Treatment of Prostate Cancer with Radiotherapy: Should the Entire Seminal Vesicles be Included in the CTV

Ryan Smith, MD
University of Pennsylvania Cancer Center
Ultima Vez Modificado: 7 de noviembre del 2001

Share article


English

Presenter: L.L. Kestin
Presenter's Affiliation: William Beaumont Hospital
Type of Session: Scientific

Background

  • Dose escalation (to upper 70s to >80 Gy) has been shown to be efficacious in the treatment of prostate cancer.
  • With this escalation, patients will likely experience toxicity directly related to volume treated, and the inclusion of the seminal vesicles (SVs).
  • Hence, there is great importance to accurately define the CTV that is needed to be treated.
  • This study was done to attempt to determine the appropriate amount of SV to include in the CTV.

    Materials and Methods

  • Study of 344 patients with T1-2N0 prostate cancer, all treated with radical prostatectomy.
  • A majority of patients had Gleason Score (GS) of 3-6 with a relative minority having a GS of 9-10.
  • Longitudinal sectioning was done in 66% of specimens to directly measure the length of tumor extension from the prostate junction to the farthest cell.
  • Transverse sectioning was done in 34% of patients, where the distance was estimated.

    Results

  • Total median SV length was 3.5 cm, with the 90th percentile being 5.2 cm.
  • There were 81 (+) SVs in 51 patients (15% of patient population).
  • 86% of patients had contiguous spread of disease (so 14% had "skip" lesions).
  • The median length of SVs involved was 1.0 cm, with the 90th percentile being 2.0 cm.
  • Predictors of SV involvement was high PSA (>20=38% involvement), high GS (7=33%, 8-10=37% involvement), and T stage (T2b=39% involvement)

    Author's Conclusions

  • A portion of the SVs should only be included for those patients at high risk of involvement (PSA >10, GS >6, Stage T2b or higher)
  • When treating the SVs, only the proximal 2 cm (50% of total) should be included in the CTV.

    Clinical/Scientific Implications
    The standard dose of radiation delivered in the treatment of prostate cancer has increased in recent years. This is being done with a paucity of data regarding long term toxicity. With increasing doses, it is important to limit the volume being treated. This study makes strides in defining the extent of SVs that need to be treated. As expected, with higher "classic" prognostic factors (high PSA, higher Gleason Score, higher T stage) comes a a higher involvement of the SVs. Regardless of the prognostic factors, the authors recommend treating, at the most, the proximal 2 cm of the SVs in patients with clinical T1-2 tumors. It should be noted, that also presented during this session, was a paper also looking into SV involvement (Davis, et al, Abstract #250). These authors reached the opposite conclusion, notably that the entire SVs should be treated in those patients at risk for SV involvement. In this study, however, a majority (75%) had stage T2b or higher tumors, and all had Gleason Score >6. In addition, the length of SVs was measured differently in terms of pathologic sectioning. This likely accounts for the discrepency, and the indiviaual patient should be considered when evaluating these data.

    Oncolink's ASTRO Coverage made possible by an unrestricted Educational Grant from Bristol-Myers Squibb Oncology and Pharmacia Oncology.

    English
    News
    Utilization predicted by treatment modality, race, younger age, and being unmarried

    Apr 18, 2011 - The utilization of penile implants is low in men who have had prostate cancer treatments, including radical prostatectomy (RP) or radiotherapy (RT), but is more likely in those who have had RP than RT, according to a study published online March 22 in The Journal of Sexual Medicine.



  • I Wish You Knew

    How cancer patients have changed my life

    View More



    Blogs and Web Chats

    OncoLink Blogs give our readers a chance to react to and comment on key cancer news topics and provides a forum for OncoLink Experts and readers to share opinions and learn from each other.




    OncoLink OncoPilot

    Frente a un nuevo diagnóstico de cáncer o de cambiar el curso de su tratamiento actual? Deje que nuestro personal de enfermería cáncer que ayudan a pasar!

    Más información