Extreme weekly locoregional hypofractionated radiation in elderly women with non-metastatic breast cancer.

BACKGROUND AND PURPOSE: Breast cancer locoregional (LR) radiation in the elderly requires careful consideration between the benefits of aggressive treatment and its potential toll on these patients. Extreme weekly LR hypofractionated radiation (HFRT), delivering >5 Gy per fraction, may be better suited in such a population. It represents a good compromise between RT omission and exhaustive daily radiation. This study aims to report the local and LR control rate as well as the acute and long-term side effects of the elderly patients treated with HFRT in our institution, and to compare these results to those from the literature. MATERIALS AND METHODS: We conducted a retrospective study by reviewing medical records of elderly patients with breast cancer treated with adjuvant once-weekly LR HFRT between 2011 and 2020. Fifty patients presenting with primary non-metastatic node-positive breast tumors were included. Treatment outcomes including local/LR control and overall survival were reported. Early and late toxicity profiles were also assessed. RESULTS: After a median follow-up of 4.8 years, only one local recurrence in the chest wall occurred and there was no regional recurrence. The distant metastatic rate was 6%. The long-term recurrence-free survival rate was 80% at 5 years. The cause specific survival rate was 90% at 5 years. The overall survival rate was 69.4% and 55.5% at 3 and 5 years, respectively. There were 44 (88%) patients with Grade 1 or 2 early toxicity. There was no Grade 3 or higher acute toxicity registered. Late toxicity was mainly Grade 1 or 2 subcutaneous fibrosis, lymphoedema, and neuropathy except for one patient with Grade 3 fibrosis. CONCLUSION: Extreme LR HFRT is well tolerated with good outcomes and is a good alternative for elderly and frail patients. Our results confirm the efficacy and safety of such a regimen. Further randomized trials assessing both oncologic outcome and toxicity profile are justified.

The Clinical Significance of Bone Mineral Density Changes Following Long-Term Androgen Deprivation Therapy in Localized Prostate Cancer Patients.

PURPOSE: Long-term androgen deprivation therapy has been associated with decreased bone mineral density in men with prostate cancer. Some evidence suggests that there is no impact on fracture risk despite this bone mineral density loss. Our study aimed to quantify changes in bone mineral density in men with high risk prostate cancer on long-term androgen deprivation therapy and calcium and vitamin D supplementation. MATERIALS AND METHODS: Bone mineral density analysis was conducted for localized high risk prostate cancer patients enrolled in the phase III randomized trial PCS-V (Prostate Cancer Study 5), comparing conventional and hypofractionated radiation therapy. Patients received 28 months of luteinizing hormone-releasing hormone agonist and calcium and vitamin D supplementation (500 mg calcium BID+400 IU vitamin D3 BID). The areal density and T-scores (spine, femoral neck and total femur) at baseline and 30 months of followup were extracted, and the absolute change was calculated. Clinical bone density status (normal, osteopenia, osteoporosis) was monitored. RESULTS: The lumbar spine, femoral neck and total femoral bone mineral density were measured for 226, 231, and 173 patients, respectively. The mean percent change in bone mineral density was -2.65%, -2.76% and -4.27% for these respective sites (p <0.001 for all). The average decrease in bone mineral density across all sites was -3.2%, with no decline in bone mineral density category in most patients (83%). Eight patients (4%) became osteoporotic. CONCLUSIONS: Despite a mild decline in bone mineral density, the change in clinical bone mineral density category remained low with long-term androgen deprivation therapy. Consequently, calcium and vitamin D supplementation alone may suffice for most localized prostate cancer patients on long-term androgen deprivation therapy.

Combined Long-Term Androgen Deprivation and Pelvic Radiotherapy in the Post-operative Management of Pathologically Defined High-Risk Prostate Cancer Patients: Results of the Prospective Phase II McGill 0913 Study.

