Prostate specific membrane antigen PET avidity in a granular cell tumour of the left supraspinatus muscle: a case report.

Granular cell tumour is a rare, mostly benign, soft tissue, neuroectodermal tumour, most commonly seen in the skin and peripheral soft tissue. There are no publications to date of PSMA-PET avidity in a granular cell tumour. In this 60 year old male, staging PSMA-PET for a localized intermediate risk prostate cancer incidentally identified a PSMA-avid left supraspinatus lesion, which was subsequently biopsy-proven as a granular cell tumour. We present the first case of PSMA-avid granular cell tumour and add to the growing literature documenting PSMA-PET avidity in benign and malignant lesions apart from prostate cancer.

Long-Term Survival After Definitive Concurrent Chemoradiation Therapy for Synchronous Small Cell Neuroendocrine Carcinoma of the Urinary Bladder and Adenocarcinoma of the Prostate: A Case Report.

Available reports of synchronous prostate and bladder cancer have exclusively described radical cystoprostatectomy with or without perioperative chemotherapy as the treatment of choice. There are no reports of curative intent or definitive chemoradiation therapy for synchronous primary bladder and primary prostate cancers. Small cell carcinoma of the bladder is a rare and aggressive tumor. We present the first case of synchronous mixed small cell carcinoma and urothelial carcinoma of the urinary bladder and adenocarcinoma of the prostate in a 70-year-old male who attained long-term survival after curative intent and definitive concurrent chemoradiotherapy with minimal acute and late toxicities. The patient remained alive and disease-free at 41 months post-treatment and achieved excellent functional outcomes with organ preservation. Definitive chemoradiation therapy offers a safe and effective, curative-intent organ preservation treatment for localized synchronous prostate and bladder cancers.

A Case Report of Kearns-Sayre Syndrome: Not an Absolute Contraindication for Radiotherapy.

Kearns-Sayre syndrome (KSS) is a rare mitochondrial disorder, and the effects of radiotherapy on such a population group are unknown. A 60-year-old male with a history of KSS was diagnosed with locally advanced basal cell carcinoma along the left inner canthus. He was treated at our institution with curative intent radiotherapy alone and tolerated it well with no major acute or late toxicities. There was a complete clinical and radiological response of the tumor, with no evidence of recurrence 2.5 years after treatment. Further research is needed to explore the effects of ionizing radiation on patients with mitochondrial DNA defects.

Patterns of practice regarding use of radiation therapy following radical prostatectomy: A survey of Radiation Oncologists and Urologists in Australia and New Zealand.

INTRODUCTION: This study aimed to investigate the patterns of practices of radiation oncologists (ROs) and urologists in Australia and New Zealand with respect to the utilisation of post-prostatectomy radiation therapy (RT) and help guide the development of an update to the existing Faculty of Radiation Oncology Genito-Urinary Group post-prostatectomy guidelines. METHODS: ROs and urologists with subspecialty practice in prostate cancer from Australia and New Zealand were invited to participate in an online survey comprised of clinical scenarios regarding post-prostatectomy RT. RESULTS: Sixty-five ROs and 28 urologists responded to the survey. In the setting of low-risk biochemical relapse, the threshold for initiating RT was lower for ROs than urologists. ROs were more likely than urologists to recommend adjuvant RT for node-positive disease. When salvage RT was advised for a pT3N0R1 recurrence, there was no consensus amongst ROs on whether to add either ADT or nodal treatment over prostate bed RT alone. For a solitary PSMA-avid pelvic lymph node recurrence, whole pelvis RT with androgen deprivation therapy was the preferred treatment option (72% ROs, 43% urologists). Most ROs (92%) recommended conventionally fractionated RT to 66-70 Gy, with a boost to any PSMA PET avid recurrent disease. CONCLUSION: This survey highlights the marked discordance in practice for the management of prostate cancer relapse post-prostatectomy. This is seen not only between specialties but also within the radiation oncology community. This emphasises the need for an updated evidence-based guideline to be produced.

