Evidence for external beam radiotherapy in mediastinal Hodgkin and non-Hodgkin lymphoma - systematic review.

INTRODUCTION AND OBJECTIVE: Proton beam therapy (PBT) provides the opportunity for a more localized delivery of high energy protons and may reduce the damage to healthy tissues and vital organs. The aim of this review was to assess the effects of proton therapy for patients diagnosed with Hodgkin or non-Hodgkin lymphoma treated with mediastinal irradiation. REVIEW METHODS: A systematic search of EMBASE, MEDLINE via OVID and Cochrane Library was conducted in May 2022 according to PRISMA guidelines to identify relevant data on the efficacy and toxicity of proton beam therapy for patients diagnosed with Hodgkin or non-Hodgkin lymphoma. BRIEF DESCRIPTION OF THE STATE OF KNOWLEDGE: Of 566 screened abstracts (430 after de-duplication) 11 studies with a total of 529 patients were included. All studies were case series published between 2011-2021. Median range of follow-up time was 15-63.6 months. The overall survival (OS) for 2 years varied from 91% - 98% for 5 of the included studies. Three of the included studies had favourable outcomes with 2-year progression-free survival (PFS) ranging from 73% - 94%. Skin reaction, oesophagitis and fatigue were found to be the most common grade 1 and grade 2 toxicities. No acute or late grade 4 and higher toxicities/adverse events were observed. SUMMARY: There are data indicating that PBT may to be an effective treatment against mediastinal Hodgkin and non-Hodgkin lymphoma. Because all the studies were case series, the authors of this review have little confidence in the evidence. There remains a need for well-designed randomized controlled trials to inform about the optimal approach to proton irradiation in HL and NHL.

Late Cardiac Toxic Effects Associated With Treatment Protocols for Hodgkin Lymphoma in Children.

Importance: Contemporary North American trials for children with Hodgkin lymphoma (HL) have decreased radiation therapy (RT) use and increased pharmacologic cardioprotection but also increased the cumulative doxorubicin dose, making overall treatment consequences for late cardiac toxic effects uncertain. Objective: To estimate the risk of cardiac toxic effects associated with treatments used in modern pediatric HL clinical trials. Design, Setting, and Participants: For this cohort study, Fine and Gray models were fitted using survivors in the Childhood Cancer Survivor Study who were diagnosed with HL between January 1, 1970, and December 31, 1999, and were followed for a median of 23.5 (range, 5.0-46.3) years. These models were applied to the exposures in the study population to estimate the 30-year cumulative incidence of cardiac disease. The study population comprised patients with intermediate-risk or high-risk HL treated in 4 consecutive Children's Oncology Group clinical trials from September 2002 to October 2022: AHOD0031, AHOD0831, AHOD1331, and S1826. Data analysis was performed from April 2020 to February 2023. Exposures: All patients received chemotherapy including doxorubicin, and some patients received mediastinal RT, dexrazoxane, or mediastinal RT and dexrazoxane. Main Outcomes and Measures: Estimated 30-year cumulative incidence of grade 3 to 5 cardiac disease. Results: The study cohort comprised 2563 patients, with a median age at diagnosis of 15 (range, 1-22) years. More than half of the patients were male (1357 [52.9%]). All 2563 patients received doxorubicin, 1362 patients (53.1%) received mediastinal RT, and 307 patients (12.0%) received dexrazoxane. Radiation therapy use and the median mean heart dose among patients receiving RT decreased, whereas the planned cumulative dose of doxorubicin and use of dexrazoxane cardioprotection increased. For patients treated at age 15 years, the estimated 30-year cumulative incidence of severe or fatal cardiac disease was 9.6% (95% CI, 4.2%-16.4%) in the AHOD0031 standard treatment group (enrolled 2002-2009), 8.6% (95% CI, 3.8%-14.9%) in the AHOD0831 trial (enrolled 2009-2012), 8.2% (95% CI, 3.6%-14.3%) in the AHOD1331 trial (enrolled 2015-2019), and 6.2% (95% CI, 2.7%-10.9%) in the S1826 trial (enrolled 2019-2022), whereas the expected rate in an untreated population was 5.0% (95% CI, 2.1%-9.3%). Despite the estimated reduction in late cardiac morbidity, the frequency of recommended echocardiographic screening among survivors will increase based on current guidelines. Conclusions and Relevance: In this cohort study of sequential HL trials, reductions in the proportion of children receiving mediastinal RT and increases in dexrazoxane use were estimated to offset the increased doxorubicin dose and produce a net reduction in late cardiac disease. Further studies on dexrazoxane are warranted to confirm whether its role in reducing cardiac toxic effects is maintained long term. These findings suggest that survivorship follow-up guidelines should be refined to align with the risks associated with treatment.

