The Value of Dose Constraints in Minimizing Rectal Toxicity in Patients Receiving Radiation Therapy for Prostate Cancer: Three-year Analysis of Toxicity Outcomes in 2 Prospective Trials of Image Guided Proton Therapy for Early- and Intermediate-Risk Prostate Cancer

152 Background: To report outcomes in two prospective proton therapy (PT) trials for localized prostate cancer. Methods: From 2006 to 2007, 171 low- and intermediate-risk prostate cancer patients were treated with PT on prospective trials. Low-risk patients (N=89) were treated on PR01 with 78 CGE/39 fractions to the prostate. Intermediate-risk patients (N=82) were treated on PR02, a dose-escalation trial, with 78-82 CGE to the prostate and proximal seminal vesicles. Based on organ-constraint goals, 57 (69%), 13 (16%), and 12 (15%) PR02 patients received 82 CGE, 80 CGE, and 78 CGE, respectively. Toxicity was scored by CTCAE v3 and biochemical failure defined as nadir + 2 ng/mL. Results: The proportions of PR01 and 02 patients alive with no evidence of disease are 83 (93%) and 73 (89%); alive with disease, 1 (1%) and 1 (1%); and dead of intercurrent disease, 5 (6%) and 8 (10%), respectively. Only 2 patients had disease progression, both isolated pelvic-node recurrences. No patient died of prostate cancer or recurred locally. Grade (GR) 3 genitourinary (GU) and gastrointestinal (GI) complications occurred in 2 of 101 (2%), 0 of 13, and 4 of 57 (7%) patients receiving 78, 80, and 82 CGE, respectively. GR 3 GU toxicity occurred in 1 PR01 and 3 PR02 patients, including hematuria in 1 PR01 patient on anticoagulation; posttreatment TURP in 2 who had pretreatment (pre-tx) TURP; and dysuria in 1 with severe chronic pre-tx prostatitis. Multivariate analysis (MVA) of protocol, dose, age, prostate volume, pre-tx IPSS, pre-tx medical or surgical GU symptom management (SM), anticoagulation, and bladder wall V70 or V30 showed only pre-tx SM (P< .0001) and age (P =.007) to be associated with GR2+ toxicity. GR 3 GI toxicity occurred in 2 PR02 patients, including rectal bleeding in a patient on anticoagulation, and rectal bleeding and proctitis in a patient on anticoagulation who had a transrectal prostate biopsy. MVA of protocol, age, dose, anticoagulation, and rectal wall V70 or rectum V30 showed only rectal wall V70 (.045) and rectum V30 (.027) to be associated with GR 2+ rectal bleeding and proctitis. Conclusions: PT may provide sufficiently reduced toxicity to permit further dose intensification and/or concomitant chemotherapy.

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Intermediate-risk prostate cancer: A Medicare-based cost comparison of five radiotherapy regimens.

Journal of Clinical Oncology ◽

10.1200/jco.2015.33.7_suppl.108 ◽

2015 ◽

Vol 33 (7_suppl) ◽

pp. 108-108

Author(s):

Romaine Charles Nichols ◽

Kathy McIntyre ◽

Juana Gifford ◽

Steve K. Ritz ◽

Stuart Klein ◽

...

Keyword(s):

Prostate Cancer ◽

Proton Therapy ◽

Therapeutic Options ◽

Cost Comparison ◽

Fiscal Year ◽

Tumor Control ◽

Intermediate Risk ◽

Image Guided ◽

Risk Prostate Cancer ◽

The Cost

108 Background: Patients with intermediate risk prostate cancer choosing radiotherapy may be treated with a number of regimens. The current study compares the direct treatment cost for five therapeutic options based on Fiscal Year 2014 Medicare allowable reimbursements. Methods: Hypothetical charge sheets were generated along with the expected Medicare allowable reimbursements (based on global billing where applicable) for the following regimens: 1.) Image Guided Intensity Modulated Radiotherapy (IGIMRT) to a dose of 78Gy in 39 fractions with one field reduction (IGIMRT); 2.) Dose escalated IGIMRT to 84.60Gy in 47 fractions with one field reduction (MSKCC-IGIMRT); 3.)IGIMRT to a dose of 45Gy in 25 fractions followed by a 90 seed I125 prostate implant (IGIMRT-BTX); 4.) Image Guided Proton Therapy to a dose of 78Gy(RBE) in 39 fractions with one field reduction (SFPT); 5.) Image Guided Hypofractionated Proton Therapy to a dose of 72.50Gy(RBE) in 29 fractions with one field reduction (HFPT). Results: Based on Fiscal Year 2014 Medicare allowable reimbursements, the direct cost for each of these interventions including professional fees, technical fees, isotope costs and facility fees is shown in the Table. Conclusions: This data presents a framework for evaluating the cost effectiveness of proton therapy as compared to competing therapeutic options. Under current Medicare allowable reimbursements, the cost of proton therapy relative to the cost of other therapeutic options is highly dependent on the number of radiotherapy fractions delivered. The feasibility of delivering hypofractionated proton therapy for patients with localized prostate cancer is being investigated at a number of institutions as well as within the framework of a multicenter protocol. Ultimately the cost of proton therapy will need to be weighed against tumor control probabilities as well as the economic and quality of life benefits associated with reduced normal tissue exposure. [Table: see text]

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