Androgen Receptor Status in Triple Negative Breast Cancer: Does It Correlate with Clinicopathological Characteristics?

Purpose: Triple negative breast cancer (TNBC) is a breast carcinoma subtype that neither expresses estrogen (ER) and progesterone receptors (PR) nor the human epidermal growth factor receptor 2 (HER2). Patients with TNBC have been shown to have poorer outcomes mainly owing to the limited treatment options available. However, some studies have shown TNBC tumors expressing androgen receptors (AR), raising hopes of its prognostic role. Patients and Methods: This retrospective study investigated the expression of AR in TNBC and its relationship with known patient demographics, tumor and survival characteristics. From the records of 205 TNBC patients, 36 had available archived tissue samples eligible for AR staining. For statistical purposes, tumors were classified as either "positive" or "negative" for AR expression. The nuclear expression of AR was scored by measuring the percentage of stained tumor cells and its staining intensity. Results: AR was expressed by 50% of the tissue samples in our TNBC cohort. The relationship between AR status with age at the time of TNBC diagnosis was statistically significant, with all AR positive TNBC patients being greater than 50 years old (vs 72.2% in AR negative TNBC). Also, the relationship between AR status and type of surgery received was statistically significant. There were no statistically significant associations between AR status with other tumor characteristics including "TNM status", tumor grade or treatments received. There was no statistically significant difference in median survival between AR negative and AR positive TNBC patients (3.5 vs 3.1 years; p = 0.581). The relationship between OS time and AR status (p = 0.581), type of surgery (p = 0.061) and treatments (p = 0.917) were not statistically significant. Conclusion: The androgen receptor may be an important prognostic marker in TNBC, with further research warranted. This research may benefit future studies investigating receptor-targeted therapies in TNBC.

Outcomes of dose-escalated IMRT and ADT in Octogenarians with prostate cancer.

INTRODUCTION: We evaluated long-term outcomes for octogenarians with localised prostate cancer treated using dose-escalated image-guided intensity-modulated radiation therapy (IMRT) at our institution. METHODS: The charts of octogenarians treated for localised prostate cancer were retrospectively reviewed. Overall survival (OS), prostate cancer-specific survival (PCaSS), toxicity rates and changes from baseline were collected. RESULTS: The median follow-up was 97 months. Of 107 eligible patients, 27.1% had intermediate-risk and 72.9% had high-risk localised prostate cancer. Median dose was 78Gy, and 97.2% received ADT. OS was 91.4% and 67.2% at 5 and 10 years. PCaSS was 98.0% and 88.7% at 5 and 10 years. In all, 39 (36.4%) of patients died, with the cause of death known in 30: in 26.7% of these patients, prostate cancer was the cause of death. Grade ≥ 2 late GI and GU toxicity was 0.9% and 24.3% respectively. In all, 11.2% and 22.4% of patients reported worsening of GI or GU function from baseline, and 13.1% and 21.5% reported improvement in GI and GU function compared to baseline. CONCLUSION: Selected octogenarian patients with localised prostate cancer appear to benefit from radiation therapy and ADT. Despite excellent long-term PCaSS, 26.7% of patients died of prostate cancer. Rates of GI and GU toxicity were acceptable, and deterioration of urinary and bowel function compared to baseline was just as common as improvement in function from baseline.

No Increase in Acute or Late Radiation Toxicities in Patients With Ehlers-Danlos Syndrome Receiving Adjuvant Breast Radiation Therapy: A Report of Four Cases With Extended Follow-Up.