Involved-site Radiotherapy Delineation Dilemmas in the Treatment of Adult Hodgkin Lymphoma: Turkish Society for Radiation Oncology Hematological Oncology, Pediatric Oncology and TBI Study Group Case-based Questionnaire Review (TROD 03-005).

AIMS: The International Lymphoma Radiation Oncology Group (ILROG) defined involved-site radiotherapy (ISRT) guidelines. These rules offer a certain variability that allows for autonomous decision-making in diverse clinical settings. However, this flexibility also gives rise to conflicts about the selection of treatment fields in the daily decision-making process. The aim of this study was to show the extent of interobserver variability when ILROG-ISRT recommendations were used in different clinical scenarios. MATERIALS AND METHODS: The 10-question survey used in our study consisted of two parts (part A and part B) and was prepared by four senior radiation oncologists experienced in the haemato-oncology field. The results were presented by stratifying according to clinical experience (<10 years, ≥10 years). Binomial tests (one-sided) were conducted to assess whether answers for each group and the whole group reached a consensus. RESULTS: Twenty-six radiation oncologists, 13 of whom had less than 10 years of experience and 13 seniors, participated in the survey. Eighty per cent of respondents thought ILROG did not bring sufficient solutions for all clinical scenarios but offered solutions in some cases. In different case-based scenarios, the consensus among the respondents decreased down to 38%. Senior radiation oncologists were found to have more doubts about the adequacy of current guidelines. CONCLUSIONS: ILROG guidelines allow for a high degree of variability in real-life clinical scenarios and different interpretation of the recommendations may lead to increased toxicity and recurrences. Therefore, there is a need for refinement in ISRT delineation strategies. On behalf of the Turkish Society for Radiation Oncology Hematological Oncology, Pediatric Oncology and TBI Study Group, we are planning to carry out further educational contouring sessions to detect the interobserver variability in real-life contouring cases.

Mediastinal Radiotherapy-induced Early-onset Valvulopathy in a 6-Year-old Boy With Hodgkin Lymphoma.

Mediastinal radiotherapy for childhood cancers, particularly Hodgkin disease, has numerous potential adverse effects, including coronary artery disease, pericarditis, cardiomyopathy, valvular disease, and conduction abnormalities. The prevalence of valvular stenosis is relatively low, and regurgitation is more common. Mediastinal radiotherapy-induced valvular disease develops more than 10 years after radiotherapy. Here, we present a case of a 6-year-old boy with moderate to significant mitral stenosis + moderate mitral regurgitation and mild aortic regurgitation that appeared 1.5 months after radiotherapy and showed a progressive course.

Is oligometastatic disease an applicable and useful concept in haematologic malignancies? A narrative review of radiation therapy standards, modern techniques, and innovations.

