The Role of Simultaneous Integrated Boost in Locally Advanced Rectal Cancer Patients with Positive Lateral Pelvic Lymph Nodes

Elisa Meldolesi; Giuditta Chiloiro; Roberta Giannini; Roberta Menghi; Roberto Persiani; Barbara Corvari; Claudio Coco; Stefania Manfrida; Carlo Ratto; Viola De Luca; Luigi Sofo; Sara Reina; Antonio Crucitti; Valeria Masiello; Nicola Dinapoli; Vincenzo Valentini; Maria Antonietta Gambacorta

doi:10.3390/cancers14071643

The Role of Simultaneous Integrated Boost in Locally Advanced Rectal Cancer Patients with Positive Lateral Pelvic Lymph Nodes

Cancers (Basel). 2022 Mar 24;14(7):1643. doi: 10.3390/cancers14071643.

Authors

Elisa Meldolesi¹, Giuditta Chiloiro¹, Roberta Giannini¹, Roberta Menghi², Roberto Persiani², Barbara Corvari¹, Claudio Coco², Stefania Manfrida¹, Carlo Ratto², Viola De Luca¹, Luigi Sofo², Sara Reina¹, Antonio Crucitti², Valeria Masiello¹, Nicola Dinapoli¹, Vincenzo Valentini¹, Maria Antonietta Gambacorta¹

Affiliations

¹ Department of Radiology, Radiation Oncology and Hematology, Catholic University of the Sacred Heart, Agostino Gemelli University Hospital Foundation IRCCS, 00168 Roma, Italy.
² Digestive Surgery Unit, Catholic University of the Sacred Heart, Agostino Gemelli University Hospital Foundation IRCCS, 00168 Rome, Italy.

Abstract

Aims: Between 11 to 14% of patients with locally advanced rectal cancer (LARC) have positive lateral pelvic lymph nodes (LPLN) at diagnosis, related to a worse prognosis with a 5-year survival rate between 30 to 40%. The best treatment choice for this group of patients is still a challenge. The optimal radiotherapy (RT) dose for LPLN patients has been investigated. Methods: We retrospectively collected data from LARC patients with LPLN at the primary staging MRI, treated in our center from March 2003 to December 2020. Patients underwent a neoadjuvant concomitant chemo-radiotherapy (CRT) treatment on the primary tumor (T), mesorectum, and pelvic nodes, associated with a fluoride-based chemotherapy. The total reached dose was 45 Gy at 1.8 Gy/fr on the elective sites and 55 Gy at 2.2 Gy/fr on the disease and mesorectum. Patients were divided in two groups based on whether they received a simultaneous integrated RT boost on the LPLN or not. Overall Survival (OS), Disease Free Survival (DFS), Metastasis Free Survival (MFS), and Local Control (LC) were evaluated in the whole group and then compared between the two groups. Results: A total of 176 patients were evaluated: 82 were included in the RT boost group and 94 in the non-RT boost group. The median follow-up period was 57.8 months. All the clinical endpoint (OS, DFS, MFS, LC), resulted were affected by the simultaneous integrated boost on LPLN with a survival rate of 84.7%, 79.5%, 84.1%, and 92%, respectively, in the entire population. From the comparison of the two groups, there was a statistical significance towards the RT boost group with a p < 0.006, 0.030, 0.042, 0.026, respectively. Conclusions: Concomitant radiotherapy boost on positive LPLN has shown to be beneficial on the survival outcomes (OS, DFS, MFR, and LC) in patients with LARC and LPLN. This analysis demonstrates that a higher dose of radiotherapy on positive pelvic lymph nodes led not only to a higher local control but also to a better survival rate. These results, if validated by future prospective studies, can bring a valid alternative to the surgery dissection without the important side effects and permanent disabilities observed during the years.

Keywords: chemoradiotherapy; lateral pelvic positive nodes; locally advanced rectal cancer; radiotherapy; simultaneous integrated boost.