Ehlers-Danlos syndrome (EDS) consists of a heterogeneous group of congenital collagen formation disorders characterised by skin hyperextensibility, atrophic scarring, and generalized joint hypermobility. Collagen vascular disorders have been implicated in increased incidence and severity of radiation toxicities; however, there are limited reports on the safety of radiation therapy with EDS. We identified all patients with EDS who received adjuvant conventional and hypofractionated breast radiation therapy at our institution and reviewed patient, treatment, and toxicity characteristics. Four patients were identified with a median follow-up of 13.2 months. Acute toxicities were limited to grade 1 dermatitis in all four patients. No late toxicities were seen. In this report, radiation therapy to the breast with conventional and hypofractionated regimens resulted in no significant acute or late toxicity.

Bone health assessment with dual energy X-ray absorptiometry in men with high-risk prostate carcinoma commencing adjuvant androgen deprivation therapy.

Background: Androgen deprivation therapy (ADT) is a key component of therapy for patients with high-risk prostate carcinoma, but it may be deleterious for bone health. We sought to determine the frequency of dual energy x-ray absorptiometry (DXA) scanning in patients commencing adjuvant ADT for treatment of high-risk prostate cancer at a large integrated regional cancer centre. Material and methods: The electronic medical records (EMR) of all patients with high-risk prostate carcinoma commenced on adjuvant ADT between January 1, 2016 and December 31, 2017 at the Mid-North Coast Cancer Institute, Coffs Harbour, Australia were reviewed. Patients commenced on neoadjuvant ADT and long-term suppressive ADT for metastatic disease were excluded. The following data were obtained: socio-demographic information, prostate cancer data, ADT details and DXA results. Results: 188 men (mean age ± SD, 75.4 ± 7 years) were commenced on adjuvant ADT for a total duration (mean ± SD) of 23.4 ± 7 months. Most (n = 155/188, 82%) were commenced on leuprorelin acetate. While only 26/188 (14%) had a DXA scan performed prior to ADT, another 133 (71%) had a DXA scan at a median of 20 days (interquartile range 7-98), later. Of the 159 men with DXA readings, 76 (48%) were osteopaenic and 38 (24%) were osteoporotic by DXA criteria. Conclusion: A high level (85%) of DXA scanning in men commencing ADT for prostate cancer can be achieved at a regional centre. The high prevalence (72%) of low bone mass in our unselected cohort underscores the importance of routine DXA scanning to guide bone health management during ADT.

Prognostic Value of the Neutrophil-Lymphocyte Ratio in Triple Negative Breast Cancer Patients.

OBJECTIVE: To assess the prognostic value of the neutrophil-lymphocyte ratio (NLR) in a cohort of triple-negative breast cancer patients (TNBC) treated in a regional cancer center. METHODS: The electronic medical records of 214 consecutive patients treated with surgery, chemotherapy, and radiotherapy between 2006 and 2016 were reviewed. The prognostic significance of the NLR for disease-free survival (DFS) and overall survival (OS) was examined in relation to clinical and treatment-related factors. Overall survival and DFS were assessed using the Kaplan-Meier method; Cox semi-parametric regression modelling was used for multivariate analysis. RESULTS: Ninety patients were eligible; median follow-up was 45.6 months (range, 6-105 months). The 3-year OS rate was 77.9% and the 5-year OS rate 61.7%. Patients with an NLR of ≤1.7 had significantly better DFS (P=0.029) than patients with an NLR>1.7; OS approached statistical significance (P=0.055). When treatment-related factors - significant on univariate analysis - were entered into the multivariate model, only nodal status N2/N3 remained as significant for DFS (P=0.0078) and advanced T-stage (T3, T4) significant for OS (P=0.014). CONCLUSION: While NLR is associated with survival in TNBC patients on univariate analysis, the prognostic value of NLR is likely due to its association with other clinicopathological factors.

Evaluation of apical clips placed during axillary dissection demonstrates potential under-coverage of axillary radiation therapy target volumes during breast cancer regional nodal irradiation.

