Disease control outcomes of stereotactic body radiation therapy or moderate hypo-fractionation for prostate cancer: Real-world experience at two Canadian centers.

BACKGROUND: Advantages of using stereotactic body radiation therapy to treat prostate cancer include short treatment times, decreased costs, and limited toxicity. Randomized trial outcomes comparing 5-fraction stereotactic body radiation therapy to conventionally fractionated radiotherapy or hypo-fractionated radiation therapy are pending. OBJECTIVE: We report the 10-year experience with 5-fraction stereotactic body radiation therapy and hypo-fractionated radiation therapy at two Canadian centers. MATERIAL AND METHODS: Patients with low- or intermediate-risk prostate cancer treated with stereotactic body radiation therapy alone (35-40 Gy in 5 fractions) or hypo-fractionated radiation therapy alone (60-62 Gy in 20 fractions) in the period of July 2010 and June 2020. The biochemical relapse-free survival, PSA nadir, interval time to PSA nadir, time to biochemical recurrence (2 ng/ml above PSA nadir) and overall survival were reviewed. Outcomes between treatment groups were compared after propensity-matching by patient baseline characteristics. Kaplan-Meier curves were used to assess biochemical relapse-free survival and overall survival. RESULTS: We identified 205 and 513 patients with low or intermediate-risk prostate cancer who were treated with stereotactic body radiation therapy or hypo-fractionation, respectively. Intermediate-risk category composed 81% and 95% of the stereotactic body radiation therapy and hypo-fractionated radiation therapy cohorts, respectively. After a median follow up of 58.6 months for the stereotactic body radiation therapy cohort and 45.0 months for the hypo-fractionated cohort, biochemical relapse-free survival and overall survival were not significantly different between treatment groups. The 5-year biochemical relapse-free survival rates were 92.1% and 93.6% and overall survival rates were 96.4% and 95.0% for the stereotactic body radiation therapy and hypo-fractionated cohorts, respectively, after propensity-matching. Stereotactic body radiation therapy resulted in a significantly lower PSA nadir (0.18 ng/ml) compared to hypo-fractionated radiation therapy (0.48 ng/ml) in patients with low-risk prostate cancer. Mean time to biochemical recurrence was not different between treatment groups. CONCLUSIONS: Stereotactic body radiation therapy is an effective treatment option for low and intermediate-risk prostate cancer with encouraging biochemical relapse-free survival and overall survival rates comparable with hypo-fractionated radiation therapy.

Salvage radiotherapy following HiFU: An institutional series and literature review.

INTRODUCTION: Algorithms for the treatment of prostate cancer (PrCa) rely on risk grouping, and those who fall into low (LR) and favourable intermediate risk (FIR) categories have multiple options for treatment. High-intensity focused ultrasound (HiFU) is a local treatment modality that uses ultrasound waves to ablate prostate cancer. In case of treatment failure, optimal salvage modality after HiFU remains unclear. METHODS: Here, we describe a retrospective review of our regional cancer database for men who underwent salvage radiotherapy after failure of HiFU treatment for prostate cancer. Oncologic and toxicity outcomes of the men identified in our database are discussed. RESULTS: We identified 14 men in our regional database who received salvage radiotherapy (70-74 Gy with or without androgen deprivation therapy (ADT) after primary HiFU, in the period of 2009-2017. No cases of any grade 3 or higher toxicity were observed. In our cohort, 50% (7/14) of patients developed secondary biochemical failure at a median follow-up of 54 months post-radiotherapy, with a mean time to biochemical failure of 39 months. We compare our data to other available reports to date consisting mostly of small, non-randomized studies. Our biochemical control rates are noticeably lower compared with those reported by other studies but our length of follow-up is longer, compared with other studies. CONCLUSION: The available data to date suggest that salvage radiotherapy after HiFU failure is well-tolerated albeit with only modest efficacy.

Quality of life research in neuro-oncology: a quantitative comparison.

