Risk evaluation of secondary malignancies after radiotherapy of breast cancer in light of the continuous development of planning techniques

Secondary cancer risk is a significant concern for women treated with breast radiation therapy due to improved long-term survival rates. We evaluated the potential of new advanced automated planning algorithms together with hybrid techniques to minimize the excess absolute risk (EAR) for secondary cancer in various organs after radiation treatment for early staged breast cancer. Using CT data set of 25 patients, we generated 4 different radiation treatment plans of different complexity, including 3-dimensional conformal radiotherapy (3D-CRT), field-in-field (FinF), hybrid-IMRT (HMRT) and automated hybrid-VMAT (HVMAT) techniques. The organ-equivalent dose (OED) was calculated from differential dose-volume histograms on the basis of the "linear-exponential," "plateau," and "full mechanistic" dose-response models and was used to evaluate the EAR for secondary cancer in the contralateral breast (CB), contralateral lung (CL), and ipsilateral lung (IL). Statistical comparisons of data were performed by a Kruskal-Wallis analysis of variance. The planning objectives were fulfilled with all the planning techniques for both target coverage and organs-at-risk sparing. The differences in EAR for CB, CL and IL secondary tumor induction were not significant among the 4 techniques. For the CB and CL, the mean absolute difference did not reach 1 case of 10000 patient-years. For the IL, the mean absolute difference was up to 5 cases of 10,000 patient-years. In conclusion, the automated HVMAT technique allows an EAR reduction at the level of well-consolidated tangential 3D-CRT or FinF techniques, keeping all the HVMAT dosimetric improvements unchanged. On the basis of this analysis, the adoption of the HVMAT technique poses no increase in EAR and could be considered safe also for younger patients.

Hybrid planning techniques for early-stage left-sided breast cancer: dose distribution analysis and estimation of projected secondary cancer-relative risk

PURPOSE

The purpose of this study was to evaluate three techniques of irradiation of left-sided breast cancer patients, three-dimensional conformal radiotherapy (3D-CRT), hybrid Intensity-Modulated Radiotherapy (h-IMRT), and hybrid Volumetric-Modulated Arc Therapy (h-VMAT, h-ARC), in terms of dose distribution in the planning target volume (PTV) and organs at risk (OARs). The second aim was to estimate the projected relative risk of radiation-induced secondary cancers for hybrid techniques.

MATERIALS AND METHODS

Three treatment plans were prepared in 3D-CRT, h-IMRT, and h-VMAT techniques for each of the 40 patients, who underwent CT simulation in deep inspiration breath-hold (DIBH). For hybrid techniques, plans were created by combining 3D-CRT and dynamic fields with an 80%/20% dose ratio for 3D-CRT and IMRT or VMAT. Cumulative dose-volume histograms were used to compare dose distributions within the PTV and OARs (heart, left anterior descending coronary artery [LAD], left and right lung [LL, RL], right breast [RB]). Projected risk ratios for secondary cancers were estimated relative to 3D-CRT using the organ equivalent dose (OED) concept for the Schneider's linear exponential, plateau, and full mechanistic dose-response model.

RESULTS

All plans fulfilled the PTV criterium: V95%≥95%. Compared to 3D-CRT, both hybrid techniques showed significantly better target coverage (PTV: V95%>98%, p < 0.001), and the best conformality was achieved by h-ARC plans (CI: 1.18 ± 0.09, p < 0.001). Compared to 3D-CRT and h-ARC, h-IMRT increased the average sum of monitor units (MU) over 129.9% (p < 0.001). H-ARC increased the mean dose of contralateral organs and the LL V5Gy parameter (p < 0.001). Both hybrid techniques significantly reduced the Dmax of the heart by 5 Gy. Compared to h-IMRT, h-ARC increased secondary cancer projected relative risk ratios for LL, RL, and RB by 18, 152, and 81%, respectively.

CONCLUSIONS

The results confirmed that both hybrid techniques provide better target quality and OARs sparing than 3D-CRT. Hybrid VMAT delivers less MU compared to hybrid IMRT but may increase the risk of radiation-induced secondary malignancies.

Conformal Radiation Therapy for Ependymoma at Age ≤3 Years: A 25-Year Experience

PURPOSE

Adjuvant radiation therapy (RT) affects survival after surgery for young children (age <3 years) diagnosed with intracranial ependymoma. Conformal photon RT promised to spare normal tissue and was introduced more than 25 years ago to improve outcomes for these vulnerable patients. Long-term results for those first treated with conformal methods provide valuable information and serve as a comparison against newer methods.

METHODS AND MATERIALS

Between 1997 and 2018, 101 patients <3.1-years-old were treated with conformal and intensity modulated photon therapy after definitive surgery for intracranial ependymoma. The median age at RT was 2.1 years and the time from diagnosis to the start of RT was 10 weeks. The extent of resection was gross-total in 82%, and 38% underwent more than 1 attempt at resection. The total prescribed dose was 54 to 59.4 Gy at 1.8 Gy per fraction.

RESULTS

The 10-year event-free and overall survivals were 58.5% ± 5.0% and 72.6% ± 4.5%, respectively, with a median follow-up of 18.4 years (range, 4.2-23.3 years). Tumor progression occurred in 34 patients with a median time of 1.6 years. Death occurred in 34 patients from ependymoma (n = 24), secondary malignancy (n = 6), necrosis (n = 2), shunt failure (n = 1), and anaphylactic reaction (n = 1). Twenty-three patients developed a secondary tumor including 6 cases of fatal high-grade glioma. Of the surviving cohort and those ≥18 years old, 98% obtained a high school diploma, 64% had a current driver's license, 89% were students or employed full or part time, 32% were living independently, and 70% received higher education or training.