INTRODUCTION: Evidence-based Australian guidelines (eviQ) recommend adjuvant supraclavicular fossa irradiation after axillary lymph node dissection (ALND) in node-positive breast cancer patients. Disparity between surgically determined versus computed tomography (CT) determined nodal volumes may result in discontiguous nodal volumes and untreated nodal tissue. We examine the extent of untreated nodal tissue in women with breast cancer post-level II or III ALND and adjuvant radiation therapy (RT) using ESTRO contouring guidelines. METHODS: Female breast cancer patients who underwent level II and III ALND with apical clip placement from 2016 to 2020 and CT simulated in supine position were included. CT-defined axillary level II-IV volumes were contoured using ESTRO guidelines. The distance between the apical clip and RT nodal volumes was measured to indicate extent of untreated tissue. RESULTS: Of 34 eligible patients treated by 7 surgeons, 76% had level II ALND and 24% level III ALND. Only 5.9% of clips entirely encompassed the corresponding RT nodal volumes. 55.9% of clips fell within and 44.1% fell inferolaterally outside the corresponding RT nodal volumes. A median 3.6 cm (range 0-7.5 cm) of undissected nodal tissue would not be included within standard RT target volumes following eviQ recommendations. CONCLUSION: There is a disparity between surgically determined versus CT determined axillary nodal volumes, leading to discontiguous nodal volumes and untreated axillary nodal tissue, despite following standard radiation contouring guidelines. Intraoperatively placed apical axillary clips may assist radiation oncologists to accurately delineate undissected nodal tissues at risk.

Metaplastic carcinoma of the breast: Clinicopathological features and treatment outcomes with long-term follow up.

Metaplastic breast carcinoma is an uncommon subtype of invasive ductal carcinoma with a tendency towards poorer clinical outcomes. Following ethical approval, the current study reviewed the institutional records of ~2,500 women with breast cancer. A total of 14 cases of metaplastic breast cancer were reviewed for management and treatment outcomes. The results demonstrated that patients had median follow up of 30 months, a 5-year disease-free survival of 57.1% and 5-year overall survival of 57.1%. The majority of patients had at least T2 disease and all tumours were high grade. Additionally, most patients were triple negative and nodal metastases were uncommon. Metaplastic breast cancer is an aggressive variant of invasive breast cancer. Most patients can be treated with breast conservation and survival parameters tend to be worse than more common breast cancer subtypes.

Assessing ISUP prostate cancer grade groups in patients treated with definitive dose escalated external beam radiation.

PURPOSE: The five grade group system has been validated for men treated with radical prostatectomy. However, the prognostic value for men treated with radiation therapy is uncertain, with prior studies utilising old techniques and doses. We aimed to validate the International Society of Urological Pathology (ISUP) groupings for men treated with contemporary radiation therapy. METHODS: Men with localised prostate cancer treated with image-guided, dose-escalated (≥78 Gy) external beam radiation were identified across four institutions. Primary outcome was time to biochemical failure. Harrell's C index assessed performance of the ISUP system against other grading stratifications. RESULTS: 2205 men were included, withmedian follow-up of 5.6 years. Seven-year actuarial rates of biochemical failure for grade groups 1-5 were 9.3%, 10.4%, 13.2%, 12.4% and 23.4%. On multivariate analysis, hazard ratios for biochemical failure were1.19, 1.00, 1.10, 1.05 and 2.10 for grade groups 1-5, relative to 2. P values were only significant for grade group 5. Harrell's C index favoured an alternative three group model (comprising Gleason scores [6 and 3 + 4 = 7] vs [4 + 3 = 7 and 8] vs [9 and 10]) over ISUP grade groups. CONCLUSIONS: The ISUP grade groups were not validated in a contemporary cohort treated with dose-escalated, image-guided radiation therapy. Grade groups 1-4 were not statistically different from each other; however, grade group 5 had a significantly worse prognosis. We identified a new three group model that better predicted biochemical outcomes. Further work is requiredto validate optimal groupings for modern radiation therapy and investigate the contrasting prognostic capability of grade groups in surgical and radiation therapy patients.

Equity should know no borders: The role of Australasian radiation oncologists in supporting radiation oncology services in low- and middle-income countries in the Asia-Pacific.

