Initial comparison of inverse optimization, modified peripheral technique, and geometric optimization as real-time intraoperative computer planning options for permanent seed implantation of the prostate

Raben, Adam; Sammons, Sarah; Sim, Sang; Chen, Hansen; Hanlon, Alexandra; Sarkar, Abhirup; Donavanik, Viroon; Grebler, Arnold; Geltzeiler, Jules; Benge, Bruce; Glick, Andrew; Jacob, Dayee; Koprowski, Paul

doi:10.1016/j.brachy.2007.08.001

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Volume 6, Issue 4 , Pages 238-245, October 2007

Initial comparison of inverse optimization, modified peripheral technique, and geometric optimization as real-time intraoperative computer planning options for permanent seed implantation of the prostate

Adam Raben
- Department of Radiation Oncology, Helen F. Graham Cancer Center, Newark, DE
- Corresponding author. Department of Radiation Oncology, Helen F. Graham Cancer Center, 4701 Ogletown-Stanton Road, Suite 1110, Newark, DE 19713. Tel.: +1-302-623-4800; fax: +1-302-623-4850.
Sarah Sammons
- Department of Radiation Oncology, Helen F. Graham Cancer Center, Newark, DE
Sang Sim
- Department of Radiation Oncology, Monmouth Medical Center, Long Branch, NJ
Hansen Chen
- Department of Radiation Oncology, Helen F. Graham Cancer Center, Newark, DE
Alexandra Hanlon
- Department of Public Health, Temple University, Philadelphia, PA
Abhirup Sarkar
- Department of Radiation Oncology, Helen F. Graham Cancer Center, Newark, DE
Viroon Donavanik
- Department of Radiation Oncology, Helen F. Graham Cancer Center, Newark, DE
Arnold Grebler
- Shore Urology Professional Associate, Monmouth Medical Center, Long Branch, NJ
Jules Geltzeiler
- Shore Urology Professional Associate, Monmouth Medical Center, Long Branch, NJ
Bruce Benge
- Brandywine Urology Consultants, Wilmington, DE
Andrew Glick
- Brandywine Urology Consultants, Wilmington, DE
Dayee Jacob
- Department of Radiation Oncology, Helen F. Graham Cancer Center, Newark, DE
Paul Koprowski
- Department of Radiation Oncology, Helen F. Graham Cancer Center, Newark, DE

Abstract

Purpose

Comparison of inverse optimization (IO) to modified peripheral (MP) and geometric optimization (GO) intraoperative computer planning options for permanent seed implantation (PSI) of the prostate.

Methods and materials

One hundred ten patients underwent PSI with iodine-125. Three computer planning options were compared including MP loading, GO, and IO. Preimplant dose goals (prescribed dose [PD] of 144Gy) and normal tissue constraints were determined at the outset by the participating physicians before intraoperative computer planning. A single computer planning system was used for this comparison. Postimplant dosimetry was performed at 4–5 weeks and compared for V₁₀₀ and D₉₀, urethral V₁₅₀, and rectal V₁₁₀ of the PD. Acute urinary morbidity was evaluated and compared.

Results

All three options achieved a similar preimplant median V₁₀₀ (97%). The median number of needles and seeds implanted was greater with GO (29, 75) compared to MP (16, 66) and IO (17, 66) (p<0.0001 and p=0.0024, respectively). Postimplant dosimetry showed that IO achieved a higher percentage with V₁₀₀ >95% of the PD in multivariate analysis (p=0.04) and a lower percentage postimplant D₉₀ <140Gy (7%) than for MP/GO (26%) (p=0.01). IO predicted for lower urethral dose (p=0.0169), despite a higher median D₉₀ (169Gy) than either MP (159Gy) or GO (151Gy) (p=0.0025). The median percentage V₁₅₀ urethra for IO was 8% vs. 16% for MP and 23% for GO (p=0.0005). With a median followup time of 6 months, acute Grade 2 urinary symptoms were higher with GO (81%) vs. MP (36%) and IO (53%) (p=0.0019).

Conclusions

Dosimetric outcomes for IO compare favorably to either MP or GO when performed in real time for PSI. In contrast to GO, IO and MP demonstrated excellent correlation between the intraoperative and postoperative plans while using fewer total and interior placed needles and seeds. IO appears feasible as an alternative intraoperative planning solution for PSI.

Keywords: Prostate, Intraoperative, Seed implant