A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology

Phase I study of picoplatin and docetaxel (D) with prednisone (P) in patients (pts) with chemotherapy-naive metastatic hormone refractory prostate cancer (HRPC)

15546 Background: Picoplatin is a sterically hindered platinum analogue specifically developed to overcome platinum resistance and to improve on the safety and efficacy of other platinum-based drugs. In &gt;600 pts, picoplatin had single-agent activity in prostate, lung, ovarian and other malignancies with rare clinically significant nephro-, oto-, or neurotoxicity (∼2% grade 3 and 0% grade 4), even in platinum pretreated pts. An objective response rate of 20% and a PSA response rate of 25% were observed following 120 mg/m2 picoplatin q 3 wk in 20 chemotherapy-naïve pts with HRPC. D + P leads to superior survival, increased PSA response and improved quality of life in HRPC pts. Picoplatin has demonstrated synergy with taxanes in pre-clinical studies. Thus the current study is designed to investigate D + P + picoplatin in chemotherapy-naïve pts with metastatic HRPC. Methods: Pts with documented progression of metastatic disease during adequate hormonal therapy, ECOG performance status of 0 or 1 and preserved organ function received D, 60 mg/m2 q 3 wks + P, 5 mg, po bid + picoplatin. Picoplatin has been given to date to sequential cohorts of subjects at 60 mg/m2, 80 mg/m2 and 100 mg/m2. Results: 16 pts have been enrolled and have received up to 8 cycles of therapy. Therapy has been well tolerated. No dose limiting toxicity has been observed. Dose reduction for thrombocytopenia has been required in 1 pt, but there has been no cumulative myelotoxity. 7 pts in the first 3 dose cohorts have been evaluated for efficacy after 4 cycles (12 weeks): at doses below the maximum tolerated dose, there were 3 PSA responses and 1 objective partial response. Dose escalation continues. Conclusion: Picoplatin can be safely administered with D + P in chemo-naïve pts with HRPC. A phase 2 study of this combination will begin when an optimal, safe dose is defined. No significant financial relationships to disclose. </jats:p

Results of a phase II study of picoplatin with docetaxel and prednisone in first-line treatment of castration-resistant prostate cancer (CRPC)

5140 Background: Picoplatin (Pico) was designed to overcome platinum resistance and has the potential for improved safety compared to other platinum agents. Previously, a PSA response rate of 25% was observed when Pico monotherapy was infused at 120 mg/m2 Q3W (N = 20). Recently, a 34-patient Phase I study was performed to investigate the safety and efficacy of Pico in combination with docetaxel (D) + prednisone (pred) as first-line therapy for metastatic CRPC. Picoplatin therapy was well-tolerated at a dose of 120 mg/m2 and 19 of 32 evaluable pts (59%) achieved a confirmed PSA response. Methods: 32 patients with chemotherapy-naïve CRPC and disease progression received Pico (120 mg/m2) and D (75 mg/m2) Q3W with pred 5 mg po bid for up to 10 cycles. PSA responses were defined as a reduction from baseline of at least 50% maintained for at least 4 weeks. CT and bone scans were also evaluated. Tumor response was measured using RECIST. Results: Patients received a median of 10 cycles (range = 1–10). Median baseline PSA was 340.8 ng/mL (range 5.6–3019). One pt had no baseline PSA data. Of the 24 patients with evaluable post-treatment PSA, 83% (95% CI 64–93%) had PSA decreases &lt;50% of baseline, and in 8 of these (33% of the evaluable population), PSA reached normal levels (&lt; 4 ng/mL). In the intent-to-treat population, the PSA response rate was 63% (95% CI 45–77%). 13 patients evaluated by CT scan had measurable disease; 6 pts had SD by RECIST, 4 had PD, and 3 were not evaluable. The most common adverse events were alopecia (36%), asthenia (32%), neutropenia (29%), increased creatinine (23%), and thrombocytopenia (19%). No neurotoxicity ≥ grade 2 was observed. Conclusions: Picoplatin was safely administered to patients with CRPC as 1st-line therapy at 120 mg/m2 Q3W with full doses of docetaxel and prednisone, resulting in a PSA response rate of 83% of evaluable patients. These results support further development of picoplatin as a novel combination with docetaxel for the treatment of CRPC. [Table: see text] </jats:p

Holmium-166 (166Ho)-DOTMP Skeletal Targeted Radiotherapy (STR™) with Melphalan and Autologous Peripheral Stem Cell Transplant (PBSCT) for Multiple Myeloma (MM)