Our understanding of the biology of neuro-oncologic disease has improved vastly over time, however overall patient survival remains relatively poor. Our goal as clinicians, therefore, should be to ensure that the quality of life (QOL) in that survival time is optimized. Here we review neuro-oncology QOL abstracts presented at major oncology conferences and the published literature to make a quantitative comparison to other common cancer subtypes. First, all abstracts presented at major oncology meetings from 2008 to 2012 were reviewed and filtered to find those related to QOL in CNS, breast, lung, and prostate cancer. Next, a Medline search was performed to identify all QOL papers published from 2003 to 2012 for the same cancer subtypes. The results were compared as absolute values and percentages. The average percentage of CNS QOL-related abstracts presented at ASCO and ASTRO over the last 5 years was 4.9 %, compared to 6.4 % for breast, 4.4 % for lung, and 6.1 % for prostate. There is a significant difference in total percentage of QOL abstracts over the time period when comparing CNS to breast and prostate, but not lung (p < 0.05). The Medline search revealed an average of 25.2 publications per year for CNS cancer, compared to 146.2 for breast, 39.3 for lung, and 64.2 for prostate. When looking at trends over time, publications in CNS cancer have not been as prolific and have not increased as rapidly as publications in breast and lung cancer, indicating that QOL is underrepresented in neuro-oncology research. We need to improve this by standardizing QOL measures and including them in every outcome study.

Categorizing segmentation quality using a quantitative quality assurance algorithm.

INTRODUCTION: Obtaining high levels of contouring consistency is a major limiting step in optimizing the radiotherapeutic ratio. We describe a novel quantitative methodology for the quality assurance (QA) of contour compliance referenced against a community set of contouring experts. METHODS: Two clinical tumour site scenarios (10 lung cases and one prostate case) were used with QA algorithm. For each case, multiple physicians (lung: n = 6, prostate: n = 25) segmented various target/organ at risk (OAR) structures to define a set of community reference contours. For each set of community contours, a consensus contour (Simultaneous Truth and Performance Level Estimation (STAPLE)) was created. Differences between each individual community contour versus the group consensus contour were quantified by consensus-based contouring penalty metric (PM) scores. New observers segmented these same cases to calculate individual PM scores (for each unique target/OAR) for each new observer-STAPLE pair for comparison against the community and consensus contours. RESULTS: Four physicians contoured the 10 lung cases for a total of 72 contours for quality assurance evaluation against the previously derived community consensus contours. A total of 16 outlier contours were identified by the QA system of which 11 outliers were due to over-contouring discrepancies, three were due to over-/under-contouring discrepancies, and two were due to missing/incorrect nodal contours. In the prostate scenario involving six physicians, the QA system detected a missing penile bulb contour, systematic inner-bladder contouring, and under-contouring of the upper/anterior rectum. CONCLUSION: A practical methodology for QA has been demonstrated with future clinical trial credentialing, medical education and auto-contouring assessment applications.

Assessment and improvement of radiation oncology trainee contouring ability utilizing consensus-based penalty metrics.

INTRODUCTION: The objective of this study was to develop and assess the feasibility of utilizing consensus-based penalty metrics for the purpose of critical structure and organ at risk (OAR) contouring quality assurance and improvement. METHODS: A Delphi study was conducted to obtain consensus on contouring penalty metrics to assess trainee-generated OAR contours. Voxel-based penalty metric equations were used to score regions of discordance between trainee and expert contour sets. The utility of these penalty metric scores for objective feedback on contouring quality was assessed by using cases prepared for weekly radiation oncology radiation oncology trainee treatment planning rounds. RESULTS: In two Delphi rounds, six radiation oncology specialists reached agreement on clinical importance/impact and organ radiosensitivity as the two primary criteria for the creation of the Critical Structure Inter-comparison of Segmentation (CriSIS) penalty functions. Linear/quadratic penalty scoring functions (for over- and under-contouring) with one of four levels of severity (none, low, moderate and high) were assigned for each of 20 OARs in order to generate a CriSIS score when new OAR contours are compared with reference/expert standards. Six cases (central nervous system, head and neck, gastrointestinal, genitourinary, gynaecological and thoracic) then were used to validate 18 OAR metrics through comparison of trainee and expert contour sets using the consensus derived CriSIS functions. For 14 OARs, there was an improvement in CriSIS score post-educational intervention. CONCLUSIONS: The use of consensus-based contouring penalty metrics to provide quantitative information for contouring improvement is feasible.

Patterns of failure in patients with primary intracranial germinoma treated with neoadjuvant chemotherapy and radiotherapy.

