An open-source development based on photogrammetry for a real-time IORT treatment planning system.

PURPOSE: This study presents a treatment planning system for intraoperative low-energy photon radiotherapy based on photogrammetry from real images of the surgical site taken in the operating room. MATERIAL AND METHODS: The study population comprised 15 patients with soft-tissue sarcoma. The system obtains the images of the area to be irradiated with a smartphone or tablet, so that the absorbed doses in the tissue can be calculated from the reconstruction without the need for computed tomography. The system was commissioned using 3D printing of the reconstructions of the tumor beds. The absorbed doses at various points were verified using radiochromic films that were suitably calibrated for the corresponding energy and beam quality. RESULTS: The average reconstruction time of the 3D model from the video sequence in the 15 patients was 229,6±7,0 s. The entire procedure, including video capture, reconstruction, planning, and dose calculation was 520,6±39,9 s. Absorbed doses were measured on the 3D printed model with radiochromic film, the differences between these measurements and those calculated by the treatment planning system were 1.4% at the applicator surface, 2.6% at 1 cm, 3.9% at 2 cm and 6.2% at 3 cm. CONCLUSIONS: The study shows a photogrammetry-based low-energy photon IORT planning system, capable of obtaining real-time images inside the operating room, immediately after removal of the tumor and immediately before irradiation. The system was commissioned with radiochromic films measurements in 3D-printed model.

Radioterapia intraoperatoria en cáncer de mama precoz: análisis observacional frente a radioterapia externa / Intraoperative radiotherapy in early breast cancer: observational comparison with whole breast radiotherapy

INTRODUCCIÓN: Una única dosis de radioterapia intraoperatoria (IORT) en cáncer de mama precoz (EBC) puede ser una opción frente a la radioterapia externa estándar (WBRT). Sin embargo, no existe consenso sobre su uso y resultados. OBJETIVO: Analizar la morbilidad y resultados oncológicos de la IORT como monoterapia en el tratamiento del EBC. MÉTODOS: Se realiza un estudio analítico observacional unicéntrico, comparando una cohorte prospectiva IORT (2015-17) con una cohorte retrospectiva WBRT (2012-17). Los criterios de selección aplicados son: ≥ 45 años de edad, carcinoma ductal infiltrante o variantes, tamaño tumoral radiológico ≤ 3 cm, receptores estrogénicos positivos, HER2 negativo, cN0; criterios de exclusión: invasión linfovascular, multicentricidad/multifocalidad, mutaciones BRCA y tratamiento neoadyuvante. Se valoran características clínicas, tumorales, quirúrgicas, oncológicas y complicaciones. RESULTADOS: Se estudiaron 425 casos: 217 tratados con IORT y 208 con WBRT. La edad media en IORT y WBRT fue 67 ± 9,5 y 64,8 ± 9,9 años, respectivamente (p = 0,01). El riesgo ASA 3 en IORT fue 17,7%, frente a 24 casos de WBRT (p = 0,027). No hubo diferencias en resultados anatomopatológicos o estadificación. El seguimiento medio de IORT fue 24,4 ± 8 meses, frente a 50,5 ± 18 meses de WBRT (p < 0,001). No se hallaron diferencias significativas en recidiva local, metástasis o mortalidad. Las complicaciones que precisaron reintervención u hospitalización resultaron equiparables. La radiodermitis precoz grave se presentó en tres casos IORT frente a 14 casos WBRT (p = 0,01). CONCLUSIONES: La IORT como monoterapia en pacientes seleccionadas con EBC representa una opción alternativa frente a WBRT, especialmente en aquellas con edad avanzada y comorbilidades. Se asocia, además, con menos radiodermitis precoz grave

