As systemic therapies, alongside radiation, for cancer treatment continue to evolve, the radiation oncology community is facing an increasing number of reirradiation (re-RT) of tumor sites subject to recurrences. There are multiple factors associated with choosing re-RT as a treatment option for a previously irradiated site. The factors include the site of previous radiotherapy (RT), the current extent of the disease, the nature of recurrence, the technique used for previous irradiation, and the previous RT details including dose and dose fractionation. There is a persistent heterogeneity in the workflow and decision-making in cancer care centers worldwide. The current review is an attempt to dive into the practices of decision-making for re-RT, interdisciplinary attention given to the re-RT patients, and acceptable doses to the organ at risk (OAR) deduced from the understanding of previous RT and radiobiology of the tumor and sites evidence of better techniques for effective execution.

UNASSIGNED: Gastric cancer has a high prevalence in Asia and may only be diagnosed in advanced stages. Therefore, patients with gastric cancer may experience fatal symptoms, such as bleeding or stenosis at the time of consultation. In this review, we aimed to describe the effectiveness and toxicity of hemostatic radiotherapy (RT).
UNASSIGNED: A total of 17 retrospective and 3 prospective studies were analyzed. The prescription dose, biologically effective dose, equivalent dose in 2 Gy fractions, response rate, survival prognosis, and toxicities were also reported.
UNASSIGNED: Using 20 studies, the following observations were made the hemostatic effect was ∼ 80 %, the mean survival time after irradiation was about 3 months, and prescribed doses of 30 Gy/10 fractions and 20 Gy/5 fractions were considered suitable.
UNASSIGNED: In this review, studies on hemostatic irradiation have been summarized, and the most optimal treatment method has been proposed. 30 Gy/10 fractions and 20 Gy/5 fractions were ideal. However, because palliative RT is preferably completed within a short period of time, a randomized trial is needed to determine whether the 8 Gy/single fraction treatment is equivalent to fractionated RT. Therefore, more prospective studies are warranted to establish a standard of care for palliative RT in gastric cancer.

UNASSIGNED: Peer review is an important component of quality assurance in radiotherapy. To our knowledge, there are no studies reporting on the feasibility and outcomes of the peer review process for magnetic resonance (MR) guided radiotherapy (MRgRT) on the MR linear accelerator (MR-Linac) despite the planning complexity involved and its evolving clinical indications. This study aimed to quantify the rate of change in treatment plans post-peer review and the time and resources required.
UNASSIGNED: Fifty-five cases presented at weekly MR-Linac peer review meetings across two centres from 8 June to 21 September 2023 were prospectively collected. Cases were analysed to determine the rate and extent of plan changes based on the Peer Review Audit Tool for radiation oncology (PRAT) developed by the Royal Australian and New Zealand College of Radiologists (RANZCR).
UNASSIGNED: Peer review resulted in changes to 36.4 % of treatment plans (n = 20), with 3.6 % (n = 2) having major changes requiring deferment of treatment. The most frequent changes were to organs at risk (OAR) volumes involving both delineation and increased OAR sparing (16.4 %, n = 9), total dose and fractionation (10.9 %, n = 6) and target volume dose coverage (5.5 %, n = 3). Patients with SBRT plans (39.1 % cf 22.2 %), oligometastatic/oligoprogressive sites (38.1 % cf 30.7 %) and reirradiation cases (41.2 % cf 34.2 %) had higher rates of change. Cases took a mean of 7 min (range 2-15 minutes) to discuss.
UNASSIGNED: The high rates of plan changes support the value of peer review in MRgRT. We recommend, where possible that all MRgRT cases, particularly those involving SBRT plans, oligometastatic/oligoprogressive sites, and/or reirradiation, be subject to peer review.

