INTRODUCTION:This note describes performance test of B-RAD, a commercial γ-survey meter/portable γ-spectrometer designed to operate in strong magnetic field. The instrument consists of an active probe housing a cylindrical LaBr3 crystal, and a central unit connected by a cable. METHODS:The measurements were performed at an MR-Linac Elekta Unity (1.5 T) and a Philips Ingenia (3 T) MRI system, by measuring the H*(10) rate and the gamma energy distributions using two certified radioactive sources of 57Co and 137Cs providing a reference irradiation while the detector was exposed to increasing values of the magnetic field. Measurements were performed in various configurations, with probe and central unit either kept close together or separate, and either aligned or orthogonal to the magnetic field. RESULTS:The results outline stable H*(10) rates and gamma spectrometry performances in the entire magnetic field range. The device's performance is unaffected when only the probe is exposed to the static magnetic field while the central unit is in a lower field zone. When the latter is exposed to a strong field, the loss in dose rate remains within 10% for all configurations tested. CONCLUSION:The results demonstrate the potential application of the instrument for operational and decommissioning measurements at MRI-Linac and PET-MRI systems.
Purpose: To present the results of the first multi-centre real-world validation of autoplanning for whole breast irradiation after breast-sparing surgery, encompassing high complexity cases (e.g. with a boost or regional lymph nodes) and a wide range of clinical practices. Methods: The 24 participating centers each included 10 IMRT/VMAT/Tomotherapy patients, previously treated with a manually generated plan ('manplan'). There were no restrictions regarding case complexity, planning aims, plan evaluation parameters and criteria, fractionation, treatment planning system or treatment machine/ technique. In addition to dosimetric comparisons of autoplans with manplans, blinded plan scoring/ranking was conducted by a clinician from the treating center. Autoplanning was performed using a single configuration for all patients in all centres. Deliverability was verified through measurements at delivery units. Results: Target dosimetry showed comparability, while reductions in OAR dose parameters were 21.4 % for D mean , 16.7 % for ipsilateral lung D mean , and 101.9 %, 45.5 %, and 35.7 % for contralateral breast D 0.03cc and D mean , respectively (all p < 0.001). Among the 240 patients included, the clinicians preferred the autoplan for 119 patients, with manplans preferred for 96 cases (p = 0.01). Per centre there were on average 5.0 (1SD) patients with a preferred autoplan (range [0-10]), compared to 4.0 +/- 2.7 with a preferred manplan ([0,9]). No differences were observed regarding deliverability. Conclusion: The automation significantly reduced the hands-on planning workload compared to manual ning, while also achieving an overall superiority. However, fine-tuning of the autoplanning configuration clinical implementation may be necessary in some centres to enhance clinicians' satisfaction with the generated autoplans.
We report on a clinical case of capecitabine-induced acute ileitis in a patient treated with pre-operative concurrent chemoradiation with capecitabine for locally advanced rectal cancer and provide a comprehensive literature review. This a rare, but life-threatening, clinical situation, that clinicians should be aware of. Severe persistent diarrhea is the most frequent clinical feature and computed tomography is a valid tool for diagnosis. Conservative management includes capecitabine withdrawal, antidiarrheal therapy and endovenous hydration, together with dietary modifications and broad-spectrum antibiotics. Pelvic irradiation represents an adjunctive risk factor, which may increase the likelihood of occurrence of terminal ileitis. Early recognition and prompt intervention are crucial for successful clinical management.
We report on the early clinical outcomes of a prospective series of early breast cancer (EBC) patients treated with ultra-hypofractionated post-operative whole-breast irradiation (WBI) after breast-conserving surgery (BCS) and axillary management. Primary endpoints were patient's compliance and acute toxicity. Secondary endpoints included physician-rated cosmesis and ipsilateral breast tumour recurrence (IBTR). Acute toxicity was evaluated at the end of WBI, 3 weeks and 6 months thereafter, according to the Common Terminology Criteria for Adverse Events (v. 5.0). Patients were treated between September 2021 and May 2022. The treatment schedule for WBI consisted of either 26 Gy in 5 fractions over one week (standard approach) or 28.5 Gy in 5 fractions over 5 weeks (reserved to elders). Inverse planned intensity-modulated radiation therapy (IMRT) was used employing a static technique. A total of 70 patients were treated. Fifty-nine were treated with the 26 Gy/5 fr/1 w and 11 with the 28.5 Gy/5 fr/5 ws schedule. Median age was 67 and 70 in the two groups. Most of the patients had left-sided tumours (53.2%) in the 26 Gy/5 fr/1 w or right-sided lesions (63.6%) in the 28.5 Gy/5 fr/5 ws group. Most of the patients had a clinical T1N0 disease and a pathological pT1pN0(sn) after surgery. Ductal invasive carcinoma was the most frequent histology. Luminal A intrinsic subtyping was most frequent. Most of the patients underwent BCS and sentinel lymph node biopsy and adjuvant endocrine therapy. All patients completed the treatment program as planned. Maximum detected acute skin toxicities were grade 2 erythema (6.7%), grade 2 induration (4.4%), and grade 2 skin colour changes. No early IBTR was observed. Ultra-hypofractionated WBI provides favourable compliance and early clinical outcomes in EBC after BCS in a real-world setting.
