Exploring Helium Ions' Potential for Post-Mastectomy Left-Sided Breast Cancer Radiotherapy

Proton therapy presents a promising modality for treating left-sided breast cancer due to its unique dose distribution. Helium ions provide increased conformality thanks to a reduced lateral scattering. Consequently, the potential clinical benefit of both techniques was explored. An explorative treatment planning study involving ten patients, previously treated with VMAT (Volumetric Modulated Arc Therapy) for 50 Gy in 25 fractions for locally advanced, node-positive breast cancer, was carried out using proton pencil beam therapy with a fixed relative biological effectiveness (RBE) of 1.1 and helium therapy with a variable RBE described by the mMKM (modified microdosimetric kinetic model). Results indicated that target coverage was improved with particle therapy for both the clinical target volume and especially the internal mammary lymph nodes compared to VMAT. Median dose value analysis revealed that proton and helium plans provided lower dose on the left anterior descending artery (LAD), heart, lungs and right breast than VMAT. Notably, helium therapy exhibited improved ipsilateral lung sparing over protons. Employing NTCP models as available in the literature, helium therapy showed a lower probability of grade ≤ 2 radiation pneumonitis (22% for photons, 5% for protons and 2% for helium ions), while both proton and helium ions reduce the probability of major coronary events with respect to VMAT.

Incidence and Risk Assessment of Capsular Contracture in Breast Cancer Patients following Post-Mastectomy Radiotherapy and Implant-Based Reconstruction

Our study aims to identify the risk factors and dosimetry characteristics associated with capsular contracture.

METHODS

We retrospectively analyzed 118 women with breast cancer who underwent PMRT following an IBR between 2010 and 2022. Patients were treated with PMRT of 50.0-50.4 Gy in 25-28 fractions. Capsular contracture was categorized according to the Baker Classification for Reconstructed Breasts.

RESULTS

After a median follow-up of 22 months, the incidence of clinically relevant capsular contracture (Baker III-IV) was 22.9%. Overall, capsular contracture (Baker I-IV) occurred in 56 patients (47.5%) after a median of 9 months after PMRT. The rate of reconstruction failure/implant loss was 25.4%. In the univariate analysis, postoperative complications (prolonged pain, prolonged wound healing, seroma and swelling) and regional nodal involvement were associated with higher rates of capsular contracture (p = 0.017, OR: 2.5, 95% CI: 1.2-5.3 and p = 0.031, respectively). None of the analyzed dosimetric factors or the implant position were associated with a higher risk for capsular contracture.

CONCLUSION

Postoperative complications and regional nodal involvement were associated with an increased risk of capsular contracture following breast reconstruction and PMRT, while none of the analyzed dosimetric factors were linked to a higher incidence. Additional studies are needed to identify further potential risk factors.

Proton Therapy for Advanced Juvenile Nasopharyngeal Angiofibroma

PURPOSE

To provide the first report on proton radiotherapy (PRT) in the management of advanced nasopharyngeal angiofibroma (JNA) and evaluate potential benefits compared to conformal photon therapy (XRT).

METHODS

We retrospectively reviewed 10 consecutive patients undergoing PRT for advanced JNA in a definitive or postoperative setting with a relative biological effectiveness weighted dose of 45 Gy in 25 fractions between 2012 and 2022 at the Heidelberg Ion Beam Therapy Center. Furthermore, dosimetric comparisons and risk estimations for short- and long-term radiation-induced complications between PRT plans and helical XRT plans were conducted.

RESULTS

PRT was well tolerated, with only low-grade acute toxicities (CTCAE I-II) being reported. The local control rate was 100% after a median follow-up of 27.0 (interquartile range 13.3-58.0) months. PRT resulted in considerable tumor shrinkage, leading to complete remission in five patients and bearing the potential to provide partial or complete symptom relief. Favorable dosimetric outcomes in critical brain substructures by the use of PRT translated into reduced estimated risks for neurocognitive impairment and radiation-induced CNS malignancies compared to XRT.