CONCLUSIONS

Long-term results of children treated using photon conformal RT after surgery demonstrate that adjuvant RT resulted in long-term disease control and functional independence. These results point to the need for new treatment strategies to improve tumor control and provide investigators hope that newer RT methods will further reduce complications.

Uncertainty and influencing factors of the placement error of three-dimensional conformal intensity-modulated radiotherapy for thoracic tumors

OBJECTIVE

Radiation therapy is an important method for the treatment of chest tumors. This study discussed the placement error of three-dimensional (3D) conformal intensity-modulated radiotherapy in patients with different types of chest tumors and analyzed the relevant influencing factors.

PATIENTS AND METHODS

100 patients with chest tumors diagnosed and treated in our hospital from March 2016 to March 2018 were randomly selected as research subjects, including 42 cases of esophageal cancer, 44 cases of breast cancer, and 14 cases of lung cancer. All patients underwent 3D conformal radiotherapy. The setup errors of patients with esophageal cancer, breast cancer, and lung cancer were detected after 3D conformal radiotherapy. Besides, the influencing factors of 3D conformal for thoracic tumors were analyzed by multiple linear regression analysis.

RESULTS

After 3D conformal radiotherapy, the systematic errors of patients with esophageal cancer in X-axis, Y-axis, and Z-axis were -0.10, 1.26 and 0.07, respectively, while the random errors in X-axis, Y-axis, and Z-axis were 1.18, -1.14, and 0.97 respectively. The times for the absolute values of the positioning error with a range of ≤5 mm in X-axis, Y-axis, and Z-axis were 40 (95.24%), 2 (4.76%) and 36 (85.71%), while these with a range of >5 mm in X-axis, Y-axis, and Z-axis were 6 (14.29%), 41 (97.62%) and 1 (2.38%), respectively. For patients with breast cancer, the systematic errors and random errors in X-axis, Y-axis, and Z-axis are -0.19, 1.19, and 0.15, as well as 0.97, 0.02 and 1.29, respectively. The times for the absolute values of the positioning error with a range of ≤5 mm and >5 mm were 41 (93.18%), 3 (6.82%), and 36 (81.82%), as well as 8 (18.18%), 42 (95.45%) and 2 (4.55%), severally. For patients with lung cancer, the systematic errors and random errors in X-axis, Y-axis, and Z-axis were 0.14, 1.42, and 0.15, as well as 1.35, -0.23 and 1.12, respectively. The times for the absolute values of the positioning error with the range of ≤5 mm and >5 mm were 14 (93.33%), 1 (6.67%), and 11 (73.33%), as well as 4 (26.67%), 14 (93.33%) and 1 (6.67%) after 3D conformal radiotherapy. After multiple linear regression analyses, gender and lung volume were the influencing factors of Z-axis setup error, and the lesion location was the influence factor of Y-axis setup error (p<0.05).

CONCLUSIONS

There are certain positioning errors in the X-axis, Y-axis, and Z-axis directions of thoracic tumors receiving 3D conformal radiotherapy. Gender, lung volume, and lesion location are all important factors that affect the placement error. The results of this study provide a certain reference for the positioning error of radiation therapy for thoracic tumors, which is conducive to improving the accuracy of radiotherapy and better protecting the surrounding tissues.

Correlation of Clinician- and Patient-Reported Outcomes in the BC2001 Trial

AIMS

To evaluate whether there is sufficient correlation between patient-reported outcomes (PROs) and clinician-reported outcomes (CROs) in bladder cancer follow-up post-radiotherapy to streamline data collection and to reduce trial follow-up burden on patients, clinicians and trial programmes.

MATERIALS AND METHODS

PROs data were collected within the BC2001 trial using the Functional Assessment of Cancer Therapy specific to bladder cancer (FACT-BL) questionnaire. CROs data were collected by clinicians using Late Effects in Normal Tissues Subjective, Objective and Management (LENT/SOM). Data were collected at baseline, post-treatment, at 6 and 12 months post-randomisation and then annually to 5 years. The percentage agreement between CROs and PROs measures was evaluated at 2 and 5 years post-randomisation. Concordance was tested using the weighted Kappa statistic with 95% confidence intervals.

RESULTS

Correlation was evaluated between six categories of the FACT-BL and LENT/SOM scores. At 2 years the percentage agreement across these domains ranged from 45 to 78%, with the weighted Kappa statistic between 0.07 and 0.35. Results were similar in year 5 with 48-83% agreement and kappa statistics between -0.02 and 0.21.

CONCLUSION

The correlation between CROs and PROs in patients treated with radiotherapy for bladder cancer were generally poor. PROs appear to be more sensitive, with higher grade events reported. Further work is needed to evaluate whether PROs alone can be used to evaluate toxicity-related outcomes in randomised controlled trials.

Determination and comparison of dosimetric parameters of three-dimensional conformal radiotherapy, field in field, and intensity-modulated radiotherapy techniques in radiotherapy of breast conserving patients

Purpose

Three radiation therapy techniques for breast are common, namely three-dimensional conformal radiotherapy (3D-CRT), Field-in-Field (FIF), and Intensıty-Modulated Radıotherapy (IMRT). The purpose of this study was to determine and compare dosimetric parameters of three different treatment planning planning types; 3D-CRT, FIF, and IMRT in target and normal tissues after breast-conserving surgery.

Methods

One hundred patients with left or right breast cancer cooperated in this study. They were divided into three categories (small, medium, and large size) based on breast volume. Three treatment planning techniques were carried out by planner for each patient in Prowess® 5.2 Treatment Planning System. The dosimetric parameters were obtained from dose-volume histograms using the CERR software (MATLAB Company, Washington, USA), which runs as an add-on in MATLAB software.