OBJECTIVE: Patients with recurrent squamous cell carcinoma of the head and neck (HNSCC) have a poor prognosis and limited therapeutic alternatives. While reirradiation is feasible, it is usually associated with high treatment toxicity and is not yet considered the standard of care. Based on current NCCN guidelines, in the context of very advanced head and neck cancer (recurrent and/or persistent disease), surgical intervention is explored initially with/without adjuvants while unresectable disease is approached with radiation and/or systemic therapies. Specific and reliable prognostic indicators for both -oncologic and functional outcomes- have yet to be defined for this population.
METHODS: Retrospective chart review of 54 patients treated with reirradiation at a tertiary academic institution between January of 1998 and January of 2024. Only patients with non-metastatic recurrent, and second primary HNSCC were included in the series. Demographics, staging, radiation dose and technique, additional therapy, histopathologic variables, EORTC toxicity, pre- and post-treatment PEG/tracheotomy dependency and oncologic outcomes were retrieved.
RESULTS: The study cohort consisted of 54 patients (37 males, 17 females) with HNSCC, averaging 62.7 years in age. Initial tumors were locally advanced in over 42 % of cases, with 58 % being node-negative. The head and cutaneous regions (24.5 %) and tongue (20.8 %) were the most common tumor sites. Primary surgical resection and adjuvant radiation were performed in 47.2 % of cases, and concurrent chemotherapy was used in 40.7 %. Reirradiation was mainly for local or regional recurrence (88.9 %), often following salvage surgery (68.5 %), with a mean dose of 5623 Gy over 52.5 fractions. Positive surgical margins were present in 29.4 % of cases, and extracapsular spread in 59.5 %. No significant differences were found between the salvage surgery and definitive reirradiation groups except for tumor site (P = 0.022). Median follow-up was 52.6 months, with 27 deaths reported. Lymphovascular invasion was significantly correlated with overall survival (P = 0.017), while initial tumor T-stage and neck disease involvement were linked to local-regional control (P = 0.030 and P = 0.033, respectively). Reirradiation increased tracheotomy and PEG-tube dependency by 20 % (P = 0.011) and 23 % (P = 0.003), respectively.
CONCLUSIONS: Reirradiation is a feasible therapeutic alternative in recurrent head and neck SCC. Oncologic outcomes observed in this series compare favorably to most published reports. Complete response and perineural invasion were independent prognostic factors for survival and locoregional control. While no mortality directly associated with treatment was observed in this series, reirradiation had a significant impact in functional outcomes in terms of increased risk of tracheotomy and peg tube dependency. Further studies are required to define the role of this treatment in head and neck cancer.

Re-irradiation with intensity-modulated radiotherapy (IMRT) remains the primary treatment modality for inoperable locally recurrent nasopharyngeal carcinoma (NPC). However, the rate of radiation-related late adverse effects is often substantially high. Therefore, we aimed to explore failure patterns and individualized treatment plans of re-irradiation for inoperable locally recurrent NPC. Ninety-seven patients who underwent IMRT were retrospectively analyzed. Sixty-two patients had clinical target volume of recurrence (rCTV) delineated, and thirty-five patients had only gross tumor volume of recurrence (rGTV) delineated. Twenty-nine patients developed second local failures after re-irradiation with IMRT (28 cases available). Among those patients, 64.3% (18/28) of patients and 35.7% (10/28) developed in-field or out-field, respectively. No statistical correlation was observed between target volume (rGTV or rCTV) and the local recurrence rate, local failure patterns, grade ≥ 3 toxicity, and survival. Multivariate analysis showed that recurrent T (rT) stage (HR 2.62, P = 0.019) and rGTV volume (HR 1.73, P = 0.037) were independent prognostic factors for overall survival (OS). Risk stratification based on rT stage and rGTV volume revealed that low risk group had a longer 3-year OS rate (66.7% vs. 23.4%), lower total grade ≥ 3 toxicity (P = 0.004), and lower re-radiation associated mortality rates (HR 0.45, P = 0.03) than high risk group. This study demonstrates that the delineation of rCTV may not be beneficial for re-irradiation using IMRT in locally recurrent NPC. Patients with low risk were most suitable for re-irradiation, with maximizing local salvage and minimizing radiation-related toxicities. More precise and individualized plans of re-irradiation are warranted.