Purpose: Following radical prostatectomy, prostate bed radiotherapy (PBRT) has been combined with either long-term androgen deprivation therapy (LT-ADT) or short-term ADT with pelvic lymph node radiotherapy (PLNRT) to provide an oncological benefit in randomized trials. McGill 0913 was designed to characterize the efficacy of combining PBRT, PLNRT, and LT-ADT. It is the first study to do so prospectively. Methods: In a single arm phase II trial conduced from 2010 to 2016, 46 post-prostatectomy prostate cancer patients at a high-risk for relapse (pathological Gleason 8+ or T3) were assessed for treatment with combined LT-ADT (24 months), PBRT, and PLNRT. Patients received PLNRT and PBRT (44 Gy in 22 fractions) followed by a PBRT boost (22 Gy in 11 fractions). The primary endpoint was progression-free survival (PFS). Toxicity and quality of life (QoL) were evaluated using CTCAE V3.0 and EQ-5D-3L questionnaires, respectively. Results: Among the 43 patients were treated as per protocol, median PSA was 0.30 µg/L. On surgical pathology, 51% had positive margins, 40% had Gleason 8+ disease, 42% had seminal vesicle involvement, and 19% had lymph node involvement. At a median follow-up of 5.2 years, there were no deaths or clinical progression. At 5 years, PFS was 78.0% (95% Confidence Interval 63.7-95.5%). Not including erectile dysfunction, patients experienced: 14% grade 2 endocrine toxicity while on ADT, one incident of long-term gynecomastia, 5% grade 2 acute urinary toxicity, 5% grade 2 late Urinary toxicity, and 24% long-term hypogonadism. No comparison between the average or minimum self-reported QoL at baseline, during ADT, nor after ADT demonstrated a statistically significant difference. Conclusions: Combining PBRT, PLNRT, and LT-ADT had an acceptable PFS in patients with significant post-operative risk factors for recurrence. While therapy was well-tolerated, long-term hypogonadism was a substantial risk. Further investigations are needed to determine if this combination is beneficial. Trial registration: NCT01255891.

Does Interfraction Cone Beam Computed Tomography Improve Target Localization in Prostate Bed Radiotherapy?

PURPOSE: In this prospective phase II study, we investigated whether cone beam computed tomography scan was a superior method of image-guided radiotherapy relative to 2D orthogonal kilovoltage images in the post-radical prostatectomy setting. METHODS: A total of 419 treatment fractions were included in this analysis. The shifts required to align the patient for each treatment were performed using 3D matching between cone beam computed tomography scans and the corresponding computed tomography images used for planning. This was compared with the shifts obtained from 2D orthogonal kilovoltage images, matching with the corresponding digitally reconstructed radiographs. Patients did not have fiducials inserted to assist with localization. Interfractional changes in the bladder and rectal volumes were subsequently measured on the cone beam computed tomography images for each fraction and compared to the shift differences between orthogonal kilovoltage and cone beam computed tomography scans. The proportion of treatment fractions with a shift difference exceeding the planning target volume of 7 mm, between orthogonal kilovoltage and cone beam computed tomography scans, was calculated. RESULTS: The mean vertical, lateral, and longitudinal shifts resulted from 2D match between orthogonal kilovoltage images and corresponding digitally reconstructed radiographs were 0.353 cm (interquartile range: 0.1-0.5), 0.346 cm (interquartile range: 0.1-0.5), and 0.289 cm (interquartile range: 0.1-0.4), compared to 0.388 cm (interquartile range: 0.1-0.5), 0.342 cm (interquartile range: 0.1-0.5), and 0.291 cm (interquartile range: 0.1-0.4) obtained from 3D match between cone beam computed tomography and planning computed tomography scan, respectively. Our results show a significant difference between the kilovoltage and cone beam computed tomography shifts in the anterior-posterior direction ( P = .01). The proportion of treatment fractions in which the differences in kilovoltage and cone beam computed tomography shifts between exceeded the 7 mm planning target volume margin was 6%, 2%, and 3% in the anterior-posterior, lateral, and superior-inferior directions, respectively. CONCLUSION: We prospectively demonstrated that the daily use of volumetric cone beam computed tomography for treatment localization in post-radical prostatectomy patients demonstrated an increased need for a shift in patient position. This suggests that in post-radical prostatectomy patients the daily cone beam computed tomography imaging improved localization of the prostate bed and may have prevented a limited number of geographic misses, compared to daily kilovoltage imaging that was not assisted with fiducials.