Results

3D-CRT technique with the highest value of Dmax creates more hot spots than the other techniques in the tumor region (P = 0.013). IMRT and FIF showed the best uniformity compared to 3D-CRT in all groups with respect to the values of the parameters D98 and D2. IMRT provided the best coverage in the tumor compared to other methods (P < 0.001). 3D-CRT technique yielded a high volume receiving ≥107% of the prescription dose (P < 0.001). Among the three methods, the FIF method results in a lower dose to the lung for treatment based on the V5 and V20 parameters (P < 0.001). Homogeneity index for IMRT was better than FIF, as well as, conformity index (CI) for IMRT and FIF was better than 3D-CRT.

Conclusion

IMRT and FIF plans offered excellent target coverage and uniformity, whereas FIF had better protection of healthy tissues. Thus FIF method is an efficient method to improve the quality of treatment for breast cancer patients.

Dosimetric comparison of three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, and volumetric-modulated arc therapy for free-breathing whole-breast irradiation: A planning study

Background

Currently, recommended heart dose constraints are difficult to meet in whole-breast irradiation (WBI) for left-sided breast cancer patients, who cannot be treated with the deep inspiration breath hold. We performed a radiotherapy planning study to establish if the use of intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT) allows for better sparing of the heart and its subvolumes than the three-dimensional conformal radiation therapy (3D-CRT), and how these attempts affect the dose delivered to the other organs.

Methods

A total of 17 left-sided and 10 right-sided consecutive patients treated with free-breathing WBI were retrospectively included. The 3D-CRT, IMRT, and VMAT plans were generated. Several dose-volume parameters and plan quality indices were compared, separately for the left- and right-sided plans.

Results

All the techniques fulfilled the planning objectives. In the left-sided plans, there was no heart or left ventricle dose reduction with IMRT, nor with VMAT; the maximum dose in the left anterior descending coronary artery was reduced with VMAT (P = 0.005); V5 for the contralateral breast, contralateral lung, and total-body increased markedly in VMAT, and for the ipsilateral lung (V5IL) also in IMRT, compared with 3D-CRT (P < 0.001). In the right-sided plans, the V5 values, except for V5IL, did not differ between the three techniques.

Conclusions

IMRT and VMAT had a limited heart-sparing benefit in the left-sided free-breathing WBI, at the cost of increased low-dose volumes, measured by V5. The low-dose volumes are not increased by IMRT or VMAT in the right-sided WBI, where heart sparing is not a problem, but the attempts to reduce cardiac doses in the left-sided WBI increase them.

Does shortening the duration of radiotherapy treatment in breast cancer increase the risk of radiation pneumonia: A retrospective study

Randomized studies evaluating hypofractionation and conventional fractionation radiotherapy treatments (RT) in patients with breast cancer have shown that hypofractionation achieves similar results to conventional fractionation in terms of survival and local control rates. It has also been shown that their long-term toxicities are similar. This study aimed to evaluate the effects of hypofractionated radiotherapy (H-RT) and conventional radiotherapy (C-RT) on lung toxicity and identify factors affecting this toxicity in patients with breast cancer. The study included 118 patients who underwent adjuvant RT following breast-conserving surgery (BCS). Out of these, 63 patients were assigned to receive C-RT, while the remaining 55 were assigned to receive H-RT. To clarify, we treated 63 patients with C-RT and 55 patients with H-RT. 60 patients were treated using 3-dimensional conformal radiotherapy (3DCRT) and 58 patients were treated using intensity modulated radiotherapy (IMRT). The patients were evaluated weekly for toxicity during radiotherapy (RT) treatment and were called every 3 months for routine controls after the treatment. The first control was performed 1 month after the treatment. Statistical analysis was performed using the SPSS20 program, and a P value of <.005 was considered statistically significant. The study found that the median age of the participants was 54.9 years and tomographic findings were observed in 70 patients. Radiological findings were detected at a median of 5 months after RT. The mean lung dose (MLD) on the treated breast side (referred to as ipsilateral lung or OAR) was 10.4 Gy for the entire group. Among patients who received 18 MV energy in RT, those with an area volume (V20) of the lung on the treated breast side >18.5%, those with a mean dose of the treated breast side lung (ipsilateral lung) >10.5 Gy, and those who received concurrent hormone therapy had significantly more tomographic findings. However, patients treated with YART had fewer tomographic findings. No symptomatic patients were observed during the follow-up period. Our findings show that the risk of lung toxicity is similar with H-RT and C-RT, and H-RT can be considered an effective and safe treatment option for breast cancer. The key factors affecting the development of lung toxicity were found to be the type of RT energy used, RT to the side breast, volume receiving 20 Gy in the side lung, side lung mean dose, and simultaneous hormonal therapy.

Characterization of the Response of 9L and U-251N Orthotopic Brain Tumors to 3D Conformal Radiation Therapy

In a study employing MRI-guided stereotactic radiotherapy (SRS) in two orthotopic rodent brain tumor models, the radiation dose yielding 50% survival (the TCD50) was sought. Syngeneic 9L cells, or human U-251N cells, were implanted stereotactically in 136 Fischer 344 rats or 98 RNU athymic rats, respectively. At approximately 7 days after implantation for 9L, and 18 days for U-251N, rats were imaged with contrast-enhanced MRI (CE-MRI) and then irradiated using a Small Animal Radiation Research Platform (SARRP) operating at 220 kV and 13 mA with an effective energy of ∼70 keV and dose rate of ∼2.5 Gy per min. Radiation doses were delivered as single fractions. Cone-beam CT images were acquired before irradiation, and tumor volumes were defined using co-registered CE-MRI images. Treatment planning using MuriPlan software defined four non-coplanar arcs with an identical isocenter, subsequently accomplished by the SARRP. Thus, the treatment workflow emulated that of current clinical practice. The study endpoint was animal survival to 200 days. The TCD50 inferred from Kaplan-Meier survival estimation was approximately 25 Gy for 9L tumors and below 20 Gy, but within the 95% confidence interval in U-251N tumors. Cox proportional-hazards modeling did not suggest an effect of sex, with the caveat of wide confidence intervals. Having identified the radiation dose at which approximately half of a group of animals was cured, the biological parameters that accompany radiation response can be examined.