CONCLUSIONS

PRT is an effective treatment option for advanced JNA with minimal acute morbidity and the potential for reduced radiation-induced long-term complications.

Vaginal cancer treated with curative radiotherapy with or without concomitant chemotherapy: oncologic outcomes and prognostic factors

BACKGROUND

Vaginal cancer is a rare disease for which prospective randomized trials do not exist. We aimed to assess survival outcomes, patterns of recurrence, prognostic factors, and toxicity in the curative treatment using image-guided radiotherapy (RT).

METHODS

In this retrospective review, we identified 53 patients who were treated at a single center with external beam radiotherapy and brachytherapy with or without concomitant chemotherapy from 2000 to 2021.

RESULTS

With a median follow-up of 64.5 months, the Kaplan-Meier 2-, 5-, and 7-year overall survival (OS) was found to be 74.8%, 62.8%, and 58.9%, respectively. Local and distant control were 67.8%, 65.0%, and 65.0% and 74.4%, 62.6%, and 62.6% at 2, 5, and 7 years, respectively. In univariate Cox proportional hazards ratio analysis, OS was significantly correlated to FIGO stage (hazard ratio [HR] 1.78, p = 0.042), postoperative RT (HR 0.41, p = 0.044), and concomitant chemotherapy (HR 0.31, p = 0.009). Local control rates were superior when an equivalent dose in 2-Gy fractions (EQD2) of ⩾65 Gy was delivered (HR 0.216, p = 0.028) and with the use of concurrent chemotherapy (HR 0.248, p = 0.011). Not surprisingly, local control was inferior for patients with a higher TNM stage (HR 3.303, p = 0.027). Minimal toxicity was observed with no patients having documentation of high-grade toxicity (CTCAE grade 3+).

CONCLUSION

In treatment of vaginal cancer, high-dose RT in combination with brachytherapy is well tolerated and results in effective local control rates, which significantly improve with an EQD2(α/β=10) ⩾65 Gy. Multivariate analyses revealed concomitant chemotherapy was a positive prognostic factor for overall and progression-free survival.

Palliative Radiotherapy for Symptomatic Locally Advanced Breast Cancer

Objective: Women with locally advanced breast cancer (LABC) or inoperable local recurrence often suffer from a significantly reduced quality of life (QOL) due to local tumor-associated pain, bleeding, exulceration, or malodorous discharge. We aimed to further investigate the benefit of radiotherapy (RT) for symptom relief while weighing the side-effects. Materials and methods: Patients who received symptom-oriented RT for palliative therapy of their LABC or local recurrence in the Department of Radiation Oncology at Heidelberg University Hospital between 2012 and 2021 were recorded. Clinical, pathological, and therapeutic data were collected and the oncological and symptomatic responses as well as therapy-associated toxicities were analyzed. Results: We retrospectively identified 26 consecutive women who received palliative RT with a median total dose of 39 Gy or single dose of 3 Gy in 13 fractions due to (impending) exulceration, pain, local hemorrhage, and/or vascular or plexus compression. With a median follow-up of 6.5 months after initiation of RT, overall survival at 6 and 12 months was 60.0% and 31.7%, and local control was 75.0% and 47.6%, respectively. Radiation had to be discontinued in 4 patients due to oncological clinical deterioration or death. When completed as initially planned, symptom improvement was achieved in 95% and WHO level reduction of analgesics in 28.6% of patients. In 36% (16%) of patients, local RT had already been indicated >3 months (>6 months) before the actual start of RT, but was delayed or not initiated among others in favor of drug alternatives or systemic therapies. RT-associated toxicities included only low-grade side-effects (CTCAE I°-II°) with predominantly skin erythema and fatigue even in the context of re-RT. Conclusion: Palliative RT in symptomatic LABC or locoregional recurrence is an effective treatment option for controlling local symptoms with only mild toxicity. It may thus improve QOL and should be considered early in palliative patient care management.