PURPOSE: Haematologic malignancies are particular in that they can generally be cured, even when distant metastases are present at diagnosis, unlike solid malignancies. Systemic treatments, including chemotherapy, targeted therapies, and immunotherapy, are the standard of care with excellent results. The considerable progress made in the management of these diseases in the last 20years has redefined the role of radiation therapy as minor in many clinical situations. We propose a literature review of data, showing that radiation therapy still has a role in curative, salvage, and palliative therapy situations. MATERIAL AND METHODS: A document and literature search was carried out in the following databases: Medline and ClinicalTrial.gov, for the terms "radiotherapy", "haematologic malignancies", "Hodgkin lymphoma", "non-Hodgkin lymphoma", "CAR T cells", "multiple myeloma", "solitary plasmocytoma", "intensity-modulated radiotherapy", "extracranial stereotactic body radiation therapy" and "proton therapy references". RESULTS: Haemopathological malignancies include a wide range of diseases and radiation therapy indications have been assessed over the past 20years. Currently, radiation therapy is indicated for localized disease (solitary plasmocytoma), as an adjuvant (Hodgkin lymphoma), in palliative settings, or after systemic treatment in relapsed patients (chimeric antigen receptor [CAR] T-cells) with a low recurrence burden, which can therefore be considered "oligorecurrence". Radiation therapy, through total body irradiation, has important indications, thanks to its immunomodulatory and/or myeloablative effects. Moreover, recent technological developments have made possible significant improvement in safety, contributing to radiation therapy being positioned in the treatment strategy of several indications. CONCLUSIONS: Given the effectiveness of systemic treatments in hematologic malignancies, the oligometastasis stage is of little importance. A curative intent after local radiation therapy, even advanced stage, is possible, both with residual disease for advanced Hodgkin lymphoma, aggressive non-Hodgkin lymphoma, or solitary plasmocytoma, and even without evidence of disease after chemotherapy for Hodgkin or non-Hodgkin lymphoma. The role of new treatments, such as CAR T cells, allows us to consider radiation therapy after systemic treatment of relapsed diseases with low volume recurrence, which can be considered oligorecurrence.

Cardiac surgery for radiation associated heart disease in Hodgkin lymphoma patients.

Much of the modern focus of Hodgkin's Lymphoma (HL) treatment involves the prevention of secondary organ injury. Despite rationalisations of radiotherapy fields, many patients still develop late radiation-related cardiotoxicity that is severe and requires interventional management. No guidelines exist to direct management of these complex patients who often present with multiple concurrent cardiac pathologies. Despite possessing a greater mortality risk than in the general population, cardiac surgery has an important role in treating radiation-associated heart disease. This review summarises the body of literature surrounding cardiac surgery in HL survivors post-radiotherapy, highlighting the benefits and risks unique to this cohort. The pathophysiology and presentation of radiation-associated heart disease is also explored in relation to HL patients.

Multi-Phenotypic Breast Cancer Post-Radiotherapy for Hodgkin Lymphoma: A Case of Secondary Malignancy.

Morbidity and mortality associated with radiation-induced secondary malignancies (RISMs) have shifted treatment paradigms to minimize or eliminate radiation from treatment regimens. In this case, a 48-year-old woman was diagnosed with Hodgkin lymphoma (HL) and treated with radiotherapy in 2000. In 2018, she was diagnosed with ductal carcinoma in situ (DCIS) of the right breast and treated with a mastectomy. Soon after, she developed triple-negative invasive ductal carcinoma (IDC) in her reconstructed breast. The patient underwent a left lumpectomy, and pathology showed ER-/PR-/HER2+ IDC. This patient's multi-phenotypic DCIS and IDC presentation are suspected to be RISM due to her previous HL treatment regimen.

[Endocrine disorders after combined chemoradiotherapy in Hodgkin Lymphoma survivors].