A shift from simple to sophisticated: using intensity-modulated radiation therapy in conventional nonstereotactic palliative radiotherapy

PURPOSE OF REVIEW

The authors aimed to highlight trends in, and evidence underlying the use of highly conformal radiotherapy (RT) techniques in conventional nonstereotactic palliative RT. The authors reviewed palliative-intent and curative-intent studies relevant to the use of intensity-modulated radiation therapy (IMRT) for the delivery of nonstereotactic conventional regimens to the brain, head and neck, thorax, abdomen and pelvis, and bone metastases.

RECENT FINDINGS

The use of IMRT has become standard with certain indications for brain metastases such as hippocampus-avoiding/limiting whole brain RT. IMRT in the treatment of bone metastases is increasing at many institutions despite limited data comparing its effectiveness with that of fluoroscopy-based and three-dimensional conformal radiation therapy techniques. There is scant data describing the use of IMRT for palliation in other extracranial anatomic sites; guidance for its use in these settings must be gleaned almost exclusively from curative-intent randomized trials, consensus recommendations and contouring atlases.

SUMMARY

Consistent with historical technology shifts in RT practice, the uptake of highly conformal techniques such as IMRT for conventional palliative RT will likely outpace rigorous evaluations of their advantages and disadvantages relative to simpler techniques. Opportunities exist in virtually all anatomic sites for observational and randomized studies to evaluate the clinical impacts of these modern techniques in the palliative setting.

Accelerated Hypofractionated Radiotherapy for Centrally Located Lung Tumours Not Suitable for Stereotactic Body Radiotherapy or Chemoradiotherapy

AIMS

Accelerated hypofractionated radiotherapy is used at our institution for non-small cell lung cancer (NSCLC) patients not eligible for stereotactic body radiotherapy or chemoradiotherapy. The purpose of this study was to report clinical outcomes of delivering 60 Gy in 15 fractions for these patients.

MATERIALS AND METHODS

All NSCLC patients who received 60 Gy in 15 fractions were reviewed. Outcomes of interest were local failure, regional failure, distant progression, overall survival and treatment-associated toxicities.

RESULTS

In total, 111 patients were included. The median age was 78.8 years and most tumours were adenocarcinoma (n = 55, 49.6%). Sixty-five patients (58.6%) were N0. The cumulative incidence of local failure at 12 and 24 months in the N0 cohort was 5.2% and 14.2%, respectively, compared with 11.5% and 14.8% for N+ patients. Tumour size >35 mm predicted for local failure (hazard ratio 2.706, 95% confidence interval 1.002-7.307, P = 0.0494). Distant progression at 12 and 24 months in N0 patients was 13.7% and 24.3% compared with 24.6% and 33.5% in N+ patients. In N0 patients, larger tumour size was associated with increased risk of distant progression. The median overall survival was 38.1 months in N0 patients versus 31.7 months in N+ patients. The most common toxicity was radiation pneumonitis (n = 6, 6.4%). The incidence of any grade 3 toxicity was 10.3% at ≥1 year. There were no deaths or hospitalisations attributed to treatment.

CONCLUSIONS

Accelerated hypofractionated radiotherapy is well tolerated and resulted in favourable clinical outcomes in various stages of NSCLC patients.

Planning study: prone versus supine position for stereotactic body radiotherapy in prostate by CyberKnife

This study aimed to clarify the differences in radiotherapy dose characteristics and delivery efficiency between the supine and prone positions in patients with prostate cancer using the CyberKnife. The planning computed tomography (CT) and delineations of the prone position were obtained by rotating the supine CT images with delineations of 180° using image processing software. The optimization parameters for planning target volume (PTV) and organs at risk (OARs) were based on the prone position. The optimization parameters determined for the prone position were applied to the supine position for optimization and dose calculation. The dosimetric characteristics of the PTV and OARs, and delivery efficiency were compared between the two different patient positions. The plans in the prone position resulted in better PTV conformity index (nCI), rectum V90%, V80%, V75%, V50% and bladder V50%. A significant difference was observed in treatment time and depth along the central axis (dCAX) between the two plans. The mean treatment time per fraction and dCAX for the supine and prone positions were 20.9 ± 1.7 min versus 19.8 ± 1.3 min (P = 0.019) and 151.1 ± 33.6 mm versus 233.2 ± 8.8 mm (P < 0.001), respectively. In this study the prone position was found to improve dosimetric characteristics and delivery efficiency compared with the supine position during prostate cancer treatment with the CyberKnife.

A prospective clinical study to assess primary hypothyroidism in head and neck cancer patients treated with external beam radiotherapy

PURPOSE

Head and neck cancers are treated by multimodality methods like surgery, radiotherapy, and chemotherapy. Hypothyroidism is one of the late side effects of radiation to the neck. The main aim of the study was to assess the incidence of primary hypothyroidism in patients with head and neck cancers, who received therapeutic external beam radiation; to evaluate the time duration and the total dose of radiation for the development of hypothyroidism.

MATERIALS AND METHODS

A prospective observational study was conducted in our institute on 200 patients from December 2018 to April 2020 with head and neck cancers, which were proven histopathologically. They received external beam radiation using Cobalt 60 or Linear accelerator. A thyroid function test was done in patients after 3 months and 6 months of completion of radiotherapy.

