancer stage and volume is still considered an investigational procedure, but has shown promise in preliminary studies.18, 19
For patients with a rising PSA level after surgery or radiation for localized prostate cancer, the estimate of total PSA alone is an imperfect predictor of a positive bone scan. In studies where bone scans have been positive in this setting, PSA values have averaged between 30.0 and 140.0 ng/mL.64-67 For this reason, the lowest PSA value at which bone scans will always be positive is uncertain. Several analyses67,68 indicate that the rate of PSA change is an additional critical variable in this setting. For men with a PSA doubling time >6 months and a serum PSA 68 Thus, the use of routine bone scans in the setting of a PSA rise following local therapy is not justified, particularly for those with a PSADT of >6 months and a PSA value of
Conclusions: IMRT can be planned using complimentary data obtained from CT & ProstaScint imaging to irradiate the entire prostate & simultaneously boost the regions of greatest tumor burden.
4. Levran, Z., Gonzalez, J.A., Diokno, A.C., et al: Are pelvic computed tomography, bone scan, and pelvic lymphadenectomy necessary in the staging of prostatic cancer? Br J Urol, 75: 778, 1995
10. Murphy, G.P., Snow, P.B., Brandt, J., et al. Evaluation of prostate cancer patients receiving multiple staging tests, including ProstaScint scintiscans. Prostate. 42:145-9, 2000
"The spectroscopic abnormalities are much less evident on thepresent study." And later, "The spectroscopic findings are much less apparent on the present scan, suggestive of positive treatment response."And again, there was no sign of any disease outside the prostate nor at thecapsule (the boundary of the gland).
This involvespre-operative MRI, perhaps CT scans and prostascint scans which arecombined (via software and hardware) with high resolution ulltrasoundimages minutes before and during the seed implantation procedures.