The rapid rise in cancer incidence within the world's poorest nations highlights the need for equitable access to evidence-based cancer care. It has been previously demonstrated that radiotherapy is a cost-effective and necessary tool in cancer treatment. However, globally there is a growing divide between demand and supply of radiotherapy services. In low- and middle-income countries, this resource gap is particularly problematic. By region, the Asia-Pacific has been demonstrated to have the highest absolute deficit in radiotherapy services. Radiation oncologists in Australia and New Zealand are geographically well positioned to assist departments within the Asia-Pacific to help to reduce these inequities. The Asia-Pacific Radiation Oncology Special Interest Group (APROSIG) aims to support oncology professionals in the Asia-Pacific to develop safe and sustainable cancer services. Members have already contributed to multiple projects throughout the region, supported by grants and departmental funding. However, the backbone of support comes from volunteers sharing their time and expertise. The Australasian oncological community has the skills and knowledge to help not only those within our borders but also beyond. Such efforts provide the potential to develop valuable clinical, educational, research and leadership experiences whilst establishing networking opportunities throughout the most populated regions of the world. More options for growth and work in global health must be investigated, encouraging future trainees to consider a role within the global cancer community. Without prompt and continued action, the resource deficit is likely to grow and the inequity in accessing radiotherapy and other cancer services further magnified.

Survival outcomes for breast cancer patients who decline recommended treatment: a propensity score-matched analysis.

BACKGROUND: For patients with breast cancer who decline recommended treatments, available data examining survival outcomes are sparse. We compared overall survival and relapse-free survival outcomes between patients with breast cancer who declined recommended primary treatments and those who received recommended primary treatments. METHODS: Using data from the BreastSurgANZ Quality Audit database, a retrospective cohort study was performed for patients diagnosed with breast carcinoma (stage 0-IV) between 2001 and 2014 who were treated in our integrated cancer centre. A propensity score-matched analysis was performed to compare overall survival and relapse-free survival between patients who either declined or received the standard recommended treatment. RESULTS: A total of 56/912 (6.1%) patients declined one or more recommended therapies. Five-year overall survival for those who declined or received treatment as recommended was 81.8% versus 88.9% (P = 0.17), respectively. Ten-year survival was 61.3% versus 67.8% (P = 0.22), respectively. For patients who declined treatments, 5-year relapse-free survival was 72.4%, compared to 87.4% for those who received them (P = 0.005). Ten-year relapse-free survival was 61.0% versus 80.6% (P = 0.002), respectively. On adjusted Cox regression analysis, treatment refusal was associated with poorer relapse-free survival (adjusted hazard ratio 2.76 (95% confidence interval 1.52-5.00), P < 0.001). CONCLUSION: In conclusion, patients who declined recommended treatment for breast cancer had poorer relapse-free survival compared to those who received them. These data may help clinicians assist patients with breast cancer in their decision-making.

Assessment of genetic referrals and outcomes for women with triple negative breast cancer in regional cancer centres in Australia.

BACKGROUND: Guidelines for referral to cancer genetics service for women diagnosed with triple negative breast cancer have changed over time. This study was conducted to assess the changing referral patterns and outcomes for women diagnosed with triple negative breast cancer across three regional cancer centres during the years 2014-2018. METHODS: Following ethical approval, a retrospective electronic medical record review was performed to identify those women diagnosed with triple negative breast cancer, and whether they were referred to a genetics service and if so, the outcome of that genetics assessment and/or genetic testing. RESULTS: There were 2441 women with newly diagnosed breast cancer seen at our cancer services during the years 2014-2018, of whom 237 women were diagnosed with triple negative breast cancer. Based on age of diagnosis criteria alone, 13% (31/237) of our cohort fulfilled criteria for genetic testing, with 81% (25/31) being referred to a cancer genetics service. Of this group 68% (21/31) were referred to genetics services within our regions and went on to have genetic testing with 10 pathogenic variants identified; 5x BRCA1, 4x BRCA2 and × 1 ATM:c.7271 T > G. CONCLUSIONS: Referral pathways for women diagnosed with TNBC to cancer genetics services are performing well across our cancer centres. We identified a group of women who did not meet eligibility criteria for referral at their time of diagnosis, but would now be eligible, as guidelines have changed. The use of cross-discipline retrospective data reviews is a useful tool to identify patients who could benefit from being re-contacted over time for an updated cancer genetics assessment.

