What Did the Pandemic Teach Us About Palliative Radiation in Head and Neck Cancer?

Aim: To assess the feasibility and efficacy of palliative radiotherapy dose regimens for patients with locally advanced head and neck cancer. Methods: Fifty patients of previously untreated, inoperable, stage IVA and IVB squamous cell carcinoma of the head and neck, deemed unfit for radical treatment, were included in the study from May 2020 to June 2020. Two palliative radiotherapy regimens were used. First was a single fraction radiation with 8 Gy for patients with limited life expectancy and poor performance status, which was repeated after 4 weeks in case of good symptom relief. The second regimen was used for patients with good performance status and consisted of fractionated radiation with 30 Gy in 10 fractions over 2 weeks, which was followed by supplementary radiation with 25 Gy in 10 fractions over 2 weeks in patients with good symptomatic response at 2 weeks. Symptoms were assessed at baseline and at the end of 4 weeks after treatment completion using the numerical rating score. Patients were followed up for a median of 4.5 months and assessed for symptom control and overall survival. Results: Forty-eight patients completed treatment and were included for analysis. Of the 24 patients who received single fraction radiation, 13 (54.2%) were given the second dose. Improvement in pain and dysphagia were reported in 57.9% and 60% patients, respectively. A total of 55.5% noted decrease in size of the neck node. Twenty-four patients received fractionated radiation and 15 (62.5%) were given the second course after 2 weeks. Relief in pain and dysphagia was reported in 68.2% and 63.6% patients, respectively. There were no grade 3/4 toxicities. Symptom control lasted for at least 3 months in 30% of the patients who received single fraction radiation and 54.2% of the patients who received fractionated radiation. The estimated 6-month overall survival of the entire cohort was 51.4%. Conclusion: Judicious use of palliative radiation in advanced incurable head and neck cancers provides effective and durable symptom relief and should be used after careful consideration of patient prognosis, logistics of treatment, and goals of care.

Dose-Response Effect and Dose-Toxicity in Stereotactic Radiotherapy for Brain Metastases: A Review

For more than two decades, stereotactic radiosurgery has been considered a cornerstone treatment for patients with limited brain metastases. Historically, radiosurgery in a single fraction has been the standard of care but recent technical advances have also enabled the delivery of hypofractionated stereotactic radiotherapy for dedicated situations. Only few studies have investigated the efficacy and toxicity profile of different hypofractionated schedules but, to date, the ideal dose and fractionation schedule still remains unknown. Moreover, the linear-quadratic model is being debated regarding high dose per fraction. Recent studies shown the radiation schedule is a critical factor in the immunomodulatory responses. The aim of this literature review was to discuss the dose–effect relation in brain metastases treated by stereotactic radiosurgery accounting for fractionation and technical considerations. Efficacy and toxicity data were analyzed in the light of recent published data. Only retrospective and heterogeneous data were available. We attempted to present the relevant data with caution. A BED10 of 40 to 50 Gy seems associated with a 12-month local control rate >70%. A BED10 of 50 to 60 Gy seems to achieve a 12-month local control rate at least of 80% at 12 months. In the brain metastases radiosurgery series, for single-fraction schedule, a V12 Gy < 5 to 10 cc was associated to 7.1–22.5% radionecrosis rate. For three-fractions schedule, V18 Gy < 26–30 cc, V21 Gy < 21 cc and V23 Gy < 5–7 cc were associated with about 0–14% radionecrosis rate. For five-fractions schedule, V30 Gy < 10–30 cc, V 28.8 Gy < 3–7 cc and V25 Gy < 16 cc were associated with about 2–14% symptomatic radionecrosis rate. There are still no prospective trials comparing radiosurgery to fractionated stereotactic irradiation.

Do sustainable palliative single fraction radiotherapy practices proliferate or perish 2 years after a knowledge translation campaign?