Radiotherapy with Helium Ions Has the Potential to Improve Both Endocrine and Neurocognitive Outcome in Pediatric Patients with Ependymoma

Ependymomas are the third most-frequent pediatric brain tumors. To prevent local recurrence, the resection site should be irradiated. Compared to photon radiation treatment, proton therapy often achieves even better results regarding target coverage and organ-sparing. Due to their physical properties, helium ions could further reduce side effects, providing better protection of healthy tissue despite similar target coverage. In our in silico study, 15 pediatric ependymoma patients were considered. All patients underwent adjuvant radiotherapeutic treatment with active-scanned protons at Heidelberg Ion Beam Therapy Center (HIT). Both helium ion and highly conformal IMRT plans were calculated to evaluate the potential dosimetric advantage of ion beam therapy compared to the current state-of-the-art photon-based treatments. To estimate the potential clinical benefit of helium ions, normal tissue complication probabilities (NTCP) were calculated. Target coverage was comparable in all three modalities. As expected, the integral dose absorbed by healthy brain tissue could be significantly reduced with protons by up to -48% vs. IMRT. Even compared to actively scanned protons, relative dose reductions for critical neuronal structures of up to another -39% were achieved when using helium ions. The dose distribution of helium ions is significantly superior when compared to proton therapy and IMRT due to the improved sparing of OAR. In fact, previous studies could clearly demonstrate that the dosimetric advantage of protons translates into a measurable clinical benefit for pediatric patients with brain tumors. Given the dose-response relationship of critical organs at risk combined with NTCP calculation, the results of our study provide a strong rationale that the use of helium ions has the potential to even further reduce the risk for treatment related sequelae.

EPEN-15. Radiotherapy with helium ions has the potential to improve both endocrine and neurocognitive outcome in pediatric patients with ependymoma

BACKGROUND: Ependymoma are the third most frequent pediatric brain tumors. To prevent local recurrence, the resection site should be irradiated. Especially the treatment of pediatric patients requires precise dose application and optimal protection of organs at risk. Compared to photon radiation treatment, proton therapy often achieves better results regarding target coverage and organ-sparing. Due to their physical properties, helium ions can further reduce side effects, providing better protection of healthy tissue despite similar target coverage. PATIENTS AND METHODS: In our in-silico study, 15 pediatric patients (median age six years) with ependymoma located in the posterior cranial fossa were considered. All patients underwent adjuvant radiotherapeutic treatment with active scanned protons at Heidelberg Ion-Beam Therapy Center (HIT). Both helium ion and highly conformal IMRT plans were calculated to evaluate the potential dosimetric (and clinical) benefit of ion beam therapy compared to the current state of the art photon-based treatments. RESULTS: Target coverage was comparable in all three modalities (He, H⁺, Ph): homogeneity indices (HI) and inhomogeneity coefficients (IC) of HI_He=5.8±3.8, HI_H⁺=7.5±4.0, HI_Ph=6.4±4.3, IC_He=0.2±0.1, IC_H+=0.2±0.1, IC_Ph=0.2±0.1. As expected, the integral dose absorbed by the healthy brain tissue could be reduced significantly using helium ions versus IMRT (-45.3%±15.1%). Based on our preliminary results, even compared to active scanned protons – currently the most precise radiation technique worldwide – the relative dose reduction for critical neuronal structures using helium ions on average amounts to -27.2%±14.4%. CONCLUSION: Previous studies could clearly demonstrate that the dosimetric advantage of protons translates into a measurable clinical benefit for pediatric patients with brain tumors. Given the dose response relationship of critical organs at risk, the results of our in-silico study provide a strong rationale that the use of helium ions has the potential to even further reduce the risk for treatment related sequelae.