BACKGROUND: Hodgkin's lymphoma (HL) is one of the most common malignant lymphoproliferative diseases. Chemotherapy and radiotherapy used in the treatment of LH induce a number of toxic effects leading to dysfunction of endocrine system. Hormonal disorders in HL and their relationships with the therapy used remain to be clarified. AIM: To assess disorders of the endocrine function of thyroid, parathyroid glands and gonads in HL survivors. MATERIALS AND METHODS: Screening of endocrine dysfunction of the thyroid, parathyroid glands and gonads was performed in 160 adult patients with HL, 55 men and 105 women, at remission stage induced by chemotherapy or chemoradiotherapy. Forty healthy subjects, matched by age, were acted as control. The levels of TSH, T3, free T4, PTH, FSH, LH, free testosterone, dehydroepiandrosterone sulfate (DHEA-S), and sex-hormone binding globulin (SHBG) were measured in blood serum by ELISA. Bone mineral density (BMD) was assessed by DEXA. RESULTS: Hypothyroidism (25%), hyperparathyroidism (15.6%) and hypogonadism (29% of men and 25.3% of women) were the most prevalent endocrine disorders in LH survivors. Hypothyroidism was significantly more common in patients after chemoradiotherapy than in those who received only chemotherapy (χ2=9.4, р=0.002). In patients with hyperparathyroidism, there were negative correlations between PTH levels and BMD in the lumbar spine (r=-0.74, p=0.00002) and in the femoral neck (r=-0.66, p=0.0003). Men with HL demonstrated lower free testosterone concentrations when compared to control (p=0.04); LH and FSH levels were elevated (p=0.0004 and p=0.04, respectively). In men with HL the levels of DHEA-S were reduced (p=0.0009). The increased SHBG concentrations were revealed in 13 (23.6%) men. Women of reproductive age with HL had higher levels of LH in the luteal phase (p=0.05) and FSH in the follicular phase (p=0.02) than controls. CONCLUSION: The data indicate a high prevalence of the dysfunctions of thyroid, parathyroid glands, and gonads in HL survivors. Screening for endocrine disorders in these patients is highly recommended.

A Quality Control Study on Involved Node Radiation Therapy in the European Organisation for Research and Treatment of Cancer/Lymphoma Study Association/Fondazione Italiana Linfomi H10 Trial on Stages I and II Hodgkin Lymphoma: Lessons Learned.

PURPOSE: Involved node radiation therapy (INRT) was introduced in the European Organisation for Research and Treatment of Cancer/Lymphoma Study Association/Fondazione Italiana Linfomi H10 trial, a large multicenter trial in early-stage Hodgkin Lymphoma. The present study aimed to evaluate the quality of INRT in this trial. METHODS AND MATERIALS: A retrospective, descriptive study was initiated to evaluate INRT in a representative sample encompassing approximately 10% of all irradiated patients in the H10 trial. Sampling was stratified by academic group, year of treatment, size of the treatment center, and treatment arm, and it was done proportional to the size of the strata. The sample was completed for all patients with known recurrences to enable future research on relapse patterns. Radiation therapy principle, target volume delineation and coverage, and applied technique and dose were evaluated using the EORTC Radiation Therapy Quality Assurance platform. Each case was reviewed by 2 reviewers and, in case of disagreement also by an adjudicator for a consensus evaluation. RESULTS: Data were retrieved for 66 of 1294 irradiated patients (5.1%). Data collection and analysis were hampered more than anticipated by changes in archiving of diagnostic imaging and treatment planning systems during the running period of the trial. A review could be performed on 61 patients. The INRT principle was applied in 86.6%. Overall, 88.5% of cases were treated according to protocol. Unacceptable variations were predominately due to geographic misses of the target volume delineations. The rate of unacceptable variations decreased during trial recruitment. CONCLUSIONS: The principle of INRT was applied in most of the reviewed patients. Almost 90% of the evaluated patients were treated according to the protocol. The present results should, however, be interpreted with caution because the number of patients evaluated was limited. Individual case reviews should be done in a prospective fashion in future trials. Radiation therapy Quality Assurance tailored to the clinical trial objectives is strongly recommended.