BACKGROUND:The aim of the present study is to evaluate the reliability of a 18F-fluorodeoxyglucose (18F-FDG) PET adaptive threshold segmentation (ATS) algorithm, previously validated in a preclinical setting on several scanners, for the biological target volume (BTV) delineation of head and neck radiotherapy planning. METHODS:[18F]FDG PET ATS algorithm was studied in treatment plans of head and neck squamous cell carcinoma on a dedicated workstation (iTaRT, Tecnologie Avanzate, Turin, Italy). BTVs segmented by the present ATS algorithm (BTVATS) were compared with those manually segmented for the original radiotherapy treatment planning (BTVVIS). We performed a qualitative and quantitative volumetric analysis with a comparison tool within the ImSimQA TM software package (Oncology Systems Limited, Shrewsbury, UK). We reported figures of merit (FOMs) to convey complementary information: Dice Similarity Coefficient, Sensitivity Index, and Inclusiveness Index. RESULTS:The study was conducted on 32 treatment plans. Median BTVATS was 11 cm3 while median BTVVIS was 14 cm3. The median Dice Similarity Coefficient, Sensitivity Index, Inclusiveness Index were 0.72, 63%, 88%, respectively. Interestingly, the median volume and the median distance of the voxels that are over contoured by ATS were respectively 1 cm3 and 1 mm. CONCLUSIONS:ATS algorithm could be a smart and an independent operator tool when implemented for 18F-FDG-PET-based tumor volume delineation. Furthermore, it might be relevant in case of BTV-based dose painting.
Background The present study assessed clinical outcomes of stereotactic body radiotherapy (SBRT) in oligometastatic prostate cancer patients. Materials and methods Between 2017 and 2020, 37 lesions (12 osseous and 25 nodal targets) detected with conventional and/or functional imaging, were treated in 29 patients (pts), in different clinical settings: de novo oligometastatic (2 pts), oligorecurrent castration-sensitive (19 pts), castration-resistant (6 pts) prostate cancers and oligoprogressive disease during systemic therapy (2 pts). SBRT was delivered with volumetric modulated arc therapy up to a total dose of 21 Gy given in 3 fractions for bone and 30 Gy in 5 fractions for nodal metastases. A total of 34% of pts received hormonal therapy. We evaluated biochemical control [prostate serum antigen (PSA) increase < 10%)], progression free-survival (PFS) (time from SBRT to biochemical progression), local control (LC) (time from SBRT to in-field radiologic progression), hormone/systemic therapy-free survival, acute and late toxicities. Results At 3 months, biochemical response was observed in 20/29 pts (69%). At a median follow-up of 17 months (range 6–33), 8/20 (40%) of the 3-month responders remained free from progression. Two-year PFS and LC were 37% and 70%, respectively. In-field progression occurred in 3/37 (8%) lesions. Hormone/systemic therapy was delayed by an average of 11.6 months (range 3–28). No significant difference in PFS based on the type of lesion or concomitant endocrine therapy was observed and no toxicity > grade 2 was reported. Conclusions SBRT for oligometastatic prostate cancer offers a good biochemical/local control and tangible delay of hormone/systemic therapy without major toxicities.
Aim and background > The present study aims to identify predictive factors for urinary toxicity and self-reported symptoms after external beam radiotherapy (EBRT) for prostate cancer. Methods > Two-hundred and eighty patients treated with EBRT for prostate cancer were included in the present study. Toxicity was scored following the grading system based on Radiation Therapy Oncology Group (RTOG) scale. International Prostatic Symptom Score (IPSS) and Consultation on Incontinence Questionnaires-Short Form (ICIQ-SF) were used to analyse self-reported symptoms. Acute and late urinary toxicities were correlated to clinical and treatment parameters, radiation dosimetry data, IPSS and ICIQ-SF. Results > Median patient age was 74 years (range, 64-83). Thirty-one percent experienced acute G1 urinary toxicity, 24% G2 and 3% G3. Fourteen percent experienced G1 late urinary toxicity and 3% G2. Bladder volume < 200 cc was associated with acute urinary toxicity (P = 0.014); use of MRI for treatment planning allowed a lower incidence of late toxicity (P = 0.062) and use of IMRT allowed for reduced incidence in late toxicity (P = 0.038). Maximum bladder dose correlated with late urinary toxicity (P = 0.014). The analysis of self-reported symptoms showed a significant correlation between IPSS baseline values (P = 0.009), presence of nocturia (P = 0.002), bladder urgency (P = 0.024) and incontinence (P = 0.024) and development of acute urinary toxicity at univariate analysis. At multivariate logistic regression analysis, bladder filling, IPSS value, nocturia, and urinary incontinence retained significant correlation with acute toxicity (P = 0.0003). Discussion > Significant independent predictors for acute urinary toxicity grade >= 2 were bladder filling, IPSS value, nocturia, and urinary incontinence at baseline assessment.