OBJECTIVE: to evaluate the outcome of partial breast re-irradiation (re-PBI) with intensity modulated RT (IMRT), using a hypofractionated scheme for breast cancer (BC) local recurrence (LR) operated on with repeat breast-conserving surgery (re-BCS).
METHODS: IMRT-based re-PBI was performed using either helical or step-and-shoot modality to deliver 37.05 Gy in 13 fractions in 2.5 weeks. Cumulative incidence (CumI) of 2ndLR, toxicity, disease-free (DFS), BC specific (BCSS), and overall (OS) survival were evaluated.
RESULTS: Between 5/2012 and 5/2021, 70 patients had re-PBI. Median follow-up (FU) was 6.3 years (Q1-Q3, 4.0-8.1.). Median age at 1stLR was 62. The median primary BC-1stLR interval was 12.4 years (range: 1.6-26.7). Luminal A-like 1stLR accounted for 41% of the cases and median size was 0.8 cm. During FU, 18 (26%) patients showed a subsequent event: three 2snLRs (corresponding to 8-y Cumulative rate of 4%), 3 regional nodal recurrences, 7 distant metastases, and 5 other primary tumors. At 8 years, DFS, BCSS and OS were 76%, 90%, and 90%, respectively. At multivariate analysis, Grade 3 and extensive intraductal component were independent predictors for DFS. For 51 and 46 patients, chronic toxicity and cosmesis were evaluated, respectively: 4% had grade 3 fibrosis and cosmesis was deemed good/excellent in just over 60% of the cases.
CONCLUSIONS: Re-PBI after re-BCS represents a feasible alternative to mastectomy with regard to local control, showing an acceptable toxicity profile. A long-term FU is crucial to better understand the pattern of relapse and consolidate the position of re-PBI in clinical practice.

OBJECTIVE: High grade glioma (HGG) is considered a lethal disease with a high recurrence rate. There is no standard of care in recurrent HGG. Many treatment options are present, such as resurgery, systemic therapy, and re-irradiation. Re-irradiation seems to be a promising option. In this study, we aimed at comparing the efficacy and toxicity of two re-irradiation protocols.
METHODS: Forty patients with recurrent HGG were randomized equally into two arms. Arm A received 30 Gy/10f/2w, and arm B received stereotactic body radiotherapy (SBRT) 30 Gy/5f/1w. Concurrent temozolamide (TMZ) was given in both arms. Median progression free survival (PFS) and overall survival (OS) were calculated, and brain MRI was done after 2 months of radiotherapy and then every 2 months, with documented toxicity using the Common Terminology of Adverse Events version 5 (CTCAE).
RESULTS: The median follow-up time after the re-irradiation course was 11 months (range 8-15 months). The median PFS after recurrence was 6.4 months (95% CI 5.3-7.4), the median OS after recurrence was 8.6 months (95% CI 7.5-8.7), and the median total OS form date of diagnosis was 18.5 months (95% CI 17.3-19.8) among the included patients. There was a statistically significant difference in PFS favoring arm B, with a median PFS of 7.3 versus 6.2 months in arm A, with p values of 0.004. There was no statistically significant difference in in median OS (9.3 months in arm B versus 8.4 months in arm A) with p values of 0.088. All patients tolerated their treatment well, and acute and subacute G1-G2 toxicity, consisting of headache, malaise, and nausea, were recorded during and shortly after the end of the re-irradiation course.
CONCLUSIONS: Re-irradiation in recurrent HGG by both protocols is safe and effective, with a significant improvement in PFS in SBRT arm but no significant improvement in OS.