Long-term outcomes of patients with conserved breast cancer treated with adjuvant hypofractionated prone breast intensity-modulated radiation therapy.

INTRODUCTION: New techniques for adjuvant radiation therapy after breast conservation include prone positioning, hypofractionation and intensity-modulated radiation therapy (IMRT). Long-term evaluations of this combination are lacking, and we report our own experience. METHODS: Patients with invasive breast cancer followed for a minimum 36 months post-IMRT were eligible. Dose used was 40 Gray in 15 fractions over 3 weeks to the whole breast via forward-planned prone, whole breast IMRT. A 10 Gy in 5 fraction supine boost was offered. RESULTS: Between January 2012 and January 2020, 2199 patients had breast conservation and adjuvant radiation: 489 received hypofractionated prone breast IMRT, with 155 eligible for our evaluation. Median follow-up was 52 months. Median age was 62 (range 36-80), 78.7% were T1, 20.6% were T2, and 12.3% were node-positive. Grade was 1 in 26.5%, 2 in 43.9% and 3 in 29.7%; 87.1% were oestrogen receptor positive, 3.2% were HER2 positive, and 11.0% were triple negative. 58.6% received a boost, 74.8% endocrine therapy and 32.3% chemotherapy. No patient developed local recurrence. One regional recurrence was successfully salvaged. Six patients (3.9%) developed metastases, and 1.9% died. Five-year actuarial local recurrence-free, regional recurrence-free and breast cancer-specific survival rates were 100.0%, 98.2% and 94.8%. Late grade 1 and 2 breast pain occurred in 20.0% and 1.3% of patients. Only 11.0% had new pain compared to pre-radiation. No patient developed radiation-induced pneumonitis, pulmonary fibrosis, rib fracture or cardiac toxicity. All patients scored cosmesis as 'good' or better. CONCLUSION: Adjuvant hypofractionated prone breast IMRT has excellent locoregional control and minimal toxicity.

Effect of Clinical and Treatment Factors on Survival Outcomes of Triple Negative Breast Cancer Patients.

PURPOSE: Triple negative breast cancer (TNBC) accounts for approximately 15% of breast cancer cases and is associated with a poor prognosis. In this retrospective study of patients undergoing radiation therapy as part of their treatment, disease-free survival (DFS) and overall survival (OS) of TNBC patients were examined in relation to clinical and treatment-related factors. PATIENTS AND METHODS: The electronic records of 214 consecutive TNBC patients treated with surgery followed by radiotherapy at the Mid North Coast Cancer Institute between 2006 and 2016 were reviewed. Overall survival and DFS times were analyzed using the Kaplan-Meier method; multivariate Cox proportional hazard regression modelling was used to assess the significance of prognostic factors. RESULTS: The majority of tumors were T1 (51.9%), followed by T2 (39.2%) and T3 (6.1%). For the whole group, mean DFS was 106.4 (SD 48.7) months; OS 109.4 (SD 52.1) months. Radiotherapy technique, fractionation protocol and laterality were not significant factors for DFS or OS (p>0.05). However, compared to breast conservation, mastectomy was associated with poorer DFS (mean 114.2 vs 65.2 months; p<0.0001) and poorer OS (mean 115.5 vs 80.5 months; p=0.0015). The mastectomy group had fewer patients with tumor size T1 (p=0.001) and higher proportions of T3 (p=0.001) and T4 (p=0.02). On multivariate analysis, tumor size T3/T4 and nodal status N2/N3 were significant factors for reduced DFS (p=0.023 and p=0.0003 respectively). Tumor size T3/T4 was the only significant prognostic factor for reduced OS (p=0.019). CONCLUSION: Advanced disease exhibited by tumor size > 5cm and positive nodal status is associated with poorer DFS in TNBC patients. Radiotherapy technique or fractionation protocol were not associated with differences in DFS or OS in our patient cohort.