Abstract Background: 166Ho-DOTMP is a beta-emitting radiophosphonate that localizes specifically to the bone surfaces and can deliver high dose radiation both to the bone and bone marrow. Follow-up data from 3 clinical trials with STR as conditioning for patients with MM undergoing autologous PBSCT are presented. Methods: In 2 Phase I/II dose-escalation trials, 83 patients received a dose of 166Ho-DOTMP STR calculated to deliver 20, 30, or 40 Gy to the red marrow; 82 pts received melphalan (140 or 200 mg/m2) ± 8 Gy TBI (n=25), followed by PBSCT. As of June, 2004, 77 subjects have been followed for at least 48 months. In a separate Phase II dosimetry trial, 12 patients received two 30 mCi tracer doses of 166Ho-DOTMP STR to determine the reproducibility of biodistribution and pharmacokinetics (PK). All pts received a 25 Gy therapy dose with concurrent IV hydration and continuous bladder irrigation, followed by 200 mg/m2 melphalan and PBSCT. These patients have been followed for at least 18 months. Results: Up to 2.3 Ci/m2, 166Ho-DOTMP STR was given in the Phase I/II trials; 29/83 (35%) patients achieved complete response (CR) and overall response rate (CR + PR) was 64% (7 pts not evaluable). The Kaplan-Meier estimate of median survival is 5.2 years for all 83 patients. In patients who are at least 4 years post transplant who achieved a CR, the survival is 74% (n=27). In patients who achieved less than a CR at least 4 years ago, the survival is 34% (n=44). Dose-related radiation-induced kidney toxicity presented in some patients more than 6 months post-therapy. The dose of 166Ho-DOTMP STR in the Phase II dosimetry trial was 550 to 860 mCi/m2, 166Ho-DOTMP. Currently, 18 months of follow-up reveals no occurrence of hemorrhagic cystitis or > Grade 2 elevated creatinine. A CR rate of 17% with an overall survival of 92%, was observed. In 10 patients who received 166Ho-DOTMP STR 750 mCi/m2 ± 10% in the Phase I/II trial, the CR rate was 40%, and the 4-year survival was 70%. Monitoring for safety and duration of response is ongoing in all 3 trials. Conclusion: Follow-up from the Phase I/II trials confirms that 166Ho-DOTMP STR provides favorable efficacy and safety as part of the conditioning regimen for patients with MM undergoing PBSCT. A Phase III, randomized multicenter study is now open to enrollment, comparing the safety and efficacy of 166Ho-DOTMP STR plus melphalan to melphalan alone as conditioning for PBSCT in subjects with primary refractory MM who have failed to respond to induction therapy, including high-dose dexamethasone, and are within 18 months of diagnosis

Holmium-166 (166Ho)-DOTMP Skeletal Targeted Radiotherapy (STR™) with Melphalan and Autologous Peripheral Stem Cell Transplant (PBSCT) for Multiple Myeloma (MM).

Abstract Background: 166Ho-DOTMP is a beta-emitting radiophosphonate that localizes specifically to the bone surfaces and can deliver high dose radiation both to the bone and bone marrow. Follow-up data from 3 clinical trials with STR as conditioning for patients with MM undergoing autologous PBSCT are presented. Methods: In 2 Phase I/II dose-escalation trials, 83 patients received a dose of 166Ho-DOTMP STR calculated to deliver 20, 30, or 40 Gy to the red marrow; 82 pts received melphalan (140 or 200 mg/m2) ± 8 Gy TBI (n=25), followed by PBSCT. As of June, 2004, 77 subjects have been followed for at least 48 months. In a separate Phase II dosimetry trial, 12 patients received two 30 mCi tracer doses of 166Ho-DOTMP STR to determine the reproducibility of biodistribution and pharmacokinetics (PK). All pts received a 25 Gy therapy dose with concurrent IV hydration and continuous bladder irrigation, followed by 200 mg/m2 melphalan and PBSCT. These patients have been followed for at least 18 months. Results: Up to 2.3 Ci/m2, 166Ho-DOTMP STR was given in the Phase I/II trials; 29/83 (35%) patients achieved complete response (CR) and overall response rate (CR + PR) was 64% (7 pts not evaluable). The Kaplan-Meier estimate of median survival is 5.2 years for all 83 patients. In patients who are at least 4 years post transplant who achieved a CR, the survival is 74% (n=27). In patients who achieved less than a CR at least 4 years ago, the survival is 34% (n=44). Dose-related radiation-induced kidney toxicity presented in some patients more than 6 months post-therapy. The dose of 166Ho-DOTMP STR in the Phase II dosimetry trial was 550 to 860 mCi/m2, 166Ho-DOTMP. Currently, 18 months of follow-up reveals no occurrence of hemorrhagic cystitis or &gt; Grade 2 elevated creatinine. A CR rate of 17% with an overall survival of 92%, was observed. In 10 patients who received 166Ho-DOTMP STR 750 mCi/m2 ± 10% in the Phase I/II trial, the CR rate was 40%, and the 4-year survival was 70%. Monitoring for safety and duration of response is ongoing in all 3 trials. Conclusion: Follow-up from the Phase I/II trials confirms that 166Ho-DOTMP STR provides favorable efficacy and safety as part of the conditioning regimen for patients with MM undergoing PBSCT. A Phase III, randomized multicenter study is now open to enrollment, comparing the safety and efficacy of 166Ho-DOTMP STR plus melphalan to melphalan alone as conditioning for PBSCT in subjects with primary refractory MM who have failed to respond to induction therapy, including high-dose dexamethasone, and are within 18 months of diagnosis.</jats:p