ABSTRACT
Background and purpose: This study assessed quality of life (QoL) and clinical outcomes in rectal cancer patients treated with magnetic resonance (MR) guided short-course radiation therapy (SCRT) on a 1.5 Tesla (T) MR-Linac during the first 12 months after treatment. Materials and methods: Rectal cancer patients treated with 25 Gy SCRT in five fractions with curative intent in the Netherlands (2019-2022) were identified in MOMENTUM (NCT04075305). Toxicity (CTCAE v5) and QoL (EORTC QLQ-C30 and -CR29) was primarily analyzed in patients without metastatic disease (M0) and no other therapies after SCRT. Patients who underwent tumor resection were censored from surgery. A generalized linear mixed-model was used to investigate clinically meaningful (≥10) and significant (P < 0.05) QoL changes. Clinical and pathological complete response (cCR and pCR) rates were calculated in patients in whom response was documented. Results: A total of 172 patients were included, of whom 112 patients were primarily analyzed. Acute and late radiation-induced high-grade toxicity were reported in one patient, respectively. CCR was observed in 8/64 patients (13 %), 14/37 patients (38 %) and 13/16 patients (91 %) at three, six and twelve months; pCR was observed in 3/69 (4 %) patients. After 12 months, diarrhea (mean difference [MD] -17.4 [95 % confidence interval [CI] -31.2 to -3.7]), blood and mucus in stool (MD -31.1 [95 % CI -46.4 to -15.8]), and anxiety (MD -22.4 [95 % CI -34.0 to -10.9]) were improved. Conclusion: High-field MR-guided SCRT for the treatment of patients with rectal cancer is associated with improved disease-related symptom management and functioning one year after treatment.
ABSTRACT
In early-stage breast cancer and DCIS patients, breast-conserving therapy is today's standard of care. The purpose of this study was to evaluate the relation between the microscopic tumor diameter (mTD), the excised specimen (ES) volume, and the irradiated postoperative complex (POC) volume, in patients treated with breast-conserving therapy. In 186 patients with pTis-2N0 breast cancer, the mTDs, ES, and POC volumes (as delineated on the radiotherapy-planning CT scan), were retrospectively determined. Linear regression analysis was performed to study the association between the mTD, and the ES and POC volumes. The explained variance (r (2)) was calculated to establish the proportion of variation in the outcome variable that could be explained by the determinant (P ≤ 0.05). Moreover, the influence of tumor characteristics, age, surgical procedures, and breast size was studied. Median mTD was 1.2 cm (range 0.1-3.6 cm), median ES volume was 60 cm(3) (range 6-230 cm(3)) and median POC volume was 15 cm(3) (range 0.5-374 cm(3)). The POC was not clearly visible on the majority of the CT scans, based on a median assigned cavity visualization score of 3 (range 1-5). The explained variance for the mTD on the ES volume was low (r(2) = 0.08, P < 0.001). A slightly stronger association was observed in palpable tumors (r(2) = 0.23, P < 0.001) and invasive lobular carcinomas (r(2) = 0.39, P = 0.01). Furthermore, weak associations were observed between POC volume and mTD (r(2) = 0.04, P = 0.01), and POC and ES volume (r(2) = 0.23, P < 0.001). A weak association was observed between breast volume and ES volume (r(2) = 0.27, P < 0.001). In conclusion, both the excised and the irradiated POC volumes did not show a clinically relevant association with the mTD in women with early-stage breast cancer treated with breast-conserving therapy. Future studies should focus on improvement of surgical localization, development of image-guided, minimally invasive operation techniques, and more accurate image-guided target volume delineation in radiotherapy.