Efficacy of phosphorus-32 brachytherapy without external-beam radiation for long-term tumor control in patients with craniopharyngioma

Abstract

<jats:sec> <jats:title>OBJECT</jats:title> <jats:p>Radioactive phosphorus-32 (P32) has been used as brachytherapy for craniopharyngiomas with the hope of providing local control of enlarging tumor cysts. Brachytherapy has commonly been used as an adjunct to the standard treatment of surgery and external-beam radiation (EBR). Historically, multimodal treatment, including EBR, has shown tumor control rates as high as 70% at 10 years after treatment. However, EBR is associated with significant long-term risks, including visual deficits, endocrine dysfunction, and cognitive decline. Theoretically, brachytherapy may provide focused local radiation that controls or shrinks a symptomatic cyst without exposing the patient to the risks of EBR. For this study, the authors reviewed their experiences with craniopharyngioma patients treated with P32 brachytherapy as the primary treatment without EBR. The authors reviewed these patients' records to evaluate whether this strategy effectively controls tumor growth, thus avoiding the need for further surgery or EBR.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>The authors performed a retrospective review of pediatric patients treated for craniopharyngioma between 1997 and 2004. This was the time period during which the authors' institution had a relatively high use of P32 for treatment of cystic craniopharyngioma. All patients who had surgery and injection of P32 without EBR were identified. The patient records were analyzed for complications, cyst control, need for further surgery, and need for future EBR.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>Thirty-eight patients were treated for craniopharyngioma during the study period. Nine patients (23.7%) were identified who had surgery (resection or biopsy) with P32 brachytherapy but without initial EBR. These 9 patients represented the study group. For 1 patient (11.1%), there was a complication with the brachytherapy procedure. Five patients (55.5%) required subsequent surgery. Seven patients (77.7%) required subsequent EBR for tumor growth. The mean time between the injection of P32 and subsequent treatment was 1.67 ± 1.50 years (mean ± SD).</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>In this small but focused population, P32 treatment provided limited local control for cyst growth. Brachytherapy alone did not reliably avert the need for subsequent surgery or EBR.</jats:p></jats:sec>

Visual functions in children with craniopharyngioma at diagnosis: A systematic review

“…These scores indicate that most of the included studies were of moderate quality. Quality was predominately limited by missing or incomplete information about VA testing and/or VF testing [ 14 , 19 , 26 – 28 , 30 , 33 – 35 , 51 , 54 – 56 , 62 , 67 , 68 , 70 , 74 , 77 , 85 , 93 , 97 , 100 , 104 , 108 ]. Other important reasons for weaker quality were studies who included only patients who are known to have an impaired visual function [ 83 , 100 ], studies who included only patients who are known to have a CP at a specific location [ 46 , 54 , 71 , 75 , 76 , 80 , 81 , 86 , 108 ] and studies who included only patients with giant or extensive CP [ 46 , 67 , 79 , 99 , 104 ].…”

Brachytherapy in craniopharyngiomas: a systematic review and meta-analysis of long-term follow-up

“…Subsequent rigorous scrutiny of the full-text articles and their data quality necessitated the dismissal of another four studies, citing various reasons including lack of comprehensive data. Ultimately, six studies met the stringent inclusion criteria, warranting their incorporation into the final meta-analysis [24,[27][28][29][30][31]. The flowchart in Fig.…”

Adamantinomatous craniopharyngioma: evolution in the management

“…Phosphorus32 (P-32) is the most used one because if offers longer half-life, lower required dose and lower half-value tissue penetrance than other radionuclides [ 98 ]. The treatment with P-32 alone can induce a cyst reduction in up to 70–80% of cases in the short-term period, but it is burdened by a high rate of recurrence in the long-term one [ 152 – 154 ]. On the other hand, if used in combination with cyst aspiration, P-32 is able to stop the AC growth in to 75% of cases and to maintain the result for some years (mean follow-up reported: 48.6 months) [ 155 ].…”