RESULTS

The incidence of hypothyroidism was 8% after 3 months (P value = 0.0088) post radiation and increased to 14% after 6 months (P value = 0.0024). Of the patients who developed hypothyroidism, a maximum number of cases (24; 86%) were given 60 Gy radiation dose, three (10%) were given 40-59 Gy, and one (3%) was given up to 40 Gy as the mean dose of radiation to the lower neck. A P value of 0.750 was not significant; hence, a dose of radiation was not a significant factor. The patients treated with the two-dimensional (2-D) technique (50%) had a higher incidence of hypothyroidism than the patients treated with three-dimensional conformal radiation therapy (3D-CRT) (14.8%) and intensity-modulated radiation therapy (IMRT) (9%). The use of concurrent cisplatin was not a significant factor for hypothyroidism (P value = 1).

CONCLUSION

Thyroid function test should be done in patients who received therapeutic external beam radiation to the neck at baseline and periodically. The early detection and treatment can prevent complications of long-term thyroid hypofunction like hypercholesterolemia, cardiovascular side effects, menstrual irregularities, infertility, peripheral neuropathy, depression, and myxoedema.

Tattoo-Free Setup for Patients With Breast Cancer Receiving Regional Nodal Irradiation

PURPOSE

Patients undergoing regional nodal irradiation (RNI) with either 3-dimensional conformal radiation therapy (3DCRT) planning or volumetric modulated arc therapy (VMAT) receive permanent tattoos to assist with daily setup alignment and verification. With the advent of surface imaging, tattoos may not be necessary to ensure setup accuracy. We compared the accuracy of conventional tattoo-based setups to those without reference to tattoos.

METHODS AND MATERIALS

Forty-eight patients receiving RNI at our institution from July 2019 to December 2020 were identified. All patients received tattoos per standard of care. Twenty-four patients underwent setup using tattoos for initial positioning followed by surface and x-ray imaging. A subsequent 24 patients underwent positioning using surface imaging followed by x-ray imaging without reference to tattoos. Patient cohorts were balanced by treatment technique and use of deep inspiration breath hold. Treatment (including setup and delivery) time and x-ray-based shifts after surface imaging were recorded.

RESULTS

Among patients in the tattoo group receiving 3DCRT RNI, the average treatment time per fraction was 21.35 versus 19.75 minutes in the 3DCRT RNI no-tattoo cohort (P = .03). Mean 3D vector shifts for patients in the tattoo cohort were 5.6 versus 4.4 mm in the no-tattoo cohort. The average treatment time per fraction for the tattoo VMAT RNI cohort was 23.16 versus 20.82 minutes in the no-tattoo VMAT RNI cohort (P = .08). Mean 3D vector shifts for the patients in the tattoo VMAT cohort were 5.5 versus 7.1 mm in the no-tattoo VMAT cohort. Breath hold technique and body mass index did not affect accuracy in a consistent or clinically relevant way.

CONCLUSIONS

Using a combination of surface and x-ray imaging, without reference to tattoos, provides excellent accuracy in alignment and setup verification among patients receiving RNI for breast cancer, regardless of treatment technique and with reduced treatment time. Skin-based tattoos are no longer warranted for patients receiving supine RNI.

Comment on Ivanov et al. Ultra-Hypofractionated vs. Moderate Fractionated Whole Breast Three Dimensional Conformal Radiotherapy during the COVID-19 Pandemic. Medicina 2022, 58, 745

I read the paper by Ivanov et al. [...].

Association of volumetric-modulated arc therapy with radiation pneumonitis in thoracic esophageal cancer

The lung volume receiving low-dose irradiation has been reported to increase in volumetric-modulated arc radiotherapy (VMAT) compared with three-dimensional conformal radiotherapy (3DCRT) for thoracic esophageal cancer, which raises concerns regarding radiation pneumonitis (RP) risk. This single institutional retrospective cohort study aimed to explore whether VMAT for thoracic esophageal cancer was associated with RP. Our study included 161 patients with thoracic esophageal cancer, of whom 142 were definitively treated with 3DCRT and 39 were treated with VMAT between 2008 and 2018. Radiotherapy details, dose-volume metrics, reported RP risk factors and RP incidence were collected. The RP risk factors were assessed via multivariate analysis. Dose-volume analysis showed that VMAT delivered more conformal dose distributions to the target volume (P < 0.001) and reduced V30 Gy of heart (57% vs 41%, P < 0.001) but increased V5 Gy (54% vs 41%, P < 0.001) and V20 Gy (20% vs 17%, P = 0.01) of lungs compared with 3DCRT. However, the 1-year incidence rates of RP did not differ between the two techniques (11.3% in 3DCRT vs 7.7% in VMAT, P = 0.53). The multivariate analysis suggested that the presence of interstitial lung disease (ILD) (P = 0.01) and V20 Gy of lungs ≥20% (P = 0.008) were associated with RP. Conclusively, VMAT increased the lung volume receiving low to middle doses irradiation, although this might not be associated with RP. Further studies are needed to investigate the effect of using VMAT for delivering conformal dose distributions on RP.