Predicted cardiac and second cancer risks for patients undergoing VMAT for mediastinal Hodgkin lymphoma

Background and purpose To predict treatment-related cardiovascular disease (CVD) and second cancer 30-yea. absolute mortality risks (AMR30) for patients with mediastinal Hodgkin lymphoma in a large multicentre radiation oncology network in Ireland. Material and methods This study includes consecutive patients treated for mediastinal lymphoma using chemotherapy and involved site radiotherapy (RT) 2016–2019. Radiation doses to heart, left ventricle, cardiac valves, lungs, oesophagus, carotid arteries and female breasts were calculated. Individual CVD and second cancer AMR30 were predicted using Irish background population rates and dose–response relationships. Results Forty-four patients with Hodgkin lymphoma were identified, 23 females, median age 28 years. Ninety-eight percent received anthracycline, 80% received 4–6 cycles ABVD. Volumetric modulated arc therapy (VMAT) ± deep inspiration breath hold (DIBH) was delivered, median total prescribed dose 30 Gy. Average mean heart dose 9.8 Gy (range 0.2–23.8 Gy). Excess treatment-related mean AMR30 from CVD was 2.18% (0.79, 0.90, 0.01, 0.13 and 0.35% for coronary disease, heart failure, valvular disease, stroke and other cardiac diseases), 1.07% due to chemotherapy and a further 1.11% from RT. Excess mean AMR30 for second cancers following RT were: lung cancer 2.20%, breast cancer in females 0.34%, and oesophageal cancer 0.28%. Conclusion For patients with mediastinal lymphoma excess mortality risks from CVD and second cancers remain clinically significant despite contemporary chemotherapy and photon-RT. Efforts to reduce the toxicity of combined modality treatment, for example, using DIBH, reduced margins and advanced RT, e.g. proton beam therapy, should be continued to further reduce potentially fatal treatment effects (AU)

Work and education interruption in long-term Hodgkin lymphoma survivors: an analysis among patients from nine EORTC-LYSA trials.

BACKGROUND: Disease-specific studies on the impact of Hodgkin lymphoma (HL) on education or work interruption and resumption are lacking. MATERIAL AND METHODS: In a cross-sectional study conducted among long-term HL survivors enrolled from 1964 to 2004 in nine randomised EORTC-LYSA trials, the interruption and resumption of education/work was investigated. Survivors alive 5-44 years after diagnosis who were studying or working at time of diagnosis were included (n = 1646). Patient and treatment characteristics were obtained from trial records. Education and work outcomes were collected using the Life Situation Questionnaire. Logistic regression was used to model education or work interruption; Cox regression was used to study resumption rates. RESULTS: Among survivors studying at time of diagnosis (n = 323), 52% (95% CI: 46-57%) interrupted their education; however, it was resumed within 24 months by 92% (95% CI: 87-96%). The probability of interruption decreased with time: the more recent the treatment era, the lower the risk (OR 0.70 per 10 years, 95% CI: 0.49-1.01). Treatment with radiotherapy (yes vs. no) was associated with a higher education resumption rate (HR 2.01, 95% CI 1.07-3.78) whereas age, sex, stage, radiotherapy field and chemotherapy were not.Among survivors working at time of diagnosis (n = 1323), 77% (95% CI: 75-79%) interrupted their work. However, it was resumed within 24 months by 86% (95% CI: 84%-88%). Women were more likely to interrupt their work as compared to men (OR 1.90, 95% CI: 1.44-2.51) and, when interrupted, less likely to resume work (HR 0.70, 95% CI: 0.61-0.80). Survivors with a higher educational level were less likely to interrupt their work (OR 0.68 for university vs. no high school, 95% CI: 0.46-1.03); and when interrupted, more likely to resume work (HR 1.50 for university vs. no high school, 95% CI: 1.21-1.86). Increasing age was also associated with lower resumption rates (HR 0.62 for age ≥50 vs. 18-29 years, 95% CI: 0.41-0.94). CONCLUSION: An interruption in education/work was common among long-term HL survivors. However, most of the survivors who interrupted their studies or work had resumed their activities within 24 months. In this study, no associations between survivors' characteristics and failure to resume education were observed. Female sex, age ≥50 years, and a lower level of education were found to be associated with not resuming work after treatment for HL.