INTRODUCTION: In early breast cancer (EBC), a single dose of intraoperative radiotherapy (IORT) might be an option to standard whole breast radiotherapy (WBRT). However, there is no consensus about its use and clinical results. AIM: to analyse the morbidity and oncological outcomes of IORT as monotherapy in EBC. METHODS: A single centre observational analytic study was performed. A prospective IORT cohort (2015-17) and a retrospective WBRT cohort (2012-17) were selected following the same criteria: ≥ 45 y.o., invasive ductal carcinoma or variants, radiological tumour size ≤ 3 cm, positive oestrogenic receptors, negative HER2, cN0; exclusion criteria: lymphovascular invasion, multicentricity/multifocality, BRCA mutation and neoadjuvant therapy. Clinical, histological, surgical, oncological characteristics and complications were collected. RESULTS: A total of 425 cases were selected: 217 in IORT cohort and 208 in WBRT cohort. Average age in IORT and WBRT groups was 67±9.5 and 64.8 ± 9.9 y.o. respectively (p = 0.01). ASA 3 risk score patients were 17.7% in IORT and 24 cases in WBRT (p = 0.027). There were no differences in histological results or tumoral stage. Average follow up was 24.4 ± 8 months in IORT and 50.5 ± 18 months in WBRT (p < 0.001). No differences were detected in local recurrence, metastases or mortality. Complications that required reintervention or hospitalization were similar in both groups. A total of 3 and 14 cases developed early severe dermatitis in IORT and WBRT groups respectively (p = 0.01). CONCLUSION: IORT as monotherapy in selected patients with EBC stands for an alternative option versus WBRT. It seems especially useful in advanced-age patients with severe comorbidities. IORT associates lesser early severe dermatitis

Intraoperative radiotherapy in early breast cancer: observational comparison with whole breast radiotherapy. / Radioterapia intraoperatoria en cáncer de mama precoz: análisis observacional frente a radioterapia externa.

INTRODUCTION: In early breast cancer (EBC), a single dose of intraoperative radiotherapy (IORT) might be an option to standard whole breast radiotherapy (WBRT). However, there is no consensus about its use and clinical results. AIM: to analyse the morbidity and oncological outcomes of IORT as monotherapy in EBC. METHODS: A single centre observational analytic study was performed. A prospective IORT cohort (2015-17) and a retrospective WBRT cohort (2012-17) were selected following the same criteria: ≥ 45 y.o., invasive ductal carcinoma or variants, radiological tumour size ≤ 3 cm, positive oestrogenic receptors, negative HER2, cN0; exclusion criteria: lymphovascular invasion, multicentricity/multifocality, BRCA mutation and neoadjuvant therapy. Clinical, histological, surgical, oncological characteristics and complications were collected. RESULTS: A total of 425 cases were selected: 217 in IORT cohort and 208 in WBRT cohort. Average age in IORT and WBRT groups was 67±9.5 and 64.8 ± 9.9 y.o. respectively (p = 0.01). ASA 3 risk score patients were 17.7% in IORT and 24 cases in WBRT (p = 0.027). There were no differences in histological results or tumoral stage. Average follow up was 24.4 ± 8 months in IORT and 50.5 ± 18 months in WBRT (p < 0.001). No differences were detected in local recurrence, metastases or mortality. Complications that required reintervention or hospitalization were similar in both groups. A total of 3 and 14 cases developed early severe dermatitis in IORT and WBRT groups respectively (p = 0.01). CONCLUSION: IORT as monotherapy in selected patients with EBC stands for an alternative option versus WBRT. It seems especially useful in advanced-age patients with severe comorbidities. IORT associates lesser early severe dermatitis.

Treatment of cervical cancer with electronic brachytherapy.

PURPOSE: We report the first cervical cancer cases treated with interstitial electronic brachytherapy (eBT) at our hospital and compare them with plans made with high-dose-rate interstitial brachytherapy based on Ir192 (HDR-BT). MATERIALS AND METHODS: Eight patients with cervical cancer were treated with the Axxent eBT device (Xoft, Inc.). Planning was with magnetic resonance imaging and computed tomography following the recommendations of the EMBRACE protocol. The dosimetry parameters of organs at risk (OAR) were evaluated for the bladder, rectum, and sigmoid colon (D2cc, D1cc, and D0.1cc). In addition, the V150 and V200 of irradiated tissue were compared for both eBT and HDR-BT. All patients received intensity-modulated external beam radiation therapy with a regimen of 23 sessions of 2 Gy followed by four sessions of 7 Gy of eBT performed over 2 weeks (two sessions followed by another two sessions a week later) following the EMBRACE recommendations. Each of the eight patients was followed to assess acute toxicity associated with treatment. RESULTS: The doses reaching OAR for eBT plans were lower than for HDR-BT plans. As for acute toxicity associated with eBT, very few cases of mucositis were detected. No cases of rectal toxicity and one case with grade 1 urinary toxicity were detected. The results at 1 month are equally good, and no relapses have occurred to date. CONCLUSIONS: The first results of treatment with the Axxent eBT device are promising, as no recurrences have been observed and toxicity is very low. eBT is a good alternative for treating cervical cancer in centers without access to conventional HDR.