Ultra-Hypofractionated vs. Moderate Fractionated Whole Breast Three Dimensional Conformal Radiotherapy during the COVID-19 Pandemic

Background and Objectives: Reducing time of treatment during COVID-19 outbreaks has been recommended by the leading Radiation Oncology societies. Still minimizing radiation induced tissue toxicity is one of the most important issues in breast cancer patients. The study aimed to investigate compliance, clinical and dosimetry normal tissue toxicity, and cosmetic results between moderated and ultra-fractionated regimes for breast cancer patients during COVID-19 pandemic. Materials and Methods: This pilot prospective randomized study included 60 patients with early breast cancer after preserving surgery, 27 patients advocated to ultra-hypofractionated whole-breast three dimensional (3D) conformal radiotherapy of 26 Gy in 5 fractions over 1 week and 33 patients with moderate fractionated breast 3D conformal radiotherapy patients between March 2020 and July 2020, during the COVID pandemic outbreak. The compliance to treatment, dosimetric parameters, acute and late skin toxicity, subcutaneous tissue toxicity, cosmetic results and clinical follow up for 18 months for the two regimes were analyzed and compared. Results: When two regimes were compared 5 fraction group had significantly lower prevalence of newly infected cases of SARS-CoV-2 and thus delayed/interrupted treatment (p = 0.05), comparable grade 1 CTCAE v5, acute skin toxicity (p = 0.18), Grade 1 Radiation Morbidity Scoring Scheme (RESS) subcutaneous tissue toxicity (p = 0.18), Grade 1 RESS late skin toxicity (p = 0.88) and cosmetic results (p = 0.46). Dosimetric results reveled that patients in 5 fraction group received significantly lower median ipsilateral lung doses (p < 0.01) in addition to left breast cancer patients that received significantly lower median heart dose (p < 0.01) and median left anterior descending artery (LAD) dose (p < 0.01). Conclusion: Ultra-hypofractionated radiotherapy for breast cancer is comparable to moderate hypofractionation regimen regarding grade 1 acute skin toxicity, grade 1 subcutaneous tissue toxicity, late skin toxicity and cosmetic results. Application of ultra-hypofractionated radiotherapy with significantly lower radiation doses for lung and heart could be crucial in reducing the risk of acute/late pulmonary and heart radiation-induced toxicity.

Association of 3D-CRT and IMRT accelerated hyperfractionated radiotherapy with local control rate and 5-year survival in esophageal squamous cell carcinoma patients

OBJECTIVES

This retrospective study examined the relevance and prognostic factors of whole-course conformal radiotherapy (CRT) and late-course accelerated hyperfractionation radiotherapy (LCAFRT) for esophageal squamous cell carcinoma (ESCC).

METHODS

A total of 110 patients with ESCC received whole-course CRT and LCAFRT between May 2004 and January 2015. All patients received conventional CRT of 2 Gy per day, up to 30-40 Gy, followed by LCAFRT using reduced fields at 1.5 Gy/fraction twice a day, up to 24-39 Gy, for a total dose of 60-69 Gy.

RESULTS

The median follow-up was 85 months. The whole groups 1-, 3-, and 5-year survival rates were 81.8%, 46.4%, and 41.8%, respectively. The local control rates for the whole group at 1, 3, and 5 years were 82.7%, 70.0%, and 68.2%, respectively. There were no significant differences among survival rates and local control rates between the 3D-CRT and intensity-modulated radiotherapy (IMRT) groups. The main reactions to acute radiotherapy were acute radiation tracheitis, esophagitis, and pneumonia. The tumor location and TNM stage were independent prognostic factors for overall survival.

CONCLUSION

The results showed that whole-course CRT and LCAFRT for ESCC can improve survival and local control with a tolerable acute reaction compared to previous studies. Local recurrence and distant metastasis are the main failure modes of treatment.

ADVANCES IN KNOWLEDGE

Whole-course CRT and LCAFRT for ESCC can improve the survival and local control rate compared with previous studies from the 2DRT era. It might provide another treatment for patients with inoperable ESCC or refusing surgery.

Comparative Effectiveness Analysis of 3D-Conformal Radiation Therapy Versus Intensity Modulated Radiation Therapy (IMRT) in a Prospective Multicenter Cohort of Patients With Breast Cancer

PURPOSE

Simple intensity modulation of radiation therapy reduces acute toxicity compared with 2-dimensional techniques in adjuvant breast cancer treatment, but it remains unknown whether more complex or inverse-planned intensity modulated radiation therapy (IMRT) offers an advantage over forward-planned, 3-dimensional conformal radiation therapy (3DCRT).

METHODS AND MATERIALS

Using prospective data regarding patients receiving adjuvant whole breast radiation therapy without nodal irradiation at 23 institutions from 2011 to 2018, we compared the incidence of acute toxicity (moderate-severe pain or moist desquamation) in patients receiving 3DCRT versus IMRT (either inverse planned or, if forward-planned, using ≥5 segments per gantry angle). We evaluated associations between technique and toxicity using multivariable models with inverse-probability-of-treatment weighting, adjusting for treatment facility as a random effect.

RESULTS

Of 1185 patients treated with 3DCRT and conventional fractionation, 650 (54.9%) experienced acute toxicity; of 774 treated with highly segmented forward-planned IMRT, 458 (59.2%) did; and of 580 treated with inverse-planned IMRT, 245 (42.2%) did. Of 1296 patients treated with hypofractionation and 3DCRT, 432 (33.3%) experienced acute toxicity; of 709 treated with highly segmented forward-planned IMRT, 227 (32.0%) did; and of 623 treated with inverse-planned IMRT, 164 (26.3%) did. On multivariable analysis with inverse-probability-of-treatment weighting, the odds ratio for acute toxicity after inverse-planned IMRT versus 3DCRT was 0.64 (95% confidence interval, 0.45-0.91) with conventional fractionation and 0.41 (95% confidence interval, 0.26-0.65) with hypofractionation.

CONCLUSIONS

This large, prospective, multicenter comparative effectiveness study found a significant benefit from inverse-planned IMRT compared with 3DCRT in reducing acute toxicity of breast radiation therapy. Future research should identify the dosimetric differences that mediate this association and evaluate cost-effectiveness.