Return to Work, Fatigue and Cancer Rehabilitation after Curative Radiotherapy and Radiochemotherapy for Pelvic Gynecologic Cancer

Simple Summary

Rehabilitation from cancer treatment and therapy-induced toxicity requires individualized and specialized expertise. Beyond the resolution of treatment-related morbidity, socio-economic and psychological factors must be considered, and lifestyle or household characteristics can have a notable impact on the gradual return to normality and return-to-work rates following cancer therapy. A better identification of patients at a higher risk of prolonged impairment, and a more in-depth understanding of the impacts of treatment is needed to optimize post-therapy recovery. We aim to add to a limited body of literature exploring the posttreatment rehabilitative factors for women following curative radiotherapy for primary gynecologic malignancies. Herein we observed therapy-induced pain and fatigue were significantly more likely to interfere with return-to-work rates. Social support services and post-treatment inpatient cancer rehabilitation programs were helpful in keeping patients connected to their professional lives. Mental issues and the development of depression during follow-up remains an issue particularly for younger patients.

Abstract

Pain, fatigue, and depression are a common cluster of symptoms among cancer patients that impair quality of life and daily activities. We aimed to evaluate the burden of cancer rehabilitation and return-to-work (RTW) rates. Tumor characteristics, lifestyle and household details, treatment data, the use of in-house social services and post-treatment inpatient rehabilitation, and RTW were assessed for 424 women, diagnosed with cervical, uterine, or vaginal/vulvar cancer, receiving curative radio(chemo)therapy. Progression-free RTW rate at 3 months was 32.3%, and increased to 58.1% and 63.2% at 12 and 18 months, respectively. Patients with advanced FIGO stages and intensified treatments significantly suffered more from acute pain and fatigue. A higher Charlson-Comorbidity-Index reliably predicted patients associated with a higher risk of acute fatigue during RT. Aside from the presence of children, no other household or lifestyle factor was correlated with increased fatigue rates. Women aged ≤ 45 years had a significantly higher risk of developing depression requiring treatment during follow-up. Post-treatment inpatient cancer rehabilitation, including exercise and nutrition counseling, significantly relieved fatigue symptoms. The burdens for recovery from cancer therapy remain multi-factorial. Special focus needs to be placed on identifying high-risk groups experiencing fatigue or pain. Specialized post-treatment inpatient cancer rehabilitation can improve RTW rates.

Age-Dependent Hematologic Toxicity Profiles and Prognostic Serologic Markers in Postoperative Radiochemotherapy Treatment for Uterine Cervical Cancer

Introduction: In the adjuvant setting for cervical cancer, classical risk factors for postoperative radiochemotherapy have been established. However, data on laboratory changes during therapy and the prognostic value of serological markers are limited and further knowledge is needed to optimize the toxic trimodal regimen. Methods: We retrospectively identified 69 women who underwent weekly postoperative radiochemotherapy with 40 mg/m² of cisplatin for cervical cancer between 2010 and 2021 at a single center. Laboratory parameters were recorded before, at each cycle and after radiochemotherapy. Kaplan-Meier and log-rank analyses were used to calculate and compare survival, groups were compared using the Mann–Whitney U, χ², and variance tests. Results: With a median follow-up of 17.7 months, the 1- and 5-year local control rates were 94.0% and 73.7%, respectively, with significantly better rates for more chemotherapy cycles and negative resection margins. Only 68.1% of patients completed all cycles. The most common reasons for early discontinuation were persistent asymptomatic leukopenia in women aged ≤ 50 years, and limiting infections in women aged > 50 years. Leukopenia was more likely to occur after the third cycle. Significantly worse survival was observed for post-radiochemotherapy elevated C-reactive-protein and lactate dehydrogenase levels, low pre-radiochemotherapy nutritional index, and raised C-reactive-protein-levels; the latter were also predictable for local control. The Glasgow prognostic score did not reliably predict survival. Conclusion: Incomplete application of simultaneous chemotherapy leads to inferior local control, and age-dependent limiting factors should be identified at an early stage. In addition to classical risk factors, serological markers (C-reactive-protein, lactate dehydrogenase, nutritional index) show prognostic significance.

Effects of CTGF Blockade on Attenuation and Reversal of Radiation-Induced Pulmonary Fibrosis

Background

Radiotherapy is a mainstay for the treatment of lung cancer that can induce pneumonitis or pulmonary fibrosis. The matricellular protein connective tissue growth factor (CTGF) is a central mediator of tissue remodeling.

