Incorporating radioligand therapy in clinical practice in the United States for patients with prostate cancer.

Prostate cancer (PC) is the second most commonly diagnosed cancer in the United States. Advanced PC evolves to metastatic castration-resistant PC (mCRPC). Theranostics combining prostate-specific membrane antigen-targeted positron emission tomography imaging and radioligand therapy (RLT) represents a precision medicine approach to PC treatment. With the recent approval of lutetium Lu 177 (177Lu) vipivotide tetraxetan for men with mCRPC, the utilization of RLT will increase. In this review, we suggest a framework for incorporating RLT for PC into clinical practice. A search of PubMed and Google Scholar was performed using keywords related to PC, RLT, prostate-specific membrane antigen, and novel RLT centers. The authors also provided opinions based on their clinical experience. The setup and operation of an RLT center requires the diligence and cooperation of a well-trained multidisciplinary team committed to patient safety and clinical efficacy. Administrative systems should ensure that treatment scheduling, reimbursement, and patient monitoring are efficient. For optimal outcomes, the clinical care team must have an organizational plan that delineates the full range of required tasks. Establishing new RLT centers for treatment of PC is possible with appropriate multidisciplinary planning. We provide an overview of the key elements to consider when establishing a safe, efficient, and high-quality RLT center.

Permanent prostate brachytherapy preplanned technique: The modern Seattle method step-by-step and dosimetric outcomes.

PURPOSE: To describe, step-by-step, the current Seattle preplan technique, and report the dosimetric outcomes on 1,131 consecutively such treated prostate brachytherapy patients. METHODS AND MATERIALS: One thousand one hundred thirty one patients with prostate cancer were treated with iodine-125 ((125)I), palladium-103 ((103)Pd), or cesium-131 ((131)Cs) using a preplanned template-guided transrectal ultrasound-guided approach between January 2005 and August 2007. Day one computed tomography (CT) scans were taken for postimplantation dose-volume histogram evaluations. Postoperative prostate contours were drawn by one author (DN) on CT images taken on postoperative day one. RESULTS: The volume of prostate receiving 100% of prescription dose (V(100)) and percent dose to 90% of the prostate (%D(90)) were 95% and 106% for 558 monotherapy (125)I implants, 91% and 102% for 327 (103)Pd implants, and 97% and 111.5% for 13 (131)Cs implants, respectively. The median V(100) and percent D(90) were 91% and 101% for five boost (125)I implants, 92% and 104% for 228 boost (103)Pd implants. The median rectal volume receiving 100% of prescription dose (RV(100)) for (125)I, (103)Pd, and (131)Cs monotherapy implants were 0.3, 0.13, and 0.38cc, and for (125)I and (103)Pd boost implants were 0.16 and 0.13cc, respectively. No patient received an RV(100) of >0.92cc. CONCLUSIONS: Modern preplanned template and ultrasound-guided prostate brachytherapy can consistently result in excellent prostate dosimetry and rectal sparing.

Long-term outcome by risk factors using conformal high-dose-rate brachytherapy (HDR-BT) boost with or without neoadjuvant androgen suppression for localized prostate cancer.

PURPOSE: The aim of this study is to analyze, during the prostate-specific antigen (PSA) era, the long-term outcome of patients treated with conformal high-dose-rate (HDR) brachytherapy boost to the prostate with or without androgen deprivation therapy (ADT) when patients are stratified by risk factors for failure. METHODS AND MATERIALS: Between 1986 and 2000, 611 patients were treated for clinically localized prostate cancer in three prospective trials of external beam radiation therapy (EBRT) and dose-escalating HDR brachytherapy (BT) boost. There were 104 patients treated at Seattle, 198 at Kiel University, and 309 at William Beaumont Hospital. Of the 611 patients, 177 received a short course of neoadjuvant/concurrent ADT. The patients were divided into three risk groups. Group I, comprised of 46 patients, had stage < or =T2a, Gleason score (GS) < or = 6, and initial PSA (iPSA) < or = 10 ng/mL. Group II comprised 188 patients with stage > or =T2b, GS > or = 7, and iPSA > or = 10, with any one factor higher. Group III included 359 patients with any two risk factors higher. The American Society for Therapeutic Radiology and Oncology definition for biochemical failure was used. RESULTS: The mean follow-up was 5 years (range, 0.2-15.3). For the 611 patients, the 5-year and 10-year biochemical control (BC) rates were 77% and 73%, disease-free survival (DFS) was 67% and 49%, and cause-specific survival (CSS) was 96% and 92%, respectively. BC at 5 years for Group I patients was 96%, for Group II 88%, and for Group III patients 69%. CSS at 5 years was 100% in Group I, 99% in Group II, and 95% in Group III patients. In univariate and multiple regression analyses for BC, risk group, stage, iPSA, and GS were significant in predicting failure. However, age, follow-up interval, and ADT did not. CONCLUSIONS: EBRT with HDR-BT produced excellent long-term outcomes in terms of BC, DFS, and CSS in patients with prostate cancer even for those at highest risk. Conformal HDR-BT is both a precise dose delivery system and an effective treatment for both favorable and unfavorable prostate cancer. The addition of a short course of neoadjuvant/concurrent ADT failed to improve outcome. The results were similar at all three institutions, giving credence to the reproducibility of the brachytherapy treatment.

Primary radiotherapy for localized orbital MALT lymphoma.

PURPOSE: To define the natural history, prognosis, and radiocurability of localized orbital extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT). METHODS AND MATERIALS: Clinical records and pathologic material of 40 patients treated with local radiotherapy for localized orbital lymphoma were reviewed. Treatment consisted of 30-40 Gy in 1.8-2-Gy fractions (mean 34 Gy) of irradiation using 9-20-MeV electrons for conjunctival lesions, or 6-MV photons with complex treatment planning for retrobulbar lesions. The lens was routinely shielded with the use of a suspended eye bar. RESULTS: Upon pathologic review, 31 cases of orbital MALT lymphoma were identified. With the median follow-up of 5.9 years (range 9 months-0.3 years), the actuarial 10-year overall survival was 73%. Local control was 100%. Five distant failures resulted in a projected 10-year freedom from relapse of 71%. Most of the failures were extranodal in sites where MALT lymphoma has previously been shown to arise. No difference in outcome was observed among patients treated to less than or equal to 34 Gy vs. those treated to higher radiation doses. Two patients experienced clinically significant retinal damage after doses > or = Gy. CONCLUSION: In this study, localized orbital MALT lymphoma was well controlled with radiotherapy. Even following relapse, patients with orbital MALT lymphoma exhibited an indolent course. Relapse occurred predominantly in extranodal mucosal sites, implying a possible homing mechanism for MALT lymphoma cells. Given the excellent local control rates, our current treatment recommendation is to use a radiation dose of 30-30.6 Gy in 1.5-.8-Gy fractions to minimize risk of late toxicity.