Surgical outcomes following breast reconstruction in patients with and without a history of chest radiotherapy for Hodgkin lymphoma: a multicentre, matched cohort study.

BACKGROUND: Breast cancer is the most common treatment-related second malignancy among women with previous chest radiotherapy for Hodgkin lymphoma (HL). Little is known about the effects of this kind of radiotherapy on the outcomes of postmastectomy breast reconstruction (BR). This study compared adverse outcomes of BR after HL-related chest radiotherapy to matched controls. METHODS: The authors conducted a retrospective, matched cohort study in two expert cancer centres in the Netherlands. BRs after therapeutic or prophylactic mastectomy in HL survivors who received chest radiotherapy were matched with BRs in nonirradiated patients without HL on age at mastectomy date, date of BR, and type of BR. The primary outcome was complication-related BR failure or conversion and secondary outcomes were complication-related re-operation, capsular contracture, major donor-site complications, and complication-related ICU admission. The authors analyzed all outcomes univariably using Fisher's exact tests and the authors assessed reconstruction failure, complication-related re-operation, and capsular contracture with multivariable Cox regression analysis adjusting for confounding and data clustering. RESULTS: Seventy BRs in 41 patients who received chest radiotherapy for HL were matched to 121 BRs in 110 nonirradiated patients. Reconstruction failure did not differ between HL survivors (12.9%) and controls (12.4%). The comparison groups showed no differences in number of reoperations, major donor-site complications, or capsular contractures. BR in HL survivors more often let to ICU admission due to complications compared with controls ( P =0.048). CONCLUSIONS: We observed no increased risk of adverse outcomes following BR after previous chest radiotherapy for HL. This is important information for counselling these patients and may improve shared decision-making.

FETAL DOSE ESTIMATION DURING PREGNANCY USING GATE MONTE CARLO SIMULATION: APPLICATION OF HODGKIN'S LYMPHOMA RADIOTHERAPY.

The aim of this study is to estimate the fetal radiation dose for a pregnant patient treated for Hodgkin's lymphoma. Due to the supradiaphragmatic extensions, two plans are used for this treatment, one for supra-clavicular and the other for cervical lymph nodes, with beam energies of 18 and 6 MV, respectively. We model the ELEKTA accelerator (Versa HD Ltd, Crawly, UK) and the pregnant patient using GATE code. The accelerator is modelled based on the vendor-supplied data and the pregnant patient is modeled with a voxelized pregnant woman phantom (Katja, 29 years old) at the 24th week of pregnancy. In each plan, we estimate the absorbed dose of each fetus organ by delivering a 2 Gy for one fraction and then multiplying the result by 15 fractions to get the total prescribed dose, then we calculate the mean fetal absorbed dose. The results indicate that the mean absorbed fetal dose was 26.18 mGy.

Voluntary deep inspiration breath-hold with volumetric modulated arc therapy in pediatric patients with mediastinal Hodgkin lymphoma.

Background: Deep inspiration breath-hold (DIBH) has been established to decrease normal tissue radiation dose in breast cancer. Methods: Forty-nine patients had two CT scans during DIBH or free breathing. Chest-wall position, setup verification and breath-hold monitoring were performed. Cone-beam CT and a surface image system were used for verification. Results: A total of 1617 breath-holds were analyzed in 401 fractions. The mean time bit was 6.01 min. The mean breaths-holds per fraction was 4.96. The median for intra-breath hold variability was 3 mm. No patient stopped treatment for intolerance. Clinical target volume margins were calculated as 0.36, 0.36 and 0.32 for the three translational positions. The mean saved volume was 26.3%. Conclusion: Voluntary DIBH is feasible, tolerable and easy to apply for children with Hodgkin lymphoma involving the mediastinum.