External beam radiotherapy has proven effective in managing intracranial germinoma. However, concerns regarding long-term neurocognitive and endocrine sequelae led to the addition of chemotherapy, to reduce radiation target volumes. There is a paucity of data on patterns of failure in patients treated with differing radiation field sizes. We review our experience at a tertiary children's hospital treating children with intracranial germinoma, using induction chemotherapy followed by radiation therapy to various treatment volumes (craniospinal irradiation, whole ventricular irradiation, whole brain radiation therapy, and focal radiotherapy). Ten patients with primary intracranial germinoma, treated from November 1995-March 2011, were included. The primary treatment involved platinum-based chemotherapy, followed by definitive radiotherapy. The median follow-up period was 4.3 years (range, 0.75-13.25 years). The 5-year overall survival for the entire group was estimated at 85.7%, and the 5-year disease-free survival was estimated at 75.0%. Two treatment failures occurred at 5 and 28 months, both in patients with single lesions in the pineal region treated with focal radiotherapy only. Based on the patterns of failure, our outcomes support the continued use of the whole ventricular field vs a focal field, even in patients with limited disease who demonstrate a complete response to neoadjuvant chemotherapy.

Trismus following treatment of head and neck cancer.

BACKGROUND: The aim of this preliminary study was to determine the prevalence of trismus in head and neck cancer patients treated with radiotherapy with or without concomitant chemotherapy and surgery. METHODS AND MATERIALS: Patients with malignant lesions in the head and neck treated with curative intent were comprehensively evaluated for trismus using subjective and objective measures. RESULTS: A large proportion of the 70 patients recruited demonstrated moderate to severe subjective trismus (45.7%). Similarly, the vast majority of patients showed slight to severe trismus (91.4%) according to objective secondary outcome measures. Of these patients, 21 (65.6%) were also treated with concurrent chemoradiotherapy. When the radiation field involved the pterygoid muscles, 30 (93.8%) patients reported subjective trismus. Similarly, bilateral pterygoid muscle inclusion resulted in 28 (87.5%) patients with trismus. CONCLUSIONS: Trismus is a significantly prevalent consequence of treatment for head and neck cancer. Predictive factors include treatment with concurrent chemoradiotherapy and bilateral inclusion of the structures of mastication in the high-dose radiotherapy volume.

Is radiotherapy an effective treatment option for recurrent metastatic malignant melanoma? A case report of short-course, large-fraction radiation and a literature review.

BACKGROUND: Malignant melanoma is regarded to be radiation resistant. A case of recurrent malignant melanoma with in-transit metastasis treated with short-course, high-fraction palliative radiation is presented to illustrate the effectiveness of radiotherapy. METHOD: An 80-year-old woman initially treated surgically for a primary malignant melanoma of the left lower leg presented with multiple in-transit metastases. Palliative radiation was offered to treat two fungating in-transit masses that were resistant to treatments of isolated limb infusion and intralesional interleukin-2. RESULTS: Treatment consisted of short-course, high-fraction radiation with 800 cGy fractions given over three weeks on days 0, 7 and 21, for a total dose of 2400 cGy. She experienced a complete response that was maintained for six months. CONCLUSIONS: Radiation is an effective treatment option for palliation of recurrent malignant melanoma. Complete response is possible even with short-course, high-fraction radiation.

An early report on outcomes from computed tomographic-based high-dose-rate brachytherapy for locally advanced cervix cancer: A single institution experience.

PURPOSE: To report our experience using high-dose-rate (HDR) brachytherapy with computed tomographic (CT) imaging for locally advanced cervix cancer, using available resources to optimize the treatment. METHODS AND MATERIALS: Fifty-seven women with cervix cancer were treated between September 2004 and March 2008. Patients received external radiotherapy, HDR brachytherapy (7 Gy x4) and concurrent chemotherapy. CT planning was done for each insertion. RESULTS: Median age was 53 years (range, 29-89 years); majority (49%) had International Federation of Gynecology and Obstetrics stage IIB. The median follow-up was 22.6 months. There were 4 patients who required laser coagulation for rectal bleeding, and one patient required hemicolectomy for sigmoid stricture. There was no grade 3 or 4 genitourinary toxicity. The Kaplan-Meier overall survival, relapse free, central pelvic and pelvic control at 3 years was 86%, 62%, 89%, and 83%, respectively. Pelvic control for tumors 2 to 5 cm was 95% and 84% for tumors greater than 5 cm. CONCLUSIONS: Our early experience confirms that CT-based HDR brachytherapy for cervix cancer achieves disease control comparable to other published series. At the same time, conformal avoidance of organs at risk allows for low rates of toxicity.

Toothache as a presenting symptom of metastatic renal cell cancer.

A 53-year-old man with a 14-year history of renal cell carcinoma (RCC) presented with a 2-month history of right-sided upper jaw pain and severe bleeding during tooth extraction. Pathology review of a lower maxillary sinus/upper gingival mass revealed metastatic RCC. The presentation, differential diagnosis and literature review of this uncommon presentation of metastatic kidney cancer are discussed in this report.