Choosing between conventional and hypofractionated prostate cancer radiation therapy: Results from a study of shared decision-making.

AIM: To evaluate patient choice of prostate cancer radiotherapy fractionation, using a decision aid. BACKGROUND: Recent ASTRO guidelines recommend patients with localised prostate cancer be offered moderately hypofractionated radiation therapy after discussing increased acute toxicity and uncertainty of long-term results compared to conventional fractionation. MATERIALS AND METHODS: A decision aid was designed to outline the benefits and potential downsides of conventionally and moderately hypofractionated radiation therapy. The aid incorporated the ASTRO guideline to outline risks and benefits. RESULTS: In all, 124 patients with localised prostate cancer were seen from June-December 2018. Median age was 72 (range 50-90), 49.6 % were intermediate risk (50.4 % high risk). All except three patients made a choice using the aid; the three undecided patients were hypofractionated. In all, 33.9 % of patients chose hypofractionation: falling to 25.3 % for patients under 75 years, 24.3 % for patients living within 30 miles of the cancer centre, and 14.3 % for patients with baseline gastrointestinal symptoms. On multivariate analysis, younger age, proximity to the centre, and having baseline gastrointestinal symptoms significantly predicted for choosing conventional fractionation. Insurance status, attending clinician, baseline genitourinary symptoms, work/carer status, ECOG, cancer risk group and driving status did not impact choice. Reasons for choosing conventional fractionation were certainty of long-term results (84 %) and lower acute bowel toxicity (51 %). CONCLUSIONS: Most patients declined the convenience of moderate hypofractionation due to potentially increased acute toxicity, and the uncertainty of long-term outcomes. We advocate that no patient should be offered hypofractionation without a thorough discussion of uncertainty and acute toxicity.

Late toxicities of prostate cancer radiotherapy with and without hydrogel SpaceAOR insertion.

INTRODUCTION: To investigate whether the implantation of a hydrogel spacer (SpaceOAR) reduces long-term rectal toxicity for prostate cancer patients treated with intensity-modulated radiotherapy (IMRT). METHODS: Patients with localised prostate cancer treated with 81 Gy in 45 fx of IMRT over 9 weeks were retrospectively compared: 65 patients with SpaceOAR and 56 patients without SpaceOAR. Planning aims restricted rectal doses to V40 Gy < 35%, V65 Gy < 17%, V75 Gy < 10%. Toxicities were evaluated between 3 months and 3 years after the completion of radiotherapy and were based on the common terminology criteria for adverse events (CTCAE) assessment tool for diarrhoea, haemorrhoids, faecal incontinence and proctitis. RESULTS: The cumulative incidence of low-grade diarrhoea (G1) was significantly higher in the non-SpaceOAR group (21.4% vs 6.2%; P = 0.016). The cumulative incidence of proctitis (grades G1 and G2) was also higher in the non-SpaceOAR group (26.7% vs 9.2%; P = 0.015); the cumulative incidence of G2 proctitis was higher in the latter group (P = 0.043). There were no differences between the treatment groups for cumulative incidences of faecal incontinence and/or haemorrhoids. Three years after IMRT, diarrhoea and proctitis were higher in the non-SpaceOAR group, without reaching statistical significance. This finding was unchanged after correcting for baseline symptoms. CONCLUSION: SpaceOAR is of benefit in reducing the cumulative incidence of low-grade diarrhoea and proctitis for up to 3 years after intensity-modulated radiotherapy.