Deep inspiration breath-hold (DIBH) is a radiotherapy maneuver to decrease the exposure of normal tissues during the radiation of the target organ. It was developed for the treatment of breast cancer, both intact breast and chest wall, after mastectomy. For mediastinal Hodgkin lymphoma, especially in children and adolescents, DIBH will benefit in decreasing the radiation dose to the lungs and heart in this category of patients who still have normal growing tissues. We treated 49 pediatric and adolescent patients with DIBH and precise radiotherapy (volumetric modulated arc therapy) to augment the benefit of lowering the dose to normal tissues. All patients were trained and coached to breath-hold for more than 20 s. No patient stopped treatment due to poor tolerance or discomfort. Only one breath-hold was required for CT simulation in all populations (100%). The mean number of breath-holds per treatment fraction was 5.1 ± 1.8. The mean treatment time was 6 ± 1.8 min. DIBH is feasible, tolerable and easy to apply for children and adolescents with Hodgkin lymphoma involving the mediastinum. A considerable dose volume could be saved, hence decreasing the rate of side effects.

Importance of Central Imaging Review in a Pediatric Hodgkin Lymphoma Trial Using Positron Emission Tomography Response Adapted Radiation Therapy.

PURPOSE: We investigated the effects of central review of the interim fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) scan response (iPET) assessment on treatment allocation in the risk-based, response-adapted, Children's Oncology Group study AHOD1331 (ClinicalTrials.gov identifier: NCT02166463) for pediatric patients with high-risk Hodgkin lymphoma. METHODS AND MATERIALS: Per protocol, after 2 cycles of systemic therapy, patients underwent iPET, with visual response assessment by 5-point Deauville score (DS) at their treating institution and a real-time central review, with the latter considered the reference standard. An area of disease with a DS of 1 to 3 was considered a rapid-responding lesion, whereas a DS of 4 to 5 was considered a slow-responding lesion (SRL). Patients with 1 or more SRLs were considered iPET positive, whereas patients with only rapid-responding lesions were considered iPET negative. We conducted a predefined exploratory evaluation of concordance in iPET response assessment between institutional and central reviews of 573 patients. The concordance rate was evaluated using the Cohen κ statistic (κ > 0.80 was considered very good agreement and κ > 0.60-0.80, good agreement). RESULTS: The concordance rate (514 of 573 [89.7%]) had a κ of 0.685 (95% CI, 0.610-0.759), consistent with good agreement. In terms of the direction of discordance, among the 126 patients who were considered iPET positive by institutional review, 38 (30.2%) were categorized as iPET negative by central review, preventing overtreatment with radiation therapy. Conversely, among the 447 patients who were considered iPET negative by institutional review, 21 patients (4.7%) were categorized as iPET positive by the central review and would have been undertreated without radiation therapy. CONCLUSIONS: Central review is integral to PET response-adapted clinical trials for children with Hodgkin lymphoma. Continued support of central imaging review and education about DS are needed.

Individualised Estimation of Quality-adjusted Survival Benefit and Cost-effectiveness of Proton Beam Therapy in Intermediate-stage Hodgkin Lymphoma.