OBJECTIVE: Recurrent head and neck cancer poses difficult management. Even after salvage surgery, many patients are considered high-risk for further recurrence and benefit from reirradiation, despite the sequelae such as chronic wounds, tissue necrosis, osteoradionecrosis and vascular damage associated with re-irradiation. Free flaps not only enable the reconstruction following salvage surgery, but there has been limited studies suggesting that free flap reconstruction may reduce the amount of reirradiation complications. However, there are no studies to date specifically examining the effects of osteocutaneous free flap reconstruction upon reirradiation outcomes.
METHODS: In this retrospective study, patients with recurrent head and neck cancer that had a history of prior head and neck radiation who underwent salvage surgery with osteocutaneous free flaps followed by reirradiation were identified. Descriptive statistics were performed to assess outcomes.
RESULTS: Five patients met criteria. Complications included chronic wound infection in one patient, fistula in one patient, plate exposure in two patients and plate removal in one patient. No patients had osteoradionecrosis or carotid rupture after reirradiation. There was an association between complications and further local disease recurrence. All patients were tube feed dependent at their most recent follow-up and two patients were tracheostomy dependent 12 months post-irradiation. Two patients had disease recurrence. Median overall survival was 16 months after reirradiation.
CONCLUSIONS: Osteocutaneous free flap surgery with reirradiation may result in high rates of complications and low functional status with an equivocal improvement in survival. Larger studies are needed to substantiate these findings and assess the risk-benefit analysis.

Reirradiation in recurrent head and neck cancer presents a considerable clinical challenge in radiation oncology. Though technically feasible due to advanced treatment delivery and planning techniques, confidence in delivering such treatments is not universal and patient selection is critical. Radiotherapy planning in reirradiation cases presents a complex technical challenge owing to the often-considerable overlap of dose from a patient\'s first treatment plan. This technical note describes three clinical case studies of recurrent head and neck cancer and the technical details of how their multidose level reirradiation was planned. Each patient had confirmed recurrence of squamous cell carcinoma and was referred for reirradiation to a previously irradiated area. The clinical details for each patient are provided before a detailed description of the treatment planning methodology is presented, which specifies how to approach such complex overlapping treatment volumes. The patient outcomes are described and a discussion is presented outlining the clinical challenges associated with these cases and the variables that must be accounted for when considering patients for potential reirradiation.

OBJECTIVE: Breast-conserving surgery followed by reirradiation for a localized ipsilateral breast tumour relapse may increase the radiation dose delivered to the heart and result in a greater risk of cardiac adverse events. This study aimed to compare the incidence of cardiac mortality in patients treated for a localized ipsilateral breast tumour relapse, either with breast-conserving surgery followed by reirradiation or with total mastectomy between 2000 and 2020.
METHODS: All patients treated for a primary non-metastatic breast cancer with breast-conserving surgery and adjuvant radiotherapy were identified in the Surveillance, Epidemiology, and End Results (SEER) program database, and those who subsequently experienced a localized ipsilateral breast tumour relapse treated with breast-conserving surgery and reirradiation (\"BCS+ReRT\" group, n=239) or with total mastectomy (\"TM\" group, n=3127) were included. The primary objective was to compare the cardiac mortality rate between the patients who underwent breast-conserving surgery followed by reirradiation and total mastectomy. Secondary endpoints were overall survival and cancer specific survival.
RESULTS: Cardiac mortality was significantly higher in patients treated with breast-conserving surgery followed by reirradiation (hazard ratio [HR]: 2.40, 95% confidence interval [95% CI]: 1.19-4.86, P=0.006) in univariate analysis; non-statistically significant differences were observed after adjusting for age, laterality and chemotherapy on multivariate analysis (HR: 1.96, 95% CI: 0.96-3.94, P=0.067), age being the only confounding factor. A non-statistically significant difference towards lower overall survival was observed in patients who had breast-conserving surgery followed by reirradiation compared with those who underwent total mastectomy (HR: 1.37, 95% CI: 0.98-1.90, P=0.066), and no differences were observed in terms of cancer specific survival (HR: 1.01, 95% CI: 0.56-1.82, P=0.965).
CONCLUSIONS: In this study, the incidence of cardiac mortality was low, and breast-conserving surgery followed by reirradiation did not independently increased the risk of cardiac mortality for a localized ipsilateral breast tumour relapse.