Perianal/perineal rhabdomyosarcoma: Results of the SIOP MMT 95, Italian RMS 96, and EpSSG RMS 2005 studies

Brachytherapy for rhabdomyosarcoma: Survey of international clinical practice and development of guidelines

BACKGROUND AND PURPOSE

The purpose of this study was to address the lack of published data on the use of brachytherapy in pediatric rhabdomyosarcoma by describing current practice as starting point to develop consensus guidelines.

MATERIALS AND METHODS

An international expert panel on the treatment of pediatric rhabdomyosarcoma comprising 24 (pediatric) radiation oncologists, brachytherapists and pediatric surgeons met for a Brachytherapy Workshop hosted by the European paediatric Soft tissue Sarcoma Study Group (EpSSG). The panel's clinical experience, the results of a previously distributed questionnaire, and a review of the literature were presented.

RESULTS

The survey indicated the most common use of brachytherapy to be in combination with tumor resection, followed by brachytherapy as sole local therapy modality. HDR was increasingly deployed in pediatric practice, especially for genitourinary sites. Brachytherapy planning was mostly by 3D imaging based on CT. Recommendations for patient selection, treatment requirements, implant technique, delineation, dose prescription, dose reporting and clinical management were defined.

CONCLUSIONS

Consensus guidelines for the use of brachytherapy in pediatric rhabdomyosarcoma have been developed through multicenter collaboration establishing the basis for future work. These have been adopted for the open EpSSG overarching study for children and adults with Frontline and Relapsed RhabdoMyoSarcoma (FaR-RMS).

Perianal rhabdomyosarcoma in an adult: A case report and review of the literature

Perianal/perineal rhabdomyosarcomas (PRMS) is rare, and the outcome is poor. A 29-year-old female presented with perineal rhabdomyosarcomas revealed metastases to inguinal lymph nodes on the bilateral side. Disease progression was discovered when the patient got adjuvant epirubicin, ifosfamide, and bevacizumab for 2 cycles. After 3 cycles of nivolumab, dacarbazine, cisplatin, and vinblastine therapy, a partial response was identified in the patient. The surgical resection was performed. The patient received neoadjuvant chemotherapy before surgery and was weak after surgery, so he did not receive chemoradiotherapy. The patient succumbed after 11 months postoperatively due to widespread intraabdominal metastasis.

Critical elements of pediatric rhabdomyosarcoma surgery

Rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children, requires multimodal therapy which is determined by risk group stratification. Local control may be achieved by surgical resection, radiation, or both. Resection may occur upfront or following induction chemotherapy as a delayed primary excision. An R1 resection may allow a reduction in radiation exposure; however, debulking is not indicated nor is excision of residual masses at the end of therapy. Regional lymph node assessment is an important component of surgical care, as positive nodal basins require radiation. Depending on the tumor site and biology, sentinel lymph node biopsy vs biopsy of clinically or radiographically concerning nodes is indicated. Therapeutic lymph node dissection is never indicated. Familiarity with site-specific oncologic principles for RMS and participation in a multidisciplinary team including Pediatric Oncology and Radiation Oncology are necessary components of surgical care to ensure optimal outcomes.

Increasing Patient Safety and Treatment Quality by Using Intraoperative MRI for Organ-Preserving Tumor Resection and High-Dose Rate Brachytherapy in Children with Bladder/Prostate and Perianal Rhabdomyosarcoma

In children with bladder/prostate (BP) and perianal rhabdomyosarcoma (RMS), we use a hybrid treatment concept for those suitable, combining organ-preserving tumor resection and high-dose rate brachytherapy (HDR-BT). This treatment concept has been shown to improve outcomes. However, it is associated with specific challenges for the clinicians. The exact position of the tubes for BT is a prerequisite for precise radiotherapy. It can finally be determined only with an MRI or CT scan. We evaluated the use of an intraoperative MRI (iMRI) to control the position of the BT tubes and for radiotherapy planning in all patients with BP and perianal RMS who received the above-mentioned combination therapy in our department since January 2021. iMRI was used in 12 children. All tubes were clearly localized. No adverse events occurred. In all 12 children, radiotherapy could be started on time. In a historical cohort without iMRI, this was not possible in 3 out of 20 children. The use of iMRI in children with BP and perianal RMS improved patient safety and treatment quality. This technology has proven to be successful for the patient population we have defined and has become a standard procedure in our institution.

Developments in the Surgical Approach to Staging and Resection of Rhabdomyosarcoma

Although survival after rhabdosarcoma treatment has improved over the years, one third of patients still develop locoregional relapse. This review aims to highlight developments pertaining to staging and local treatment of specific RMS tumor sites, including head and neck, chest/trunk, bladder-prostate, female genito-urinary, perianal, and extremity sites.