AIMS: Radiotherapy for Hodgkin lymphoma leads to the irradiation of organs at risk (OAR), which may confer excess risks of late effects. Comparative dosimetry studies show that proton beam therapy (PBT) may reduce OAR irradiation compared with photon radiotherapy, but PBT is more expensive and treatment capacity is limited. The purpose of this study is to inform the appropriateness of PBT for intermediate-stage Hodgkin lymphoma (ISHL). MATERIALS AND METHODS: A microsimulation model simulating the course of ISHL, background mortality and late effects was used to estimate comparative quality-adjusted life years (QALYs) lived and healthcare costs after consolidative pencil beam scanning PBT or volumetric modulated arc therapy (VMAT), both in deep-inspiration breath-hold. Outcomes were compared for 606 illustrative patients covering a spectrum of clinical presentations, varying by two age strata (20 and 40 years), both sexes, three smoking statuses (never, former and current) and 61 pairs of OAR radiation doses from a comparative planning study. Both undiscounted and discounted outcomes at 3.5% yearly discount were estimated. The maximum excess cost of PBT that might be considered cost-effective by the UK's National Institute for Health and Care Excellence was calculated. RESULTS: OAR doses, smoking status and discount rate had large impacts on QALYs gained with PBT. Current smokers benefited the most, averaging 0.605 undiscounted QALYs (range -0.341 to 2.171) and 0.146 discounted QALYs (range -0.067 to 0.686), whereas never smokers benefited the least, averaging 0.074 undiscounted QALYs (range -0.196 to 0.491) and 0.017 discounted QALYs (range -0.030 to 0.086). For the gain in discounted QALYs to be considered cost-effective, PBT would have to cost at most £4812 more than VMAT for current smokers and £645 more for never smokers. This is below preliminary National Health Service cost estimates of PBT over photon radiotherapy. CONCLUSION: In a UK setting, PBT for ISHL may not be considered cost-effective. However, the degree of unquantifiable uncertainty is substantial.

Association of Radiation and Procarbazine Dose With Risk of Colorectal Cancer Among Survivors of Hodgkin Lymphoma.

Importance: Hodgkin lymphoma (HL) survivors have higher rates of colorectal cancer, which may be associated with subdiaphragmatic radiation therapy and/or alkylating chemotherapy. Although radiation dose-response associations with breast, lung, stomach, pancreatic, and esophageal cancer after HL have been demonstrated, the association of radiation therapy with colorectal cancer remains unclear. Objective: To quantify the rate of colorectal cancer according to radiation dose to the large bowel and procarbazine dose among HL survivors. Design, Setting, and Participants: A nested case-control study examined 5-year HL survivors at 5 hospital centers in the Netherlands. Participants had been diagnosed with HL in 1964 to 2000, when they were 15 to 50 years of age, and were followed for a median of approximately 26 years. Survivors of HL who developed colorectal cancer and survivors who were selected as controls were individually matched on sex, age at HL diagnosis, and date of HL diagnosis. Data were analyzed from July 2021 to October 2022. Exposures: Mean radiation doses to the large bowel were estimated by reconstructing individual radiation therapy treatments on representative computed tomography data sets. Main Outcomes and Measures: Excess rate ratios (ERRs) were modeled to evaluate the excess risk associated with each 1-gray increase in radiation dose, and potential effect modification by procarbazine was explored. Results: The study population included 316 participants (mean [SD] age at HL diagnosis, 33.0 [9.8] years; 221 [69.9%] men), 78 of whom were HL survivors who developed colorectal cancer (cases) and 238 who did not (controls). The median (IQR) interval between HL and colorectal cancer was 25.7 (18.2-31.6) years. Increased colorectal cancer rates were seen for patients who received subdiaphragmatic radiation therapy (rate ratio [RR], 2.4; 95% CI, 1.4-4.1) and those who received more than 8.4 g/m2 procarbazine (RR, 2.5; 95% CI, 1.3-5.0). Overall, colorectal cancer rate increased linearly with mean radiation dose to the whole large bowel and dose to the affected bowel segment. The association between radiation dose and colorectal cancer rate became stronger with increasing procarbazine dose: the ERR per gray to the whole bowel was 3.5% (95% CI, 0.4%-12.6%) for patients who did not receive procarbazine, and increased 1.2-fold (95% CI, 1.1-1.3) for each 1-g/m2 increase in procarbazine dose. Conclusions and Relevance: This nested case-control study of 5-year HL survivors found a dose-response association between radiation therapy and colorectal cancer risk, and modification of this association by procarbazine. These findings may enable individualized colorectal cancer risk estimations, identification of high-risk survivors for subsequent screening, and optimization of treatment strategies.