Purpose: To analyze the dosimetric implications of seminal vesicle (SV) resection at the time of laparoscopic pelvic lymph node (PLN) dissection in patients presenting with high-risk prostate cancer regarding PLN and SV involvement.
Patients and methods: Between June and September 2005, twelve patients underwent laparoscopic SV resection and PLN dissection before delivering a total dose of 80 Gy through a three-dimensional conformal radiation therapy (3D-CRT). Dose-volume histograms (DVHs; rectum, bladder, femoral heads) were obtained from G1 (group 1 with SV) and G2 (group 2 without SV) according to either three- dimensional or intensity-modulated treatment planning. All DVH medians were compared using the nonparametric sign test.
Results: SV resection during laparoscopic PLN dissection was performed in all twelve patients without major complications. DVH obtained with three-dimensional and intensity-modulated treatment planning showed that the median doses of RV(25%) (25% of rectal volume), RV(50%), RFHV(5%) (5% of right femoral head volume) and LFHV(5%) (5% of left femoral head volume) in G1 were significantly higher compared to those obtained in G2.
Conclusion: For patients presenting with high-risk prostate cancer, SV resection performed at the time of laparoscopic PLN dissection allows to significantly decrease the dose delivered to the rectum, using either three-dimensional or intensity-modulated treatment planning, and to reduce the risk of acute and late rectal toxicity.