Methods

A radiation-induced mouse model of pulmonary fibrosis was used to determine if transient administration of a human antibody to CTGF (FG-3019) started at different times before or after 20 Gy thoracic irradiation reduced acute and chronic radiation toxicity. Mice (25 mice/group; 10 mice/group in a confirmation study) were examined by computed tomography, histology, gene expression changes, and for survival. In vitro experiments were performed to directly study the interaction of CTGF blockade and radiation. All statistical tests were two-sided.

Results

Administration of FG-3019 prevented (∼50%-80%) or reversed (∼50%) lung remodeling, improved lung function, improved mouse health, and rescued mice from lethal irradiation ( P < .01). Importantly, when antibody treatment was initiated at 16 weeks after thoracic irradiation, FG-3019 reversed established lung remodeling and restored lung function. CTGF blockade abrogated M2 polarized macrophage influx, normalized radiation-induced gene expression changes, and reduced myofibroblast abundance and Osteopontin expression.

Conclusion

These results indicate that blocking CTGF attenuates radiation-induced pulmonary remodeling and can reverse the process after initiation. CTGF has a central role in radiation-induced fibrogenesis, and FG-3019 may benefit patients with radiation-induced pulmonary fibrosis or patients with other forms or origin of chronic fibrotic diseases.

Combined inhibition of TGFβ and PDGF signaling attenuates radiation-induced pulmonary fibrosis

Background: Radiotherapy (RT) is a mainstay for the treatment of lung cancer, but the effective dose is often limited by the development of radiation-induced pneumonitis and pulmonary fibrosis. Transforming growth factor β (TGFβ) and platelet-derived growth factor (PDGF) play crucial roles in the development of these diseases, but the effects of dual growth factor inhibition on pulmonary fibrosis development remain unclear. Methods: C57BL/6 mice were treated with 20 Gy to the thorax to induce pulmonary fibrosis. PDGF receptor inhibitors SU9518 and SU14816 (imatinib) and TGFβ receptor inhibitor galunisertib were applied individually or in combinations after RT. Lung density and septal fibrosis were measured by high-resolution CT and MRI. Lung histology and gene expression analyses were performed and Osteopontin levels were studied. Results: Treatment with SU9518, SU14816 or galunisertib individually attenuated radiation-induced pulmonary inflammation and fibrosis and decreased radiological and histological signs of lung damage. Combining PDGF and TGFβ inhibitors showed to be feasible and safe in a mouse model, and dual inhibition significantly attenuated radiation-induced lung damage and extended mouse survival compared to blockage of either pathway alone. Gene expression analysis of irradiated lung tissue showed upregulation of PDGF and TGFβ-dependent signaling components by thoracic irradiation, and upregulation patterns show crosstalk between downstream mediators of the PDGF and TGFβ pathways. Conclusion: Combined small-molecule inhibition of PDGF and TGFβ signaling is a safe and effective treatment for radiation-induced pulmonary inflammation and fibrosis in mice and may offer a novel approach for treatment of fibrotic lung diseases in humans. Translational statement: RT is an effective treatment modality for cancer with limitations due to acute and chronic toxicities, where TGFβ and PDGF play a key role. Here, we show that a combined inhibition of TGFβ and PDGF signaling is more effective in attenuating radiation-induced lung damage compared to blocking either pathway alone. We used the TGFβ-receptor I inhibitor galunisertib, an effective anticancer compound in preclinical models and the PDGFR inhibitors imatinib and SU9518, a sunitinib analog. Our signaling data suggest that the reduction of TGFβ and PDGF signaling and the attenuation of SPP1 (Osteopontin) expression may be responsible for the observed benefits. With the clinical availability of similar compounds currently in phase-I/II trials as cancer therapeutics or already approved for certain cancers or idiopathic lung fibrosis (IPF), our study suggests that the combined application of small molecule inhibitors of TGFβ and PDGF signaling may offer a promising approach to treat radiation-associated toxicity in RT of lung cancer.