Modified simultaneous integrated boost radiotherapy for large retroperitoneal malignant tumor: A case report

Area of Science:

• Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Retroperitoneal tumors present significant treatment challenges due to their size and location.
• Large, poorly-differentiated adenocarcinomas often have a poor prognosis, especially when surgery is contraindicated.
• Simultaneous integrated boost (SIB) radiotherapy offers dose escalation to the target while sparing surrounding tissues.

Purpose of the Study:

• To report the successful management of a large retroperitoneal adenocarcinoma using modified simultaneous integrated boost (SIB) radiotherapy.
• To evaluate the efficacy and safety of this radiotherapy technique in a patient with a radioresistant tumor and poor physical condition.
• To assess long-term outcomes, including recurrence-free survival and complications.

Main Methods:

• A 45-year-old female with a 12×16×16 cm retroperitoneal adenocarcinoma underwent modified SIB radiotherapy.
• The radiotherapy regimen delivered approximately 96 Gy to the tumor core and <60 Gy to surrounding tissues over 33 fractions.
• Following radiotherapy, residual tumor was surgically resected.

Main Results:

• Radiotherapy resulted in an 80% reduction in tumor volume.
• Surgical resection of the residual tumor confirmed a complete pathological response.
• The patient remained recurrence-free for over 3 years without complications.

Conclusions:

• Modified SIB radiotherapy is a safe and effective treatment for large retroperitoneal adenocarcinomas, even in radioresistant cases.
• This technique can achieve favorable outcomes, including complete pathological response and long-term disease control.
• SIB radiotherapy, combined with surgical resection, offers a viable treatment option when surgery is not initially feasible.