Estimating cancer risks due to whole lungs low dose radiotherapy with different techniques for treating COVID-19 pneumonia

BACKGROUND

Low dose radiotherapy (LDRT) of whole lungs with photon beams is a novel method for treating COVID-19 pneumonia. This study aimed to estimate cancer risks induced by lung LDRT for different radiotherapy delivery techniques.

METHOD

Four different radiotherapy techniques, including 3D-conformal with anterior and posterior fields (3D-CRT AP-PA), 3D-conformal with 8 coplanar fields (3D-CRT 8 fields), eight fields intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy using 2 full arcs (VMAT) were planned on the CT images of 32 COVID-19 patients with the prescribed dose of 1 Gy to the lungs. Organ average and maximum doses, and PTV dose distribution indexes were compared between different techniques. The radiation-induced cancer incidence and cancer-specific mortality, and cardiac heart disease risks were estimated for the assessed techniques.

RESULTS

In IMRT and VMAT techniques, heart (mean and max), breast (mean, and max), and stomach (mean) doses and also maximum dose in the body were significantly lower than the 3D-CRT techniques. The calculated conformity indexes were similar in all the techniques. However, the homogeneity indexes were lower (i.e., better) in intensity-modulated techniques (P < 0.03) with no significant differences between IMRT and VMAT plans. Lung cancer incident risks for all the delivery techniques were similar (P > 0.4). Cancer incidence and mortality risks for organs located closer to lungs like breast and stomach were higher in 3D-CRT techniques than IMRT or VMAT techniques (excess solid tumor cancer incidence risks for a 30 years man: 1.94 ± 0.22% Vs. 1.68 ± 0.17%; and women: 6.66 ± 0.81% Vs. 4.60 ± 0.43%: cancer mortality risks for 30 years men: 1.63 ± 0.19% Vs. 1.45 ± 0.15%; and women: 3.63 ± 0.44% Vs. 2.94 ± 0.23%).

CONCLUSION

All the radiotherapy techniques had low cancer risks. However, the overall estimated risks induced by IMRT and VMAT radiotherapy techniques were lower than the 3D-CRT techniques and can be used clinically in younger patients or patients having greater concerns about radiation induced cancers.

Preoperative chemoradiotherapy for locally advanced low rectal cancer using intensity-modulated radiotherapy to spare the intestines: a single-institutional pilot trial

The irradiated volume of intestines is associated with gastrointestinal toxicity in preoperative chemoradiotherapy for rectal cancer. The current trial prospectively explored how much of the irradiated volume of intestines was reduced by intensity-modulated radiotherapy (IMRT) compared with 3-dimensional conformal radiotherapy (3DCRT) and whether IMRT might alleviate the acute gastrointestinal toxicity in this population. The treatment protocol encompassed preoperative chemoradiotherapy using IMRT plus surgery for patients with clinical T3-4, N0-2 low rectal cancer. IMRT delivered 45 Gy per 25 fractions for gross tumors, mesorectal and lateral lymph nodal regions, and tried to reduce the volume of intestines receiving 15 Gy (V15 Gy) < 120 cc and V45 Gy ≤ 0 cc, respectively, while keeping target coverage. S-1 and irinotecan were concurrently administered. Acute gastrointestinal toxicity, rates of clinical downstaging, sphincter preservation, local regional control (LRC) and overall survival (OS) were evaluated. Twelve enrolled patients completed the chemoradiotherapy protocol. The volumes of intestines receiving medium to high doses were reduced by the current IMRT protocol compared to 3DCRT; however, the predefined constraint of V15 Gy was met only in three patients. The rate of ≥ grade 2 gastrointestinal toxicity excluding anorectal symptoms was 17%. The rates of clinical downstaging, sphincter preservation, three-year LRC and OS were 75%, 92%, 92% and 92%, respectively. In conclusion, preoperative chemoradiotherapy using IMRT for this population might alleviate acute gastrointestinal toxicity, achieving high LRC and sphincter preservation; although further advancement is required to reduce the irradiated volume of intestines, especially those receiving low doses.

Clinical practice of epidermal growth factor receptor-tyrosine kinase inhibitor targeted drugs combined with gadolinium oxide nanoparticles in the treatment of non-small cell lung cancer

It was to explore the clinical efficacy and safety of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) targeted drugs combined with hyaluronic acid-gadolinium sesquioxide-nanoparticles (HA-Gd2O3-NPs) in non-small cell lung cancer (NSCLC). In this study, 70 patients with stage IV EGFR mutant NSCLC diagnosed in the First Affiliated Hospital of Jinzhou Medical University were selected. They were randomly divided into the combined group (35 cases) and the control group (35 cases). HA-Gd2O3-NPs were prepared by hydrothermal polymerization, and combined with EGFR-TKI in the clinical treatment of NSCLC. The results showed that HA-Gd2O3-NPs were spherical with a uniform particle size of about 124 nm. The NSCLC survival rate of the combined group was 37.2 ± 5.3% under 6 Gy X-ray irradiation, and that of the control group was 98.4 ± 12.6% under 6 Gy X-ray irradiation. The total effective rate of the control group (20%) was significantly lower than that of the study group (42.86%) (P < 0.05). The one-year survival rate of the combined group (94%) was significantly higher than that of the control group (75%) (P < 0.05). The median progression-free survival (PFS) in the control group was 8 months, and that in the combined group was 12 months, with statistical difference (P < 0.05). EGFR-TKI targeted drugs combined with HA-Gd2O3-NPs can significantly improve the clinical efficacy of stage IV EGFR mutant NSCLC patients and benefit their survival.