BACKGROUND There is a paucity of data regarding the time-dependent effects of knowledge translation (KT) campaign derived Radiation Oncologist (RO) prescription behaviour. In early 2017, the XXXX and XXXX undertook a comprehensive KT campaign to improve utilization of single fraction radiotherapy (SFRT) over multiple fraction radiotherapy (MFRT) in accordance with clinical guidelines for palliative management of bone metastases. The campaign significantly increased short-term SFRT utilization. We assess the time-dependent effects of KT-derived SFRT utilization 12-24 months removed from the KT campaign in a Canadian Provincial Cancer Program. METHODS This retrospective, population-based cohort study identified all patients receiving palliative radiotherapy for bone metastases in XXXX from 1 Jan 2018 to 31 Dec 2018 using provincial radiotherapy databases. Baseline characteristics were tabulated by fractionation schedule. The proportion of patients treated with SFRT in 2018 was compared to 2017 levels overall and by prescribing RO. Logistic regression analyses identified risk factors associated with MFRT receipt. RESULTS In 2018, 1,008 patients received palliative radiotherapy for bone metastasis, of which 63.3% received SFRT, a small overall increase in SFRT use over 2017 (59.1%). However, 41.1% of ROs demonstrated year-over-year decreases in SFRT utilization, indicative of a time-dependent loss of SFRT prescription habits derived from KT. CONCLUSION Although SFRT use increased slightly overall in 2018, evidence of compliance fatigue was observed suggestive of a time-perishing property of RO prescription behaviours derived from KT methodologies. These findings highlight the need for additional longitudinal KT reinforcement practices in the years following KT campaigns.

Three-staged stereotactic radiosurgery for brain metastases: a single institution experience

Aims Stereotactic radiosurgery (SRS) using the Leksell Gamma Knife system is a commonly used modality for the treatment of brain metastases (BMs). As the size of the target volume (TV) increases, so too does the dose of radiation delivered to surrounding healthy tissue. Large BMs are therefore a contraindication to the use of SRS. Critical organs adjacent to the TV may also be a contraindication to SRS. Staged SRS was proposed as a novel method of delivering three SRS treatments at a reduced radiation dose with a gap of two weeks between each session as a way of shrinking the TV. This allows treatment of TVs otherwise considered untreatable with standard, single-fraction SRS. Little data exists in the literature as to its efficacy. The objective of this study was to evaluate the efficacy of this novel approach and to identify factors which may predict treatment failure. Method A retrospective analysis was undertaken at a single, tertiary Gamma Knife centre. All patients who underwent treatment of their BMs with three-staged Gamma Knife SRS from January 2014 to December 2020 were identified and included. Patient demographics and primary cancer status was ascertained. SRS treatment details for each lesion were collected, including TV, dose and dosimetric data. The percentage reduction in volume of the TVs between the first and second stage, the second and third stage and the first and third stage were calculated. Follow-up data was collected to include follow-up imaging, further intracranial treatments received and survival status. The percentage reduction in volume between each stage was demonstrated on box-and-whisker plots. Statistical significance in reduction in TV between each stage was ascertained by paired samples T-tests. Correlation between initial TV size and percentage reduction post-SRS was determined by a correlation coefficient. Differences were deemed significant with p-values &lt;0.05. Results 12 patients with 14 staged BMs were identified and included. The median age was 61.5 (range 45-79). Seven had a primary malignancy of breast cancer, five non-small cell lung cancer, one melanoma and one colorectal. Median follow-up was 140.5 days (range 10-821). Median TV was 7.44cc (range 1.14-21.53). All TVs received 10Gy at each stage. The median percentage reduction in size of the TV was 7.41% between 1st-2nd stage (range -16.0-42.49%, p-value 0.06), 19.47% between 2nd-3rd stage (range -5.38-53.53%, p-value &lt;0.01) and 24.25% between 1st-3rd stage (range 10.69-68.67%, p-value &lt;0.01). The correlation coefficient between initial TV size and percentage reduction post-SRS was -0.41 (p-value 0.07). 13/14 lesions showed a partial response on first follow-up scan post-SRS, 1/14 lesions showed a mixed response. One patient died 184 days from completion of treatment but without intracranial progression. Two patients had salvage intracranial surgery, 154 and 536 days from completion of treatment respectively. Conclusion Three-staged Gamma Knife is shown to be effective at shrinking the TV and can therefore be used to treat lesions otherwise considered unsuitable for SRS. The presence of extra-cranial metastases did not predict for poor outcomes. Though local control with SRS is thought to diminish with increasing TV size, all staged lesions showed a reduction in size between first and last treatment, and no significant effect was seen between initial TV size and percentage reduction in TV. No patients experienced disease progression on first follow up scan, with 13 of 14 lesions showing disease response. There were only two cases of intracranial progression, with one occurring 536 days post-SRS. Though limited by small numbers and short median follow up period, our data demonstrate encouraging results for three-stage SRS for lesions otherwise unsuitable for single fraction treatment, and should lead to further study.