Assessing inter-fraction changes in the size and position of the penile bulb during daily MR-guided radiation therapy to the prostate bed: Do we need to adjust how we plan radiation in the post-radical prostatectomy setting to reduce risk of erectile dysfunction?

Introduction: prostate cancer (PCa) is the second cancer after lung one among all males. The main treatmentfor patients with localized prostate cancer is a radical prostatectomy (RP). After RP PCa occurs in patients at the T1-T2 stage - in 25 - 35% of all cases and in patients at the T3 stage - in 33.5 - 66% of all cases. Currently, one of the treatment options for patients with recurrence PCa after RP is a «salvage» radiation therapy. Materials and methods: medical records of 59 patients with PCa recurrence after radical prostatectomy (pT1-3pN0M0) were analyzed. Biochemical recurrence was observed in 25 (42,4%) and clinical recurrence in 34 (57,6%) patients. Radiotherapy have been prescribed to the regional lymphatic nodes to 44,0 Gy of 2,0 Gy each, to the prostate bed to 66,0 Gy of 2,0 Gy each and if the region of the clinical recurrence was identified - to 72 Gy of 2,0 Gy. Treatment was realized on linear electron accelerators using 3D technology radiotherapy: 3DCRT, IMRT, VMAT. Results: all 59 patients were treated by the «salvage» radiotherapy. Median follow-up was 48 months (24-91). Biochemical control w as achieved in 51 (86.4%) patients, locoregional control in 58 (98.3%) patients. No acute and late grade 3 or greater toxicities were observed.

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Radiotherapy for patients with locoregional and oligometastatic relapses of prostate cancer after radical prostatectomy

Cancer Urology ◽

10.17650/1726-9776-2020-16-3-102-108 ◽

2020 ◽

Vol 16 (3) ◽

pp. 102-108

Author(s):

P. V. Bulychkin ◽

S. I. Tkachev ◽

V. B. Matveev ◽

A. V. Klimov ◽

F. A. Kossov

Keyword(s):

Prostate Cancer ◽

Radiation Therapy ◽

Radical Prostatectomy ◽

Chemotherapy Treatment ◽

Salvage Radiation Therapy ◽

Prostate Bed ◽

High Incidence ◽

Solitary Metastases ◽

Radiotherapy Treatment

Materials and methods. In our study, 21 patients with recurrent prostate cancer after radical prostatectomy and oligometastases were treated by salvage radiation therapy, which included radiotherapy treatment of recurrent tumors, regional pelvic lymph nodes, the prostate bed and stereotactic body radiation therapy to detected solitary metastases.Results. The average follow-up period was 19 ± 3.5 months. At the same time, 12 (57 %) of 21 patients are currently under observation for more than 1 year, and 1 patient for more than 5 years without signs of a biochemical recurrence. The indicator of biochemical control of the disease was 86 % (18 / 21 patients) with an average follow-up period of 19 months.Conclusion. It seems to us that further study of this problem can replace today's palliative standard of treatment for this special category of patients — hormonal and chemotherapy treatment, which has low effectiveness at a high incidence of toxicity.

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Effect of incorporation of preoperative CT scan on bladder doses and irradiated volume in postprostatectomy radiation therapy (pPRT).

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.6_suppl.e561 ◽

2017 ◽

Vol 35 (6_suppl) ◽

pp. e561-e561

Author(s):

Mani Akhtari ◽

Denley Ming Kee Yuan ◽

Eugene C. Endres ◽

Bao Minh Tran ◽

Todd A. Swanson

Keyword(s):

Radiation Therapy ◽

Ct Scan ◽

Radiation Therapy Oncology Group ◽

Progression Free Survival ◽

Target Volume ◽

Consensus Definition ◽

Prostate Bed ◽

Patients At Risk ◽

Preoperative Ct ◽

Penile Bulb

e561 Background: pPRT increases local control, biochemical progression free survival, and even overall survival in patients with adverse features undergoing prostatectomy. The Radiation Therapy Oncology Group (RTOG) consensus definition of the clinical target volume (CTV) in 2010 was based on patterns of failure and anatomy without consideration of pre-operative imaging. This results in large volumes of bladder in the treatment field. Our study evaluates whether incorporation of pre-operative prostate volume can reduce the post-operative CTV and minimize dose to adjacent normal tissue. Methods: We reviewed records of all patients with available pre-operative pelvic CT scans treated at our institution with pPRT. The pre-operative CT scan was fused to the simulation CT. Post-operative CTV (CTV1) was delineated based on RTOG guidelines. A separate CTV (CTV2) was constructed, based on the intact prostate and proximal seminal vesicles. Plans were constructed for each CTV and doses to rectum, bladder, and penile bulb calculated, as well as concordance between the two CTVs and planning target volumes (PTVs). Paired student’s t-test was used to calculate difference between doses in the two different plans. Results: 10 patients’ plans were analyzed. Dosimetric parameters are shown in table 1. Volume of the bladder receiving 65 Gy or higher (V65) was significantly higher in CTV1. As would be expected, there were no significant differences in dose to either the rectum or penile bulb. Additionally, there was on average only 39% overlap between the CTVs and 60% between the PTVs in the two plans. Conclusions: Utilization of the pre-operative pelvic CT scan can aid in more accurate delineation of the CTV/PTV in prostate bed radiation therapy and decrease the bladder dose. As many patients at risk for pPRT have had this imaging performed preoperatively, in accordance with guidelines, incorporation of this data appears prudent. These findings need to be validated in a larger cohort. [Table: see text]

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