Conformal radiotherapy in management of soft tissue sarcoma in adults

We present the update of the recommendations of the French society of radiation oncology on soft tissue sarcomas. Currently, the initial management of sarcomas is very important as it may impact on patients' quality of life, especially in limb soft tissue sarcomas, and on overall survival in trunk sarcomas. Radiotherapy has to be discussed within a multidisciplinary board meeting with results of biopsy, eventually reexamined by a dedicated sarcoma pathologist. The role of radiotherapy varies according to localization of soft tissue sarcoma. It is part of the standard treatment in grade 2 and 3 sarcomas of the extremities and superficial trunk>5cm. In case of R1 or R2 resection, reexcision should be discussed. In such cases, it may be delivered preoperatively (50Gy/25 fractions of 2Gy) or postoperatively. In retroperitoneal sarcomas, preoperative conformal radiotherapy with or without modulated intensity cannot be proposed systematically in daily practice. Concomitant chemoradiotherapy cannot be considered a standard treatment. Intensity-modulated radiotherapy has become widely available. Other soft tissue sarcoma sites such as trunk, head and neck and gynaecological soft tissue sarcomas will be addressed, as well as other techniques that may be used such as brachytherapy and proton therapy.

POstmastectomy radioThErapy in Node-posiTive breast cancer with or without Internal mAmmary nodaL irradiation (POTENTIAL): a study protocol for a multicenter prospective phase III randomized controlled trial

BACKGROUND

Various randomized trials have demonstrated that postmastectomy radiotherapy (RT) to the chest wall and comprehensive regional nodal areas improves survival in patients with axillary node-positive breast cancer. Controversy exists as to whether the internal mammary node (IMN) region is an essential component of regional nodal irradiation. Available data on the survival benefit of IMN irradiation (IMNI) are conflicting. The patient populations enrolled in previous studies were heterogeneous and most studies were conducted before modern systemic treatment and three-dimensional (3D) radiotherapy (RT) techniques were introduced. This study aims to assess the efficacy and safety of IMNI in the context of modern systemic treatment and computed tomography (CT)-based RT planning techniques.

METHODS

POTENTIAL is a prospective, multicenter, open-label, parallel, phase III, randomized controlled trial investigating whether IMNI improves disease-free survival (DFS) in high-risk breast cancer with positive axillary nodes (pN+) after mastectomy. A total of 1800 patients will be randomly assigned in a 1:1 ratio to receive IMNI or not. All patients are required to receive ≥ six cycles of anthracycline and/or taxane-based chemotherapy. Randomization will be stratified by institution, tumor location (medial/central vs. other quadrants), the number of positive axillary nodes (1-3 vs. 4-9 vs. ≥10), and neoadjuvant chemotherapy (yes vs. no). Treatment will be delivered with CT-based 3D RT techniques, including 3D conformal RT, intensity-modulated RT, or volumetric modulated arc therapy. The prescribed dose is 50 Gy in 25 fractions or 43.5 Gy in 15 fractions. Tiered RT quality assurance is required. After RT, patients will be followed up at regular intervals. Oncological and toxilogical outcomes, especially cardiac toxicities, will be assessed.

DISCUSSION

This trial design is intended to overcome the limitations of previous prospective studies by recruiting patients with pN+ breast cancer, using DFS as the primary endpoint, and prospectively assessing cardiac toxicities and requiring RT quality assurance. The results of this study will provide high-level evidence for elective IMNI in patients with breast cancer after mastectomy.

TRIAL REGISTRATION

ClinicalTrails.gov , NCT04320979 . Registered 25 Match 2020, https://clinicaltrials.gov/ct2/show/NCT04320979.

Radiation Therapy Techniques and Treatment-Related Toxicity in the PORTEC-3 Trial: Comparison of 3-Dimensional Conformal Radiation Therapy Versus Intensity-Modulated Radiation Therapy

PURPOSE

Radiation therapy techniques have developed from 3-dimensional conformal radiation therapy (3DCRT) to intensity modulated radiation therapy (IMRT), with better sparing of the surrounding normal tissues. The current analysis aimed to investigate whether IMRT, compared to 3DCRT, resulted in fewer adverse events (AEs) and patient-reported symptoms in the randomized PORTEC-3 trial for high-risk endometrial cancer.

METHODS AND MATERIALS

Data on AEs and patient-reported quality of life (QoL) of the PORTEC-3 trial were available for analysis. Physician-reported AEs were graded using Common Terminology Criteria for Adverse Events v3.0. QoL was assessed by the European Organisation for Research and Treatment of Cancer QLQC30, CX24, and OV28 questionnaires. Data were compared between 3DCRT and IMRT. A P value of ≤ .01 was considered statistically significant due to the risk of multiple testing. For QoL, combined scores 1 to 2 ("not at all" and "a little") versus 3 to 4 ("quite a bit" and "very much") were compared between the techniques.

RESULTS

Of 658 evaluable patients, 559 received 3DCRT and 99 IMRT. Median follow-up was 74.6 months. During treatment no significant differences were observed, with a trend for more grade ≥3 AEs, mostly hematologic and gastrointestinal, after 3DCRT (37.7% vs 26.3%, P = .03). During follow-up, 15.4% (vs 4%) had grade ≥2 diarrhea, and 26.1% (vs 13.1%) had grade ≥2 hematologic AEs after 3DCRT (vs IMRT) (both P < .01). Among 574 (87%) patients evaluable for QoL, 494 received 3DCRT and 80 IMRT. During treatment, 37.5% (vs 28.6%) reported diarrhea after 3DCRT (vs IMRT) (P = .125); 22.1% (versus 10.0%) bowel urgency (P = 0039), and 18.2% and 8.6% abdominal cramps (P = .058). Other QoL scores showed no differences.

CONCLUSIONS

IMRT resulted in fewer grade ≥3 AEs during treatment and significantly lower rates of grade ≥2 diarrhea and hematologic AEs during follow-up. Trends toward fewer patient-reported bowel urgency and abdominal cramps were observed after IMRT compared to 3DCRT.